Securities - Available for Sale Securities (Unrealized Loss Position) (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Held-to-maturity securities:
Temporarily impaired securities, fair value, less than 12 months	$ 25,091	$ 29,680
Temporarily impaired securities, gross unrealized losses, less than 12 months	2,751	568
Temporarily impaired securities, fair value, 12 months or longer	22,266	5,511
Temporarily impaired securities, gross unrealized losses, 12 months or longer	4,110	316
Temporarily impaired securities, fair value	47,357	35,191
Temporarily impaired securities, gross unrealized losses	6,861	884
U.S. Treasury, agencies and corporations
Securities available for sale:
Fair value, less than 12 months	1,197	9,078
Gross unrealized losses, less than 12 months	94	98
Fair value, 12 months or longer	8,189	243
Gross unrealized losses, 12 months or longer	582	3
Fair value	9,386	9,321
Gross unrealized losses	676	101
Agency residential collateralized mortgage obligations
Securities available for sale:
Fair value, less than 12 months	9,673	12,603
Gross unrealized losses, less than 12 months	1,489	315
Fair value, 12 months or longer	7,562	1,255
Gross unrealized losses, 12 months or longer	1,980	95
Fair value	17,235	13,858
Gross unrealized losses	3,469	410
Held-to-maturity securities:
Fair value, less than 12 months	3,407	96
Gross unrealized losses, less than 12 months	250	0
Fair value, 12 months or longer	9	0
Gross unrealized losses, 12 months or longer	1	0
Fair value	3,416	96
Gross unrealized losses	251	0
Agency residential mortgage-backed securities
Held-to-maturity securities:
Fair value, less than 12 months	167
Gross unrealized losses, less than 12 months	18
Fair value, 12 months or longer	0
Gross unrealized losses, 12 months or longer	0
Fair value	167
Gross unrealized losses	18
Agency residential mortgage-backed securities \| Maximum
Held-to-maturity securities:
Gross unrealized losses	1	1
Agency residential mortgage-backed securities \| Mortgage-backed securities
Securities available for sale:
Fair value, less than 12 months	1,584	3,793
Gross unrealized losses, less than 12 months	219	49
Fair value, 12 months or longer	2,398	178
Gross unrealized losses, 12 months or longer	538	3
Fair value	3,982	3,971
Gross unrealized losses	757	52
Agency commercial mortgage-backed securities
Securities available for sale:
Fair value, less than 12 months	5,221	1,645
Gross unrealized losses, less than 12 months	383	75
Fair value, 12 months or longer	4,104	3,834
Gross unrealized losses, 12 months or longer	1,008	215
Fair value	9,325	5,479
Gross unrealized losses	1,391	290
Held-to-maturity securities:
Fair value, less than 12 months	2,324
Gross unrealized losses, less than 12 months	190
Fair value, 12 months or longer	0
Gross unrealized losses, 12 months or longer	0
Fair value	2,324
Gross unrealized losses	190
Asset-backed securities
Held-to-maturity securities:
Fair value, less than 12 months	1,511	2,450
Gross unrealized losses, less than 12 months	108	31
Fair value, 12 months or longer	1	1
Gross unrealized losses, 12 months or longer	0	0
Fair value	1,512	2,451
Gross unrealized losses	108	31
Other securities
Held-to-maturity securities:
Fair value, less than 12 months	7	15
Gross unrealized losses, less than 12 months	0	0
Fair value, 12 months or longer	3	0
Gross unrealized losses, 12 months or longer	1	0
Fair value	10	15
Gross unrealized losses	$ 1	$ 0

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