Income Taxes - Provision for Federal Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Tax Provision (Benefit)
Current income tax benefit (provision)	$ (3,154)	$ (3,317)	$ (3,505)
Deferred income tax provision (provision)	(1,137)	(1,231)	195
Provision for federal income taxes	$ (4,291)	$ (4,548)	$ (3,310)
Effective Income Tax Rate Reconciliation
Statutory corporate tax rate	21.00%	21.00%	21.00%
Research tax credits	(0.30%)	(0.20%)	(1.50%)
Equity investments in affordable housing projects	(0.30%)	(0.20%)	(0.10%)
Valuation allowance	(0.10%)	0.10%	0.70%
Other	(0.10%)	0.00%	0.30%
Effective tax rate	20.20%	20.70%	20.40%