1.0.0.3 true Consolidated Statements of Earnings (USD $) In Millions, except Share data false 1 $ false false Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 false 2 $ false false Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 false 3 $ false false Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 2 2 us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 12 2 us-gaap_Revenues us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 true true 112493000000 112493 false false 2 true true 107786000000 107786 false false 3 true true 118245000000 118245 false false No definition available. No authoritative reference available. true 13 2 us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 22 2 us-gaap_CostsAndExpenses us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 100941000000 100941 false false 2 false true 100212000000 100212 false false 3 false true 98084000000 98084 false false No definition available. No authoritative reference available. true 23 2 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 11552000000 11552 false false 2 false true 7574000000 7574 false false 3 false true 20161000000 20161 false false No definition available. No authoritative reference available. true 24 2 us-gaap_IncomeTaxExpenseBenefit us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 3538000000 3538 false false 2 false true 1978000000 1978 false false 3 false true 6594000000 6594 false false No definition available. No authoritative reference available. false 25 2 us-gaap_IncomeLossFromEquityMethodInvestments us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 427000000 427 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. No authoritative reference available. false 26 2 us-gaap_ProfitLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 8441000000 8441 false false 2 false true 5596000000 5596 false false 3 false true 13567000000 13567 false false No definition available. No authoritative reference available. true 27 2 us-gaap_NetIncomeLossAttributableToNoncontrollingInterest us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 386000000 386 false false 2 false true 602000000 602 false false 3 false true 354000000 354 false false No definition available. No authoritative reference available. false 28 2 us-gaap_NetIncomeLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 8055000000 8055 false false 2 false true 4994000000 4994 false false 3 false true 13213000000 13213 false false No definition available. No authoritative reference available. true 29 2 us-gaap_WeightedAverageNumberOfSharesOutstandingBasic us-gaap true na duration shares No definition available. false false false false false false false false false 1 false true 1551174 1551174.00 [1] false false 2 false true 1548960 1548960.00 [1] false false 3 false true 1545751 1545751.00 [1] false false No definition available. No authoritative reference available. false 32 0 na true na na na No definition available. false true false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. No authoritative reference available. false 61 2 us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 62 2 us-gaap_EarningsPerShareBasic us-gaap true na duration decimal No definition available. false false false false false false false false true 1 true true 5193 5193 false false 2 true true 3224 3224 false false 3 true true 8548 8548 false false No definition available. No authoritative reference available. true 63 0 na true na na na No definition available. false true false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. No authoritative reference available. false 92 2 us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 93 2 us-gaap_EarningsPerShareBasic us-gaap true na duration decimal No definition available. false false false false false false false false true 1 true true 3.46 3.46 false false 2 true true 2.15 2.15 false false 3 true true 5.70 5.70 false false No definition available. No authoritative reference available. true 94 0 na true na na na No definition available. false true false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. No authoritative reference available. false 95 2 us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 96 2 us-gaap_PremiumsEarnedNet us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 27884000000 27884 false false 2 false true 25525000000 25525 false false 3 false true 31783000000 31783 false false No definition available. No authoritative reference available. false 97 2 us-gaap_SalesRevenueNet us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 62555000000 62555 false false 2 false true 65854000000 65854 false false 3 false true 58243000000 58243 false false No definition available. No authoritative reference available. false 98 2 us-gaap_InvestmentIncomeInterestAndDividend us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 5245000000 5245 false false 2 false true 4966000000 4966 false false 3 false true 4979000000 4979 false false No definition available. No authoritative reference available. false 99 2 brka_GainLossOnInvestmentsExcludingOtherThanTemporaryImpairments brka false credit duration monetary This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of... false false false false false false false false false 1 false true 251000000 251 false false 2 false true 1166000000 1166 false false 3 false true 5405000000 5405 false false 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. No authoritative reference available. false 104 2 brka_OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet brka false debit duration monetary The amount of other than temporary impairment losses on equity securities, other than temporary impairment related to credit... false false false false false false false false false 1 false true -3155000000 -3155 false false 2 false true -1813000000 -1813 false false 3 false false 0 0 false false 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. No authoritative reference available. false 105 2 us-gaap_Revenues us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 92780000000 92780 false false 2 false true 95698000000 95698 false false 3 false true 100410000000 100410 false false No definition available. No authoritative reference available. true 106 2 us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 107 2 us-gaap_IncurredClaimsPropertyCasualtyAndLiability us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 18251000000 18251 false false 2 false true 16259000000 16259 false false 3 false true 21010000000 21010 false false No definition available. No authoritative reference available. false 108 2 us-gaap_PolicyholderBenefitsAndClaimsIncurredNet us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 1838000000 1838 false false 2 false true 1840000000 1840 false false 3 false true 1786000000 1786 false false No definition available. No authoritative reference available. false 109 2 us-gaap_ExpenseRelatedToDistributionOrServicingAndUnderwritingFees us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 6236000000 6236 false false 2 false true 4634000000 4634 false false 3 false true 5613000000 5613 false false No definition available. No authoritative reference available. false 110 2 us-gaap_CostOfGoodsAndServicesSold us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 52647000000 52647 false false 2 false true 54103000000 54103 false false 3 false true 47477000000 47477 false false No definition available. No authoritative reference available. false 111 2 us-gaap_SellingGeneralAndAdministrativeExpense us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 8117000000 8117 false false 2 false true 8052000000 8052 false false 3 false true 7098000000 7098 false false No definition available. No authoritative reference available. false 113 2 us-gaap_InterestExpense us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 130000000 130 false false 2 false true 156000000 156 false false 3 false true 164000000 164 false false No definition available. No authoritative reference available. false 115 2 us-gaap_CostsAndExpenses us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 87219000000 87219 false false 2 false true 85044000000 85044 false false 3 false true 83148000000 83148 false false No definition available. No authoritative reference available. true 125 0 na true na na na No definition available. false true false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. No authoritative reference available. false 126 2 us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 131 2 us-gaap_RegulatedAndUnregulatedOperatingRevenue us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 11204000000 11204 false false 2 false true 12668000000 12668 false false 3 false true 12376000000 12376 false false No definition available. No authoritative reference available. false 133 2 us-gaap_OtherIncome us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 239000000 239 false false 2 false true 1303000000 1303 false false 3 false true 252000000 252 false false No definition available. No authoritative reference available. false 136 2 us-gaap_Revenues us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 11443000000 11443 false false 2 false true 13971000000 13971 false false 3 false true 12628000000 12628 false false No definition available. No authoritative reference available. true 137 2 us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 143 2 us-gaap_UtilitiesOperatingExpense us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 8739000000 8739 false false 2 false true 9840000000 9840 false false 3 false true 9696000000 9696 false false No definition available. No authoritative reference available. false 144 2 us-gaap_InterestExpense us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 1176000000 1176 false false 2 false true 1168000000 1168 false false 3 false true 1158000000 1158 false false No definition available. No authoritative reference available. false 146 2 us-gaap_CostsAndExpenses us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 9915000000 9915 false false 2 false true 11008000000 11008 false false 3 false true 10854000000 10854 false false No definition available. No authoritative reference available. true 156 0 na true na na na No definition available. false true false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. No authoritative reference available. false 157 2 us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 160 2 us-gaap_InvestmentIncomeInterestAndDividend us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 1886000000 1886 false false 2 false true 1790000000 1790 false false 3 false true 1717000000 1717 false false No definition available. No authoritative reference available. false 161 2 brka_GainLossOnInvestmentsExcludingOtherThanTemporaryImpairments brka false credit duration monetary This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of... false false false false false false false false false 1 false true 67000000 67 false false 2 false true 7000000 7 false false 3 false true 193000000 193 false false 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. No authoritative reference available. false 163 2 us-gaap_GainLossOnDerivativeInstrumentsNetPretax us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 3624000000 3624 false false 2 false true -6821000000 -6821 false false 3 false true -89000000 -89 false false No definition available. No authoritative reference available. false 165 2 us-gaap_RevenueOtherFinancialServices us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 2693000000 2693 false false 2 false true 3141000000 3141 false false 3 false true 3386000000 3386 false false No definition available. No authoritative reference available. false 167 2 us-gaap_Revenues us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 8270000000 8270 false false 2 false true -1883000000 -1883 false false 3 false true 5207000000 5207 false false No definition available. No authoritative reference available. true 168 2 us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 175 2 us-gaap_InterestExpense us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 686000000 686 false false 2 false true 639000000 639 false false 3 false true 588000000 588 false false No definition available. No authoritative reference available. false 176 2 us-gaap_OtherFinancialServicesCosts us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 3121000000 3121 false false 2 false true 3521000000 3521 false false 3 false true 3494000000 3494 false false No definition available. No authoritative reference available. false 177 2 us-gaap_CostsAndExpenses us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 true true 3807000000 3807 false false 2 true true 4160000000 4160 false false 3 true true 4082000000 4082 false false No definition available. No authoritative reference available. true 1 Average shares outstanding include average Class A common shares and average Class B common shares determined on an equivalent Class A common stock basis. Net earnings per share attributable to Berkshire Hathaway shareholders shown above represents net earnings per equivalent Class A common share. Net earnings per Class B common share is equal to one-fifteen-hundredth (1/1,500) of such amount or $3.46 per share for 2009, $2.15 per share for 2008 and $5.70 per share for 2007 after giving effect to the 50-for-1 Class B stock split that became effective on January 21, 2010. See Note 19. false 3 53 false Millions NoRounding UnKnown false true