Capital Structure - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015 USD ($) ClassOfCommonStock $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Dec. 30, 2014 USD ($)	Nov. 07, 2013 USD ($)
Equity, Class of Treasury Stock [Line Items]
Number of classes of common stock outstanding | ClassOfCommonStock	1
Acquisition of restricted stock from employees in connection with withholding tax payments (in shares) | shares	15,078	18,256
Withholding tax payments related to the vesting of restricted stock for total consideration	$ 484,000	$ 459,000
Weighted average purchase price per share prior to the vesting date (in dollars per share) | $ / shares	$ 32.1	$ 25.14
2014 Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Repurchase of common stock authorized by board of directors up to			$ 20,000,000
Stock repurchase program, period start (year)	2015
Stock repurchase program, period end (year)	2017
2013 Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Repurchase of common stock authorized by board of directors up to				$ 25,000,000
Common stock shares purchased under the repurchase program (in shares) | shares	377,015	109,500
Common stock aggregate purchase price including commissions	$ 13,711,000	$ 2,863,000
Common stock average purchase price per share (in dollars per share) | $ / shares	$ 36.37	$ 26.14