Condensed Financial Information - Balance Sheets (Detail) € in Millions, £ in Millions, $ in Millions, ¥ in Billions	Dec. 31, 2020 USD ($)	Dec. 31, 2020 EUR (€)	Dec. 31, 2020 JPY (¥)	Dec. 31, 2020 GBP (£)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Assets:
Total assets	$ 873,729				$ 817,729	$ 707,794
Liabilities and Shareholders’ Equity:
Income taxes, principally deferred	74,098				66,799
Notes payable and other borrowings		€ 6,850	¥ 625.5	£ 1,750
Total liabilities	422,393				389,166
Berkshire Hathaway shareholders’ equity	443,164				424,791
Total liabilities and shareholders' equity	873,729				817,729
Berkshire Hathaway Inc. (Parent) [Member]
Assets:
Cash and cash equivalents	12,329				15,004	$ 3,437	$ 4,039
Short-term investments in U.S. Treasury Bills	29,773				25,514
Investments in and advances to/from consolidated subsidiaries	411,826				392,162
Investment in The Kraft Heinz Company	13,336				13,757
Other assets	108				131
Total assets	467,372				446,568
Liabilities and Shareholders’ Equity:
Accounts payable, accrued interest and other liabilities	369				320
Income taxes, principally deferred	1,174				1,554
Notes payable and other borrowings	22,665				19,903
Total liabilities	24,208				21,777
Berkshire Hathaway shareholders’ equity	443,164				424,791
Total liabilities and shareholders' equity	$ 467,372				$ 446,568