Shareholders' Equity - Summary of Information about Stock Options (Detail) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) $ / shares shares
Number of shares
Outstanding Beginning Balance | shares	18,732
Options granted | shares	2,973
Options exercised | shares	(3,732)
Options forfeited | shares	(351)
Options canceled | shares	(248)
Outstanding Ending Balance | shares	17,374
Exercisable at December 31, 2016 | shares	7,334
Weighted average exercise price per share
Outstanding Beginning Balance | $ / shares	$ 43.39
Options granted | $ / shares	47.39
Options exercised | $ / shares	42.17
Options forfeited | $ / shares	43.48
Options cancelled | $ / shares	49.38
Outstanding Ending Balance | $ / shares	44.25
Exercisable at December 31, 2016 | $ / shares	$ 44.21
Weighted average remaining contractual life
Outstanding at December 31, 2016	6 years 2 months 8 days
Exercisable at December 31, 2016	3 years 8 months 9 days
Aggregate intrinsic value
Outstanding at December 31, 2016 | $	$ 151,274
Exercisable at December 31, 2016 | $	$ 64,181