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, 2016	$ 3,757	$ 123,166	$ 148,027	$ 10,371	$ (19,585)
Acquisition of treasury stock					(5,308)
Shares issued under employee benefit plans					265
Equity based compensation		97
Shares issued under employee benefit plans (value)		(107)
Net income (loss)			(924)			$ (924)
Additional minimum pension liability, net of tax				70
Unrealized holding gains arising during period, net of tax				5,335
Reclassification adjustment for losses (gains) included in net income, net of tax				(3,691)
Balance at Sep. 30, 2017	3,757	123,156	147,103	12,085	(24,628)	261,473
Balance at Jun. 30, 2017	3,757	123,110	148,663	13,933	(23,763)
Acquisition of treasury stock					(883)
Shares issued under employee benefit plans					18
Equity based compensation		51
Shares issued under employee benefit plans (value)		(5)
Net income (loss)			(1,560)			(1,560)
Additional minimum pension liability, net of tax				24
Unrealized holding gains arising during period, net of tax				200
Reclassification adjustment for losses (gains) included in net income, net of tax				(2,072)
Balance at Sep. 30, 2017	3,757	123,156	147,103	12,085	(24,628)	261,473
Balance at Dec. 31, 2017	3,757	123,180	136,474	12,234	(24,527)	251,118
Acquisition of treasury stock					(1,464)
Reclassification of certain tax effects from accumulated other comprehensive income at January 1, 2018			(2,619)	2,619
Shares issued under employee benefit plans					406
Equity based compensation		37
Shares issued under employee benefit plans (value)		(164)
Net income (loss)			15,422			15,422
Additional minimum pension liability, net of tax				63
Unrealized holding gains arising during period, net of tax				1,508
Reclassification adjustment for losses (gains) included in net income, net of tax				126
Balance at Sep. 30, 2018	3,757	123,053	166,270	(443)	(25,585)	267,052
Balance at Jun. 30, 2018	3,757	123,017	156,585	(865)	(25,585)
Equity based compensation		36
Net income (loss)			9,685			9,685
Additional minimum pension liability, net of tax				21
Unrealized holding gains arising during period, net of tax				270
Reclassification adjustment for losses (gains) included in net income, net of tax				131
Balance at Sep. 30, 2018	$ 3,757	$ 123,053	166,270	(443)	$ (25,585)	$ 267,052
Cumulative effect of adoption of updated accounting guidance for equity financial instruments at January 1, 2018			$ 16,993	$ (16,993)