Consolidated Statements of Earnings (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Revenues:
Sales and service revenues	$ 102,200		$ 97,600		$ 85,800
Investment gains/losses	3,575		4,065		1,462
Total revenues	194,673		182,150		162,463
Costs and expenses:
Total costs and expenses	166,568		153,354		140,227
Earnings before income taxes	28,105		28,796		22,236
Income tax expense	7,935		8,951		6,924
Net earnings	20,170		19,845		15,312
Less: Earnings attributable to noncontrolling interests	298		369		488
Net earnings attributable to Berkshire Hathaway shareholders	19,872		19,476		14,824
Average common shares outstanding	1,643,456	[1]	1,643,613	[1]	1,651,294	[1]
Class A [Member]
Net earnings per share attributable to Berkshire Hathaway shareholders:
Net earnings per share attributable to Berkshire Hathaway shareholders	$ 12,092.00	[1]	$ 11,850.00	[1]	$ 8,977.00	[1]
Insurance and Other [Member]
Revenues:
Insurance premiums earned	41,253		36,684		34,545
Sales and service revenues	97,097		92,993		81,447
Interest, dividend and other investment income	5,026		4,934		4,532
Investment gains/losses	3,503		3,881		990
Total revenues	146,879		138,492		121,514
Costs and expenses:
Insurance losses and loss adjustment expenses	26,406		21,275		20,113
Life, annuity and health insurance benefits	5,181		5,072		5,114
Insurance underwriting expenses	6,998		7,248		7,693
Cost of sales and services	78,873		75,953		66,419
Selling, general and administrative expenses	12,198		11,732		10,307
Interest expense	419		395		363
Total costs and expenses	130,075		121,675		110,009
Railroad, Utilities and Energy [Member]
Revenues:
Total revenues	40,690		34,757		32,582
Costs and expenses:
Cost of sales and operating expenses	29,378		25,157		23,816
Interest expense	2,378		1,865		1,745
Total costs and expenses	31,756		27,022		25,561
Finance and Financial Products [Member]
Revenues:
Sales and service revenues	5,094		4,635		4,358
Interest, dividend and other investment income	1,432		1,474		1,574
Investment gains/losses	72		184		472
Derivative gains/losses	506		2,608		1,963
Total revenues	7,104		8,901		8,367
Costs and expenses:
Cost of sales and services	2,758		2,566		2,458
Selling, general and administrative expenses	1,523		1,550		1,563
Interest expense	456		541		636
Total costs and expenses	$ 4,737		$ 4,657		$ 4,657

[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 or $8.06 per share for 2014, $7.90 per share for 2013 and $5.98 per share for 2012.