General form of registration statement for all companies including face-amount certificate companies

Stock-based compensation - Common Stock and Receivable from Shareholder - Narrative (Details)

v2.4.0.8
Stock-based compensation - Common Stock and Receivable from Shareholder - Narrative (Details) (USD $)
 0 Months Ended 12 Months Ended 12 Months Ended 0 Months Ended 12 Months Ended
Dec. 07, 2012
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Sep. 30, 2013
Jun. 03, 2010
Dec. 31, 2010
Warrant [Member]
Jun. 13, 2011
Common stock
Dec. 31, 2012
Common stock
Dec. 31, 2011
Common stock
Dec. 31, 2010
Common stock
Class of Stock [Line Items]                      
Shares of common stock issued in private placements                 212,500 1,179,230 465,866
Private placements, price in usd per share                 $ 3.20 $ 2.60 $ 2.60
Net cash proceeds from private placements                 $ 680,000 $ 3,610,993 $ 1,211,249
Redeemable common stock   0 0   0     500,000      
Redeemable common stock, redemption right maximum period               5 years      
Common stock, shares outstanding   13,611,974 13,498,471 12,232,762 13,574,474            
Promissory note to investor   0 345,000     345,000          
Promissory note to investor, interest rate margin on Bank Prime Rate           3.00%          
Promissory note to investor, shares held as collateral           287,500          
Promissory note to investor, repaid with cash 105,000 105,000 0 0              
Options repurchased from consultant, fair value in usd per share 100,000                    
Promissory note to investor, repaid with return of shares, price in usd per share $ 2.40                    
Granted (shares)             118,750        
Proceeds from Warrant Exercises   $ 0 $ 0 $ 142,500     $ 142,500        
Warrant expired             6,250