Goodwill and Other Intangible Assets Narrative (Details)	12 Months Ended
	Dec. 31, 2017 USD ($) reporting_unit	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Goodwill [Line Items]
Number of Reporting Units | reporting_unit	13
Goodwill, Impairment Loss	$ 0	$ 0	$ 0
Total amortization expense	65,000,000	$ 86,000,000	$ 89,000,000
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2018	97,000,000
2019	93,000,000
2020	88,000,000
2021	85,000,000
2022	81,000,000
Minimum [Member]
Goodwill [Line Items]
Goodwill by reporting unit	7,000,000
Maximum [Member]
Goodwill [Line Items]
Goodwill by reporting unit	$ 1,100,000,000
Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	13 years	14 years