Accumulated Other Comprehensive Loss and Shareholders' Equity - Accumulated Other Comprehensive (Loss) Income Activity (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 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			(239)	$ 340
Amounts reclassified from accumulated other comprehensive loss			16	1
Net other comprehensive (loss) income	$ (385)	$ 156	(223)	341
Balance at end of period	2,841		2,841
Other comprehensive income (loss) before reclassification related to foreign current translation adjustment, loss on intra-equity foreign currency transaction			38	(106)
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			(247)	350
Amounts reclassified from accumulated other comprehensive loss			8	0
Net other comprehensive (loss) income			(239)	350
Balance at end of period	(262)	(153)	(262)	(153)
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			8	(8)
Amounts reclassified from accumulated other comprehensive loss			8	1
Net other comprehensive (loss) income			16	(7)
Balance at end of period	6	(12)	6	(12)
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	(2)
Amounts reclassified from accumulated other comprehensive loss			0	0
Net other comprehensive (loss) income			0	(2)
Balance at end of period	0	4	0	4
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			(223)
Balance at end of period	$ (244)	$ (156)	$ (244)	$ (156)
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)