Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Balance		$ 6,916	$ 6,693	$ 6,842	$ 6,711
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Cumulative Effect, Period of Adoption, Adjustment
Balance	[1]				$ (10)
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Common Stock (Par Value: $0.01)
Dividends paid on common stock, per share		$ 0.17	$ 0.17	$ 0.51	$ 0.51
Balance		$ 5	$ 5	$ 5	$ 5
Preferred Stock (Par Value: $0.01)
Dividends paid on preferred stock, per share		$ 15.94	$ 15.94	$ 47.82	$ 47.82
Balance		$ 503	$ 503	$ 503	$ 503
Retained Earnings
Balance		$ 617	$ 363	$ 494	342
Retained Earnings | Cumulative Effect, Period of Adoption, Adjustment
Balance	[1]				$ (10)
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[1] Amount represents a $10 million cumulative adjustment, net of tax, to retained earnings as of January 1, 2020, as a result of the adoption of ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which became effective January 1, 2020.