Consolidated Statements of Earnings (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Revenues:
Investment gains/losses	$ 492		$ 125		$ 997		$ 19
Total revenues	44,693		38,546		88,560		76,693
Costs and expenses:
Total costs and expenses	37,802		33,931		74,374		67,147
Earnings before income taxes	6,891		4,615		14,186		9,546
Income tax expense	2,279		1,384		4,557		2,949
Net earnings	4,612		3,231		9,629		6,597
Less: Earnings attributable to noncontrolling interests	71		123		196		244
Net earnings attributable to Berkshire Hathaway	4,541		3,108		9,433		6,353
Average common shares outstanding	1,643,599	[1]	1,651,511	[1]	1,643,391	[1]	1,651,228	[1]
Class A [Member]
Net earnings per share attributable to Berkshire Hathaway shareholders:
Net earnings per share attributable to Berkshire Hathaway shareholders	$ 2,763	[1]	$ 1,882	[1]	$ 5,740	[1]	$ 3,847	[1]
Insurance and Other [Member]
Revenues:
Insurance premiums earned	8,815		8,428		18,192		16,493
Sales and service revenues	23,873		20,814		46,291		40,078
Interest, dividend and other investment income	1,610		1,420		2,621		2,487
Investment gains/losses	455		102		889		(5)
Total revenues	34,753		30,764		67,993		59,053
Costs and expenses:
Insurance losses and loss adjustment expenses	5,269		4,586		10,413		9,357
Life, annuity and health insurance benefits	1,063		1,351		2,324		2,443
Insurance underwriting expenses	1,657		1,534		3,240		3,651
Cost of sales and services	19,373		16,821		37,657		32,417
Selling, general and administrative expenses	2,926		2,476		5,780		4,904
Interest expense	107		106		208		209
Total costs and expenses	30,395		26,874		59,622		52,981
Railroad, Utilities and Energy [Member]
Revenues:
Operating revenues	8,310		7,769		16,661		15,618
Other	68		41		117		88
Total revenues	8,378		7,810		16,778		15,706
Costs and expenses:
Cost of sales and operating expenses	6,094		5,767		12,205		11,637
Interest expense	452		439		899		867
Total costs and expenses	6,546		6,206		13,104		12,504
Finance and Financial Products [Member]
Revenues:
Interest, dividend and other investment income	342		372		683		747
Investment gains/losses	37		23		108		24
Derivative gains/losses	461		(1,068)		1,667		(66)
Other	722		645		1,331		1,229
Total revenues	1,562		(28)		3,789		1,934
Costs and expenses:
Interest expense	132		151		270		311
Other	729		700		1,378		1,351
Total costs and expenses	$ 861		$ 851		$ 1,648		$ 1,662

[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 common share attributable to Berkshire Hathaway 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.