Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
ASSETS
Cash and cash equivalents	$ 47,776	$ 37,299
Investments in equity securities	88,027	76,991
Inventories	9,476	8,975
Goodwill	54,143	53,213
Total assets	424,115	392,647
LIABILITIES
Income taxes, principally deferred	44,514	37,804
Total liabilities	235,041	223,686
SHAREHOLDERS' EQUITY
Common stock	8	8
Capital in excess of par value	37,890	37,807
Accumulated other comprehensive income	27,050	17,654
Retained earnings	119,721	109,448
Treasury stock, at cost	(67)	(67)
Berkshire Hathaway shareholders' equity	184,602	164,850
Noncontrolling interests	4,472	4,111
Total shareholders' equity	189,074	168,961
Total liabilities and shareholders' equity	424,115	392,647
Insurance and Other [Member]
ASSETS
Cash and cash equivalents	41,820	33,513
Investments in fixed maturity securities	31,021	31,222
Investments in equity securities	87,088	76,063
Other investments	14,980	13,111
Receivables	21,327	19,012
Inventories	9,476	8,975
Property, plant and equipment	18,924	18,177
Goodwill	33,015	32,125
Other	17,582	18,121
Total assets	275,233	250,319
LIABILITIES
Losses and loss adjustment expenses	63,382	63,819
Unearned premiums	11,042	8,910
Life, annuity and health insurance benefits	10,394	9,924
Accounts payable, accruals and other liabilities	18,978	18,466
Notes payable and other borrowings	13,405	13,768
Total liabilities	117,201	114,887
Railroad, Utilities and Energy [Member]
ASSETS
Cash and cash equivalents	4,119	2,246
Property, plant and equipment	85,923	82,214
Goodwill	20,092	20,056
Other	13,076	12,861
Total assets	123,210	117,377
LIABILITIES
Accounts payable, accruals and other liabilities	12,924	13,016
Notes payable and other borrowings	35,732	32,580
Total liabilities	48,656	45,596
Finance and Financial Products [Member]
ASSETS
Cash and cash equivalents	1,837	1,540
Investments in fixed maturity securities	868	966
Other investments	4,719	3,810
Loans and finance receivables	13,230	13,934
Goodwill	1,036	1,032
Other	3,982	3,669
Total assets	25,672	24,951
LIABILITIES
Accounts payable, accruals and other liabilities	1,208	1,224
Derivative contract liabilities	10,090	10,139
Notes payable and other borrowings	13,372	14,036
Total liabilities	$ 24,670	$ 25,399