Summary of Stock Option Activity (Detail) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) $ / shares shares
Number of options
Number of options, Outstanding at beginning of year | shares	29,273	[1]
Number of options, Granted | shares	10,227	[1]
Number of options, Exercised | shares	(3,424)	[1]
Number of options, Forfeited | shares	(1,253)	[1]
Number of options, Expired | shares	(189)	[1]
Number of options, Equitable adjustment | shares	1,165
Number of options, Outstanding at end of year | shares	35,799
Number of options, Vested or expected to vest at end of year | shares	33,545
Number of options , Exercisable at end of year | shares	19,415
Stock options grant weighted-average exercise price
Weighted-average exercise price, Outstanding at beginning of year | $ / shares	$ 60.41	[1]
Weighted-average exercise price, Granted | $ / shares	66.79	[1]
Weighted-average exercise price, Exercised | $ / shares	40.43	[1]
Weighted-average exercise price, Forfeited | $ / shares	49.75	[1]
Weighted-average exercise price, Expired | $ / shares	44.67	[1]
Weighted-average exercise price, Equitable adjustment | $ / shares	37.47
Weighted Average Exercise Price Outstanding at end of year | $ / shares	34.16
Weighted Average Exercise Price Vested or expected to vest at end of year | $ / shares	34.12
Weighted Average Exercise Price Exercisable at end of year | $ / shares	$ 31.47
Stock options grant Weighted-average remaining contractual life
Weighted average remaining contractual life, Outstanding at end of year	6 years 4 months 24 days
Weighted average remaining contractual life, Vested or expected to vest at end of year	6 years 4 months 24 days
Weighted average remaining contractual life, Exercisable at end of year	4 years 6 months
Stock options grant aggregate intrinsic value
Aggregate intrinsic value, outstanding, ending balance | $	$ 142,970
Aggregate intrinsic value,Vested or expected to vest at end of year | $	135,652
Aggregate intrinsic value, Exercisable at end of year | $	$ 129,748

[1] The share price for activity prior to the separation on July 1, 2015 was not adjusted for the separation. See the discussion regarding the equitable adjustment below for additional details.