Capital Structure - Additional Information (Detail)			12 Months Ended
	Feb. 28, 2017 USD ($)	Dec. 30, 2014 USD ($)	Dec. 31, 2017 USD ($) ClassOfCommonStock $ / shares shares	Dec. 31, 2016 USD ($) $ / shares shares
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			69,154	17,676
Withholding tax payments related to the vesting of restricted stock for total consideration			$ 3,267,000	$ 807,000
Weighted average purchase price per share prior to the vesting date (in dollars per share) | $ / shares			$ 47.24	$ 45.65
2014 Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, period start (year)		2015
Stock repurchase program, period end (year)		2017
Repurchase of common stock authorized by board of directors up to		$ 20,000,000
Common stock shares purchased under the repurchase program | shares				364,056
Common stock aggregate purchase price including commissions				$ 17,396,000
Common stock average purchase price per share (in dollars per share) | $ / shares				$ 47.78
2017 Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, period start (year)	2017
Stock repurchase program, period end (year)	2019
Additional authorized amount	$ 100,000,000
Authorized increase in repurchase amount, 2018	40,000,000
Authorized increase in repurchase amount, 2019	40,000,000
2017 Repurchase Program | Minimum
Equity, Class of Treasury Stock [Line Items]
Authorized increase in repurchase amount	20,000,000
2017 Repurchase Program | Maximum
Equity, Class of Treasury Stock [Line Items]
Authorized increase in repurchase amount	$ 40,000,000
2014 and 2017 Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Common stock shares purchased under the repurchase program | shares			761,154
Common stock aggregate purchase price including commissions			$ 40,187,000
Common stock average purchase price per share (in dollars per share) | $ / shares			$ 52.80