Condensed Financial Information - Balance Sheets (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets:
Total assets	$ 707,794	$ 702,095	$ 620,854
Liabilities and Shareholders' Equity:
Income taxes, principally deferred	51,375	56,607
Total liabilities	355,294	350,141
Berkshire Hathaway shareholders' equity	348,703	348,296
Total liabilities and shareholders' equity	707,794	702,095
Berkshire Hathaway Inc. (Parent) [Member]
Assets:
Cash and cash equivalents	3,437	4,039	$ 3,221	$ 10,609
Short-term investments in U.S. Treasury Bills	22,957	13,132
Investments in and advances to/from consolidated subsidiaries	328,898	335,668
Investment in The Kraft Heinz Company	13,813	17,635
Other assets	80	79
Total assets	369,185	370,553
Liabilities and Shareholders' Equity:
Accounts payable, accrued interest and other liabilities	1,507	196
Income taxes, principally deferred	2,104	3,294
Notes payable and other borrowings	16,871	18,767
Total liabilities	20,482	22,257
Berkshire Hathaway shareholders' equity	348,703	348,296
Total liabilities and shareholders' equity	$ 369,185	$ 370,553