Share-Based Compensation - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015 USD ($) $ / shares shares
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Expected volatility term	5 years
Closing stock price | $ / shares	$ 118.90
Equity Incentive Plan
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	2,664,121
Maximum aggregate number of shares that may be awarded and sold	9,528,505
Conversion ratio for awards granted	2
Conversion ratio for awards forfeited	2
Options granted under the 2006 Incentive Plan, expiration period	7 years
Options, exercisable period	4 years
Equity Incentive Plan | Restricted stock units | Lower Limit
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Vesting period	3 years
Equity Incentive Plan | Performance-based restricted stock | Lower Limit
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Vesting period	12 months
Employee Stock Purchase Plan
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Maximum percentage of gross compensation that participating employees may annually contribute towards ESPP	10.00%
Maximum amount that participating employees may annually contribute towards ESPP | $	$ 25,000
Percentage of fair market value of common stock at which employees may purchase shares under ESPP	85.00%
Number of shares issued under ESPP	140,471
Proceeds from issuance of shares under ESPP | $	$ 13,900,000
Number of shares available for issuance	425,728