Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]	Treasury Stock [Member]	Total
Balance at Dec. 31, 2014	$ 3,757	$ 123,194	$ 119,638	$ 17,801	$ (12,353)
Acquisition of treasury stock					(730)
Shares issued under employee benefit plans					707
Equity based compensation		537
Shares issued under employee benefit plans (value)		(113)
Net income			11,719			$ 11,719
Additional minimum pension liability, net of tax				34
Unrealized holding (losses) gains arising during period, net of tax				1,926
Reclassification adjustment for (gains) losses included in net income, net of tax				(3,805)
Balance at Jun. 30, 2015	3,757	123,618	131,357	15,956	(12,376)	262,312
Balance at Mar. 31, 2015	3,757	123,555	124,981	21,853	(12,428)
Acquisition of treasury stock					(443)
Shares issued under employee benefit plans					495
Equity based compensation		166
Shares issued under employee benefit plans (value)		(103)
Net income			6,376			6,376
Additional minimum pension liability, net of tax				17
Unrealized holding (losses) gains arising during period, net of tax				(2,669)
Reclassification adjustment for (gains) losses included in net income, net of tax				(3,245)
Balance at Jun. 30, 2015	3,757	123,618	131,357	15,956	(12,376)	262,312
Balance at Dec. 31, 2015	3,757	123,480	141,501	7,418	(14,130)	262,026
Acquisition of treasury stock					(4,745)
Shares issued under employee benefit plans					58
Equity based compensation		228
Shares issued under employee benefit plans (value)		(58)
Net income			5,140			5,140
Additional minimum pension liability, net of tax				37
Unrealized holding (losses) gains arising during period, net of tax				3,724
Reclassification adjustment for (gains) losses included in net income, net of tax				(315)
Balance at Jun. 30, 2016	3,757	123,650	146,641	10,864	(18,817)	266,095
Balance at Mar. 31, 2016	3,757	123,619	145,575	8,279	(15,423)
Acquisition of treasury stock					(3,452)
Shares issued under employee benefit plans					58
Equity based compensation		89
Shares issued under employee benefit plans (value)		(58)
Net income			1,066			1,066
Additional minimum pension liability, net of tax				19
Unrealized holding (losses) gains arising during period, net of tax				2,833
Reclassification adjustment for (gains) losses included in net income, net of tax				(267)
Balance at Jun. 30, 2016	$ 3,757	$ 123,650	$ 146,641	$ 10,864	$ (18,817)	$ 266,095