Stockholders' Equity (Components Of Other Comprehensive Income) (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Equity [Abstract]
Net income (loss)	$ 3	$ 36	$ (104)	$ (15)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Document Period End Date			Jun. 30, 2017
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax			$ 1	2
Document Fiscal Year Focus			2017
Currency translation adjustments (net of tax of $17, $(5), $20 and $4, respectively)	48	8	$ 73	80
Net unrealized gain (loss) on available-for-sale securities (net of tax of $0 in each period)	1	0	1	0
Net unrealized gain (loss) on cash flow hedges (net of tax of $1, $3, $1 and $5, respectively)	(2)	(5)	(1)	(8)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	1	1	3	2
Other comprehensive income (loss)	48	4	76	74
Total comprehensive income (loss)	51	40	(28)	59
Other Comprehensive Income (Loss), Available-for-sale Securities, Tax	0	0	0	0
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	2	4
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	0	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	4	3
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, after Tax	$ 2	$ 1	$ 3	$ 2