Intangible Assets (Schedule Of Intangible Assets) (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Finite And Indefinite Lived Intangible Assets [Line Items]
Document Fiscal Year Focus	2018
Amortized Intangible Assets, Gross Carrying Amount	$ 610	$ 574
Amortized Intangible Assets, Accumulated Amortization	316	277
Amortized Intangible Assets, Net Carrying Amount	294	297
Unamortized Intangible Assets, Goodwill, Gross Carrying Amount	1,064	1,073
License agreements (a)
Finite And Indefinite Lived Intangible Assets [Line Items]
Amortized Intangible Assets, Gross Carrying Amount	319	281
Amortized Intangible Assets, Accumulated Amortization	160	140
Amortized Intangible Assets, Net Carrying Amount	159	141
Customer relationships
Finite And Indefinite Lived Intangible Assets [Line Items]
Amortized Intangible Assets, Gross Carrying Amount	240	242
Amortized Intangible Assets, Accumulated Amortization	136	119
Amortized Intangible Assets, Net Carrying Amount	104	123
Other
Finite And Indefinite Lived Intangible Assets [Line Items]
Amortized Intangible Assets, Gross Carrying Amount	51	51
Amortized Intangible Assets, Accumulated Amortization	20	18
Amortized Intangible Assets, Net Carrying Amount	31	33
Goodwill (b)
Finite And Indefinite Lived Intangible Assets [Line Items]
Unamortized Intangible Assets, Goodwill, Gross Carrying Amount	1,064	1,073
Trademarks
Finite And Indefinite Lived Intangible Assets [Line Items]
Unamortized Intangible Assets, Trademarks, Gross Carrying Amount	$ 550	$ 553