Condensed Financial Information - Balance Sheets (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Assets:
Cash and cash equivalents	$ 63,269	$ 48,186	$ 46,992	$ 37,299
Total assets	526,186	484,931	427,452
Liabilities and Shareholders' Equity:
Total liabilities	283,159	260,446
Berkshire Hathaway shareholders' equity	240,170	221,890
Total liabilities and shareholders' equity	526,186	484,931
Berkshire Hathaway (Parent) [Member]
Assets:
Cash and cash equivalents	9,449	3,412	10,557	7,289
Investments in fixed maturity and equity securities	152	178
Investments in and advances to/from consolidated subsidiaries	227,615	215,465
Investments in H.J. Heinz Holding Corporation	11,660	12,111
Other assets	91	97
Total assets	248,967	231,263
Liabilities and Shareholders' Equity:
Accounts payable, accrued interest and other liabilities	100	209
Income taxes	343	853
Notes payable and other borrowings	8,354	8,311
Total liabilities	8,797	9,373
Berkshire Hathaway shareholders' equity	240,170	221,890
Total liabilities and shareholders' equity	$ 248,967	$ 231,263