Consolidated Balance Sheets Parentheticals (USD $)
Mar. 31, 2013
Dec. 31, 2012
Current assets:    
Allowance for doubtful accounts $ 2,722,436 $ 2,745,419
Customer relationships and other intangible assets, accumulated amortization $ 9,347,494 $ 8,749,057
Stockholders' equity:    
Common stock, par value $ 0.0001 $ 0.0001
Common stock, shares authorized 100,000,000 100,000,000
Common stock, shares issued 22,843,739 22,694,836
Common stock, shares oustanding 22,843,739 22,694,836