Goodwill and Other Intangible Assets - Schedule of Intangible Assets (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 2,741	$ 2,786
Accumulated Amortization and Impairment	2,212	2,146
Total	529	640
Estimated amortization for intangible assets
Remainder of 2021	34
2022	101
2023	90
2024	73
2025	59
2026	37
Thereafter	135
Total	529	640
Customer-related and contract-based
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	2,314	2,337
Accumulated Amortization and Impairment	1,842	1,775
Total	472	562
Estimated amortization for intangible assets
Total	472	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	413	435
Accumulated Amortization and Impairment	357	358
Total	56	77
Estimated amortization for intangible assets
Total	$ 56	$ 77