Condensed Financial Information - Statements of Cash Flows (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net earnings (loss) attributable to Berkshire shareholders		$ 88,995	$ 96,223	$ (22,759)
Adjustments to reconcile net earnings (loss) to operating cash flows:
Income taxes payable		(8,163)	14,865	(12,872)
Other		(892)	(513)	(3,074)
Net cash flows from operating activities		30,592	49,196	37,350
Cash flows from investing activities:
Net cash flows from investing activities		(10,287)	(32,663)	(87,601)
Cash flows from financing activities:
Acquisitions of treasury stock		(2,918)	(9,171)	(7,854)
Other		(5,622)	(4,147)	(1,979)
Net cash flows from financing activities		(10,360)	(14,405)	(1,662)
Increase (decrease) in cash and cash equivalents and restricted cash		9,733	2,244	(52,307)
Other cash flow information:
Income taxes paid		28,544	7,765	4,236
Class B common stock issued in exchange for noncontrolling interests		1,045
Berkshire Hathaway Inc. (Parent) [Member]
Cash flows from operating activities:
Net earnings (loss) attributable to Berkshire shareholders		88,995	96,223	(22,759)
Adjustments to reconcile net earnings (loss) to operating cash flows:
Undistributed (earnings) losses of consolidated subsidiaries		(14,314)	(85,550)	39,579
Non-cash dividends from subsidiaries		(58,339)	(1,811)	(7,220)
Income taxes payable		294	(44)	661
Other	[1]	(2,666)	(1,207)	(1,799)
Net cash flows from operating activities		13,970	7,611	8,462
Cash flows from investing activities:
Investments in and advances to consolidated subsidiaries, net		(1,332)	2,649	(11,852)
Purchases of U.S. Treasury Bills		(52,864)	(27,278)	(44,187)
Sales and maturities of U.S. Treasury Bills and other		40,244	31,234	38,043
Net cash flows from investing activities		(13,952)	6,605	(17,996)
Cash flows from financing activities:
Proceeds from borrowings		5,525	2,054	1,970
Repayments of borrowings		(1,854)	(4,310)	(602)
Acquisitions of treasury stock		(2,918)	(9,171)	(7,854)
Net cash flows from financing activities		753	(11,427)	(6,486)
Increase (decrease) in cash and cash equivalents and restricted cash		771	2,789	(16,020)
Cash and cash equivalents at the beginning of the year		5,566	2,777	18,797
Cash and cash equivalents at the end of the year		6,337	5,566	2,777
Other cash flow information:
Income taxes paid		26,455	5,630	2,259
Interest paid		318	$ 297	$ 332
Class B common stock issued in exchange for noncontrolling interests		$ 1,045

[1] Includes discount accretion on investments and foreign currency exchange (gains) losses.