Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Common Stock [Member] Series A	Common Stock [Member] Series B	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock Series A	Treasury Stock	Accumulated Other Comprehensive Loss [Member]	Accumulated Deficit [Member]	Total
Beginning Balance at Dec. 31, 2018			$ 233	$ 494,389		$ (12,601)	$ (37,641)	$ (393,582)	$ 50,798
Beginning Balance, Shares Common Stock at Dec. 31, 2018	20,854,728	2,469,555
Beginning Balance, Treasury Stock at Dec. 31, 2018					(1,697,370)
Net income (loss)								14,393	14,393
Other comprehensive income							125		125
Shares repurchased, shares					(131,613)
Shares repurchased						(527)			(527)
Conversion of Series B to Series A, shares	43	(43)
Dividends declared								(3,436)	(3,436)
Ending Balance at Jun. 30, 2019			233	494,389		(13,128)	(37,516)	(382,625)	61,353
Ending Balance, Shares Common Stock at Jun. 30, 2019	20,854,771	2,469,512
Ending Balance, Shares Treasury Stock at Jun. 30, 2019					(1,828,983)
Beginning Balance at Mar. 31, 2019			233	494,389		(12,941)	(37,578)	(397,437)	46,666
Beginning Balance, Shares Common Stock at Mar. 31, 2019	20,854,739	2,469,544
Beginning Balance, Treasury Stock at Mar. 31, 2019					(1,780,899)
Net income (loss)								16,528	16,528
Other comprehensive income							62		62
Shares repurchased, shares					(48,084)
Shares repurchased						(187)			(187)
Conversion of Series B to Series A, shares	32	(32)
Dividends declared								(1,716)	(1,716)
Ending Balance at Jun. 30, 2019			233	494,389		(13,128)	(37,516)	(382,625)	61,353
Ending Balance, Shares Common Stock at Jun. 30, 2019	20,854,771	2,469,512
Ending Balance, Shares Treasury Stock at Jun. 30, 2019					(1,828,983)
Beginning Balance at Dec. 31, 2019			233	494,389		(13,443)	(32,294)	(391,148)	57,737
Beginning Balance, Shares Common Stock at Dec. 31, 2019	20,854,975	2,469,308
Beginning Balance, Treasury Stock at Dec. 31, 2019					(1,913,860)
Net income (loss)								(5,035)	(5,035)
Other comprehensive income							438		438
Conversion of Series B to Series A, shares	225	(225)
Dividends declared								(2,569)	(2,569)
Ending Balance at Jun. 30, 2020			233	494,389		(13,443)	(31,856)	(398,752)	50,571
Ending Balance, Shares Common Stock at Jun. 30, 2020	20,855,200	2,469,083
Ending Balance, Shares Treasury Stock at Jun. 30, 2020					(1,913,860)
Beginning Balance at Mar. 31, 2020			233	494,389		(13,443)	(32,075)	(394,482)	54,622
Beginning Balance, Shares Common Stock at Mar. 31, 2020	20,855,200	2,469,083
Beginning Balance, Treasury Stock at Mar. 31, 2020					(1,913,860)
Net income (loss)								(3,414)	(3,414)
Other comprehensive income							219		219
Dividends declared								(856)	(856)
Ending Balance at Jun. 30, 2020			$ 233	$ 494,389		$ (13,443)	$ (31,856)	$ (398,752)	$ 50,571
Ending Balance, Shares Common Stock at Jun. 30, 2020	20,855,200	2,469,083
Ending Balance, Shares Treasury Stock at Jun. 30, 2020					(1,913,860)