Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net earnings	$ 10,644	$ 30,413	$ 50,909	$ 7,123
Other comprehensive income:
Unrealized appreciation of investments	(89)	19	(164)	42
Applicable income taxes	20	(4)	38	(13)
Foreign currency translation	(643)	791	(616)	(77)
Applicable income taxes	6	(3)	(8)	34
Defined benefit pension plans	54	(24)	158	86
Applicable income taxes	(13)	8	(42)	(14)
Other, net	38	16	45	(19)
Other comprehensive income, net	(627)	803	(589)	39
Comprehensive income	10,017	31,216	50,320	7,162
Comprehensive income attributable to noncontrolling interests	288	302	762	423
Comprehensive income attributable to Berkshire Hathaway shareholders	$ 9,729	$ 30,914	$ 49,558	$ 6,739