Goodwill and Other Intangible Assets (Other Intangible Assets) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Net Amount	$ 1,084,000,000	$ 875,000,000
Amortization expense	213,000,000	173,000,000	$ 174,000,000
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2019	268,000,000
2020	232,000,000
2021	190,000,000
2022	149,000,000
2023	106,000,000
Thereafter	139,000,000
Net Amount	$ 1,084,000,000	$ 875,000,000
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Remaining Amortization Period	31 months	31 months
Gross Carrying Amount	$ 24,000,000	$ 71,000,000
Accumulated Amortization	16,000,000	62,000,000
Net Amount	8,000,000	9,000,000
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Net Amount	$ 8,000,000	$ 9,000,000
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Remaining Amortization Period	7 years	9 years
Gross Carrying Amount	$ 2,148,000,000	$ 1,750,000,000
Accumulated Amortization	1,076,000,000	884,000,000
Net Amount	1,072,000,000	866,000,000
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Net Amount	$ 1,072,000,000	$ 866,000,000
Trade names and associated trademarks
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Remaining Amortization Period	5 years
Gross Carrying Amount	$ 5,000,000
Accumulated Amortization	1,000,000
Net Amount	4,000,000
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Net Amount	4,000,000
BakerCorp and BlueLine
Finite-Lived Intangible Assets [Line Items]
Residual value	$ 0
BakerCorp | Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Remaining Amortization Period	7 years
Net Amount	$ 149,000,000
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Net Amount	$ 149,000,000
BakerCorp | Trade names and associated trademarks
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Remaining Amortization Period	5 years
Net Amount	$ 4,000,000
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Net Amount	$ 4,000,000
BlueLine | Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Remaining Amortization Period	5 years
Net Amount	$ 217,000,000
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Net Amount	$ 217,000,000