Investment Securities - Contractual Maturities and Weighted-Average Yields of Securities (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2022	Dec. 31, 2021
Securities available for sale
Due in 1 year or less	$ 416
Due after 1 year through 5 years	7,942
Due after 5 years through 10 years	4,514
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after 10 Years, Fair Value	62,431
Securities available for sale	75,303	$ 95,261
Amortized cost of securities available for sale
Due in 1 year or less	417
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after One Through Five Years, Amortized Cost	8,199
Due after 5 years through 10 years	5,059
Due > 10 Years	72,422
Amortized Cost	$ 86,097
Weighted average yield for securities available for sale
Due in 1 Year or Less	3.34%
Due > 1 Year through 5 Years	1.69%
Due > 5 Years through 10 Years	2.28%
Due > 10 Years	2.23%
Total weighted average yield	2.19%
U.S. Treasury securities
Securities available for sale
Due in 1 year or less	$ 0
Due after 1 year through 5 years	5,027
Due after 5 years through 10 years	0
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after 10 Years, Fair Value	0
Securities available for sale	5,027	9,442
RMBS, Agency
Securities available for sale
Due in 1 year or less	0
Due after 1 year through 5 years	113
Due after 5 years through 10 years	1,123
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after 10 Years, Fair Value	59,977
Securities available for sale	61,213	72,620
RMBS, Non-agency
Securities available for sale
Due in 1 year or less	0
Due after 1 year through 5 years	0
Due after 5 years through 10 years	0
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after 10 Years, Fair Value	769
Securities available for sale	769	996
RMBS
Securities available for sale
Due in 1 year or less	0
Due after 1 year through 5 years	113
Due after 5 years through 10 years	1,123
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after 10 Years, Fair Value	60,746
Securities available for sale	$ 61,982	73,616
Weighted average yield for securities available for sale
Weighted-average expected life	7 years 1 month 6 days
CMBS, Agency
Securities available for sale
Due in 1 year or less	$ 174
Due after 1 year through 5 years	2,046
Due after 5 years through 10 years	3,391
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after 10 Years, Fair Value	1,685
Securities available for sale	$ 7,296	9,369
Weighted average yield for securities available for sale
Weighted-average expected life	5 years 1 month 6 days
Other securities
Securities available for sale
Due in 1 year or less	$ 242
Due after 1 year through 5 years	756
Due after 5 years through 10 years	0
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after 10 Years, Fair Value	0
Securities available for sale	$ 998	$ 2,834

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

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Debt Maturities, Available-for-Sale, Weighted Average Expected Life

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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