Intangible Assets (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Finite-Lived Intangible Assets [Line Items]
Amortization expense relating to all intangible assets	$ 17	$ 13	$ 46	$ 44
Amortization expense for remainder of the year	18		$ 18
Document Fiscal Year Focus			2020
Intangible assets amortization expense, year one	64		$ 64
Intangible assets amortization expense, year two	33		33
Intangible assets amortization expense, year three	25		25
Intangible assets amortization expense, year four	22		22
Intangible assets amortization expense, year five	$ 16		$ 16