Investment Securities (Available For Sale with Unrealized Losses, Aggregated by Category and Period of Continuous Unrealized Loss) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Available for sale securities
Less than 12 months Unrealized Losses, excluding PLM adjustment	$ 126
12 months or longer Unrealized Losses, excluding PLM adjustment	11,006
Total Unrealized Losses, excluding PLM adjustment	11,132
Less than 12 months Fair Value	5,905	$ 81,299
Less than 12 months Unrealized Losses		3,622
12 months or longer Fair Value	119,610	65,941
12 months or longer Unrealized Losses		8,669
Total Fair Value	125,515	147,240
Total Unrealized Losses		12,291
Portfolio layer method fair value hedge basis adjustments, excluded from unrealized losses on available for sale securities	26
U.S. agency mortgage-backed securities [Member]
Available for sale securities
Less than 12 months Unrealized Losses, excluding PLM adjustment	111
12 months or longer Unrealized Losses, excluding PLM adjustment	7,697
Total Unrealized Losses, excluding PLM adjustment	7,808
Less than 12 months Fair Value	2,811	34,938
Less than 12 months Unrealized Losses		2,025
12 months or longer Fair Value	68,687	42,558
12 months or longer Unrealized Losses		6,281
Total Fair Value	71,498	77,496
Total Unrealized Losses		8,306
U.S. Treasury securities [Member]
Available for sale securities
Less than 12 months Unrealized Losses, excluding PLM adjustment	6
12 months or longer Unrealized Losses, excluding PLM adjustment	1,485
Total Unrealized Losses, excluding PLM adjustment	1,491
Less than 12 months Fair Value	2,371	27,063
Less than 12 months Unrealized Losses		716
12 months or longer Fair Value	26,153	12,519
12 months or longer Unrealized Losses		1,161
Total Fair Value	28,524	39,582
Total Unrealized Losses		1,877
Asset-backed securities [Member]
Available for sale securities
Less than 12 months Unrealized Losses, excluding PLM adjustment	2
12 months or longer Unrealized Losses, excluding PLM adjustment	540
Total Unrealized Losses, excluding PLM adjustment	542
Less than 12 months Fair Value	263	6,717
Less than 12 months Unrealized Losses		217
12 months or longer Fair Value	10,669	6,299
12 months or longer Unrealized Losses		432
Total Fair Value	10,932	13,016
Total Unrealized Losses		649
Corporate debt securities [Member]
Available for sale securities
Less than 12 months Unrealized Losses, excluding PLM adjustment	7
12 months or longer Unrealized Losses, excluding PLM adjustment	1,138
Total Unrealized Losses, excluding PLM adjustment	1,145
Less than 12 months Fair Value	192	8,552
Less than 12 months Unrealized Losses		542
12 months or longer Fair Value	12,090	3,998
12 months or longer Unrealized Losses		733
Total Fair Value	12,282	12,550
Total Unrealized Losses		1,275
Certificates of deposit [Member]
Available for sale securities
Less than 12 months Unrealized Losses, excluding PLM adjustment	0
12 months or longer Unrealized Losses, excluding PLM adjustment	2
Total Unrealized Losses, excluding PLM adjustment	2
Less than 12 months Fair Value	250	2,033
Less than 12 months Unrealized Losses		10
12 months or longer Fair Value	98	196
12 months or longer Unrealized Losses		4
Total Fair Value	348	2,229
Total Unrealized Losses		14
Foreign government agency securities [Member]
Available for sale securities
Less than 12 months Unrealized Losses, excluding PLM adjustment	0
12 months or longer Unrealized Losses, excluding PLM adjustment	56
Total Unrealized Losses, excluding PLM adjustment	56
Less than 12 months Fair Value	0	756
Less than 12 months Unrealized Losses		50
12 months or longer Fair Value	978	214
12 months or longer Unrealized Losses		14
Total Fair Value	978	970
Total Unrealized Losses		64
U.S. state and municipal securities [Member]
Available for sale securities
Less than 12 months Unrealized Losses, excluding PLM adjustment	0
12 months or longer Unrealized Losses, excluding PLM adjustment	65
Total Unrealized Losses, excluding PLM adjustment	65
Less than 12 months Fair Value	18	482
Less than 12 months Unrealized Losses		31
12 months or longer Fair Value	554	157
12 months or longer Unrealized Losses		44
Total Fair Value	572	639
Total Unrealized Losses		75
Non-agency commercial mortgage-backed securities [Member]
Available for sale securities
Less than 12 months Unrealized Losses, excluding PLM adjustment	0
12 months or longer Unrealized Losses, excluding PLM adjustment	19
Total Unrealized Losses, excluding PLM adjustment	19
Less than 12 months Fair Value	0	443
Less than 12 months Unrealized Losses		23
12 months or longer Fair Value	263	0
12 months or longer Unrealized Losses		0
Total Fair Value	263	443
Total Unrealized Losses		23
Other [Member]
Available for sale securities
Less than 12 months Unrealized Losses, excluding PLM adjustment	0
12 months or longer Unrealized Losses, excluding PLM adjustment	4
Total Unrealized Losses, excluding PLM adjustment	4
Less than 12 months Fair Value	0	315
Less than 12 months Unrealized Losses		8
12 months or longer Fair Value	118	0
12 months or longer Unrealized Losses		0
Total Fair Value	$ 118	315
Total Unrealized Losses		$ 8