Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Allowance for accounts receivable	$ 618	$ 519
Accumulated amortization on other intangibles, deferred costs and investments	$ 15,984	$ 15,944
Preferred stock, shares authorized (in shares)	1,500	1,500
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Treasury stock, shares (in shares)	1,754	1,753
Class A Common Stock
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	35,000	35,000
Common stock, shares issued (in shares)	8,007	7,867
Class B Common Stock
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	3,500	3,500
Common stock, shares issued (in shares)	0	0