Intangible Assets (Schedule Of Intangible Assets) (Detail) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Finite And Indefinite Lived Intangible Assets [Line Items]
Amortized Intangible Assets, Gross Carrying Amount	$ 557	$ 546
Amortized Intangible Assets, Accumulated Amortization	307	298
Amortized Intangible Assets, Net Carrying Amount	250	248
Unamortized Intangible Assets, Goodwill, Gross Carrying Amount	1,069	1,101
License agreements
Finite And Indefinite Lived Intangible Assets [Line Items]
Amortized Intangible Assets, Gross Carrying Amount	257	241
Amortized Intangible Assets, Accumulated Amortization	112	108
Amortized Intangible Assets, Net Carrying Amount	145	133
Customer relationships
Finite And Indefinite Lived Intangible Assets [Line Items]
Amortized Intangible Assets, Gross Carrying Amount	250	255
Amortized Intangible Assets, Accumulated Amortization	169	165
Amortized Intangible Assets, Net Carrying Amount	81	90
Other
Finite And Indefinite Lived Intangible Assets [Line Items]
Amortized Intangible Assets, Gross Carrying Amount	50	50
Amortized Intangible Assets, Accumulated Amortization	26	25
Amortized Intangible Assets, Net Carrying Amount	24	25
Goodwill
Finite And Indefinite Lived Intangible Assets [Line Items]
Unamortized Intangible Assets, Goodwill, Gross Carrying Amount	1,069	1,101
Trademarks
Finite And Indefinite Lived Intangible Assets [Line Items]
Unamortized Intangible Assets, Trademarks, Gross Carrying Amount	$ 544	$ 550