Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 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)	57,713
Common stock issued due to exercise of stock options (in shares)	222,378
Common stock issued in connection with employee stock purchase plan (in shares)	32,358
Proceeds from Issuance of Common Stock	$ 3,065	$ 1,554
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)	21,538	24,932
Payments Related to Tax Withholding for Share-based Compensation	$ 400	$ 400
Stock Repurchase Program, Remaining Authorized Repurchase Amount	35,000
Share-based compensation expense recognized	1,921	1,980
Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense recognized	1,100	$ 1,400
Total unrecognized compensation expense related to non-vested stock options	$ 6,700
Expected weighted-average period of recognition for unrecognized compensation expense	2 years 7 months
Weighted-average grant date fair value of stock options granted (in usd per share)	$ 8.55	$ 5.85
Stock options granted (in shares)	230,261	626,413
Restricted stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense recognized	$ 800	$ 600
Expected weighted-average period of recognition for unrecognized compensation expense	2 years 8 months
Total unrecognized compensation expense related to non-vested restricted stock	$ 6,700
Weighted-average grant date fair value of stock options granted (in usd per share)	$ 21.06	$ 15.39
Stock options granted (in shares)	289,338	131,972