Goodwill and Other Intangible Assets - Definite-lived Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Definite-lived Intangible assets
Gross Carrying Amount	$ 761	$ 642
Accumulated Amortization	(568)	(534)
Net Carrying Amount	193	108
Definite-lived intangible assets acquired	$ 89
Definite-lived intangible assets acquired, weighted-average amortization period	10 years
Aggregate amortization expense for definite-lived intangible assets	$ 34	31	$ 37
Estimated future intangible amortization expense
2022	31
2023	27
2024	16
2025	10
2026	7
Customer relationships
Definite-lived Intangible assets
Gross Carrying Amount	254	193
Accumulated Amortization	(163)	(155)
Net Carrying Amount	91	38
Contracts
Definite-lived Intangible assets
Gross Carrying Amount	235	223
Accumulated Amortization	(217)	(211)
Net Carrying Amount	18	12
Other
Definite-lived Intangible assets
Gross Carrying Amount	272	226
Accumulated Amortization	(188)	(168)
Net Carrying Amount	$ 84	$ 58