Investment Securities - Available For Sale with Unrealized Losses, Aggregated by Category and Period of Continuous Unrealized Loss (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Available for sale securities
Less than 12 months Fair Value	$ 1,622	$ 81,299
Less than 12 months Unrealized Losses	3	3,622
12 months or longer Fair Value	108,638	65,941
12 months or longer Unrealized Losses	11,854	8,669
Total Fair Value	110,260	147,240
Total Unrealized Losses	11,857	12,291
Portfolio layer method fair value hedge basis adjustments, excluded from unrealized losses on available for sale securities	57
U.S. agency mortgage-backed securities
Available for sale securities
Less than 12 months Fair Value	97	34,938
Less than 12 months Unrealized Losses	1	2,025
12 months or longer Fair Value	64,763	42,558
12 months or longer Unrealized Losses	8,656	6,281
Total Fair Value	64,860	77,496
Total Unrealized Losses	8,657	8,306
U.S. Treasury securities
Available for sale securities
Less than 12 months Fair Value	1,493	27,063
Less than 12 months Unrealized Losses	2	716
12 months or longer Fair Value	20,295	12,519
12 months or longer Unrealized Losses	1,349	1,161
Total Fair Value	21,788	39,582
Total Unrealized Losses	1,351	1,877
Asset-backed securities
Available for sale securities
Less than 12 months Fair Value	32	6,717
Less than 12 months Unrealized Losses	0	217
12 months or longer Fair Value	9,580	6,299
12 months or longer Unrealized Losses	487	432
Total Fair Value	9,612	13,016
Total Unrealized Losses	487	649
Corporate debt securities
Available for sale securities
Less than 12 months Fair Value	0	8,552
Less than 12 months Unrealized Losses	0	542
12 months or longer Fair Value	12,155	3,998
12 months or longer Unrealized Losses	1,207	733
Total Fair Value	12,155	12,550
Total Unrealized Losses	1,207	1,275
Certificates of deposit
Available for sale securities
Less than 12 months Fair Value	0	2,033
Less than 12 months Unrealized Losses	0	10
12 months or longer Fair Value	99	196
12 months or longer Unrealized Losses	1	4
Total Fair Value	99	2,229
Total Unrealized Losses	1	14
Foreign government agency securities
Available for sale securities
Less than 12 months Fair Value	0	756
Less than 12 months Unrealized Losses	0	50
12 months or longer Fair Value	985	214
12 months or longer Unrealized Losses	49	14
Total Fair Value	985	970
Total Unrealized Losses	49	64
U.S. state and municipal securities
Available for sale securities
Less than 12 months Fair Value	0	482
Less than 12 months Unrealized Losses	0	31
12 months or longer Fair Value	555	157
12 months or longer Unrealized Losses	81	44
Total Fair Value	555	639
Total Unrealized Losses	81	75
Non-agency commercial mortgage-backed securities
Available for sale securities
Less than 12 months Fair Value	0	443
Less than 12 months Unrealized Losses	0	23
12 months or longer Fair Value	188	0
12 months or longer Unrealized Losses	20	0
Total Fair Value	188	443
Total Unrealized Losses	20	23
Other
Available for sale securities
Less than 12 months Fair Value	0	315
Less than 12 months Unrealized Losses	0	8
12 months or longer Fair Value	18	0
12 months or longer Unrealized Losses	4	0
Total Fair Value	18	315
Total Unrealized Losses	$ 4	$ 8