Condensed Consolidated Statement of Changes in Shareholders' Equity (Unaudited) - 6 months ended Jun. 30, 2016 - USD ($) $ in Thousands	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Earnings [Member]	Accumulated Other Comprehensive Loss [Member]
Beginning Balance at Dec. 31, 2015	$ 453,981	$ 203	$ (22,370)	$ 204,688	$ 268,873	$ 2,587
Beginning Balance, Shares at Dec. 31, 2015	20,388,396	20,388,396
Treasury Stock Beginning Balance, Shares at Dec. 31, 2015	(1,258,250)		(1,258,250)
Comprehensive income	$ 46,618				40,896	5,722
Common stock issued upon exercise of options	$ 501	$ 1		500
Common stock issued upon exercise of options, Shares	38,879	38,879
Tax benefit from share-based payments	$ 546			546
Restricted common stock issued	602			602
Restricted common stock issued, Shares		32,015
Share-based compensation	608			608
Dividends to shareholders	(6,909)				(6,909)
Ending Balance at Jun. 30, 2016	$ 495,947	$ 204	$ (22,370)	$ 206,944	$ 302,860	$ 8,309
Ending Balance, Shares at Jun. 30, 2016	20,459,290	20,459,290
Treasury Stock Ending Balance, Shares at Jun. 30, 2016	(1,258,250)		(1,258,250)