Consolidated Statements of Earnings - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Revenues:
Leasing revenues		$ 9,227	$ 8,416	$ 7,514
Total revenues		371,433	364,482	302,020
Investment gains (losses)		52,799	74,855	(67,899)
Costs and expenses:
Interest expense		5,200	5,003	4,352
Total costs and expenses		315,697	321,144	266,484
Earnings (loss) before income taxes and equity method earnings		108,535	118,193	(32,363)
Equity method earnings		1,841	1,973	1,863
Earnings (loss) before income taxes		110,376	120,166	(30,500)
Income tax expense (benefit)		20,815	23,019	(8,502)
Net earnings (loss)		89,561	97,147	(21,998)
Earnings attributable to noncontrolling interests		566	924	761
Net earnings (loss) attributable to Berkshire shareholders		$ 88,995	$ 96,223	$ (22,759)
Equivalent Class A [Member]
Earnings per share:
Net earnings (loss) per average equivalent		$ 61,900	$ 66,412	$ (15,494)
Average equivalent shares outstanding		1,437,720	1,448,880	1,468,876
Equivalent Class B [Member]
Earnings per share:
Net earnings (loss) per average equivalent	[1]	$ 41.27	$ 44.27	$ (10.33)
Average equivalent shares outstanding		2,156,580,296	2,173,319,709	2,203,313,642
Insurance and Other [Member]
Revenues:
Insurance premiums earned		$ 88,257	$ 83,403	$ 74,576
Sales and service revenues		202,334	207,148	157,518
Leasing revenues		9,227	8,416	7,514
Interest, dividend and other investment income		21,825	15,764	10,263
Total revenues		321,643	314,731	249,871
Costs and expenses:
Insurance losses and loss adjustment expenses		56,186	57,187	57,646
Life, annuity and health benefits		3,858	4,029	5,243
Insurance underwriting expenses		16,808	15,270	11,706
Cost of sales and services		163,642	169,281	124,319
Cost of leasing		7,069	6,037	5,550
Selling, general and administrative expenses		25,642	25,458	19,506
Interest expense		1,594	1,671	1,187
Total costs and expenses		274,799	278,933	225,157
Railroad, Utilities and Energy [Member]
Revenues:
Railroad transportation revenues		23,355	23,791	25,802
Utility and energy operating revenues		21,518	21,232	21,023
Service revenues and other income		4,917	4,728	5,324
Total revenues		49,790	49,751	52,149
Costs and expenses:
Freight rail transportation expenses		15,965	16,464	17,282
Utilities and energy cost of sales and other expenses		16,984	18,399	15,896
Other expenses		4,343	4,016	4,984
Interest expense		3,606	3,332	3,165
Total costs and expenses		$ 40,898	$ 42,211	$ 41,327

[1] Net earnings (loss) per average equivalent Class B share outstanding are equal to one-fifteen-hundredth of the equivalent Class A amount. See Note 22.