Income Taxes - Reconciliation of Expected Income Tax Expense at Federal Statutory Rate to the Applicable Income Tax Expense (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2025	Jun. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Income Tax Disclosure [Abstract]
Tax at statutory rate	$ 532		$ 435	$ 1,467	$ 1,218
State income tax, at statutory rates, net of federal tax benefit	119		106	330	289
Tax credits and benefits, net of related expenses	(115)		(140)	(381)	(284)
Revaluation of tax related assets and liabilities	0	$ 72	0	72	0
Exam resolutions	(1)		(1)	(1)	(98)
Tax-exempt income	(39)		(38)	(112)	(105)
Other items	28		(12)	64	122
Total income tax provision	$ 524		$ 350	$ 1,439	$ 1,142