Shareholders' Equity - Summary of Information about Stock Options (Detail) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) $ / shares shares
Number of shares
Outstanding Beginning Balance | shares	19,372
Options granted | shares	2,956
Options exercised | shares	(2,819)
Options forfeited | shares	(593)
Options canceled | shares	(184)
Outstanding Ending Balance | shares	18,732
Exercisable at December 31, 2015 | shares	8,918
Weighted average exercise price per share
Outstanding Beginning Balance | $ / shares	$ 41.92
Options granted | $ / shares	47.27
Options exercised | $ / shares	37.33
Options forfeited | $ / shares	42.21
Options cancelled | $ / shares	47.88
Outstanding Ending Balance | $ / shares	43.39
Exercisable at December 31, 2015 | $ / shares	$ 44.36
Weighted average remaining contractual life
Outstanding at December 31, 2015	5 years 9 months 7 days
Exercisable at December 31, 2015	3 years 5 months 17 days
Aggregate intrinsic value
Outstanding at December 31, 2015 | $	$ 60,057
Exercisable at December 31, 2015 | $	$ 23,546