Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Jul. 25, 2019
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Trading Symbol	BRKA
Entity File Number	001-14905
Entity Tax Identification Number	470813844
Entity Address, Address Line One	3555 Farnam Street
Entity Address, City or Town	Omaha
Entity Address, State or Province	Nebraska
Entity Address, Postal Zip Code	68131
City Area Code	402
Local Phone Number	346-1400
Entity Registrant Name	BERKSHIRE HATHAWAY INC
Entity Central Index Key	0001067983
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Current Reporting Status	Yes
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Class A [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		709,836
Class B [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		1,386,311,473