Stockholders' Equity - Summary of Restricted Stock Unit Activity (Detail) - Restricted Stock $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2015 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Number of Units outstanding, beginning of year | shares	1,226
Number of Units, Granted | shares	400
Number of Units, Released | shares	(399)
Number of Units, Forfeited | shares	(101)
Number of Units outstanding, end of year | shares	1,126
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted Average Grant Date Fair Value, Units outstanding, beginning of year	$ 13.23
Weighted Average Grant Date Fair Value, Granted	27.24
Weighted Average Grant Date Fair Value, Released	11.23
Weighted Average Grant Date Fair Value, Forfeited	16.45
Weighted Average Grant Date Fair Value, Units outstanding, end of year	$ 18.59
Aggregate intrinsic value at year end (in thousands) | $	$ 24,801