Investment Securities - Contractual Maturities and Weighted-Average Yields of Securities (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023
Fair value of securities available for sale:
Due in 1 Year or Less	$ 3,854
Due > 1 Year through 5 Years	7,658
Due > 5 Years through 10 Years	5,427
Due > 10 Years	66,074
Total	83,013	$ 79,117
Amortized cost of securities available for sale
Due in 1 Year or Less	3,863
Due > 1 Year through 5 Years	7,800
Due > 5 Years through 10 Years	5,761
Due > 10 Years	75,571
Total	$ 92,995	88,063
Weighted-average yield for securities available for sale
Due in 1 Year or Less	2.46%
Due > 1 Year through 5 Years	4.05%
Due > 5 Years through 10 Years	3.68%
Due > 10 Years	3.72%
Total	3.69%
U.S. Treasury securities
Fair value of securities available for sale:
Due in 1 Year or Less	$ 2,995
Due > 1 Year through 5 Years	1,445
Due > 5 Years through 10 Years	1,670
Due > 10 Years	0
Total	6,110	5,282
Amortized cost of securities available for sale
Total	6,114	5,330
RMBS, Agency
Fair value of securities available for sale:
Due in 1 Year or Less	0
Due > 1 Year through 5 Years	68
Due > 5 Years through 10 Years	1,133
Due > 10 Years	63,506
Total	64,707	62,948
Amortized cost of securities available for sale
Total	74,177	71,294
RMBS, Non-agency
Fair value of securities available for sale:
Due in 1 Year or Less	0
Due > 1 Year through 5 Years	0
Due > 5 Years through 10 Years	16
Due > 10 Years	605
Total	621	690
Amortized cost of securities available for sale
Total	567	610
Total RMBS
Fair value of securities available for sale:
Due in 1 Year or Less	0
Due > 1 Year through 5 Years	68
Due > 5 Years through 10 Years	1,149
Due > 10 Years	64,111
Total	65,328	63,638
Amortized cost of securities available for sale
Total	$ 74,744	71,904
Weighted-average yield for securities available for sale
Weighted-average expected life	8 years 1 month 6 days
Agency CMBS
Fair value of securities available for sale:
Due in 1 Year or Less	$ 633
Due > 1 Year through 5 Years	2,621
Due > 5 Years through 10 Years	2,608
Due > 10 Years	1,963
Total	7,825	8,323
Amortized cost of securities available for sale
Total	$ 8,389	8,961
Weighted-average yield for securities available for sale
Weighted-average expected life	4 years 9 months 18 days
Other securities
Fair value of securities available for sale:
Due in 1 Year or Less	$ 226
Due > 1 Year through 5 Years	3,524
Due > 5 Years through 10 Years	0
Due > 10 Years	0
Total	3,750	1,874
Amortized cost of securities available for sale
Total	$ 3,748	$ 1,868

Available-for-sale Securities, Expected Debt Maturities, Amortized Cost Basis, Rolling Maturity

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