Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Insurance and Other [Member]
Investments in The Kraft Heinz Company, Fair Value	$ 28,418	$ 32,042

The fair value of an investment in preferred stock and common stock of an equity method investee.

No definition available.

Name:	brka_InvestmentOwnedPreferredStockAndCommonStockFairValue
Namespace Prefix:	brka_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant