Goodwill And Other Intangibles (Identifiable Intangible Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Accumulated Amortization	$ 442	$ 379
Finite-Lived Intangible Assets, Net	482	547
Finite And Indefinite Lived Intangible Assets Gross	924	926
Customer-Related Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	610	605
Finite-Lived Intangible Assets, Accumulated Amortization	247	211
Finite-Lived Intangible Assets, Net	363	394
Noncompete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	72	69
Finite-Lived Intangible Assets, Accumulated Amortization	72	64
Finite-Lived Intangible Assets, Net	0	5
Intellectual Property [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	172	173
Finite-Lived Intangible Assets, Accumulated Amortization	72	56
Finite-Lived Intangible Assets, Net	100	117
Use Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	8	10
Finite-Lived Intangible Assets, Accumulated Amortization	2	2
Finite-Lived Intangible Assets, Net	6	8
Computer Software, Intangible Asset [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	24	21
Finite-Lived Intangible Assets, Accumulated Amortization	23	20
Finite-Lived Intangible Assets, Net	1	1
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	38	48
Finite-Lived Intangible Assets, Accumulated Amortization	26	26
Finite-Lived Intangible Assets, Net	$ 12	$ 22