Condensed Consolidated Balance Sheets (Parenthetical) (USD $)
In Thousands, except Share data
Jun. 30, 2011
Dec. 31, 2010
Accounts receivable, allowance for doubtful accounts $ 489 $ 356
Preferred stock, no par value    
Preferred stock, shares authorized 3,000 3,000
Preferred stock, shares issued 0 0
Treasury stock, shares 1,562 1,241
Class A Common Stock [Member]
   
Common stock, no par value    
Common stock, shares authorized 30,000 30,000
Common stock, shares issued 16,671 16,363
Common stock, shares outstanding 15,064 15,122
Class B Common Stock [Member]
   
Common stock, no par value    
Common stock, shares authorized 5,000 5,000
Common stock, shares issued 0 0