Intangible Assets (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense relating to all intangible assets	$ 14	$ 16	$ 32	$ 29
Amortization expense for remainder of the year	26		26
Intangible assets amortization expense, year one	34		34
Intangible assets amortization expense, year two	26		26
Intangible assets amortization expense, year three	23		23
Intangible assets amortization expense, year four	17		17
Intangible assets amortization expense, year five	$ 16		$ 16