Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax		$ 1	$ 2
Beginning Balance	$ (2,350)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(249)	71	(292)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	(24)	(130)	129
Net change	(249)	(51)	(147)
Ending Balance	(2,599)	(2,350)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(1,627)	(1,734)	(1,567)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax	(249)	71	(292)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	213	36	148
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax
Net change		107	(144)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(36)
Ending Balance	(1,663)	(1,627)	(1,734)
Pension and Other Post retirement Benefit Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(724)	(568)	(493)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(237)	(167)	(12)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	24	11	21
Net change	(213)	(156)	9
Ending Balance	(937)	(724)	(568)
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassifications of Temporary to Permanent Equity			(107)
Net change	(249)	(50)	(136)
Unrealized Gain (Loss) on Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	1	2	3
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	1	(7)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	(2)	6
Net change	0	(1)	(1)
Ending Balance	1	1	2
Parent
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(2,350)	(2,300)	(2,057)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	24	9	27
Net change	(249)	(50)	(136)
Ending Balance	$ (2,599)	$ (2,350)	$ (2,300)