Consolidated Statements of Earnings (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Revenues:
Investment gains/losses	$ 1,714		$ 917		$ 2,711		$ 936
Total revenues	46,541		41,050		135,101		117,743
Costs and expenses:
Total costs and expenses	39,163		35,114		113,537		102,261
Earnings before income taxes	7,378		5,936		21,564		15,482
Income tax expense	2,225		1,882		6,782		4,831
Net earnings	5,153		4,054		14,782		10,651
Less: Earnings attributable to noncontrolling interests	100		134		296		378
Net earnings attributable to Berkshire Hathaway	5,053		3,920		14,486		10,273
Average common shares outstanding	1,643,779	[1]	1,652,184	[1]	1,643,522	[1]	1,651,549	[1]
Class A [Member]
Net earnings per share attributable to Berkshire Hathaway shareholders:
Net earnings per share attributable to Berkshire Hathaway shareholders	$ 3,074	[1]	$ 2,373	[1]	$ 8,814	[1]	$ 6,220	[1]
Insurance and Other [Member]
Revenues:
Insurance premiums earned	9,270		8,851		27,462		25,344
Sales and service revenues	23,890		20,982		70,181		61,060
Interest, dividend and other investment income	1,119		994		3,740		3,481
Investment gains/losses	1,640		725		2,529		720
Total revenues	35,919		31,552		103,912		90,605
Costs and expenses:
Insurance losses and loss adjustment expenses	5,466		5,016		15,879		14,373
Life, annuity and health insurance benefits	1,575		1,284		3,899		3,727
Insurance underwriting expenses	1,966		1,943		5,206		5,594
Cost of sales and services	19,399		16,992		57,056		49,409
Selling, general and administrative expenses	2,909		2,573		8,689		7,477
Interest expense	109		105		317		314
Total costs and expenses	31,424		27,913		91,046		80,894
Railroad, Utilities and Energy [Member]
Revenues:
Operating revenues	8,984		8,353		25,645		23,971
Other	59		66		176		154
Total revenues	9,043		8,419		25,821		24,125
Costs and expenses:
Cost of sales and operating expenses	6,429		5,930		18,634		17,567
Interest expense	472		439		1,371		1,306
Total costs and expenses	6,901		6,369		20,005		18,873
Finance and Financial Products [Member]
Revenues:
Interest, dividend and other investment income	341		366		1,024		1,113
Investment gains/losses	74		192		182		216
Derivative gains/losses	427		(118)		2,094		(184)
Other	737		639		2,068		1,868
Total revenues	1,579		1,079		5,368		3,013
Costs and expenses:
Interest expense	125		148		395		459
Other	713		684		2,091		2,035
Total costs and expenses	$ 838		$ 832		$ 2,486		$ 2,494

[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.