Consolidated Balance Sheets (Parenthetical) $ in Thousands	Dec. 31, 2021 USD ($) Vote $ / shares shares	Dec. 31, 2020 USD ($) Vote $ / shares shares
Accounts receivable, allowance | $	$ 82	$ 82
Treasury stock, shares	11,634,806	11,634,806
Class B Common Stock [Member]
Common Stock, votes per share | Vote	10	10
Common Stock, par value | $ / shares	$ 1	$ 1
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	$ 1	$ 1
Common Stock, shares authorized	62,000,000	62,000,000
Common Stock, shares issued	43,789,528	43,204,671
Common Stock, shares outstanding	32,154,722	31,569,865