Condensed Consolidated Statement of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Noncontrolling Interest [Member]	Accumulated Other Comprehensive Loss
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 438,636
Beginning Balance, Issued Shares at Dec. 31, 2016	32,093,294	32,093,294
Beginning Balance, Value at Dec. 31, 2016	$ 426,896	$ 3,209	$ 0	$ 457,364	$ 11,740	$ (33,677)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss) Attributable to Parent	74,045			74,045
Net Income (Loss) Attributable to Noncontrolling Interest	1,013				1,013
Cumulative translation adjustment	3,917					3,917
Repurchase and retirement of common stock, Shares		(687,048)
Repurchase and retirement of common stock, Value	(39,382)	$ (68)	(1,852)	(37,462)
Vesting of restricted stock, Shares		59,047
Vesting of restricted stock, Value	0	$ 5	(5)
Exercise of stock options, Shares		3,500
Exercise of stock options, Value	52	$ 0	52
Share based compensation	1,994		1,994
Forfeiture of certain shares to satisfy exercise costs and the recipients income tax obligations related to stock options exercised and restricted stock vested, Shares		(5,190)
Forfeiture of certain shares to satisfy exercise costs and the recipients income tax obligations related to stock options exercised and restricted stock vested	(327)	$ 0	(327)
Recognized controlling ownership of joint venture	27,586				27,586
Loans by non-controlling interest converted to capital contribution to joint venture	1,563		797	0	766
Dividends paid	$ (7,176)			(7,176)
Ending Balance, Issued Shares at Sep. 30, 2017	31,463,603	31,463,603
Ending Balance, Value at Sep. 30, 2017	$ 460,816	$ 3,146	$ 659	$ 486,771	$ 41,105	$ (29,760)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 501,921