Changes in Accumulated Other Comprehensive Loss by Component (Net of Tax) - Changes in AOCI By Components (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Beginning balance			$ (1,318)
Ending balance	$ (1,329)		(1,329)
Other comprehensive income (loss) attributable to noncontrolling interests, net of tax	1	$ 0	4	$ (2)
Foreign Currency Translation Adjustments [Member]
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Beginning balance	(675)	(599)	(714)	(482)
Other comprehensive income (loss) before reclassifications	(58)	22	(18)	(95)
Reclassification from other comprehensive income (loss)	0	0	(1)	0
Other comprehensive income (loss), net of tax	(58)	22	(19)	(95)
Ending balance	(733)	(577)	(733)	(577)
Post- employment Benefits [Member]
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Beginning balance	(583)	(622)	(587)	(643)
Other comprehensive income (loss) before reclassifications	0	(3)	0	11
Reclassification from other comprehensive income (loss)	3	4	7	11
Other comprehensive income (loss), net of tax	3	1	7	22
Ending balance	(580)	(621)	(580)	(621)
Gains and Losses on Cash Flow Hedges [Member]
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Beginning balance	(17)	(16)	(17)	(17)
Other comprehensive income (loss) before reclassifications	0	(3)	(1)	(2)
Reclassification from other comprehensive income (loss)	1	1	2	1
Other comprehensive income (loss), net of tax	1	(2)	1	(1)
Ending balance	$ (16)	$ (18)	$ (16)	$ (18)