Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Allowance for accounts receivable	$ 578	$ 577
Accumulated amortization on other intangibles, deferred costs and investments	$ 12,205	$ 11,984
Preferred stock, shares authorized (in shares)	1,500	1,500
Treasury stock, shares (in shares)	1,488	1,491
Common Class A [Member]
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)	6,409	6,369
Common Class B [Member]
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)	816	797
Common Stock, shares outstanding (in shares)	816	797