CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - 3 months ended Mar. 31, 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	14,928			14,928
Other comprehensive income (loss)	10,967				10,967
Stock options exercised	564	14	550
Stock issued to directors	0	2	(2)
Shares issued for employees stock purchase plan	427	9	418
Shares issued for restricted stock, net of cancellations for tax withholding	(1,175)	51	(1,226)
Shares repurchased	(1,997)	(37)	(1,960)
Stock-based compensation expense	1,992		1,992
Balance, End of Period at Mar. 31, 2016	$ 610,288	$ 17,996	$ 111,789	$ 557,994	$ (77,491)