Stock-based Compensation - Summary of Restricted Stock Units Activity (Detail) - Restricted Stock Units [Member]	6 Months Ended
	Jun. 30, 2016 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of shares, Beginning Balance | shares	191,617
Number of shares, Granted | shares	149,989
Number of shares, Forfeited | shares	(1,193)
Number of shares, Settled | shares	(50,773)
Number of shares, Ending Balance | shares	289,640
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted Average Grant Date Fair Value, Beginning Balance (in $ per share) | $ / shares	$ 156.66
Weighted Average Grant Date Fair Value, Granted (in $ per share) | $ / shares	75.22
Weighted Average Grant Date Fair Value, Forfeited (in $ per share) | $ / shares	127.42
Weighted Average Grant Date Fair Value, Settled (in $ per share) | $ / shares	170.75
Weighted Average Grant Date Fair Value, Ending Balance (in $ per share) | $ / shares	$ 112.14