Goodwill and Identifiable Intangible Assets, Identifiable Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets Subject to Amortization [Abstract]
Weighted average amortization period	14 years
Gross carrying amount	$ 621	$ 547
Accumulated amortization	383	348
Net carrying amount	238	199
Amortization expense	35	35	$ 39
Estimated Amortization Expense for Identifiable Intangible Assets
Estimated amortization expense, 2017	39
Estimated amortization expense, 2018	35
Estimated amortization expense, 2019	32
Estimated amortization expense, 2020	28
Estimated amortization expense, 2021	$ 24
Customer Contractual Relationships [Member]
Finite-Lived Intangible Assets Subject to Amortization [Abstract]
Weighted average amortization period	15 years
Gross carrying amount	$ 409	370
Accumulated amortization	269	246
Net carrying amount	$ 140	124
Technology [Member]
Finite-Lived Intangible Assets Subject to Amortization [Abstract]
Weighted average amortization period	11 years
Gross carrying amount	$ 191	156
Accumulated amortization	102	91
Net carrying amount	$ 89	65
Other [Member]
Finite-Lived Intangible Assets Subject to Amortization [Abstract]
Weighted average amortization period	18 years
Gross carrying amount	$ 21	21
Accumulated amortization	12	11
Net carrying amount	$ 9	$ 10