Consolidated Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Allowances on accounts receivable	$ 354,542	$ 260,676
Accumulated depreciation on property and equipment	$ 17,926,959	$ 18,580,547
Series A redeemable convertible preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Series A redeemable convertible preferred stock, shares authorized	2,000,000	2,000,000
Series A redeemable convertible preferred stock, shares issued	900,000	900,000
Series A redeemable convertible preferred stock, shares outstanding	900,000	900,000
Series A redeemable convertible preferred stock, redemption value	$ 9,000,000	$ 9,000,000
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 issued	60,091,560	59,482,989
Common stock, shares outstanding	44,563,490	43,954,919
Common Stock, held in treasury, shares	15,528,070	15,528,070

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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