Stockholders' Equity - Accumulated Other Comprehensive Loss, Net of Tax (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income Before Reclassifications	$ (167)	$ (76)
Income tax provision	710	868	$ 772
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(46)	(51)
Accumulated other comprehensive income (loss), net	(579)	(366)	(239)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(213)	(127)
Accumulated Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income Before Reclassifications	(169)	(135)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0
Accumulated other comprehensive income (loss), net	(356)	(187)	(52)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(169)	(135)
Accumulated Net Unrealized Investment Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income Before Reclassifications	(16)	57
Income tax provision	(5)	31	18
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(43)	(39)
Accumulated other comprehensive income (loss), net	(10)	49	31
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(59)	18
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income Before Reclassifications	21	24
Income tax provision	(56)	(64)	(66)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(11)	(18)
Accumulated other comprehensive income (loss), net	(89)	(99)	(105)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	10	6
Accumulated Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income Before Reclassifications	(7)	(22)
Income tax provision	(71)	(70)	(61)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	8	6
Accumulated other comprehensive income (loss), net	(125)	(126)	(110)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	1	(16)
Non-controlling Interests
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income Before Reclassifications	4	0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0
Accumulated other comprehensive income (loss), net	1	(3)	$ (3)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	$ 4	$ 0