Consolidated Statements of Earnings (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Revenues:
Investment gains/losses	$ (376)		$ 1,714		$ 3,121		$ 2,711
Total revenues	51,199		46,541		146,414		135,101
Costs and expenses:
Total costs and expenses	44,449		39,163		124,150		113,537
Earnings before income taxes	6,750		7,378		22,264		21,564
Income tax expense	2,029		2,225		6,312		6,782
Net earnings	4,721		5,153		15,952		14,782
Less: Earnings attributable to noncontrolling interests	104		100		235		296
Net earnings attributable to Berkshire Hathaway	4,617		5,053		15,717		14,486
Average common shares outstanding	1,642,558	[1]	1,643,779	[1]	1,643,657	[1]	1,643,522	[1]
Class A [Member]
Net earnings per share attributable to Berkshire Hathaway shareholders:
Net earnings per share attributable to Berkshire Hathaway shareholders	$ 2,811	[1]	$ 3,074	[1]	$ 9,562	[1]	$ 8,814	[1]
Insurance and Other [Member]
Revenues:
Insurance premiums earned	12,717		9,270		31,456		27,462
Sales and service revenues	25,078		23,431		72,252		68,839
Interest, dividend and other investment income	1,171		1,118		3,909		3,736
Investment gains/losses	(376)		1,640		3,049		2,529
Total revenues	38,590		35,459		110,666		102,566
Costs and expenses:
Insurance losses and loss adjustment expenses	8,791		5,466		19,923		15,879
Life, annuity and health insurance benefits	1,355		1,575		3,844		3,899
Insurance underwriting expenses	1,596		1,966		5,361		5,206
Cost of sales and services	20,410		19,125		58,610		56,239
Selling, general and administrative expenses	2,991		2,860		8,845		8,552
Interest expense	109		102		323		293
Total costs and expenses	35,252		31,094		96,906		90,068
Railroad, Utilities and Energy [Member]
Revenues:
Total revenues	10,697		9,043		30,296		25,821
Costs and expenses:
Cost of sales and operating expenses	7,383		6,429		21,957		18,634
Interest expense	597		472		1,753		1,371
Total costs and expenses	7,980		6,901		23,710		20,005
Finance and Financial Products [Member]
Revenues:
Sales and service revenues	1,322		1,196		3,732		3,410
Interest, dividend and other investment income	332		342		999		1,028
Investment gains/losses			74		72		182
Derivative gains/losses	258		427		649		2,094
Total revenues	1,912		2,039		5,452		6,714
Costs and expenses:
Cost of sales and services	713		648		2,043		1,902
Selling, general and administrative expenses	393		388		1,144		1,143
Interest expense	111		132		347		419
Total costs and expenses	$ 1,217		$ 1,168		$ 3,534		$ 3,464

[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.