Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Jan. 01, 2017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			$ 167,496
Net income	$ 5,863	$ 4,913	9,949	$ 8,713
Cumulative effect adjustment of adopting ASU 2016-09					$ 97
Foreign currency translation adjustment			4,476
Repurchases of common stock			(2,419)
Stock-based compensation expense			1,838
Issuance of stock for employer contributions to retirement plan			1,354
Other			(132)
Ending Balance	182,527		$ 182,527
Stock repurchased during period, shares			101,000	340,000
Stock repurchased during period, value			$ 2,400	$ 8,000
Stock repurchase program, remaining authorized repurchase amount	3,600		3,600
Common stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			172
Ending Balance	172		172
Additional paid-in capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			106,569
Cumulative effect adjustment of adopting ASU 2016-09					234
Stock-based compensation expense			1,838
Issuance of stock for employer contributions to retirement plan			(62)
Other			(966)
Ending Balance	107,613		107,613
Retained earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			93,845
Net income			9,949
Cumulative effect adjustment of adopting ASU 2016-09					$ (137)
Ending Balance	103,657		103,657
Treasury stock at cost
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			(11,628)
Repurchases of common stock			(2,419)
Issuance of stock for employer contributions to retirement plan			1,416
Other			834
Ending Balance	(11,797)		(11,797)
Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			(21,462)
Foreign currency translation adjustment			4,476
Ending Balance	$ (17,118)		(17,118)
Interest Rate Cap
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in fair value of interest rate derivative instrument, net of tax			(109)
Interest Rate Cap | Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in fair value of interest rate derivative instrument, net of tax			(109)
Interest Rate Swap
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in fair value of interest rate derivative instrument, net of tax			(23)
Interest Rate Swap | Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in fair value of interest rate derivative instrument, net of tax			$ (23)