Consolidated Statements of Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Restricted Stock [Member]	Restricted Stock Units (RSUs) [Member]	Common Stock [Member]	Common Stock [Member] Restricted Stock [Member]	Common Stock [Member] Restricted Stock Units (RSUs) [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] Restricted Stock [Member]	Additional Paid-in Capital [Member] Restricted Stock Units (RSUs) [Member]	Retained Earnings [Member]	Retained Earnings [Member] Restricted Stock [Member]	Retained Earnings [Member] Restricted Stock Units (RSUs) [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Other Comprehensive Income (Loss) [Member] Restricted Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member] Restricted Stock Units (RSUs) [Member]	Noncontrolling Interest [Member]	Noncontrolling Interest [Member] Restricted Stock [Member]	Noncontrolling Interest [Member] Restricted Stock Units (RSUs) [Member]
Balance at Dec. 31, 2011	$ 648,989			$ 394			$ 260,680			$ 373,796			$ 5,862			$ 8,257
Balance (in Shares) at Dec. 31, 2011	39,352,375
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	56,849			0			0			52,661			0			4,188
Issuance of common stock upon stock option exercises, including tax benefit	1,176			1			1,175			0			0			0
Issuance of common stock upon stock option exercises, including tax benefit (in shares)	52,676
Restricted shares issued		2	0		2	0		0	0		0	0		0	0		0	0
Restricted shares issued (in Shares)		239,523	15,177
Issuance of shares pursuant to deferred stock unit awards (in Shares)	34,132
Forfeitures of restricted shares	0			0			0			0			0			0
Forfeitures of restricted shares (in Shares)	(36,325)
Repurchase of common stock	(12,308)			(7)			(12,301)			0			0			0
Repurchase of common stock (in Shares)	(704,997)
Equity-based compensation expense	6,767			0			6,767			0			0			0
Investment by non-controlling interests	4,939			0			0			0			0			4,939
Distribution to non-controlling interests	(5)			0			888			0			0			(893)
Currency translation adjustment and derivative transactions, net	9,711			0			0			0			9,398			313
Balance at Dec. 31, 2012	716,120			390			257,209			426,457			15,260			16,804
Balance (in Shares) at Dec. 31, 2012	38,952,561
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	45,546			0			0			44,351			0			1,195
Issuance of common stock upon stock option exercises, including tax benefit	899			0			899			0			0			0
Issuance of common stock upon stock option exercises, including tax benefit (in shares)	29,511			29,511
Restricted shares issued		4	0		4	0		0	0		0	0		0	0		0	0
Restricted shares issued (in Shares)					435,025	13,761
Issuance of shares pursuant to deferred stock unit awards (in Shares)				7,029
Forfeitures of restricted shares	(2)			(2)			0			0			0			0
Forfeitures of restricted shares (in Shares)				(236,388)
Repurchase of common stock	(27,648)			(12)			(27,636)			0			0			0
Repurchase of common stock (in Shares)				(1,218,385)
Equity-based compensation expense	5,647			0			5,647			0			0			0
Currency translation adjustment and derivative transactions, net	(13,645)			0			9			0			(13,208)			(446)
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	(35,412)			0			0			(37,167)			0			1,755
Issuance of common stock upon stock option exercises, including tax benefit	8,075			5			8,070			0			0			0
Issuance of common stock upon stock option exercises, including tax benefit (in shares)	526,359			526,359
Restricted shares issued		2	0		2	0		0	0		0	0		0	0		0	0
Restricted shares issued (in Shares)					242,722	15,277
Issuance of shares pursuant to deferred stock unit awards (in Shares)				31,794
Forfeitures of restricted shares	(1)			(1)			0			0			0			0
Forfeitures of restricted shares (in Shares)				(104,013)
Repurchase of common stock	(31,085)			(12)			(31,073)			0			0			0
Repurchase of common stock (in Shares)				(1,334,738)
Equity-based compensation expense	5,073			0			5,073			0			0
Purchase of non-controlling interests	(617)			0			(909)			0			0			292
Currency translation adjustment and derivative transactions, net	(27,871)			0			0			0			(26,721)			(1,150)
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