Investment Securities - Components and Unrealized Losses on Held-to-Maturity Securities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract]
AFS securities transferred to HTM securities	$ 8,800
AFS securities transferred to HTM securities, unrealized gains (losses)	132
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	98,202	$ 91,327
Unrealized Gains	368	2
Unrealized Losses	(1,343)	(15,160)
Fair Value	97,227	76,169
Allowance for credit losses	7	6	$ 1
Net Carry Value	98,195	91,321
U.S. agency debentures
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	609	486
Unrealized Gains	8	0
Unrealized Losses	(2)	(52)
Fair Value	615	434
Allowance for credit losses	0	0
Net Carry Value	609	486
Agency-issued MBS
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	64,439	57,705
Unrealized Gains	124	0
Unrealized Losses	(887)	(9,349)
Fair Value	63,676	48,356
Allowance for credit losses	0	0
Net Carry Value	64,439	57,705
Agency-issued CMO | Fixed rate
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	10,226	10,461
Unrealized Gains	9	0
Unrealized Losses	(145)	(1,885)
Fair Value	10,090	8,576
Allowance for credit losses	0	0
Net Carry Value	10,226	10,461
Agency-issued CMO | Variable rate
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	100	79
Unrealized Gains	1	0
Unrealized Losses	0	(2)
Fair Value	101	77
Allowance for credit losses	0	0
Net Carry Value	100	79
Agency-issued CMBS
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	14,959	14,471
Unrealized Gains	39	0
Unrealized Losses	(277)	(2,494)
Fair Value	14,721	11,977
Allowance for credit losses	0	0
Net Carry Value	14,959	14,471
Municipal bonds and notes
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	7,157	7,417
Unrealized Gains	185	2
Unrealized Losses	(27)	(1,269)
Fair Value	7,315	6,150
Allowance for credit losses	1	1
Net Carry Value	7,156	7,416
Corporate bonds
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	712	708
Unrealized Gains	2	0
Unrealized Losses	(5)	(109)
Fair Value	709	599
Allowance for credit losses	6	5
Net Carry Value	$ 706	$ 703