Stockholders' Equity (Components Of Other Comprehensive Income) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Equity [Abstract]
Net income	$ 245	$ 209	$ 141	$ 194
Accumulated Other Comprehensive Income (Loss) [Line Items]
Document Period End Date			Sep. 30, 2017
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax			$ 2	3
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	9	3	29	7
Other Comprehensive Income (Loss), Available-for-sale Securities, Tax	(1)	0	(1)	0
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	(1)	(3)	0	2
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax	(1)	0	$ (2)	(1)
Document Fiscal Year Focus			2017
Currency translation adjustments (net of tax of $9, $3, $29 and $7, respectively)	32	20	$ 105	100
Net unrealized gain (loss) on available-for-sale securities (net of tax of $(1), $0, $(1), $0, respectively)	0	1	1	1
Net unrealized gain (loss) on cash flow hedges (net of tax of $(1), $(3), $0 and $2, respectively)	1	4	0	(4)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	1	1	4	3
Other comprehensive income (loss)	34	26	110	100
Total comprehensive income (loss)	279	235	251	294
Corporate Interest Expense [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	1	2	3	6
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	1	1	2	3
Operating Expense [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, before Tax		1		1
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, after Tax		1		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	1	6	4
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, after Tax	$ 1	$ 1	$ 4	$ 3