Accumulated Other Comprehensive Loss and Shareholders' Equity - Accumulated Other Comprehensive (Loss) Income Activity (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Jan. 01, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period			$ 3,731
Other comprehensive income (loss) before reclassifications			(306)	$ 443
Amounts reclassified from accumulated other comprehensive loss			18	5
Net other comprehensive (loss) income	$ (65)	$ 107	(288)	448
Balance at end of period	2,324		2,324
Other comprehensive income (loss) before reclassification related to foreign current translation adjustment, loss on intra-equity foreign currency transaction			27	(142)
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period			(23)	(503)
Other comprehensive income (loss) before reclassifications			(313)	457
Amounts reclassified from accumulated other comprehensive loss			10	0
Net other comprehensive (loss) income			(303)	457
Balance at end of period	(326)	(46)	(326)	(46)
Derivative Instrument Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period			(10)	(5)
Other comprehensive income (loss) before reclassifications			7	(13)
Amounts reclassified from accumulated other comprehensive loss			8	5
Net other comprehensive (loss) income			15	(8)
Balance at end of period	5	(13)	5	(13)
Available-For-Sale Securities Unrealized Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period			4	6
Other comprehensive income (loss) before reclassifications			0	(1)
Amounts reclassified from accumulated other comprehensive loss			0	0
Net other comprehensive (loss) income			0	(1)
Balance at end of period	0	5	0	5
Pension and Postretirement Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period			12	5
Other comprehensive income (loss) before reclassifications			0	0
Amounts reclassified from accumulated other comprehensive loss			0	0
Net other comprehensive (loss) income			0	0
Balance at end of period	12	5	12	5
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period			(17)	(497)
Net other comprehensive (loss) income			(288)
Balance at end of period	$ (309)	$ (49)	$ (309)	$ (49)
Adoption of ASU 2016-01
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Cumulative effect adjustment of accounting principle					$ 0
Adoption of ASU 2016-01 | Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Cumulative effect adjustment of accounting principle					0
Adoption of ASU 2016-01 | Derivative Instrument Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Cumulative effect adjustment of accounting principle					0
Adoption of ASU 2016-01 | Available-For-Sale Securities Unrealized Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Cumulative effect adjustment of accounting principle					(4)
Adoption of ASU 2016-01 | Pension and Postretirement Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Cumulative effect adjustment of accounting principle					0
Adoption of ASU 2016-01 | Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Cumulative effect adjustment of accounting principle					$ (4)