Stockholders' Equity (Components Of Other Comprehensive Income) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Equity [Abstract]
Net loss	$ (91)	$ (87)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Document Fiscal Year Focus	2019
Currency translation adjustments (net of tax of $(6) and $5, respectively)	$ 1	1
Net unrealized gain (loss) on available-for-sale securities (net of tax of $0 and $0, respectively)	0	0
Net unrealized gain (loss) on cash flow hedges (net of tax of $3 and $(2), respectively)	(8)	6
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	2	1
Other comprehensive income (loss)	(5)	8
Total comprehensive income (loss)	$ (96)	(79)
Document Period End Date	Mar. 31, 2019
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	$ (1)	0
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	(6)	5
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	3	(2)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax	0	$ (1)
Corporate Interest Expense [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	2
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	1
Selling, General and Administrative Expenses [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, before Tax	2
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, after Tax	$ 1