Stockholders' Equity (Accumulated 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	Dec. 31, 2017
Stockholders Equity [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets					$ (6)
Document Period End Date			Sep. 30, 2018
Currency Translation Adjustments, Balance			$ 71	$ (39)
Net Unrealized Gains (Losses) on Cash Flow Hedges, Balance	$ 14	$ 2	14	2
Net Unrealized Gains on Available- For-Sale Securities, Balance			2	1
Currency Translation Adjustments, Balance			(102)	(118)
Accumulated Other Comprehensive Income, Balance			(24)	(154)
Currency Translation Adjustments, Current period change	(8)	32	(61)	105
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	0	1	8	0
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	(2)	(1)	(5)	(4)
Other comprehensive income (loss)	(6)	34	(48)	110
Currency Translation Adjustments, Balance	17	66	17	66
Net Unrealized Gains (Losses) on Cash Flow Hedges, Balance			5	2
Net Unrealized Gains on Available- For-Sale Securities, Balance	0	2	0	2
Currency Translation Adjustments, Balance	(109)	(114)	(109)	(114)
Accumulated Other Comprehensive Income, Balance	(78)	(44)	(78)	(44)
Derivatives used in Net Investment Hedge, Net of Tax	56		56
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent			(61)	105
Other Comprehensive Income Unrealized Gain Loss On Cash Flow Hedges Arising During Period Net Of Tax			9	(2)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax			8	0
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	0	0	0	1
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net (Gain) Loss, Net of Tax			4	4
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax			(51)	104
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			3	6
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax			0	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax			0	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax			1	(2)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Reclassification Adjustments, Net of Tax			0	1
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax			1	0
Corporate Interest Expense [Member]
Stockholders Equity [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]
Stockholders Equity [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
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Stockholders Equity [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets					7
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Stockholders Equity [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets					1
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Stockholders Equity [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets					(2)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Stockholders Equity [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets					$ (12)
Including Beginning Balance Adjustment due to Cumulative Effect of Accounting Change [Member]
Stockholders Equity [Line Items]
Currency Translation Adjustments, Balance			78
Net Unrealized Gains on Available- For-Sale Securities, Balance			0
Currency Translation Adjustments, Balance			(114)
Accumulated Other Comprehensive Income, Balance			(30)
Net Unrealized Gains (Losses) on Cash Flow Hedges, Balance			$ 6