Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock issued in conjunction with the vesting and release of restricted stock units (in shares)			95,669
Common stock issued due to exercise of stock options (in shares)			411,781
Common stock issued in connection with employee stock purchase plan (in shares)			32,358
Proceeds from issuance of common stock			$ 5,265	$ 2,098
Repurchase of common stock, shares (in shares)			0	1,152,386
Repurchase of common stock				$ 19,600
Shares Paid for Tax Withholding for Share Based Compensation (in shares)		24,932	23,579
Payments related to tax withholding for share-based compensation			$ 500	400
Stock repurchase program, remaining authorized repurchase amount	$ 35,000		35,000
Share-based compensation expense recognized	2,138	$ 2,106	4,059	4,086
Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense recognized	1,000	1,100	2,100	$ 2,500
Total unrecognized compensation expense related to non-vested stock options	$ 6,200		$ 6,200
Expected weighted-average period of recognition for unrecognized compensation expense			2 years 4 months 9 days
Weighted-average grant date fair value of stock options granted (in usd per share)			$ 8.71	$ 5.97
Stock options granted (in shares)	253,844			670,733
Restricted stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense recognized	$ 1,100	$ 1,000	$ 2,000	$ 1,600
Expected weighted-average period of recognition for unrecognized compensation expense			2 years 7 months
Total unrecognized compensation expense related to non-vested restricted stock	$ 6,700		$ 6,700
Weighted-average grant date fair value of stock options granted (in usd per share)			$ 21.55	$ 15.51
Stock options granted (in shares)			332,216	167,925