Condensed Financial Information - Statements of Cash Flows (Detail) - USD ($) $ in Millions	3 Months Ended																12 Months Ended
	Dec. 31, 2015		Sep. 30, 2015	[1]	Jun. 30, 2015	[1]	Mar. 31, 2015		Dec. 31, 2014		Sep. 30, 2014	[1]	Jun. 30, 2014	[1]	Mar. 31, 2014		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net earnings attributable to Berkshire Hathaway shareholders	$ 5,478	[1]	$ 9,428		$ 4,013		$ 5,164	[1]	$ 4,155	[1]	$ 4,617		$ 6,395		$ 4,705	[1]	$ 24,083	$ 19,872	$ 19,476
Adjustments to reconcile net earnings to cash flows from operating activities:
Investment gains/losses																	(9,373)	(3,575)	(4,065)
Income taxes payable																	5,718	4,905	3,514
Other																	751	(341)	373
Net cash flows from operating activities																	31,491	32,010	27,704
Cash flows from investing activities:
Net cash flows from investing activities																	(26,668)	(19,369)	(27,535)
Cash flows from financing activities:
Acquisitions of noncontrolling interests																	(72)	(1,287)	(2,890)
Other																	(161)	22	(134)
Net cash flows from financing activities																	3,803	2,731	961
Increase (decrease) in cash and cash equivalents																	8,461	15,083	1,194
Cash and cash equivalents at beginning of year							63,269								48,186		63,269	48,186	46,992
Cash and cash equivalents at end of year	71,730								63,269								71,730	63,269	48,186
Other cash flow information:
Income taxes paid																	4,535	4,014	5,401
Berkshire Hathaway (Parent) [Member]
Cash flows from operating activities:
Net earnings attributable to Berkshire Hathaway shareholders																	24,083	19,872	19,476
Adjustments to reconcile net earnings to cash flows from operating activities:
Investment gains/losses																	(6,854)
Undistributed earnings of subsidiaries																	(8,508)	(14,496)	(13,657)
Non-cash dividends from subsidiaries																	(3,938)
Income taxes payable																	2,227	136	396
Other																	222	(75)	112
Net cash flows from operating activities																	7,232	5,437	6,327
Cash flows from investing activities:
Investments in The Kraft Heinz Company																	(5,258)		(12,250)
Investments in and advances to/repayments from subsidiaries																	(2,274)	1,673	(433)
Net cash flows from investing activities																	(7,532)	1,673	(12,683)
Cash flows from financing activities:
Proceeds from borrowings																	3,165	832	2,611
Repayments of borrowings																	(1,775)	(792)	(2,656)
Acquisitions of noncontrolling interests																	(10)	(1,231)	(836)
Other																	80	118	92
Net cash flows from financing activities																	1,460	(1,073)	(789)
Increase (decrease) in cash and cash equivalents																	1,160	6,037	(7,145)
Cash and cash equivalents at beginning of year							$ 9,449								$ 3,412		9,449	3,412	10,557
Cash and cash equivalents at end of year	$ 10,609								$ 9,449								10,609	9,449	3,412
Other cash flow information:
Income taxes paid																	3,180	2,512	4,080
Interest paid																	206	$ 233	$ 205
Non-cash investments in subsidiaries																	$ 3,938

[1] Includes investment gains/losses, other-than-temporary impairment losses on investments and derivative gains/losses. Derivative gains/losses include significant amounts related to non-cash changes in the fair value of long-term contracts arising from short-term changes in equity prices, interest rates and foreign currency rates, among other factors. 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 - 2015 $ 920 $ 123 $ 4,877 $ 805 Investment and derivative gains/losses - 2014 1,172 2,064 (107 ) 192