Other Assets (Intangible Assets) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Finite-Lived Intangible Assets [Line Items]
Accumulated amortization	$ (86)	$ (78)
Total intangible assets, gross	207	207
Net intangible assets	121	129
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2022	23
2023	25
2024	18
2025	14
2026	14
Technology
Finite-Lived Intangible Assets [Line Items]
Gross intangible assets	83	83
Accumulated amortization	(12)	(9)
Net carrying value	71	74
Customer lists
Finite-Lived Intangible Assets [Line Items]
Gross intangible assets	58	58
Accumulated amortization	(44)	(42)
Net carrying value	14	16
Purchased credit card relationships
Finite-Lived Intangible Assets [Line Items]
Gross intangible assets	25	25
Accumulated amortization	(1)	0
Net carrying value	24	25
Trademarks
Finite-Lived Intangible Assets [Line Items]
Gross intangible assets	2	2
Accumulated amortization	0	0
Net carrying value	2	2
Other
Finite-Lived Intangible Assets [Line Items]
Gross intangible assets	39	39
Accumulated amortization	(29)	(27)
Net carrying value	$ 10	$ 12