Consolidated Statements of Earnings - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Revenues:
Sales and service revenues		$ 42,392	$ 41,509
Leasing revenues		1,436
Total revenues		60,678	58,473
Investment and derivative contract gains (losses):
Investment gains (losses)		19,552	(7,809)
Derivative contract gains (losses)		770	(206)
Investment and derivative gains/losses		20,322	(8,015)
Costs and expenses:
Total costs and expenses		53,521	52,382
Earnings (loss) before income taxes and equity method earnings (losses)		27,479	(1,924)
Equity method earnings		168	401
Earnings (loss) before income taxes		27,647	(1,523)
Income tax expense (benefit)		5,915	(452)
Net earnings (loss)		21,732	(1,071)
Earnings attributable to noncontrolling interests		71	67
Net earnings (loss) attributable to Berkshire Hathaway shareholders		$ 21,661	$ (1,138)
Equivalent Class A [Member]
Costs and expenses:
Net earnings (loss) per average equivalent share		$ 13,209	$ (692)
Average equivalent shares outstanding		1,639,821	1,644,958
Equivalent Class B [Member]
Costs and expenses:
Net earnings (loss) per average equivalent share	[1]	$ 8.81	$ (0.46)
Average equivalent shares outstanding		2,459,731,886	2,467,436,888
Insurance and Other [Member]
Revenues:
Insurance premiums earned		$ 14,319	$ 13,373
Sales and service revenues		32,409	31,882
Leasing revenues		1,436	1,434
Interest, dividend and other investment income		2,117	1,682
Total revenues		50,281	48,371
Costs and expenses:
Insurance losses and loss adjustment expenses		10,174	8,963
Life, annuity and health insurance benefits		904	1,287
Insurance underwriting expenses		2,756	2,604
Cost of sales and services		25,767	25,461
Cost of leasing		1,020	983
Selling, general and administrative expenses		4,432	4,708
Interest expense		262	265
Total costs and expenses		45,315	44,271
Freight Rail Transportation [Member]
Revenues:
Total revenues		5,725	5,590
Costs and expenses:
Expenses		3,982	3,852
Utilities and Energy [Member]
Revenues:
Sales and service revenues		3,825	3,679
Costs and expenses:
Cost of sales and other expenses		2,842	2,800
Railroad, Utilities and Energy [Member]
Revenues:
Service revenues and other income		847	833
Total revenues		10,397	10,102
Costs and expenses:
Other expenses		653	749
Interest expense		729	710
Total costs and expenses		$ 8,206	$ 8,111

[1] Class B shares are economically equivalent to one-fifteen-hundredth of a Class A share. Accordingly, net earnings/loss per average equivalent Class B share outstanding is equal to one-fifteen-hundredth of the equivalent Class A amount. See Note 20.