Stockholders' Equity (Components Of Other Comprehensive Income) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Equity [Abstract]
Net income	$ 213	$ 245	$ 152	$ 141
Accumulated Other Comprehensive Income (Loss) [Line Items]
Document Fiscal Year Focus			2018
Currency translation adjustments (net of tax of $(1), $9, $(6) and $29, respectively)	(8)	32	$ (61)	105
Net unrealized gain (loss) on available-for-sale securities (net of tax of $0, $(1), $0, $(1), respectively)	0	0	0	1
Net unrealized gain (loss) on cash flow hedges (net of tax of $0, $(1), $(3) and $0, respectively)	0	1	8	0
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	2	1	5	4
Other comprehensive income (loss)	(6)	34	(48)	110
Total comprehensive income (loss)	207	279	$ 104	251
Document Period End Date			Sep. 30, 2018
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax			$ (1)	2
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	(1)	9	(6)	29
Other Comprehensive Income (Loss), Available-for-sale Securities, Tax	0	(1)	0	(1)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	0	(1)	(3)	0
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax	0	(1)	(1)	(2)
Corporate Interest Expense [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	2	1	2	3
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	1	1		2
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	2	6
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, after Tax	$ 2	$ 1	$ 4	4
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax				$ 6