AFS and HTM Debt Securities, Income Statement Impacts (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
AFS And HTM Debt Securities [Abstract]
Debt securities, held-to-maturity, sold, realized gain (Loss)	$ 0	$ 0	$ 0	$ 0
Available For Sale and Held To Maturity Debt Securities Income Statement Impacts [Abstract]
Interest income, Available-for-sale	777	676	2,162	2,142
Interest income, Held-to-maturity	1,640	1,166	4,423	3,186
Total interest income	2,417	1,842	6,585	5,328
Provision for credit losses, Available-for-sale,	(2)	(5)	2	7
Provision for credit losses, Held-to-maturity	13	(3)	(1)	33
Total provision for credit losses	11	(8)	1	40
Gross realized gains	27	291	276	443
Gross realized losses	(21)	0	(125)	(1)
Impairment write-downs	0	(8)	0	(8)
Net realized gains	$ 6	$ 283	$ 151	$ 434