Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ (2,356)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	542	$ (299)	$ (630)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	(295)	(135)	(24)
Net change	316	336	(599)
Ending Balance	(2,057)	(2,356)
Unrealized Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(1,798)	(1,332)	(628)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax	542	(299)	(630)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	(311)	(167)	(74)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax
Net change		(466)	(704)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	231
Ending Balance	(1,567)	(1,798)	(1,332)
Pension and Other Post retirement Benefit Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(571)	(1,379)	(1,492)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	20	29	9
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	58	779	104
Net change	78	808	113
Ending Balance	(493)	(571)	(1,379)
Unrealized Gain (Loss) on Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	13	9	4
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(4)	3	41
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(6)	1	(36)
Net change	(10)	4	5
Ending Balance	3	13	9
Accumulated Other Comprehensive (Loss) Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(2,356)	(2,702)	(2,116)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	52	780	68
Net change	299	346	(586)
Ending Balance	$ (2,057)	$ (2,356)	$ (2,702)