Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net earnings (loss)	$ 16,657	$ 18,707	$ 52,562	$ 29,713
Other comprehensive income:
Net change in unrealized appreciation of investments	18	5	232	(132)
Applicable income taxes	(2)	(1)	(51)	19
Reclassification of investment appreciation in net earnings	(57)	(34)	(53)	(299)
Applicable income taxes	12	7	11	63
Foreign currency translation	(700)	(79)	(534)	(842)
Applicable income taxes	6	9	3	46
Defined benefit pension plans	(45)	(13)	47	50
Applicable income taxes	7	3	(16)
Other, net	10	(21)	(35)	(57)
Other comprehensive income, net	(751)	(124)	(396)	(1,152)
Comprehensive income	15,906	18,583	52,166	28,561
Comprehensive income attributable to noncontrolling interests	112	162	301	271
Comprehensive income attributable to Berkshire Hathaway shareholders	$ 15,794	$ 18,421	$ 51,865	$ 28,290