Capital Structure - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2016 USD ($) ClassOfCommonStock $ / shares shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 30, 2014 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	17,676	15,078
Withholding tax payments related to the vesting of restricted stock for total consideration	$ 807,000	$ 484,000
Weighted average purchase price per share prior to the vesting date (in dollars per share) | $ / shares	$ 45.65	$ 32.10
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
Common stock shares purchased under the repurchase program (in shares) | shares	364,056	377,015
Common stock aggregate purchase price including commissions	$ 17,396,000	$ 13,711,000
Common stock average purchase price per share (in dollars per share) | $ / shares	$ 47.78	$ 36.37