Consolidated Statements of Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total USD ($)	Common Stock [Member] USD ($)	Additional Paid-in Capital [Member] USD ($)	Retained Earnings [Member] USD ($)	Accumulated Other Comprehensive Income [Member] USD ($)	Noncontrolling Interest [Member] USD ($)	Restricted Shares [Member] USD ($)	Restricted Shares [Member] Common Stock [Member] USD ($)	Restricted Stock Units [Member] Common Stock [Member]
Balance at Dec. 31, 2013	$ 726,921	$ 380	$ 236,128	$ 470,808	$ 2,052	$ 17,553
Balance (in Shares) at Dec. 31, 2013		37,983,114
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	4,428			4,397		31
Issuance of common stock upon stock option exercises	1,092	1	1,091
Issuance of common stock upon stock option exercises (in Shares)		75,657
Restricted shares issued							2	2
Restricted shares issued (in Shares)								216,880	15,277
Issuance of shares pursuant to deferred stock unit awards (in Shares)		4,171
Forfeitures of restricted shares (in Shares)		(8,921)
Shares repurchased and retired	(5,475)	(3)	(5,472)
Shares repurchased and retired (in Shares)		(239,075)
Equity-based compensation expense	1,284		1,284
Purchase of non-controlling interest	(617)		(909)			292
Currency translation adjustment and derivative transactions, net	(2,534)				(2,305)	(229)
Balance at Mar. 31, 2014	725,101	380	232,122	475,205	(253)	17,647
Balance (in Shares) at Mar. 31, 2014		38,047,103
Balance at Dec. 31, 2014	645,085	374	217,289	433,641	(24,669)	18,450
Balance (in Shares) at Dec. 31, 2014	37,360,515	37,360,515
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,372			1,359		13
Issuance of common stock upon stock option exercises	1,114	1	1,113
Issuance of common stock upon stock option exercises (in Shares)	100,191	100,191
Restricted shares issued (in Shares)									10,856
Issuance of shares pursuant to deferred stock unit awards (in Shares)		3,257
Forfeitures of restricted shares (in Shares)		(18,195)
Shares repurchased and retired	(7,622)	(5)	(7,617)
Shares repurchased and retired (in Shares)		(437,669)
Equity-based compensation expense	1,663		1,663
Currency translation adjustment and derivative transactions, net	(15,666)				(14,659)	(1,007)
Balance at Mar. 31, 2015	$ 625,946	$ 370	$ 212,448	$ 435,000	$ (39,328)	$ 17,456
Balance (in Shares) at Mar. 31, 2015	37,018,955	37,018,955