Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net earnings	$ 81,792	$ 4,322	$ 45,353
Other comprehensive income:
Net change in unrealized appreciation of investments	204	(185)	30,450
Applicable income taxes	(44)	31	(10,566)
Reclassification of investment appreciation in net earnings	(62)	(253)	(1,399)
Applicable income taxes	13	53	490
Foreign currency translation	323	(1,531)	2,364
Applicable income taxes	(28)	62	(95)
Prior service cost and actuarial gains/losses of defined benefit pension plans	(711)	(571)	225
Applicable income taxes	155	143	(45)
Other, net	(48)	(12)	(9)
Other comprehensive income, net	(198)	(2,263)	21,415
Comprehensive income	81,594	2,059	66,768
Comprehensive income attributable to noncontrolling interests	405	249	555
Comprehensive income attributable to Berkshire Hathaway shareholders	$ 81,189	$ 1,810	$ 66,213