Schedule of Goodwill (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Line Items]
Gross goodwill			$ 3,210
Goodwill [Roll Forward]
Goodwill	$ 1,101	$ 1,092
Goodwill, Impaired, Accumulated Impairment Loss			(2,118)
Acquisition		21
Adjustments to the allocation of purchase price	36	(12)
Goodwill	1,137	1,101
Americas
Goodwill [Line Items]
Gross goodwill			2,126
Goodwill [Roll Forward]
Goodwill	554	539
Goodwill, Impaired, Accumulated Impairment Loss			(1,587)
Acquisition		21
Adjustments to the allocation of purchase price	(1)	(6)
Goodwill	553	554
International
Goodwill [Line Items]
Gross goodwill			1,084
Goodwill [Roll Forward]
Goodwill	547	553
Goodwill, Impaired, Accumulated Impairment Loss			$ (531)
Acquisition		0
Adjustments to the allocation of purchase price	37	(6)
Goodwill	$ 584	$ 547