Summary of Activity Relating to Securitization Arrangement (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Sold receivables at beginning of period	$ 63	$ 62	$ 68	$ 81
Proceeds from sales of receivables	69	75	198	272
Cash collections (remitted to the owners of the receivables)	(66)	(71)	(203)	(299)
Effect of currency exchange rate changes		2	3	14
Sold receivables at end of period	$ 66	$ 68	$ 66	$ 68