Summary of Significant Accounting Policies - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Accounting Policies [Abstract]
Net income (loss)	$ (1,427,718)	$ (632,205)	$ (3,550,538)	$ 803,025
Cumulative dividend on convertible preferred stock	(357,194)	(357,518)	(710,704)	(711,107)
Net loss attributable to convertible preferred stock				(42,936)
Net income (loss) attributable to common stockholders	$ (1,784,912)	$ (989,723)	$ (4,261,242)	$ 48,982
Shares used for basic EPS-weighted average shares	60,052,673	58,926,545	59,936,606	45,019,358
Restricted stock units				267,936
Warrants				441,438
Weighted average number of common shares and equivalents:	60,052,673	58,926,545	59,936,606	45,728,732
Basic EPS	$ (0.03)	$ (0.02)	$ (0.07)	$ (0.00)
Diluted EPS	$ (0.03)	$ (0.02)	$ (0.07)	$ 0.00