Goodwill and Other Intangible Assets (Other Intangible Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Total	$ 895	$ 1,084
Amortization expense	290	213	$ 173
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2020	250
2021	205
2022	160
2023	116
2024	75
Thereafter	89
Total	$ 895	$ 1,084
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Remaining Amortization Period	43 months	31 months
Gross Carrying Amount	$ 24	$ 24
Accumulated Amortization	14	16
Total	10	8
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Total	$ 10	$ 8
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Remaining Amortization Period	7 years	7 years
Gross Carrying Amount	$ 2,246	$ 2,148
Accumulated Amortization	1,364	1,076
Total	882	1,072
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Total	$ 882	$ 1,072
Trade names and associated trademarks
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Remaining Amortization Period	4 years	5 years
Gross Carrying Amount	$ 5	$ 5
Accumulated Amortization	2	1
Total	3	4
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Total	$ 3	$ 4