CONDENSED CONSOLIDATED STATEMENT OF SHAREHOLDERS' EQUITY (Unaudited) - 6 months ended Jun. 30, 2016 - USD ($) $ in Thousands	Total	Capital Stock/Capital Shares	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Balance, Beginning of Period at Dec. 31, 2015	$ 584,582	$ 17,957	$ 112,017	$ 543,066	$ (88,458)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	20,305			20,305
Other comprehensive income (loss)	5,279				5,279
Stock options exercised	2,058	56	2,002
Stock issued to directors	0	20	(20)
Shares issued for employees stock purchase plan	427	12	415
Shares issued for restricted stock, net of cancellations for tax withholding	(1,201)	52	(1,253)
Shares repurchased	(3,997)	(70)	(3,927)
Stock-based compensation expense	5,740		5,740
Balance, End of Period at Jun. 30, 2016	$ 613,193	$ 18,027	$ 114,974	$ 563,371	$ (83,179)