Consolidated Statements of Earnings - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues:
Sales and service revenues		$ 45,169	$ 45,427	$ 132,021	$ 131,191
Leasing revenues		1,438		4,365
Total revenues		64,972	63,450	189,248	184,123
Investment and derivative contract gains (losses):
Investment gains (losses)		10,692	14,569	40,079	12,750
Derivative contract gains (losses)		234	137	1,217	303
Investment and derivative gains/losses		10,926	14,706	41,296	13,053
Costs and expenses:
Total costs and expenses		56,053	55,325	165,585	161,498
Earnings (loss) before income taxes and equity method earnings		19,845	22,831	64,959	35,678
Equity method earnings		644	316	936	1,044
Earnings (loss) before income taxes		20,489	23,147	65,895	36,722
Income tax expense (benefit)		3,832	4,440	13,333	7,009
Net earnings (loss)		16,657	18,707	52,562	29,713
Earnings attributable to noncontrolling interests		133	167	304	300
Net earnings (loss) attributable to Berkshire Hathaway shareholders		$ 16,524	$ 18,540	$ 52,258	$ 29,413
Equivalent Class A [Member]
Costs and expenses:
Net earnings (loss) per average equivalent share		$ 10,119	$ 11,280	$ 31,944	$ 17,885
Average equivalent shares outstanding		1,633,002	1,643,556	1,635,903	1,644,519
Equivalent Class B [Member]
Costs and expenses:
Net earnings (loss) per average equivalent share	[1]	$ 6.75	$ 7.52	$ 21.30	$ 11.92
Average equivalent shares outstanding		2,449,502,430	2,465,333,662	2,453,854,768	2,466,777,764
Insurance and Other [Member]
Revenues:
Insurance premiums earned		$ 15,323	$ 14,333	$ 44,505	$ 41,855
Sales and service revenues		34,026	33,832	100,563	99,492
Leasing revenues		1,438	1,474	4,365	4,378
Interest, dividend and other investment income		2,483	1,993	6,895	5,583
Total revenues		53,270	51,632	156,328	151,308
Costs and expenses:
Insurance losses and loss adjustment expenses		10,858	9,932	31,701	28,296
Life, annuity and health insurance benefits		1,176	1,448	3,245	4,153
Insurance underwriting expenses		2,708	2,352	8,033	7,079
Cost of sales and services		26,950	27,084	79,764	79,254
Cost of leasing		1,010	978	3,030	2,949
Selling, general and administrative expenses		4,384	4,494	13,645	13,434
Interest expense		261	252	790	772
Total costs and expenses		47,347	46,540	140,208	135,937
Freight Rail Transportation [Member]
Revenues:
Total revenues		5,982	6,112	17,558	17,547
Costs and expenses:
Expenses		3,839	4,012	11,706	11,838
Utilities and Energy [Member]
Revenues:
Sales and service revenues		4,338	4,419	11,729	11,818
Costs and expenses:
Cost of sales and other expenses		2,981	2,981	8,503	8,637
Railroad, Utilities and Energy [Member]
Revenues:
Service revenues and other income		1,382	1,287	3,633	3,450
Total revenues		11,702	11,818	32,920	32,815
Costs and expenses:
Other expenses		1,162	1,094	2,990	2,976
Interest expense		724	698	2,178	2,110
Total costs and expenses		$ 8,706	$ 8,785	$ 25,377	$ 25,561

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