Goodwill and Other Intangible Assets - Schedule of Intangible Assets (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 2,761	$ 2,786
Accumulated Amortization and Impairment	2,167	2,146
Total	594	640
Estimated amortization for intangible assets
Remainder of 2021	106
2022	100
2023	89
2024	72
2025	57
2026	36
Thereafter	134
Total	594	640
Customer-related and contract-based
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	2,316	2,337
Accumulated Amortization and Impairment	1,793	1,775
Total	523	562
Estimated amortization for intangible assets
Total	523	562
Tradenames
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	14	14
Accumulated Amortization and Impairment	13	13
Total	1	1
Estimated amortization for intangible assets
Total	1	1
Technology and other
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	431	435
Accumulated Amortization and Impairment	361	358
Total	70	77
Estimated amortization for intangible assets
Total	$ 70	$ 77