Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Jan. 01, 2017	Dec. 31, 2016
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2016			$ 167,496
Net income	$ 3,281	$ 4,802	13,230	$ 13,515
Cumulative effect adjustment of adopting ASU 2016-09					$ 97
Adjusted balance at December 31, 2016						$ 167,593
Foreign currency translation adjustment			7,051
Repurchases of common stock			(2,419)
Stock-based compensation expense			2,823
Issuance of stock for employer contributions to retirement plan			2,053
Other			(485)
Ending Balance	189,707		$ 189,707
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]
Balance at December 31, 2016			172
Adjusted balance at December 31, 2016						172
Ending Balance	172		172
Additional paid-in capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2016			106,569
Cumulative effect adjustment of adopting ASU 2016-09					234
Adjusted balance at December 31, 2016						106,803
Stock-based compensation expense			2,823
Issuance of stock for employer contributions to retirement plan			11
Other			(1,962)
Ending Balance	107,675		107,675
Retained earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2016			93,845
Net income			13,230
Cumulative effect adjustment of adopting ASU 2016-09					$ (137)
Adjusted balance at December 31, 2016						93,708
Ending Balance	106,938		106,938
Treasury stock at cost
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2016			(11,628)
Adjusted balance at December 31, 2016						(11,628)
Repurchases of common stock			(2,419)
Issuance of stock for employer contributions to retirement plan			2,042
Other			1,477
Ending Balance	(10,528)		(10,528)
Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2016			(21,462)
Adjusted balance at December 31, 2016						$ (21,462)
Foreign currency translation adjustment			7,051
Ending Balance	$ (14,550)		(14,550)
Interest Rate Cap
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in fair value of interest rate derivative instrument, net of tax			(137)
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			(137)
Interest Rate Swap
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in fair value of interest rate derivative instrument, net of tax			(2)
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			$ (2)