Stockholders' Equity (Narrative) (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Stockholders Equity [Line Items]
Currency translation adjustments (net of tax of $(4), and $(6) respectively)	$ (83)	$ 1
Stock Repurchased During Period, Shares	5.0
Stock Repurchased During Period, Value	$ 113
Other Comprehensive Income Unrealized Gain Loss On Cash Flow Hedges Arising During Period Net Of Tax	(18)	(7)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	0	(1)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	(18)	(8)
Stock Repurchase Program, Authorized Amount	1,800
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 76
Stock Repurchased During Period, Average Price	$ 22.49
Proceeds from Issuance of Common Stock	$ 15	$ 15	$ 0