Consolidated Balance Sheets (Parenthetical) $ in Thousands	Dec. 31, 2016 USD ($) Vote $ / shares shares	Dec. 31, 2015 USD ($) Vote $ / shares shares
Accounts receivable, allowance | $	$ 153	$ 171
Preferred Stock, par value | $ / shares	$ 0.01	$ 0.01
Preferred Stock, shares authorized	1,000,000	1,000,000
Preferred Stock, shares issued	0	0
Treasury stock, shares	11,671,486	11,671,486
Class B Common Stock [Member]
Common Stock, votes per share | Vote	10	10
Common Stock, par value | $ / shares	$ 0.01	$ 0.01
Common Stock, shares authorized	14,000,000	14,000,000
Common Stock, shares issued	11,758,218	11,758,218
Common Stock, shares outstanding	11,758,218	11,758,218
Common Stock [Member]
Common Stock, votes per share | Vote	1	1
Common Stock, par value | $ / shares	$ 0.01	$ 0.01
Common Stock, shares authorized	62,000,000	62,000,000
Common Stock, shares issued	38,922,489	38,705,564
Common Stock, shares outstanding	27,251,003	27,034,078