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)								10,388	10,388
Other comprehensive income							188		188
Shares repurchased, shares					(183,458)
Shares repurchased						(719)			(719)
Conversion of Series B to Series A, shares	207	(207)
Dividends declared								(5,148)	(5,148)
Ending Balance at Sep. 30, 2019			233	494,389		(13,320)	(37,453)	(388,342)	55,507
Ending Balance, Shares Common Stock at Sep. 30, 2019	20,854,935	2,469,348
Ending Balance, Shares Treasury Stock at Sep. 30, 2019					(1,880,828)
Beginning Balance at Jun. 30, 2019			233	494,389		(13,128)	(37,516)	(382,625)	61,353
Beginning Balance, Shares Common Stock at Jun. 30, 2019	20,854,771	2,469,512
Beginning Balance, Treasury Stock at Jun. 30, 2019					(1,828,983)
Net income (loss)								(4,005)	(4,005)
Other comprehensive income							63		63
Shares repurchased, shares					(51,845)
Shares repurchased						(192)			(192)
Conversion of Series B to Series A, shares	164	(164)
Dividends declared								(1,712)	(1,712)
Ending Balance at Sep. 30, 2019			233	494,389		(13,320)	(37,453)	(388,342)	55,507
Ending Balance, Shares Common Stock at Sep. 30, 2019	20,854,935	2,469,348
Ending Balance, Shares Treasury Stock at Sep. 30, 2019					(1,880,828)
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)								(5,133)	(5,133)
Other comprehensive income							657		657
Conversion of Series B to Series A, shares	225	(225)
Dividends declared								(3,425)	(3,425)
Ending Balance at Sep. 30, 2020			233	494,389		(13,443)	(31,637)	(399,706)	49,836
Ending Balance, Shares Common Stock at Sep. 30, 2020	20,855,200	2,469,083
Ending Balance, Shares Treasury Stock at Sep. 30, 2020					(1,913,860)
Beginning Balance at Jun. 30, 2020			233	494,389		(13,443)	(31,856)	(398,752)	50,571
Beginning Balance, Shares Common Stock at Jun. 30, 2020	20,855,200	2,469,083
Beginning Balance, Treasury Stock at Jun. 30, 2020					(1,913,860)
Net income (loss)								(98)	(98)
Other comprehensive income							219		219
Dividends declared								(856)	(856)
Ending Balance at Sep. 30, 2020			$ 233	$ 494,389		$ (13,443)	$ (31,637)	$ (399,706)	$ 49,836
Ending Balance, Shares Common Stock at Sep. 30, 2020	20,855,200	2,469,083
Ending Balance, Shares Treasury Stock at Sep. 30, 2020					(1,913,860)