Consolidated Statement of Stockholders' Equity - USD ($) $ in Thousands	Stockholders' Equity of the Company Common Stock [Member]	Stockholders' Equity of the Company Treasury Stock [Member]	Stockholders' Equity of the Company Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss)	Stockholders' Equity of the Company Retained Earnings [Member]	Noncontrolling Interest [Member]	Total
Beginning balance, value at Dec. 31, 2016				$ (126,964)
Net income							$ 20,167
Dividends distributed to noncontrolling interest							(945)
Foreign currency translation adjustments							$ 6,228
Ending balance, value at Mar. 31, 2017				(112,515)
Preferred stock beginning balance, share at Dec. 31, 2017							0
Common stock beginning balance, share at Dec. 31, 2017	45,862,000						45,861,959
Beginning balance, value at Dec. 31, 2017	$ 459	$ (615,677)	$ 351,725	(102,304)	$ 721,664	$ 6,978	$ 362,845
Net income					4,591	1,341	5,932
Dividends to shareholders					(12,414)		(12,414)
Dividends distributed to noncontrolling interest						(945)	(945)
Foreign currency translation adjustments				(5,700)		101	(5,599)
Derivatives valuation, net of tax				(7)			(7)
Vesting of restricted stock units, share	117,000
Vesting of restricted stock units, value	$ 1	1,939	(3,662)				(1,722)
Equity-based compensation expense			3,609				3,609
Other, net of tax.				108			$ 108
Preferred stock ending balance, share at Mar. 31, 2018							0
Common stock ending balance, share at Mar. 31, 2018	45,979,000						45,979,290
Ending balance, value at Mar. 31, 2018	$ 460	$ (613,738)	$ 351,672	$ (107,903)	707,257	$ 7,475	$ 345,223
Cumulative Effect of New Accounting Principle in Period of Adoption					$ (6,584)		$ (6,584)