CONDENSED CONSOLIDATED BALANCE SHEETS (Parentheticals) (USD $)	Jun. 30, 2011	Dec. 31, 2010
Statement Of Financial Position [Abstract]
Allowances on accounts receivable (in dollars)	$ 1,692,826	$ 3,242,458
Accumulated depreciation on Property and equipment (in dollars)	$ 21,489,285	$ 19,468,420
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized	2,000,000	2,000,000
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issused	54,699,671	54,147,234
Common stock, shares outstanding	46,694,436	46,141,999
Common Stock held in treasury, shares	8,005,235	8,005,235