Equity - Additional Information About Stock Options Outstanding (Detail)	12 Months Ended
	Dec. 31, 2015 $ / shares shares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding and Exercisable | shares	1,677,154
Options Outstanding and Exercisable	3 years 9 months 4 days
Options Outstanding and Exercisable | $ / shares	$ 29.48
$20.49 to $25.41 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding and Exercisable | shares	311,704
Options Outstanding and Exercisable	3 years 7 months 24 days
Options Outstanding and Exercisable | $ / shares	$ 21.34
$25.42 to $30.59 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding and Exercisable | shares	593,387
Options Outstanding and Exercisable	4 years 26 days
Options Outstanding and Exercisable | $ / shares	$ 29.53
$30.60 to $35.73 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding and Exercisable | shares	772,063
Options Outstanding and Exercisable	3 years 6 months 26 days
Options Outstanding and Exercisable | $ / shares	$ 32.72