Income taxes - Income tax expense (benefit) reconciliation (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income tax expense reconciliation
Earnings (loss) before income taxes		$ 110,376	$ 120,166	$ (30,500)
Hypothetical income tax expense (benefit) at the U.S. federal statutory rate		23,179	25,235	(6,405)
Dividends received deduction		(491)	(678)	(512)
State income taxes, less U.S. federal income tax effect		606	603	602
U.S. income tax credits	[1]	(2,575)	(2,186)	(2,187)
Other differences, net		96	45
Total income taxes		$ 20,815	$ 23,019	$ (8,502)
Effective income tax rate		18.90%	19.20%	27.90%

[1] U.S. income tax credits derive primarily from production tax credits associated with wind-energy generation of BHE and tax credits arising from affordable housing investments.