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
Common stock beginning balance, share at Dec. 31, 2017	45,862,000
Beginning balance, value at Dec. 31, 2017	$ 459	$ (615,677)	$ 351,725	$ (102,304)	$ 721,664	$ 6,978	$ 362,845
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income					15,484	3,489	18,973
Dividends to shareholders					(25,346)		(25,346)
Dividends distributed to noncontrolling interest						(2,025)	(2,025)
Foreign currency translation adjustments				(27,921)		(218)	(28,139)
Derivatives valuation, net of tax				3,935			3,935
Vesting of restricted stock units, share	315,000
Vesting of restricted stock units, value	$ 3	5,215	(9,836)				(4,618)
Exercise of stock options, share	15,000
Exercise of stock options, value		248	(40)				208
Equity-based compensation expense			9,292				9,292
Other, net of tax.				317			317
Common stock ending balance, share at Sep. 30, 2018	46,192,000
Ending balance, value at Sep. 30, 2018	$ 462	(610,214)	351,141	(125,973)	705,218	8,224	328,858
Common stock beginning balance, share at Jun. 30, 2018	46,034,000
Beginning balance, value at Jun. 30, 2018	$ 460	(612,841)	352,784	(129,325)	712,775	7,811	331,664
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income					5,375	1,369	6,744
Dividends to shareholders					(12,932)		(12,932)
Dividends distributed to noncontrolling interest						(900)	(900)
Foreign currency translation adjustments				(2,199)		(56)	(2,255)
Derivatives valuation, net of tax				5,448			5,448
Vesting of restricted stock units, share	143,000
Vesting of restricted stock units, value	$ 2	2,379	(4,712)				(2,331)
Exercise of stock options, share	15,000
Exercise of stock options, value		248	(40)				208
Equity-based compensation expense			3,109				3,109
Other, net of tax.				103			103
Common stock ending balance, share at Sep. 30, 2018	46,192,000
Ending balance, value at Sep. 30, 2018	$ 462	(610,214)	351,141	(125,973)	705,218	8,224	328,858
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption					(6,584)		$ (6,584)
Preferred stock beginning balance, share at Dec. 31, 2018							0
Common stock beginning balance, share at Dec. 31, 2018	46,195,000						46,194,717
Beginning balance, value at Dec. 31, 2018	$ 462	(610,177)	353,932	(124,596)	725,551	7,677	$ 352,849
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income					48,901	5,168	54,069
Dividends to shareholders					(28,739)		(28,739)
Capital contribution from noncontrolling interest						3,362	3,362
Dividends distributed to noncontrolling interest						(3,600)	(3,600)
Foreign currency translation adjustments				(2,573)		(185)	(2,758)
Derivatives valuation, net of tax				8,415			8,415
Vesting of restricted stock units, share	291,000
Vesting of restricted stock units, value	$ 3	4,807	(10,223)				(5,413)
Equity-based compensation expense			9,663				9,663
Other, net of tax.				54			$ 54
Preferred stock ending balance, share at Sep. 30, 2019							0
Common stock ending balance, share at Sep. 30, 2019	46,486,000						46,485,595
Ending balance, value at Sep. 30, 2019	$ 465	(605,370)	353,372	(118,700)	744,954	12,422	$ 387,143
Common stock beginning balance, share at Jun. 30, 2019	46,387,000
Beginning balance, value at Jun. 30, 2019	$ 464	(607,004)	354,068	(110,686)	741,728	12,079	390,649
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income					18,101	1,878	19,979
Dividends to shareholders					(14,875)		(14,875)
Dividends distributed to noncontrolling interest						(1,350)	(1,350)
Foreign currency translation adjustments				(8,953)		(185)	(9,138)
Derivatives valuation, net of tax				902			902
Vesting of restricted stock units, share	99,000
Vesting of restricted stock units, value	$ 1	1,634	(3,825)				(2,190)
Equity-based compensation expense			3,129				3,129
Other, net of tax.				37			$ 37
Preferred stock ending balance, share at Sep. 30, 2019							0
Common stock ending balance, share at Sep. 30, 2019	46,486,000						46,485,595
Ending balance, value at Sep. 30, 2019	$ 465	$ (605,370)	$ 353,372	$ (118,700)	744,954	$ 12,422	$ 387,143
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption					$ (759)		$ (759)