Income taxes - Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Currently payable (receivable)	$ (482)	$ (276)
Deferred	89,679	73,261
Other	1,046	1,113
Income taxes, principally deferred	$ 90,243	$ 74,098

Sum of the carrying amounts as of the balance sheet date for a) payments made in advance for income taxes, which will be charged against earnings, b) income taxes previously overpaid to tax authorities representing refunds of overpayments or recoveries based on agreed-upon resolutions of disputes, c) the net cumulative amount for all deferred taxes arising from temporary differences between accounting income in accordance with generally accepted accounting principles and tax-basis income, and d) unpaid sum of the known and estimated amounts payable to satisfy all currently due domestic and foreign income tax obligations.

No definition available.

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Namespace Prefix:	brka_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant