Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Total
Balance at Dec. 31, 2018	$ 3,757	$ 123,168	$ 161,195	$ (6,660)	$ (25,928)
Acquisition of treasury stock					(1,380)
Equity based compensation		197
Shares issued under employee benefit plans					2,107
Shares issued under employee benefit plans		(587)
Net income (loss)			28,054			$ 28,054
Additional minimum pension liability, net of tax				57
Unrealized holding gains arising during period, net of tax				8,874
Reclassification adjustment for losses (gains) included in net income, net of tax				(3,318)
Ending balance at Jun. 30, 2019	3,757	122,778	189,249	(1,047)	(25,201)	289,536
Balance at Mar. 31, 2019	3,757	122,638	176,220	(3,762)	(25,201)
Equity based compensation		140
Net income (loss)			13,029			13,029
Additional minimum pension liability, net of tax				29
Unrealized holding gains arising during period, net of tax				2,733
Reclassification adjustment for losses (gains) included in net income, net of tax				(47)
Ending balance at Jun. 30, 2019	3,757	122,778	189,249	(1,047)	(25,201)	289,536
Balance at Dec. 31, 2019	3,757	123,468	160,570	688	(25,201)	263,282
Equity based compensation		(570)
Shares issued under employee benefit plans					169
Shares issued under employee benefit plans		(169)
Net income (loss)			(57,609)			(57,609)
Additional minimum pension liability, net of tax				55
Unrealized holding gains arising during period, net of tax				1,139
Reclassification adjustment for losses (gains) included in net income, net of tax				(4,125)
Ending balance at Jun. 30, 2020	3,757	122,729	102,961	(2,243)	(25,032)	202,172
Balance at Mar. 31, 2020	3,757	122,718	96,260	(9,257)	(25,032)
Equity based compensation		11
Net income (loss)			6,701			6,701
Additional minimum pension liability, net of tax				28
Unrealized holding gains arising during period, net of tax				6,659
Reclassification adjustment for losses (gains) included in net income, net of tax				327
Ending balance at Jun. 30, 2020	$ 3,757	$ 122,729	$ 102,961	$ (2,243)	$ (25,032)	$ 202,172