ASSETS BS Cash and cash equivalents Cash and cash equivalents at beginning of year Cash and cash equivalents at end of first six months Investments in fixed maturity securities Investments in equity securities Inventories Property, plant and equipment BS Goodwill Other assets Loans and finance receivables Losses and loss adjustment expenses Unearned premiums Derivative contract liabilities Total liabilities Income taxes, principally deferred Life, annuity and health insurance benefits Accounts payable, accruals and other liabilities Accumulated other comprehensive income LIABILITIES AND SHAREHOLDERS' EQUITY LIABILITIES BS SHAREHOLDERS' EQUITY Retained earnings BS Berkshire Hathaway shareholders' equity Noncontrolling interests Total shareholders' equity Revenues: Insurance premiums earned Sales and service revenues Interest, dividend and other investment income Other income Derivative gains/losses Insurance losses and loss adjustment expenses Life and health insurance benefits expense Insurance underwriting expenses Cost of sales and services Selling, general and administrative expenses Interest expense Income tax expense/benefit Earnings from equity method investments Net earnings Less: Earnings attributable to noncontrolling interests Net earnings attributable to Berkshire Hathaway Average common shares outstanding Net earnings per share attributable to Berkshire Hathaway shareholders Net cash flows from operating activities Cash flows from investing activities: Net cash flows from investing activities Purchases of other investments Acquisitions of businesses Purchases of property, plant and equipment Other, investing activities Cash flows from financing activities: Net cash flows from financing activities Proceeds from sale of marketable securities fixed maturities Proceeds from redemptions and maturities of marketable securities fixed maturities Proceeds from sale of marketable securities equity securities Purchases of loans and finance receivables Change in short term borrowings, net Repayments of borrowings Effects of foreign currency exchange rate changes Increase (decrease) in cash and cash equivalents Principal collections on loans and finance receivables Statement Scenario [Axis] Scenario Unspecified Domain Statement Business Segment [Axis] Segment [Domain] Statement items [Line Items] Statement [Table] Consolidated Statements of Cash Flows Cash and cash equivalents period increase decrease Cash flows from operating activities: Total assets Total liabilities and shareholders' equity Consolidated Statements of Earnings Net income loss attributable to reporting entity Income loss from continuing operations before income taxes minority Total revenues Benefits losses and expenses Costs and expenses, other Note 1. General Investments In Marketable Securities Equity Securities Disclosure Text Block Other investments Investments In Marketable Securities Fixed Maturities Disclosure Text Block Document Information [Line Items] Document type Amendment flag Document period end date Amendment description Entity Legal Entity [Axis] Entity [Domain] Entity Information Entity registrant name Entity central index key Current fiscal year end date Entity well-known seasoned issuer Entity voluntary filers Entity current reporting status Entity filer category Entity public float Entity Listing items Entity common stock, shares outstanding Other Investments Disclosure Text Block Note 12. Derivative contracts Note 15. Fair value measurements Note 8. Receivables Note 11. Property, plant and equipment Note 9. Inventories Note 14. Notes payable and other borrowings Note 17. Business segment data Note 18. Contingencies and Commitments Consolidated Balance Sheets Purchases of other investments Purchases of loans and finance receivables Acquisitions of businesses, net of cash acquired Purchases of property, plant and equipment Other Repayments of borrowings Receivables Notes payable and other borrowings Note 3. Acquisition of Burlington Northern Santa Fe Corporation Revenues, other financial services Costs and expenses: Other costs and expenses Payments to acquire marketable securities fixed maturities Purchases of fixed maturity securities Payments to acquire marketable securities equity securities Purchases of equity securities Total costs and expenses Gain Loss On Investments Text Block Total assets Total liabilities Total liabilities and shareholders' equity Total shareholders' equity Total revenues Life, annuity and health insurance benefits Total costs and expenses Decrease in cash and cash equivalents Note 2. New accounting pronouncements Other than temporary impairment losses, investments, portion recognized in earnings, net Other-than-temporary impairment losses on investments Payments to minority shareholders and proceeds from (payments for) other financing activities The cash outflow to return capital to noncontrolled interest, which generally occurs when noncontrolling shareholders reduce their ownership stake (in a subsidiary of the entity). Additionally, the balance includes the net cash inflow (outflow) from other financing activities. Net cash flows from operating activities Net cash flows from investing activities Net earnings Net earnings attributable to Berkshire Hathaway Net earnings per share attributable to Berkshire Hathaway shareholders Sum of the carrying amounts as of the balance sheet date for a) payments made in advance for income taxes, which will be charged against earnings, b) income taxes previously overpaid to tax authorities representing refunds of overpayments or recoveries based on agreed-upon resolutions of disputes, c) the net cumulative amount for all deferred taxes arising from temporary differences between accounting income in accordance with generally accepted accounting principles and tax-basis income, and d) unpaid sum of the known and estimated amounts payable to satisfy all currently due domestic and foreign income tax obligations. The amount of other than temporary impairment losses on equity securities, other than temporary impairment related to credit losses on debt securities, and other than temporary impairment losses on debt securities when the entity intends to sell the securities or it is more likely than not that the entity will be required to sell the securities before recovery of its amortized cost basis. Additionally, this item includes other than temporary impairment losses recognized during the period on investments accounted for under the cost method of accounting. Gain (loss) on investments excluding other than temporary impairments This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain or loss of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain or loss which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any gains or losses realized during the period from the sale of investments accounted for under the cost method of accounting. Increase (decrease) in deferred charges reinsurance assumed The change during the reporting period in deferred charges reinsurance assumed. Increase (decrease) in derivative contract assets and liabilities The change during the period in derivative contract assets and liabilities due to cash payments and receipts and changes in the value of derivative instruments. Increase (decrease) in income taxes The change during the period due to cash payments and receipts from taxing authorities for taxes that are based on the reporting entity's earnings and the change during the reporting period for deferred and other tax assets and liabilities. Adjustments to reconcile net earnings to operating cash flows: Investment (gains) losses and other-than-temporary impairment losses Depreciation Other adjustments to reconcile net earnings to operating cash flows Other Changes in operating assets and liabilities before business acquisitions: Changes in losses and loss adjustment expenses Changes in unearned premiums Receivables and originated loans Other assets and liabilities The cash outflow from purchases of investments in securities having predetermined or determinable maturity dates. The cash outflow from purchases of investments in common stocks and other forms of securities that provide ownership interests in a corporation. The cash inflow associated with the sale of investments in securities having predetermined or determinable maturity dates. The cash inflow associated with redemption or maturity of investments in securities having predetermined or determinable maturity dates. The cash inflow associated with the sale of investments in common stocks and other forms of securities that provide ownership interests in a corporation. This item represents the entire disclosure related to the investments in securities having predetermined or determinable maturity dates. This item represents the entire disclosure related to the investments in common stocks and other forms of securities that provide ownership interests in a corporation. This item represents the entire disclosure related to other investments not otherwise specified in the taxonomy. Losses and loss adjustment expenses Unearned premiums Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities, Other Increase (Decrease) in Loss and Loss Adjustment Expense Reserve Increase (Decrease) in Unearned Premiums Cash and cash equivalents: Proceeds from borrowings Berkshire Hathaway shareholders' equity Class of Stock [Axis] Class of Stock [Domain] Common Stock Class A Class B Receivables and originated loans Net cash flows from financing activities Investment (gains) losses and other-than-temporary impairment losses Derivative contract assets and liabilities Income taxes Other assets and liabilities Acquisitions of noncontrolling interests and other Sales of fixed maturity securities Redemptions and maturities of fixed maturity securities Sales of equity securities Investment gains/losses Deferred charges reinsurance assumed General [Abstract] Investments in fixed maturity securities [Abstract] Investments in equity securities [Abstract] Investment gains losses [Abstract] Fair value measurements [Abstract] Receivables [Abstract] Property, plant and equipment [Abstract] Other Investments [Abstract] Inventories [Abstract] Notes payable and other borrowings [Abstract] Business segment data [Abstract] Contingencies and Commitments [Abstract] Supplemental cash flow information [Abstract] Note 13. Supplemental cash flow information Other revenues Other Parent Company [Member] Document fiscal year focus Document fiscal period focus Document Information [Table] Entity Listings [Table] Entities [Table] Insurance and Other [Member] Railroad, Utilities and Energy [Member] Finance and Financial Products [Member] Other Net earnings per share attributable to Berkshire Hathaway shareholders: Other Other Stock Split Conversion Rate Net Earnings Per Share Ratio Ratio representing the net earnings per equivalent Class A common share. Ratio of earnings per Class B share to earnings per Class A share Element represents the conversion rate to reflect a stock split. Stock split conversion rate for a Class B common share, number of shares Stock Issued During Period Value New Issues And Other Interests Acquired And Other Transactions Reclassification Of Investment Appreciation In Net Earnings Before Tax Portion Attributable To Parent Reclassification Of Investment Appreciation In Net Earnings Tax Portion Attributable To Parent Other Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent Statement, Equity Components [Axis] Equity Component [Domain] Total Berkshire Hathaway shareholders' equity Common stock and capital in excess of par value Accumulated other comprehensive income Retained earnings Non-controlling interests Balance Balance Other comprehensive income, net Issuance of common stock and other transactions Value of new stock issued during the period and other transactions which are not separately disclosed or provided for elsewhere in the taxonomy. Changes in noncontrolling interests: Changes in shareholder equity as a result of redeeming or purchasing the interests of non-controlling shareholders. Additionally, this element represents other transactions which are not separately disclosed or provided for elsewhere in the taxonomy. Interests acquired and other transactions Interests acquired and other transactions Consolidated Statements of Changes in Shareholders' Equity [Abstract] Consolidated Statements of Comprehensive Income [Abstract] Comprehensive income attributable to Berkshire: Net earnings Other comprehensive income: Net change in unrealized appreciation of investments Applicable income taxes Applicable income taxes Other Comprehensive Income Available for sale Securities Tax Portion Attributable To Parent Reclassification of investment appreciation in earnings Reclassification adjustment from Other Comprehensive Income (Loss) to net earnings, which are attributable to the parent entity. Includes reclassification due to write-downs, sales and other. Tax effect of the reclassification adjustment from Other Comprehensive Income (Loss) to net earnings, which are attributable to the parent entity. Applicable income taxes Other Comprehensive Income Foreign Currency Translation Adjustment Tax Portion Attributable To Parent Applicable income taxes Prior service cost and actuarial gains/losses of defined benefit plans Prior service cost and actuarial gains/losses of defined benefit plans Applicable income taxes This element represents Other Comprehensive Income (Loss), Net of Tax, for the period, which are not separately disclosed or provided for elsewhere in the taxonomy. Other Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Other comprehensive income, net Comprehensive income attributable to Berkshire Comprehensive income attributable to Berkshire Comprehensive income of noncontrolling interests Comprehensive income of noncontrolling interests Comprehensive income of noncontrolling interests Common stock value (Class A and Class B) Common stock Capital in excess of par value Foreign currency translation Applicable income taxes Acquisition of Burlington Northern Santa Fe Corporation [Abstract] Goodwill [Abstract] Note 10. Goodwill Derivative contracts [Abstract] Common Stock [Abstract] Note 16. Common stock Retained earnings Accumulated other comprehensive income BS Note 5. Investments in equity securities Note 4. Investments in fixed maturity securities Note 6. Other Investments Note 7. Investment gains/losses Costs Of Services And Operating Expenses The aggregate costs related to services rendered and total operating expenses. Cost of sales and operating expenses Cargo and Freight Revenue and Regulated and Unregulated Operating Revenue Operating revenues The total amount of revenues from transporting cargo and freight between locations and the total regulated and unregulated operating revenues of utilities and energy businesses, and other revenues related to these activities. Net earnings Allocation of the aggregate purchase price to the assets and liabilities of the acquired entity [Text Block] Proforma consolidated earnings data for acquisition [Text Block] Acquisition of Burlington Northern Santa Fe Corporation [Line Item] Acquisition of Burlington Northern Santa Fe Corporation Narrative [Line Item] Business Acquisition Purchase Price Allocation Assets [Abstract] Assets: Business Acquisition Purchase Price Allocation Other Assets Other Cash and cash equivalents detail Property, plant and equipment detail Goodwill detail Total assets Detail Business Acquisition Purchase Price Allocation Liabilities [Abstract] Liabilities and Net assets acquired: The amount of acquisition cost of a business combination allocated to other assets of the acquired entity. Business Acquisition Purchase Price Allocation Liabilities Accounts Payable And Other Liabilities Accounts payable and other liabilities Business Acquisition Purchase Price Allocation Notes Payable And Other Borrowings Business Acquisition Purchase Price Allocation Income Taxes Principally Deferred The amount of acquisition cost of a business combination allocated to accounts payable and other liabilities of the acquired entity. Notes payable and other borrowings The amount of acquisition cost of a business combination allocated to notes payable and other borrowings of the acquired entity. Income taxes, principally deferred The amount of acquisition cost of a business combination allocated to the sum of the carrying amounts as of the balance sheet date for a) payments made in advance for income taxes, which will be charged against earnings, b) income taxes previously overpaid to tax authorities representing refunds of over-payments or recoveries based on agreed-upon resolutions of disputes, c) the net cumulative amount for all deferred taxes arising from temporary differences between accounting income in accordance with generally accepted accounting principles and tax-basis income, and d) unpaid sum of the known and estimated amounts payable to satisfy all currently due domestic and foreign income tax obligations, assumed from the acquired entity. Total liabilities detail Net assets acquired Total liabilities Total assets Business Acquisition Purchase Price Allocation Liabilities Assumed And Net Assets The amount of acquisition cost of a business combination allocated to liabilities assumed and net assets. Total liabilities and net assets acquired Proforma consolidated earnings data for acquisition [Abstract] Narrative [Abstract] Preliminary allocation of the aggregate purchase price for BNSF Total revenues detail Earnings per equivalent Class A common share attributable to Berkshire Hathaway shareholders Business Acquisition Shares Of Voting Interests Acquired Business Acquisition Funded Through Existing Cash Balance Percentage Number of voting equity interests acquired in the business combination. The percentage of the acquisition funded through existing cash balances. Business Acquisition Funded Through New Debt Percentage The percentage of the acquisition funded through new debt. Acquisition of remaining BNSF common stock outstanding, shares Acquisition of remaining BNSF common stock outstanding, percentage Aggregate consideration for acquisition of remaining BNSF common stock outstanding, amount Acquisition of remaining BNSF common stock outstanding, paid in cash Percentage of acquisition funded through existing cash balances, percentage Percentage of acquisition funded through new debt, percentage Business Combination Step Acquisition Equity Interest In Acquiree Shares BNSF shares owned prior to acquisition, shares Equity method investment carrying value in BNSF prior to acquisition Holding gain recognized for the difference between the fair value and carrying value of shares held under the equity method Investments In Fixed Maturity Securities [Table] Schedule Of Investments In Marketable Securities Fixed Maturities [Text Block] Schedule Of Amortized Cost And Estimated Fair Value Of Securities With Fixed Maturities By Contractual Maturity Dates [Text Block] Investments in securities with fixed maturities [Line Item] Investment In Securities With Fixed Maturities [Abstract] Marketable Securities Fixed Maturities Amortized Cost For an unclassified balance sheet, this item represents investments in debt securities having predetermined or determinable maturity dates, net of adjustments made for accretion, amortization, other-than-temporary impairments and hedging, if any. Investments securities with fixed maturities Fair value Unrealized Gains This item represents the total unrealized holding loss on marketable securities with fixed maturities, at reporting date. Amortized Cost Amortized cost and estimated fair value of securities with fixed maturities [Line Item] Amortized cost and estimated fair value of securities with fixed maturities [Abstract] Marketable Securities Fixed Maturities Within One Year Amortized Cost Marketable Securities Fixed Maturities Within One Year Fair Value This item represents marketable securities with fixed maturities, at cost, net of adjustments made for accretion, amortization, other-than-temporary impairments, and hedging, if any, which are expected to mature within one year of the balance sheet date. This item represents the fair value of marketable securities with fixed maturities which are expected to mature within one year of the balance sheet date. Marketable Securities Fixed Maturities After One Through Five Years Amortized Cost Marketable Securities Fixed Maturities After One Through Five Years Fair Value Marketable Securities Fixed Maturities After Five Through Ten Years Amortized Cost Marketable Securities Fixed Maturities After Five Through Ten Years Fair Value This item represents marketable securities with fixed maturities, at cost, net of adjustments made for accretion, amortization, other-than-temporary impairments, and hedging, if any, which are expected to mature after one year and through five years from the balance sheet date. This item represents the fair value of marketable securities with fixed maturities which are expected to mature after one year and through five years from the balance sheet date. This item represents marketable securities with fixed maturities, at cost, net of adjustments made for accretion, amortization, other-than-temporary impairments, and hedging, if any, which are expected to mature after five years and through ten years from the balance sheet date. This item represents the fair value of marketable securities with fixed maturitiess which are expected to mature after five years and through ten years from the balance sheet date. Marketable Securities Fixed Maturities After Ten Years Amortized Cost This item represents marketable securities with fixed maturities, at cost, net of adjustments made for accretion, amortization, other-than-temporary impairments, and hedging, if any, which are expected to mature after ten years from the balance sheet date. Marketable Securities Fixed Maturities After Ten Years Fair Value Marketable Securities Fixed Maturities Without Single Maturity Date Amortized Cost Marketable Securities Fixed Maturities Without Single Maturity Date Fair Value This item represents the fair value of marketable securities with fixed maturities, which do not have a single maturity date and which the Company has decided to disclose separately, rather than allocating such cost over several maturity groupings. This item represents marketable securities with fixed maturities, which do not have a single maturity date and which the Company has decided to disclose separately rather than allocating such cost, net of adjustments made for accretion, amortization, other-than-temporary impairments, and hedging, if any, over several maturity groupings. This item represents the fair value of marketable securities with fixed maturities which are expected to mature after ten years from the balance sheet date. Due in one year or less, amortized cost Due in one year or less, fair value Due after one year through five years, amortized cost Due after one year through five years, fair value Due after five years through ten years, amortized cost Due after five years through ten years, fair value Due after ten years, amortized cost Due after ten years, fair value Mortgage-backed securities, amortized cost Mortgage-backed securities, fair value Total amortized cost Total fair value U.S. Treasury, U.S. government corporations and agencies Schedule Of Trading Securities and Other Trading Assets Major Types Of Trading Securities and Assets [Axis] Major Types Of Trading Securities And Assets [Domain] States, municipalities and political subdivisions Foreign governments Corporate bonds Mortgage-backed securities Schedule Of Investments In Marketable Securities Equity Securities [Text Block] Investments in equity securities Schedule related to the investments in common stocks and other forms of securities that provide ownership interests in a corporation. Investments in equity securities [Table] Investments in equity securities [Line Item] Marketable Securities Equity Securities Cost Basis For an unclassified balance sheet, this item represents the cost basis, net of adjustments made for accretion, amortization, other-than-temporary impairments, and hedging, if any, of investments in common and preferred stocks and other forms of securities that provide ownership interests in a corporation. Cost Basis Unrealized Gains Unrealized Losses Fair Value The Coca Cola Company [Member] American Express Company [Member] The Procter and Gamble Company [Member] Wells Fargo and Company [Member] Other Investment [Member] Equity Securities [Member] Investment Type [Domain] Investment Type [Axis] Schedule Of Other Investments [Text Block] Schedule of other investments. Other Investments [Table] Other Investments [Line Item] Cost Fair Value Carrying Value Fixed Maturities [Member] Other Investments Narrative [Line Item] Investment Owned Stated Dividend Rate Percentage Preferred Stock Dividend payment percentage rate for preferred stock. Investment Owned Class Of Warrant Or Right Number Of Securities Called By Warrants Or Rights For investments owned, the specified number of securities that each class of warrants or rights outstanding give the holder the right but not the obligation to purchase from the issuer at a specific price, on or before a certain date. Investment Owned Redeemable Preferred Stock Redemption Price Per Share For investments owned, the amount to be received per share by the entity upon redemption by the issuer. Investment Owned Redeemable Preferred Stock Aggregate Redemption Amount For investments owned, the aggregate amount to be received by the entity upon redemption by the issuer. Investment Owned Class Of Warrant Or Right Total Value At Exercise Price Of Warrants Or Rights Investment Owned Class Of Warrant Or Right Exercise Price Of Warrants Or Rights Investment Owned Notes Coupon Rate Investment Owned Stated Dividend Rate Percentage Capital Instrument Convertible Perpetual Capital Instrument Redemption Percentage Within Two Years Of Issuance Convertible Perpetual Capital Instrument Redemption Percentage After Two Years Of Issuance Conversion Of Convertible Perpetual Capital Instrument To Common Stock Shares Conversion Of Convertible Perpetual Capital Instrument To Common Stock Value Per Share Investment Owned Redeemable Preferred Stock Redemption Ratio Common Stock Threshold Price Per Share Minimum Number Of Trading Days Range Of Trading Days For investments owned, the total value of each class of warrants or rights outstanding calculated by taking the exercise price times the number of warrants held. For investments owned, the exercise price of each class of warrants or rights outstanding. For investments which are quantified by principal amount, the coupon rate of the note. Dividend payment percentage rate for capital instrument. Represents the redemption percentage of a convertible perpetual capital instrument at which the issuer may redeem the instrument, within two years of issuance. Represents the redemption percentage of a convertible perpetual capital instrument at which the issuer may redeem the instrument, after two years of issuance. Represents the conversion option of convertible perpetual capital instrument into shares of the issuer's common stock. Conversion rate per share of convertible perpetual capital instrument to common stock. For investments owned, the per share conversion ratio to be used by the entity upon redemption. Option to convert preferred stock when the common stock price exceeds a set threshold price per share. The minimum number of trading days in a consecutive period window, which will trigger an event. The range of days ("window") used to measure the number of trading days in a consecutive period, which will trigger an event. Investment owned, shares detail Investment in Preferred Stock, stated percent Investment in Warrants to purchase common stock, number of shares Investment owned, total cost Redemption value of Cumulative Perpetual Preferred Stock, per share Redemption value of Cumulative Perpetual Preferred Stock, aggregate value Exercise price for warrants, value Exercise price for warrants, value, per share Investment owned, face value Investment in notes, stated percent Investment in convertible perpetual capital instrument, stated percent Convertible perpetual capital instrument redemption before adjustment, percentage Convertible perpetual capital instrument redemption adjusted, percentage Conversion of non-voting subordinated convertible perpetual capital instrument into common stock, number of shares Conversion of non-voting subordinated convertible perpetual capital instrument into common stock, CHF per share Conversion ratio of Series A Cumulative Convertible Perpetual Preferred Stock, shares Common stock threshold price, per share Minimum number of trading days in a consecutive day period Range of trading days in a consecutive day period, number of days BNSF shares owned prior to acquisition, percentage of shares Equity in net assets Excess of our carrying value over our equity in net assets Schedule Of Investment Gains Losses [Text Block] Schedule Of Investment Gains Losses By Business [Text Block] Investment gains/losses Net investment gains/losses are reflected in the Consolidated Statements of Earnings Investment gains / losses [Table] Other Investment Gain / Loss [Member] Investment Income Categories [Domain] Schedule Of Investment Income Reported Amounts By Category [Axis] Investment gains / losses [Line Item] Schedule of investment gains and losses. Schedule of investment gains and losses by business. Gain On Investments Excluding Other Than Temporary Impairments This item represents the gross total realized and unrealized gain included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any gains realized during the period from the sale of investments accounted for under the cost method of accounting. Loss On Investments Excluding Other Than Temporary Impairments This item represents the gross total realized and unrealized loss included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding loss of held-to-maturity securities transferred to the trading security category and the cumulative unrealized loss which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any losses realized during the period from the sale of investments accounted for under the cost method of accounting. Gross gains from sales and other disposals Gross losses from sales Footnote Narrative [Abstract] One-time holding gain related to BNSF acquisition Investment gains/losses: Receivables of insurance and other businesses Loans and finance receivables of finance and financial products businesses Receivables [Table] Receivables [Line Item] Reinsurance Recoverables Gross The known and estimated amount recoverable as of the balance sheet date from reinsurers for claims paid or incurred by the ceding insurer and associated claims settlement expenses, including estimated amounts for claims incurred but not reported, and policy benefits. Reinsurance recoverables Insurance premiums receivable Receivables of insurance and other businesses: Trade and other receivables Allowances for uncollectible accounts Total receivables of insurance and other businesses Loans and finance receivables of finance and financial products businesses: Consumer installment loans and finance receivables Commercial loans and finance receivables Allowances for uncollectible loans Total loans and finance receivables of finance and financial products businesses Reconciliation of the change in the carrying value of goodwill Goodwill [Table] Goodwill [Line Item] Reconciliation of the change in the carrying value of goodwill: Beginning balance Acquisition of BNSF Ending balance BNSF shares owned prior to acquisition, percentage Investment [Axis] Investment [Domain] Capital Instrument [Member] Goldman Sachs Group Inc [Member] General Electric Company [Member] Wm Wrigley Jr Company [Member] Swiss Reinsurance Company Limited [Member] The Dow Chemical Company [Member] Burlington Northern Santa Fe Corporation [Member] Cumulative Perpetual Preferred Stock [Member] Preferred Stock [Member] Subordinated Debt [Member] Senior Notes [Member] Warrant [Member] Schedule Of Inventory [Text Block] Schedule related to inventories. Inventories Inventories [Table] Inventories [Line Item] Inventory Work In Process And Other Inventory Represents the a) Carrying amount as of the balance sheet date of merchandise or goods which are partially completed, are generally comprised of raw materials, labor and factory overhead costs, and which require further materials, labor and overhead to be converted into finished goods, and which generally require the use of estimates to determine percentage complete and pricing, and b) Carrying amount as of the balance sheet date of inventories of a nature not otherwise specified in the taxonomy. Raw materials Work in process and other Finished manufactured goods Purchased goods Total inventory Marketable Securities Fixed Maturities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses This item represents the amount of unrealized losses related to securities with fixed maturities that have been in an unrealized loss position for twelve months or longer. Unrealized losses related to securities that have been in an unrealized loss position for 12 months or more Marketable Securities Equity Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses This item represents the amount of unrealized losses related to equity securities that have been in an unrealized loss position for twelve months or longer. Unrealized losses related to securities that have been in an unrealized loss position for 12 months or more Marketable Securities Equity Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Percent This item represents the percentage of unrealized losses on equity securities that have been in a continuous unrealized loss position for twelve months or longer. Concentration of unrealized losses, percentage Marketable Securities Equity Securities Unrealized Gain Loss Net This item represents the total net unrealized holding gain as a result of holding marketable equity securities. Investment in Wells Fargo & Company net unrealized gain Schedule Of Premiums And Other Receivables Net [Text Block] Schedule disclosing net premiums and other types of receivables due from other persons or entities. Schedule Of Loans And Leases Receivable Net Reported Amount [Text Block] Schedule disclosing the carrying amount of all categories of loans and leases held in portfolio, net of unearned income and the allowance for losses on loans and leases. Goodwill Period Increase Decrease Excluding Acquisitions Property, plant and equipment [Line Item] Property, plant and equipment [Text Block] Narrative: Pro-forma consolidated earnings data for acquisition: Acquisition of Burlington Northern Santa Fe Corporation Narrative [Abstract] Acquisition of Burlington Northern Santa Fe Corporation Narrative: Amortized cost and estimated fair value of securities with fixed maturities: Equity Securities Investments [Abstract] Investments in equity securities: Investment, Other [Abstract] Other Investments: Inventory [Abstract] In a business combination achieved in stages, this element represents the acquisition-date number of shares in the acquiree held by the acquirer immediately before the acquisition date. Business Acquisition Pro Forma Net Income Loss Attributable To Parent Net earnings attributable to Berkshire Hathaway shareholders The pro forma net income (loss) for the period attributable to the parent as if the business combination or combinations had been completed at the beginning of a period. Significant Accounting Policies [Abstract] Significant Accounting Policies [Table] Significant Accounting Policies [Line Items] Property Plant And Equipment Policy [Text Block] Other Investments Narrative [Abstract] Other Investments Narrative: Footnote Narrative: Inventory: Allocation of the aggregate purchase price to the assets and liabilities of the acquired entity Pro-forma consolidated earnings data for acquisition Property Plant And Equipment Policy Schedule Of Investments In Marketable Securities Fixed Maturities Schedule Of Amortized Cost And Estimated Fair Value Of Securities With Fixed Maturities Schedule Of Other Investments Property, plant and equipment details [Abstract] Property, plant and equipment: Furniture And Fixtures And Other Gross Carrying amount as of the balance sheet date of long-lived, depreciable asset commonly used in offices and stores and other. Examples include desks, chairs, and store fixtures and other items not individually reported. Land Buildings and improvements Machinery and equipment Furniture, fixtures and other Assets held for lease Public Utilities Property Plant And Equipment Generation Or Processing And Transmission And Distribution Sum of period end amount of property, plant and equipment (PPE) related to a) generation or processing owned by public utility, and b) transmission and distribution owned by public utility. Utility generation, distribution and transmission system Construction in progress Public Utilities Property Plant And Equipment Pipeline Interstate pipeline assets Period end amount of property, plant and equipment (PPE) related to pipeline assets. Construction in progress Utilities Construction in progress Total Property, plant and equipment, gross Accumulated depreciation Total Property, plant and equipment, net Furniture fixtures and other [Member] Track structure and other roadway [Member] Locomotives freight cars and other equipment [Member] Utility generation, distribution And transmission system [Member] Property Plant and Equipment By Type [Axis] Property Plant And Equipment Type [Domain] Buildings and improvements [Member] Machinery and equipment [Member] Assets held for lease [Member] Railroad transportation equipment [Member] Energy equipment [Member] Interstate pipeline assets [Member] Independent power plants and other assets [Member] Property, plant and equipment - Useful life [Abstract] Property, plant and equipment - Useful life: Property, plant and equipment, useful life, minimum number of years Property, plant and equipment, useful life, maximum number of years Depreciation expense Accumulated depreciation and amortization balance for regulated assets Fair Value Assets And Liabilities Measured On Recurring Basis [Text Block] This element represents the disclosure related to assets and liabilities, including financial instruments measured at fair value that are classified in stockholders' equity, if any, that are measured at fair value on a recurring basis. The disclosures contemplated herein include the fair value measurements at the reporting date by the level within the fair value hierarchy in which the fair value measurements in their entirety fall, segregating fair value measurements using quoted prices in active markets for identical assets (Level 1), significant other observable inputs (Level 2), and significant unobservable inputs (Level 3). Financial assets and liabilities measured and carried at fair value on a recurring basis in the financial statements Fair values of financial assets and liabilities Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Text Block] This element represents, for the fair value measurement of assets and liabilities using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances, separately presenting changes during the period attributable to the following: (1) total gains or losses for the period (realized and unrealized), segregating those gains or losses included in earnings (or changes in net assets), and a description of where those gains or losses included in earnings (or changes in net assets) are reported in the statement of income (or activities); (2) purchases, sales, issuances, and settlements (net); and (3) transfers in and transfers out of Level 3 (for example, transfers due to changes in the observability of significant inputs). Reconciliations of assets and liabilities measured and carried at fair value on a recurring basis with the use of significant unobservable inputs (Level 3) Fair Value By Balance Sheet Grouping Disclosure Item Amounts [Axis] Fair Value Disclosure Item Amounts [Domain] Carrying Value [Member] Fair Value [Member] Quoted Prices (Level 1) [Member] Significant Other Observable Inputs (Level 2) [Member] Significant Unobservable Inputs (Level 3) [Member] Total Fair Value [Domain] Fair Value, Assets Measured on Recurring Basis, Disclosure Items [Axis] Other investments at fair value Fair Value Net Derivative Contract Assets Liabilities [Abstract] Net derivative contract (assets)/liabilities: Equity Index Put Options Derivatives At Fair Value Net Other Derivatives At Fair Value Net Fair value as of the balance sheet date of equity index put option derivative assets, net of derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized on the balance sheet. Net derivative contract (assets)/liabilities Equity index put options Credit default obligations Fair value as of the balance sheet date of other derivative assets, net of derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized on the balance sheet. Other Other investments [Member] Net derivative contract liabilities [Member] Investments in fixed maturity securities [member] Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation By Asset Type [Axis] Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation Asset Types [Domain] Gains Losses Included In [Abstract] Gains (losses) included in: Balance Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Regulatory Assets And Liabilities Earnings Other comprehensive income This element represents amounts recorded to regulatory assets and liabilities arising from net derivative contract liabilities measured at fair value on a recurring basis using unobservable inputs (Level 3). Regulatory assets and liabilities Purchases, sales, issuances and settlements Transfers into (out of) Level 3 Ending Balance Beginning Balance Derivative contract assets Reconciliations of assets and liabilities measured on recurring basis [Abstract] Reconciliations of assets and liabilities measured on a recurring basis: Fair value measurements: Reconciliation of consolidated segment data (Revenues) Reconciliation of consolidated segment data (Earnings before taxes) Geico [Member] General Re [Member] Berkshire Hathaway Reinsurance Group [Member] Berkshire Hathaway Primary Group [Member] Insurance Group [Member] Other Businesses [Member] Marmon [Member] McLane Company [Member] MidAmerican [Member] Business segment data [Line item] Business segment data: Premiums earned Investment income Revenues Gain Loss On Investments And Gain Loss On Derivative Instruments Net Pretax This element represents the sum of a) Net total realized and unrealized gain (loss) included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain or loss of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain or loss which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any gains or losses realized during the period from the sale of investments accounted for under the cost method of accounting and losses recognized for other than temporary impairments of the subject investments, and b) Aggregate net gain (loss) on all derivative instruments recognized in earnings during the period, before tax effects. Investment and derivative gains/losses Segment Reporting, Reconciling Items, Revenue Segment Reporting Information, by Segment [Axis] Reporting Segment [Domain] Segment Reporting, Segment Revenue Reconciliation of segments to consolidated amount: Segment Reporting Information, Operating Income (Loss) Earnings before income taxes and equity method earnings Earnings (loss) before income taxes and equity method earnings Revenues Eliminations and other - revenues Net investment income Interest Expense Excluding Interest Allocated To Operating Businesses Interest expense, excluding interest allocated to operating businesses Eliminations and other - earnings Segment Reporting Reconciling Item Eliminations and Other Business segment data detail [Abstract] Cash and cash equivalents Goodwill Property, plant and equipment Property, plant and equipment Total revenues Investment owned, shares Allocation Of Aggregate Purchase Price To Assets And Liabilities Of Acquired Entity Abstract Allocation of the aggregate purchase price to the assets and liabilities of the acquired entity [Abstract] Earnings (loss) before income taxes and equity method earnings Derivative contracts outstanding Derivative gains/losses included in the Consolidated Statements of Earnings High Yield Indexes [Member] States Municipalities [Member] Individual Corporate [Member] Derivative Instruments Gain Loss By Derivative Instrument Risk [Axis] Derivative Contract Type [Domain] Equity index put options [Member] Credit default obligations [Member] Other [Member] Derivative contracts: Assets Liabilities Notional Value Counterparty netting and funds held as collateral, assets Counterparty netting and funds held as collateral, liabilities Derivative gains/losses included in the Consolidated Statements of Earnings: Derivative, Gain (Loss) on Derivative, Net, Total Equity Derivative Intrinsic Value Represents the undiscounted liability assuming the contracts are settled on their future expiration dates based on the index values at the most recent balance sheet date. Derivative Weighted Average Remaining Life The weighted average remaining life for the derivative or group of derivatives. Percent Of Derivative Liability By Notional Amount That Cannot Be Settled Before Maturity Date Of Underlying Obligations Aggregate intrinsic value of equity index put option contracts Weighted average remaining life of derivative contract, years The percent of derivative liability measured using the notional amount of derivative contracts which cannot be settled before the maturity dates of the underlying obligations. Potential obligation percent of the notional amount derivative contracts cannot be settled before the maturity dates of the underlying obligations, percentage Collateral posting requirements under contracts with collateral provisions Additional collateral posting requirements Accounts Payable and Accrued Liabilities [Member] Derivatives Fair Value By Balance Sheet Location [Axis] Balance Sheet Location [Domain] Other Assets [Member] Other Liabilities [Member] Schedule Of Cash Flow Supplemental Disclosures [Text Block] Schedule designated to encapsulate the entire footnote disclosure that provides information on the supplemental cash flow activities. Cash paid during the period for: Income taxes Interest Non-cash investing and financing activity: Liabilities assumed in connection with acquisition of BNSF Common stock issued in connection with acquisition of BNSF Schedule Of Stock Rollforward By Class [Text Block] Changes in issued and outstanding Berkshire common stock This element is used to roll-forward outstanding shares of each class of stock. Common stock: Stock Authorized Prior To Shares Stock Splits The number of authorized shares before an increase in the number of shares due to a stock split. Conversion Of Shares From One Class To Another And Other Changes in shares outstanding as a result of conversion from one class to another and other transactions occurring from time to time. Common Stock Voting Rights Number The number of votes an owner is entitled per Class B share. Class Equivalent Shares Outstanding Class A equivalent shares outstanding. Common Stock, par value per share Common Stock, shares authorized Common Stock, shares outstanding Common Stock, shares issued in the acquisition of BNSF (See Note 3) Conversions of Class A common stock to Class B common stock and other, shares Increase in the number of authorized shares due to a stock split from, shares Ratio of dividend and distribution rights per Class B share to earnings per Class A share Number of votes entitled per share, number Class A equivalent shares outstanding Preferred Stock, shares authorized Preferred Stock, shares issued Preferred Stock, shares outstanding Contingencies and Commitments: Settlement agreement Loss Contingencies By Loss [Axis] Loss Contingency Loss [Domain] General Re Segment [Member] Department Of Justice [Member] Civil Class Action [Member] Securities and Exchange Commission [Member] Track structure and other roadway Locomotives, freight cars and other equipment Carrying amount as of the balance sheet date of long-lived, depreciable assets commonly used in the railroad industry relating to railway track structure and other roadway related assets. Carrying amount as of the balance sheet date of long-lived, depreciable assets commonly used in the railroad industry relating to locomotives, freight cars and other related equipment. Independent power plants and other assets Period end amount of total gross PPE related to independent power plants and other energy related assets. Accumulated depreciation Total Property, plant and equipment, gross Shares Balance at December 31, 2009 Shares Balance at June 30, 2010 ASSETS LIABILITIES Cash paid during the period for [Abstract] Subsidiaries [Member] Berkshire Hathaway Finance Corporation [Member] Short-term borrowings Debt Weighted Average Interest Rate Average Interest Rate, percentage Senior unsecured debt Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Unsecured Debt [Member] Floating Rate Notes Due 2011 [Member] Floating Rate Notes Due 2012 [Member] Floating Rate Notes Due 2013 [Member] Notes Due 2012 at 1.4% [Member] Notes Due 2013 at 2.125% [Member] Floating Rate Notes Due In 2012 [Member] Par amount of debt Debt Instrument, Interest Rate, Stated Percentage Long Term Debt Maturities Repayments Of Principal In Remainder Of Calendar Year End Long Term Debt Maturities Repayments Of Principal In Year Two Of Calendar Year End Long Term Debt Maturities Repayments Of Principal In Year Three Of Calendar Year End Long Term Debt Maturities Repayments Of Principal In Year Four Of Calendar Year End Long Term Debt Maturities Repayments Of Principal In Year Five Of Calendar Year End Principal payments on debt - 2010 Principal payments on debt - 2011 Principal payments on debt - 2012 Principal payments on debt - 2013 Principal payments on debt - 2014 Increase in other borrowings and consumer installment loans receivable as a result of implementing a new accounting principle Unused lines of credit available New Accounting Pronouncement Effect Of Change On Balance Sheet Amount of the effect of adoption of a new accounting pronouncement. Amount of long-term debt maturing within the remaining months in the current calendar year-end following the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates. Amount of long-term debt maturing in year two of the calendar year-end following the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates. Amount of long-term debt maturing in year three of the calendar year-end following the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates. Amount of long-term debt maturing in year four of the calendar year-end following the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates. Amount of long-term debt maturing in year five of the calendar year-end following the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates. Reflects the calculation as of the balance-sheet date of the average interest rate weighted by the amount of total debt (short and long-term) outstanding by type or by instrument at that time. Short-term Debt, Type [Axis] Short-term Debt, Type [Domain] Short-term Debt [Member] Notes Due 2015 at 3.2% [Member] Notes Due In 2040 at 5.75% [Member] Cumulative amount of debt repaid Debt repaid Marketable Securities Fixed Maturities Unrealized Loss At Reporting Date Unrealized Losses Marketable Securities Fixed Maturities Unrealized Gain At Reporting Date This item represents the total unrealized holding gain on marketable securities with fixed maturities, at reporting date. Marketable Securities Equity Securities Unrealized Gain At Reporting Date This item represents the total unrealized holding gain on marketable equity securities, at reporting date. Marketable Securities Equity Securities Unrealized Loss At Reporting Date This item represents the total unrealized holding loss on marketable equity securities, at reporting date. Investment Owned Unrealized Appreciation Depreciation Net At Reporting Date Unrealized Gains Allowances for uncollectible accounts Allowances for uncollectible loans Other The change during the reporting period in the carrying value of goodwill, excluding goodwill acquired in the period. The change could be the result of goodwill impairment during the period, goodwill written off related to the sale of a business or other adjustments to goodwill. Interest expense, excluding interest allocated to operating businesses. Schedule of amortized cost and estimated fair value of securities with fixed maturities by contractual maturity dates. Schedule related to the investments in securities having predetermined or determinable maturity dates. Segment reporting reconciling item eliminations and other items relating to segment earnings. Insurance Investment Income Investment income Credit default derivatives whose values are tied to high yield indexes. Credit default derivatives whose values are tied to the creditworthiness of states and municipalities. Credit default derivatives whose values are tied to the creditworthiness of individual corporations. Financial instruments owned other at fair value Other investments This element represents the unrealized net excess or deficiency of the fair value of an investment (security, contract) over or under its cost (face amount, notional amount), respectively, at reporting date. The cumulative cash outflow for debt repayment, expressed at the reporting date. Stock Issued Shares Stock Splits The number of authorized shares after an increase in the number of shares due to a stock split. Increase in the number of authorized shares due to a stock split to, shares Fair value measurements [Line Item] Other investments - carrying value Other investments - fair value Value measurements [Line Items] Value measurements: Schedule of short and long term outstanding debt disclosure [Text Block] Schedule of short and long term outstanding debt. Subsequent event [Abstract] Note 19. Subsequent event Net derivative contract liabilities Fair Value of Net Derivative Assets and Liabilities Without Collateral Posting Requirements Value of equity index put option and credit default contract liabilities Income tax expense New accounting pronouncements Schedule of notes payable and other borrowings [Abstract] Net assets acquired Fair Value Earnings before income taxes and equity method earnings before reconciling items Number of Shares obtainable from converting one share from one class to another class Number of shares of Class B stock obtainable from converting one Class A share Unrealized losses related to securities that have been in an unrealized loss position for 12 months or more Acquisition of remaining BNSF common stock outstanding, paid in common stock, shares The number of shares obtainable from converting one share from one class to another share in another class. Value of equity index put option and credit default contract liabilities.