Consolidated Statements of Earnings (USD $) In Millions, except Per Share data	3 Months Ended				9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2011		Sep. 30, 2010
Revenues:
Investment gains/losses	$ 100		$ 473		$ 1,488		$ 2,174
Total revenues	33,739		36,274		105,733		100,020
Costs and expenses:
Total costs and expenses	30,376		31,740		94,871		87,450
Earnings before income taxes	3,363		4,534		10,862		12,570
Income tax expense	953		1,415		3,307		3,599
Earnings from equity method investment							50
Net earnings	2,410		3,119		7,555		9,021
Less: Earnings attributable to noncontrolling interests	132		130		349		431
Net earnings attributable to Berkshire Hathaway	2,278		2,989		7,206		8,590
Average common shares outstanding	1,651,290	[1]	1,647,593	[1]	1,649,585	[1]	1,631,489	[1]
Insurance and Other [Member]
Revenues:
Insurance premiums earned	7,645		9,054		24,076		23,344
Sales and service revenues	18,573		17,408		53,681		50,149
Interest, dividend and other investment income	1,051		1,239		3,754		4,048
Investment gains/losses	100		473		1,314		2,169
Other-than-temporary impairment losses on investments	(8)		(15)		(514)		(15)
Total revenues	27,361		28,159		82,311		79,695
Costs and expenses:
Insurance losses and loss adjustment expenses	3,827		6,254		16,107		14,357
Life, annuity and health insurance benefits	1,041		861		3,032		3,240
Insurance underwriting expenses	1,082		1,634		4,527		4,381
Cost of sales and services	15,281		14,439		44,095		41,537
Selling, general and administrative expenses	2,105		1,896		6,262		5,650
Interest expense	79		71		216		206
Total costs and expenses	23,415		25,155		74,239		69,371
Railroad, Utilities and Energy [Member]
Revenues:
Operating revenues	7,781		7,155		22,594		18,889
Other	47		60		115		142
Total revenues	7,828		7,215		22,709		19,031
Costs and expenses:
Cost of sales and operating expenses	5,675		5,251		16,898		14,143
Interest expense	428		421		1,280		1,162
Total costs and expenses	6,103		5,672		18,178		15,305
Finance and Financial Products [Member]
Revenues:
Interest, dividend and other investment income	384		395		1,141		1,197
Investment gains/losses					174		5
Derivative gains/losses	(2,443)		(146)		(2,356)		(1,911)
Other	609		651		1,754		2,003
Total revenues	(1,450)		900		713		1,294
Costs and expenses:
Interest expense	162		176		493		530
Other	696		737		1,961		2,244
Total costs and expenses	$ 858		$ 913		$ 2,454		$ 2,774
Class A [Member]
Net earnings per share attributable to Berkshire Hathaway shareholders:
Net earnings per share attributable to Berkshire Hathaway shareholders	$ 1,380	[1]	$ 1,814	[1]	$ 4,368	[1]	$ 5,265	[1]

[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.