Condensed Financial Information - Statements of Earnings and Comprehensive Income (Detail) - USD ($) $ in Millions	3 Months Ended																12 Months Ended
	Dec. 31, 2016		Sep. 30, 2016		Jun. 30, 2016		Mar. 31, 2016		Dec. 31, 2015		Sep. 30, 2015		Jun. 30, 2015		Mar. 31, 2015		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
From consolidated subsidiaries:
Investment gains/losses																	$ 7,553	$ 9,373	$ 3,575
Equity in net earnings of The Kraft Heinz Company																	923	(122)	(26)
Total revenues	$ 58,344		$ 58,843		$ 54,254		$ 52,163		$ 51,731		$ 59,070		$ 51,549		$ 48,593		223,604	210,943	194,699
Cost and expense items:
Interest expense																	3,497	3,515	3,253
Income taxes																	9,240	10,532	7,935
Total costs and expenses																	190,860	175,875	166,568
Net earnings attributable to Berkshire Hathaway shareholders	$ 6,286	[1]	$ 7,198	[1]	$ 5,001	[1]	$ 5,589	[1]	$ 5,478	[1]	$ 9,428	[1]	$ 4,013	[1]	$ 5,164	[1]	24,074	24,083	19,872
Comprehensive income attributable to Berkshire Hathaway shareholders																	27,390	15,333	18,579
Berkshire Hathaway Inc. (Parent) [Member]
From consolidated subsidiaries:
Dividends																	9,862	10,519	4,969
Undistributed earnings																	13,264	8,508	14,496
Total income from consolidated subsidiaries																	23,126	19,027	19,465
Investment gains/losses																	700	6,854
Equity in net earnings of The Kraft Heinz Company																	923	(122)	(26)
Other income																	262	963	784
Total revenues																	25,011	26,722	20,223
Cost and expense items:
General and administrative																	80	73	(1)
Interest expense																	208	302	236
Income taxes																	649	2,264	116
Total costs and expenses																	937	2,639	351
Net earnings attributable to Berkshire Hathaway shareholders																	24,074	24,083	19,872
Other comprehensive income attributable to Berkshire Hathaway shareholders																	3,316	(8,750)	(1,293)
Comprehensive income attributable to Berkshire Hathaway shareholders																	$ 27,390	$ 15,333	$ 18,579

[1] Includes investment and derivative gains/losses. After-tax investment and derivative gains/losses for the periods presented above are as follows (in millions): 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter Investment and derivative gains/losses-2016 $ 1,852 $ 394 $ 2,347 $ 1,904 Investment and derivative gains/losses-2015 920 123 4,877 805