Consolidated Statements of Equity (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interest [Member]	Restricted Stock [Member]	Restricted Stock [Member] Common Stock [Member]	Restricted Stock [Member] Additional Paid-in Capital [Member]	Restricted Stock [Member] Retained Earnings [Member]	Restricted Stock [Member] Accumulated Other Comprehensive Income (Loss) [Member]	Restricted Stock [Member] Noncontrolling Interest [Member]	Restricted Stock Units (RSUs) [Member]	Restricted Stock Units (RSUs) [Member] Common Stock [Member]	Restricted Stock Units (RSUs) [Member] Additional Paid-in Capital [Member]	Restricted Stock Units (RSUs) [Member] Retained Earnings [Member]	Restricted Stock Units (RSUs) [Member] Accumulated Other Comprehensive Income (Loss) [Member]	Restricted Stock Units (RSUs) [Member] Noncontrolling Interest [Member]
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	16,756	0	0	15,924	0	832
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period		29,511
Stock Issued During Period, Value, Stock Options Exercised	897	0	897	0	0	0
Restricted shares issued							4	4	0	0	0	0	0	0	0	0	0	0
Restricted shares issued (in Shares)								398,497						11,112
Issuance of shares pursuant to deferred stock unit awards (in Shares)		3,171
Forfeitures of restricted shares	0	0	0	0	0	0
Forfeitures of restricted shares (in Shares)		(13,992)
Shares repurchased and retired	15,822	(7)	(15,815)	0	0	0
Shares repurchased and retired (in Shares)		(696,310)
Equity-based compensation expense	3,973	0	3,973	0	0	0
Currency translation adjustment and derivative transactions, net	(10,195)	0	0	0	(9,913)	(282)
Balance at Jun. 30, 2013	711,733	387	246,264	442,381	5,347	17,354
Balance (in Shares) at Jun. 30, 2013		38,684,550
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	37,983,114
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	16,840	0	0	16,783	0	57
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	322,173	322,173
Stock Issued During Period, Value, Stock Options Exercised	5,031	3	5,028	0	0	0
Restricted shares issued							2	2	0	0	0	0	0	0	0	0	0	0
Restricted shares issued (in Shares)								222,944						15,277
Issuance of shares pursuant to deferred stock unit awards (in Shares)		30,594
Forfeitures of restricted shares	(1)	(1)	0	0	0	0
Forfeitures of restricted shares (in Shares)		(59,632)
Shares repurchased and retired	20,661	(8)	(20,653)	0	0	0
Shares repurchased and retired (in Shares)		(882,840)
Equity-based compensation expense	3,120	0	3,120	0	0
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests	(617)	0	(909)	0	0	292
Currency translation adjustment and derivative transactions, net	(587)	0	0	0	(553)	(34)
Balance at Jun. 30, 2014	$ 730,048	$ 376	$ 222,714	$ 487,591	$ 1,499	$ 17,868
Balance (in Shares) at Jun. 30, 2014	37,631,630	37,631,630