Stockholders' Equity (Narrative) (Detail) $ / shares in Units, shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) $ / shares shares	Jun. 30, 2019 USD ($)
Stockholders Equity [Line Items]
Currency translation adjustments (net of tax of $4, $4, $0, and $(2) respectively)	$ 39,000,000	$ 9,000,000	$ (44,000,000)	$ 10,000,000
Other Comprehensive Income Unrealized Gain Loss On Cash Flow Hedges Arising During Period Net Of Tax			(28,000,000)	(19,000,000)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax			2,000,000	(2,000,000)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax			(26,000,000)	(21,000,000)
Stockholders' Equity Note [Abstract]
Option Premiums Paid		$ (16,000,000)		$ (16,000,000)
Open Option Contracts Written, Number of Shares		600,000		600,000
Stock Repurchase Program, Authorized Amount	1,800,000,000		$ 1,800,000,000
Stock Repurchased During Period, Shares | shares			5.0
Stock Repurchased During Period, Value			$ 113,000,000
Stock Repurchased During Period, Average Price | $ / shares			$ 22.49
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 76,000,000		$ 76,000,000
Proceeds from Issuance of Common Stock			$ 15,000,000	$ 0