CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($)	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Total
Balance at Dec. 31, 2015	$ 54,240,247	$ 13,280,920	$ (29,132,390)	$ 38,388,777
Balance (in shares) at Dec. 31, 2015	21,111,585
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 0	1,003,305	0	1,003,305
Issuance of restricted stock	$ 0	0	0	0
Issuance of restricted stock (in shares)	255,800
Stock option exercises	$ 3,569	(1,269)	0	2,300
Stock option exercises (in shares)	2,500
Net loss	$ 0	0	(4,525,761)	(4,525,761)
Balance at Dec. 31, 2016	$ 54,243,816	14,282,956	(33,658,151)	34,868,621
Balance (in shares) at Dec. 31, 2016	21,369,885
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 0	443,482	0	443,482
Issuance of restricted stock	$ 0	0	0	0
Issuance of restricted stock (in shares)	210,217
Net loss	$ 0	0	(453,477)	(453,477)
Balance at Dec. 31, 2017	$ 54,243,816	14,726,438	(34,111,628)	34,858,626
Balance (in shares) at Dec. 31, 2017	21,580,102
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 0	235,633	0	235,633
Issuance of restricted stock	$ 0	0	0	0
Issuance of restricted stock (in shares)	125,071
Net loss	$ 0	0	(1,275,826)	(1,275,826)
Balance at Jun. 30, 2018	$ 54,243,816	$ 14,962,071	$ (35,387,454)	$ 33,818,433
Balance (in shares) at Jun. 30, 2018	21,705,173