Condensed Consolidated Statements of Stockholders' Equity - USD ($)	Total	Public Offering [Member]	At the Market Offering [Member]	Common Stock [Member]	Common Stock [Member] Public Offering [Member]	Common Stock [Member] At the Market Offering [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] Public Offering [Member]	Additional Paid-in Capital [Member] At the Market Offering [Member]	Accumulated Other Comprehensive Loss [Member]	Accumulated Deficit [Member]
Balance at Dec. 31, 2017	$ 1,400,997			$ 22,653			$ 150,114,671			$ (25,900)	$ (148,710,427)
Balance (in shares) at Dec. 31, 2017				2,265,320
Issuance of units, net of offering costs		$ 10,721,400			$ 30,192			$ 10,691,208
Issuance of units, net of offering costs (in shares)					3,019,230
Issuance of RSUs				$ 54			(54)
Issuance of RSUs (in shares)				5,400
Stock compensation expense	238,190						238,190
Stock cancellation (in shares)				(31)
Foreign currency translation	(12,579)									(12,579)
Net loss	(3,048,084)										(3,048,084)
Balance at Mar. 31, 2018	9,299,924			$ 52,899			161,044,015			(38,479)	(151,758,511)
Balance (in shares) at Mar. 31, 2018				5,289,919
Balance at Dec. 31, 2017	1,400,997			$ 22,653			150,114,671			(25,900)	(148,710,427)
Balance (in shares) at Dec. 31, 2017				2,265,320
Net loss	(6,380,297)
Balance at Jun. 30, 2018	6,398,765			$ 60,670			161,449,185			(20,366)	(155,090,724)
Balance (in shares) at Jun. 30, 2018				6,067,039
Balance at Dec. 31, 2017	1,400,997			$ 22,653			150,114,671			(25,900)	(148,710,427)
Balance (in shares) at Dec. 31, 2017				2,265,320
Balance at Dec. 31, 2018	3,308,741			$ 86,457			165,313,902			(13,093)	(162,078,525)
Balance (in shares) at Dec. 31, 2018				8,645,720
Balance at Mar. 31, 2018	9,299,924			$ 52,899			161,044,015			(38,479)	(151,758,511)
Balance (in shares) at Mar. 31, 2018				5,289,919
Issuance of units, net of offering costs		6,731	$ 192,320		$ 6,731	$ 1,040			$ 191,280
Issuance of units, net of offering costs (in shares)					673,077	104,043
Stock compensation expense	213,890						213,890
Foreign currency translation	18,113									18,113
Net loss	(3,332,213)										(3,332,213)
Balance at Jun. 30, 2018	6,398,765			$ 60,670			161,449,185			(20,366)	(155,090,724)
Balance (in shares) at Jun. 30, 2018				6,067,039
Balance at Dec. 31, 2018	3,308,741			$ 86,457			165,313,902			(13,093)	(162,078,525)
Balance (in shares) at Dec. 31, 2018				8,645,720
Issuance of units, net of offering costs		$ 4,782,509			$ 90,000			$ 4,692,509
Issuance of units, net of offering costs (in shares)					9,000,000
Stock compensation expense	98,033						98,033
Foreign currency translation	2,826									2,826
Net loss	(3,853,116)										(3,853,116)
Balance at Mar. 31, 2019	4,338,993			$ 176,457			170,104,444			(10,267)	(165,931,641)
Balance (in shares) at Mar. 31, 2019				17,645,720
Balance at Dec. 31, 2018	3,308,741			$ 86,457			165,313,902			(13,093)	(162,078,525)
Balance (in shares) at Dec. 31, 2018				8,645,720
Net loss	(6,446,127)
Balance at Jun. 30, 2019	1,827,003			$ 176,457			170,190,415			(15,217)	(168,524,652)
Balance (in shares) at Jun. 30, 2019				17,645,720
Balance at Mar. 31, 2019	4,338,993			$ 176,457			170,104,444			(10,267)	(165,931,641)
Balance (in shares) at Mar. 31, 2019				17,645,720
Stock compensation expense	85,971						85,971
Foreign currency translation	(4,950)									(4,950)
Net loss	(2,593,011)										(2,593,011)
Balance at Jun. 30, 2019	$ 1,827,003			$ 176,457			$ 170,190,415			$ (15,217)	$ (168,524,652)
Balance (in shares) at Jun. 30, 2019				17,645,720