Condensed Consolidated Balance Sheets (unaudited) (Parentheticals) (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Allowance for doubtful accounts (in Dollars)	$ 187	$ 244
Preferred stock, par value (in Dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares issued	0	0
Common Class A [Member]
Common stock, par value (in Dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	60,000,000	60,000,000
Common stock, shares issued	25,249,029	25,129,776
Common stock, shares outstanding	20,732,784	20,624,976
Treasury stock, shares	4,516,245	4,504,800
Common Class B [Member]
Common stock, par value (in Dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	80,000,000	80,000,000
Common stock, shares issued	4,208,118	4,188,296
Common stock, shares outstanding	3,455,411	3,437,496
Treasury stock, shares	752,707	750,800