Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net earnings (loss)	$ 21,732	$ (1,071)
Other comprehensive income:
Net change in unrealized appreciation of investments	117	(45)
Applicable income taxes	(27)	(2)
Reclassification of investment appreciation in net earnings	5	(221)
Applicable income taxes	(1)	46
Foreign currency translation	183	601
Applicable income taxes	(3)	(6)
Defined benefit pension plans	66	(24)
Applicable income taxes	(17)	17
Other, net	(13)	(31)
Other comprehensive income, net	310	335
Comprehensive income	22,042	(736)
Comprehensive income attributable to noncontrolling interests	93	75
Comprehensive income attributable to Berkshire Hathaway shareholders	$ 21,949	$ (811)

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=114867106&loc=d3e557-108580

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1B
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=114867106&loc=SL7669625-108580

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1A
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=114867106&loc=SL7669619-108580