Condensed Consolidated Balance Sheets (Unaudited) (Parentheticals) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Allowance for doubtful accounts (in Dollars)	$ 915	$ 730
Common stock, par value (in Dollars per share)	$ 0	$ 0
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	57,324,919	57,010,878
Treasury stock, shares	4,791,481	4,768,925
Common Class A [Member]
Common stock, par value (in Dollars per share)	$ 0	$ 0
Common stock, shares authorized	15,000,000	15,000,000
Common stock, shares issued	7,567,868	7,331,574
Treasury stock, shares	1,578,554	1,578,554