Business segment data (Tables)

12 Months Ended

Dec. 31, 2017

Segment Reporting [Abstract]

Schedule of revenues, earnings before income taxes, interest expense, income tax expense, capital expenditures, depreciation, goodwill and identifiable assets by segment

A disaggregation of our consolidated data for each of the three most recent years is presented in the tables which follow (in millions).

	Revenues									Earnings before income taxes
	2017			2016			2015			2017			2016			2015
Operating Businesses:
Insurance:
Underwriting:
GEICO	$	29,441		$	25,483		$	22,718		$	(310	)	$	462		$	460
Berkshire Hathaway Reinsurance Group		24,013			14,141			13,182			(3,648	)		1,012			553
Berkshire Hathaway Primary Group		7,143			6,257			5,394			719			657			824
Insurance underwriting		60,597			45,881			41,294			(3,239	)		2,131			1,837
Investment income		4,911			4,522			4,562			4,902			4,482			4,550
Total insurance		65,508			50,403			45,856			1,663			6,613			6,387
BNSF		21,387			19,829			21,967			6,328			5,693			6,775
Berkshire Hathaway Energy		18,939			17,859			18,231			2,584			2,973			2,851
Manufacturing		50,445			46,506			36,136			6,861			6,211			4,893
McLane Company		49,775			48,075			48,223			299			431			502
Service and retailing		26,313			25,478			23,466			2,083			1,820			1,720
Finance and financial products		8,376			7,675			6,964			2,058			2,130			2,086
		240,743			215,825			200,843			21,876			25,871			25,214
Reconciliation to consolidated amount:
Investment and derivative gains/losses		2,128			8,304			10,347			2,128			8,304			10,347
Interest expense, not allocated to segments		—			—			—			(1,494	)		(230	)		(374	)
Investments in Kraft Heinz		—			180			852			2,938			1,103			730
Corporate, eliminations and other		(734	)		(705	)		(1,099	)		(1,610	)		(1,381	)		(971	)
	$	242,137		$	223,604		$	210,943		$	23,838		$	33,667		$	34,946

	Interest expense						Income tax expense
	2017		2016		2015		2017		2016		2015
Operating Businesses:
Insurance	$	—	$	—	$	—	$	(55)	$	1,585	$	1,475
BNSF		1,016		992		928		2,369		2,124		2,527
Berkshire Hathaway Energy		2,254		1,715		1,830		178		403		450
Manufacturing		189		164		50		2,155		1,945		1,548
McLane Company		19		—		13		94		169		195
Service and retailing		56		50		40		726		669		651
Finance and financial products		397		411		384		723		702		708
		3,931		3,332		3,245		6,190		7,597		7,554
Reconciliation to consolidated amount:
Investment and derivative gains/losses		—		—		—		742		1,807		3,622
Interest expense, not allocated to segments		1,494		230		374		(523)		(81)		(131)
Investments in Kraft Heinz		—		—		—		832		397		(111)
Income tax net benefit – Tax Cuts and Jobs Act of 2017		—		—		—		(28,200)		—		—
Corporate, eliminations and other		(31)		(65)		(104)		(556)		(480)		(402)
	$	5,394	$	3,497	$	3,515	$	(21,515)	$	9,240	$	10,532

	Capital expenditures						Depreciation of tangible assets
	2017		2016		2015		2017		2016		2015
Operating Businesses:
Insurance	$	170	$	128	$	115	$	84	$	85	$	77
BNSF		3,256		3,819		5,651		2,304		2,079		1,932
Berkshire Hathaway Energy		4,571		5,090		5,875		2,548		2,560		2,451
Manufacturing		1,905		1,813		1,292		1,357		1,287		938
McLane Company		289		258		338		193		165		161
Service and retailing		587		804		574		583		611		504
Finance and financial products		930		1,042		2,237		650		624		610
	$	11,708	$	12,954	$	16,082	$	7,719	$	7,411	$	6,673

	Goodwill at year-end				Identifiable assets at year-end
	2017		2016		2017		2016		2015
Operating Businesses:
Insurance	$	15,499	$	15,474	$	297,048	$	234,037	$	219,451
BNSF		14,845		14,845		69,438		69,277		66,613
Berkshire Hathaway Energy		9,935		9,266		80,195		76,428		74,221
Manufacturing		32,981		32,041		72,630		69,900		34,141
McLane Company		734		734		6,090		5,896		5,871
Service and retailing		5,771		5,745		18,215		17,450		16,299
Finance and financial products		1,493		1,381		40,392		40,329		37,621
	$	81,258	$	79,486		584,008		513,317		454,217
Reconciliation to consolidated amount:
Corporate and other						36,829		28,051		35,332
Goodwill						81,258		79,486		62,708
					$	702,095	$	620,854	$	552,257

Schedule of premiums written and earned

Premiums written and earned by the property/casualty and life/health insurance businesses are summarized below (in millions).

	Property/Casualty									Life/Health
	2017			2016			2015			2017			2016			2015
Premiums Written:
Direct	$	39,377		$	34,001		$	30,544		$	866		$	1,060		$	821
Assumed		17,815			8,037			7,049			4,925			4,672			5,187
Ceded		(694	)		(798	)		(877	)		(47	)		(62	)		(57	)
	$	56,498		$	41,240		$	36,716		$	5,744		$	5,670		$	5,951
Premiums Earned:
Direct	$	37,755		$	33,207		$	29,608		$	866		$	1,060		$	821
Assumed		17,813			7,848			6,584			4,866			4,671			5,192
Ceded		(677	)		(843	)		(854	)		(26	)		(62	)		(57	)
	$	54,891		$	40,212		$	35,338		$	5,706		$	5,669		$	5,956

Schedule of insurance premiums written by geographic region

Insurance premiums written by geographic region (based upon the domicile of the insured or reinsured) are summarized below. Dollars are in millions.

	Property/Casualty						Life/Health
	2017		2016		2015		2017		2016		2015
United States	$	50,604	$	35,878	$	31,171	$	3,320	$	3,473	$	3,247
Asia Pacific		3,307		3,616		3,472		879		715		673
Western Europe		1,516		1,406		1,638		909		822		1,263
All other		1,071		340		435		636		660		768
	$	56,498	$	41,240	$	36,716	$	5,744	$	5,670	$	5,951