Consolidated Statements of Earnings - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenues:
Sales and service revenues		$ 43,494	$ 45,169	$ 122,324	$ 132,021
Leasing revenues		1,316	1,438	3,905	4,365
Total revenues		63,024	64,972	181,129	189,248
Investment and derivative contract gains/losses		31,582	10,926	1,392	41,296
Costs and expenses:
Total costs and expenses		56,966	56,053	172,564	165,585
Earnings before income taxes and equity method earnings		37,640	19,845	9,957	64,959
Equity method earnings		290	644	333	936
Earnings before income taxes		37,930	20,489	10,290	65,895
Income tax expense		7,517	3,832	3,167	13,333
Net earnings		30,413	16,657	7,123	52,562
Earnings attributable to noncontrolling interests		276	133	437	304
Net earnings attributable to Berkshire Hathaway shareholders		$ 30,137	$ 16,524	$ 6,686	$ 52,258
Equivalent Class A [Member]
Costs and expenses:
Net earnings per average equivalent share		$ 18,994	$ 10,119	$ 4,160	$ 31,944
Average equivalent shares outstanding		1,586,698	1,633,002	1,607,041	1,635,903
Equivalent Class B [Member]
Costs and expenses:
Net earnings per average equivalent share	[1]	$ 12.66	$ 6.75	$ 2.77	$ 21.30
Average equivalent shares outstanding		2,380,046,304	2,449,502,430	2,410,561,550	2,453,854,768
Insurance and Other [Member]
Revenues:
Insurance premiums earned		$ 15,913	$ 15,323	$ 47,256	$ 44,505
Sales and service revenues		32,703	34,026	93,332	100,563
Leasing revenues		1,316	1,438	3,905	4,365
Interest, dividend and other investment income		1,717	2,483	6,143	6,895
Total revenues		51,649	53,270	150,636	156,328
Costs and expenses:
Insurance losses and loss adjustment expenses		11,667	10,858	32,712	31,701
Life, annuity and health insurance benefits		1,311	1,176	4,101	3,245
Insurance underwriting expenses		3,228	2,708	9,219	8,033
Cost of sales and services		25,957	26,950	74,565	79,764
Cost of leasing		854	1,010	2,605	3,030
Selling, general and administrative expenses		5,181	4,384	14,304	13,645
Goodwill and intangible asset impairments		25		10,659
Interest expense		263	261	817	790
Total costs and expenses		48,486	47,347	148,982	140,208
Freight Rail Transportation [Member]
Revenues:
Total revenues		5,148	5,982	15,101	17,558
Costs and expenses:
Expenses		3,161	3,839	9,625	11,706
Utilities and Energy [Member]
Revenues:
Sales and service revenues		4,451	4,338	11,504	11,729
Costs and expenses:
Cost of sales and other expenses		3,101	2,981	8,326	8,503
Railroad, Utilities and Energy [Member]
Revenues:
Service revenues and other income		1,776	1,382	3,888	3,633
Total revenues		11,375	11,702	30,493	32,920
Costs and expenses:
Other expenses		1,481	1,162	3,422	2,990
Interest expense		737	724	2,209	2,178
Total costs and expenses		$ 8,480	$ 8,706	$ 23,582	$ 25,377

[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. See Note 18.