Stockholders' Equity - Summary of Changes in Stockholders' Equity (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Jun. 13, 2012	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning Balance				$ 173,834
Beginning Balance, Shares				41,685,048
Net loss		$ 781	$ 1,071	$ (7,246)	$ 3,704
Share-based compensation expense				8,406
Excess tax benefits from stock-based compensation				2,514
Exercise of stock options and vesting of restricted stock awards				1,767
Issuance of common stock upon vesting of early exercised options				$ 340
Issuance of common stock upon vesting of early exercised options, Shares	573,941			769,070
Foreign currency translation gain		(87)	$ 0	$ (36)	$ 0
Ending Balance		$ 179,579		$ 179,579
Ending Balance, Shares		42,458,162		42,458,162
Common Stock [Member]
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning Balance				$ 42
Beginning Balance, Shares				41,685,048
Exercise of stock options and vesting of restricted stock awards, Shares				584,239
Issuance of common stock upon vesting of early exercised options, Shares				188,875
Ending Balance		$ 42		$ 42
Ending Balance, Shares		42,458,162		42,458,162
Treasury Stock [Member]
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning Balance				$ (3,966)
Ending Balance		$ (3,966)		(3,966)
Additional Paid-In Capital [Member]
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning Balance				199,169
Share-based compensation expense				8,406
Excess tax benefits from stock-based compensation				2,514
Exercise of stock options and vesting of restricted stock awards				1,767
Issuance of common stock upon vesting of early exercised options				340
Ending Balance		212,196		212,196
Accumulated Deficit [Member]
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning Balance				(21,191)
Net loss				(7,246)
Ending Balance		(28,437)		(28,437)
Accumulated Other Comprehensive Loss [Member]
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning Balance				(220)
Foreign currency translation gain				(36)
Ending Balance		$ (256)		$ (256)