CONSOLIDATED STATEMENTS OF SHAREHOLDERS’ EQUITY - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income/(Loss) [Member]	Treasury Stock [Member]
Balance at Dec. 31, 2015	$ 410,316	$ 1,817	$ 73,396	$ 395,633	$ (9,401)	$ (51,129)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	30,069	0	0	30,069	0	0
Other comprehensive income (loss)	6,989	0	0	0	6,989	0
Omnibus Equity Incentive Plan	513	2	511	0	0	0
Payments for Repurchase of Common Stock	(19,396)		0	0	0
Dividends, Common Stock, Cash	(6,117)	0	0	(6,117)	0	0
Balance at Sep. 30, 2016	422,374	1,819	73,907	419,585	(2,412)	(70,525)
Balance at Jun. 30, 2016	413,224	1,818	73,737	411,423	(3,493)	(70,261)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	8,162	0	0	8,162	0	0
Other comprehensive income (loss)	1,081	0	0	0	1,081	0
Omnibus Equity Incentive Plan	171	1	170	0	0	0
Payments for Repurchase of Common Stock	(264)	0	0	0	0
Dividends, Common Stock, Cash	0			0
Balance at Sep. 30, 2016	422,374	1,819	73,907	419,585	(2,412)	(70,525)
Balance at Dec. 31, 2016	414,395	1,820	74,525	421,826	(14,164)	(69,612)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	26,515	0	0	26,515	0	0
Other comprehensive income (loss)	8,733	0	0	0	8,733	0
Omnibus Equity Incentive Plan	530	2	528	0	0	0
Payments for Repurchase of Common Stock	(503)		0	0	0
Dividends, Common Stock, Cash	(6,112)	0	0	(6,112)	0	0
Balance at Sep. 30, 2017	443,558	1,822	75,053	442,229	(5,431)	(70,115)
Balance at Jun. 30, 2017	434,454	1,821	74,877	433,435	(5,564)	(70,115)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	8,794	0	0	8,794	0	0
Other comprehensive income (loss)	133	0	0	0	133	0
Omnibus Equity Incentive Plan	177	1	176	0	0	0
Dividends, Common Stock, Cash	0			0
Balance at Sep. 30, 2017	$ 443,558	$ 1,822	$ 75,053	$ 442,229	$ (5,431)	$ (70,115)