Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
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			53,003
Common stock issued due to exercise of stock options			27,931
Common stock issued in connection with employee stock purchase plan			25,080
Employee stock purchase plan, net proceeds			$ 800
Repurchase of common stock, shares			632,150
Repurchase of common stock			$ 14,400
Shares Paid for Tax Withholding for Share Based Compensation			15,811
Share-based compensation expense recognized	$ 1,926	$ 1,242	$ 3,994	$ 3,479
Payments Related to Tax Withholding for Share-based Compensation			400
Stock Repurchase Program, Remaining Authorized Repurchase Amount	35,600		35,600
Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense recognized	1,000	1,000	2,400	$ 2,400
Total unrecognized compensation expense related to non-vested stock options	8,600		$ 8,600
Expected weighted-average period of recognition for unrecognized compensation expense			2 years 7 months
Weighted-average grant date fair value of stock options granted			$ 9.61	$ 10.96
Stock options granted			615,183	535,128
Restricted stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense recognized	900	$ 300	$ 1,600	$ 1,100
Expected weighted-average period of recognition for unrecognized compensation expense			2 years 11 months
Total unrecognized compensation expense related to non-vested restricted stock	$ 3,300		$ 3,300
Weighted-average grant date fair value of stock options granted			$ 23.58	$ 25.46
Stock options granted			137,214	108,030