Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net earnings	$ 4,203	$ 7,333	$ 12,697	$ 18,072
Other comprehensive income:
Net change in unrealized appreciation of investments	4,952	1,581	18,040	(1,381)
Applicable income taxes	(1,716)	(515)	(6,247)	478
Reclassification of investment appreciation in net earnings	(646)	(3,088)	(1,235)	(4,904)
Applicable income taxes	226	1,080	432	1,716
Foreign currency translation	771	(44)	2,127	(158)
Applicable income taxes	(24)	9	(116)	23
Prior service cost and actuarial gains/losses of defined benefit pension plans	(3)	(21)	(57)	34
Applicable income taxes	6	13	31	(6)
Other, net	32	3	38	(3)
Other comprehensive income, net	3,598	(982)	13,013	(4,201)
Comprehensive income	7,801	6,351	25,710	13,871
Comprehensive income attributable to noncontrolling interests	203	132	436	267
Comprehensive income attributable to Berkshire Hathaway shareholders	$ 7,598	$ 6,219	$ 25,274	$ 13,604