Intangible Assets (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Amortization expense relating to all intangible assets	$ 17	$ 14
Amortization expense for remainder of the year	$ 41
Document Fiscal Year Focus	2019
Intangible assets amortization expense, year one	$ 48
Intangible assets amortization expense, year two	34
Intangible assets amortization expense, year three	25
Intangible assets amortization expense, year four	22
Intangible assets amortization expense, year five	$ 20