CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Mar. 31, 2013	Dec. 31, 2012
CONSOLIDATED BALANCE SHEETS
Accounts receivable, allowance (in dollars)	$ 568,429	$ 525,556
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	46,874,484	46,259,009
Common stock, shares outstanding	46,606,703	46,063,822
Treasury stock, shares	267,781	195,187