Quarterly report pursuant to Section 13 or 15(d)

Shareholders' Equity - Summary of Changes in Shareholders' Equity (Detail)

Shareholders' Equity - Summary of Changes in Shareholders' Equity (Detail) - USD ($)			3 Months Ended				6 Months Ended
	May 01, 2019	Feb. 01, 2019	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Shareholders Equity [Line Items]
Beginning Balances			$ 29,123,771	$ 20,881,983	$ 4,315,236	$ 6,316,309	$ 20,881,983	$ 6,316,309
Compensation expense relating to option issuances			164,588	145,829	81,986	118,324
Issuance of common stock - shelf takedown, net of expenses			(65,000)	11,415,676	1,510,327
Issuance of common stock in exchange for services			6,001	6,000
Issuance of restricted common stock					24,320
Net loss			(4,806,460)	(3,325,717)	(2,281,289)	(2,119,397)	(8,132,177)	(4,400,686)
Ending Balances			24,422,900	29,123,771	3,650,580	4,315,236	24,422,900	3,650,580
Common Stock [Member]
Shareholders Equity [Line Items]
Beginning Balances			$ 46,112	$ 29,433	$ 5,187	$ 4,928	$ 29,433	$ 4,928
Beginning Balances, Shares			46,112,303	29,433,135	5,186,635	4,928,335	29,433,135	4,928,335
Issuance of common stock - shelf takedown, net of expenses				$ 16,667	$ 900
Issuance of common stock - shelf takedown, net of expenses, Shares				16,666,668	900,000
Issuance of common stock in exchange for services			$ 13	$ 12
Issuance of common stock in exchange for services, Shares	12,500	12,500	12,500	12,500
Issuance of restricted common stock					$ 16
Issuance of restricted common stock, Shares					16,000
Ending Balances			$ 46,125	$ 46,112	$ 6,103	$ 5,187	$ 46,125	$ 6,103
Ending Balances, Shares			46,124,803	46,112,303	6,102,635	5,186,635	46,124,803	6,102,635
Common Stock [Member] \| Series A Preferred Stock [Member]
Shareholders Equity [Line Items]
Conversion of preferred stock to common stock						$ 259
Conversion of preferred stock to common stock, Shares						258,300
Preferred Stock [Member]
Shareholders Equity [Line Items]
Beginning Balances			$ 6,513,396	$ 6,100,182	$ 6,100,182	$ 6,309,608	$ 6,100,182	$ 6,309,608
Beginning Balances, Shares			16,017,113.941	16,017,101.733	16,017,101.7330	18,600,100.000	16,017,101.733	18,600,100.000
Series C dividend				$ 413,214		$ 58,670
Series C dividend, Shares				12.208		1.733
Ending Balances			$ 6,513,396	$ 6,513,396	$ 6,100,182	$ 6,100,182	$ 6,513,396	$ 6,100,182
Ending Balances, Shares			16,017,113.941	16,017,113.941	16,017,101.733	16,017,101.7330	16,017,113.941	16,017,101.733
Preferred Stock [Member] \| Series A Preferred Stock [Member]
Shareholders Equity [Line Items]
Conversion of preferred stock to common stock						$ (268,096)
Conversion of preferred stock to common stock, Shares						(2,583,000)
Additional Paid In Capital [Member]
Shareholders Equity [Line Items]
Beginning Balances			$ 137,676,802	$ 126,125,976	$ 101,788,731	$ 101,402,570	$ 126,125,976	$ 101,402,570
Compensation expense relating to option issuances			164,588	145,829	81,986	118,324
Issuance of common stock - shelf takedown, net of expenses			(65,000)	11,399,009	1,509,427
Issuance of common stock in exchange for services			5,988	5,988
Issuance of restricted common stock					24,304
Ending Balances			137,782,378	137,676,802	103,404,448	101,788,731	137,782,378	103,404,448
Additional Paid In Capital [Member] \| Series A Preferred Stock [Member]
Shareholders Equity [Line Items]
Conversion of preferred stock to common stock						267,837
Accumulated Deficit [Member]
Shareholders Equity [Line Items]
Beginning Balances			(115,112,539)	(111,373,608)	(103,578,864)	(101,400,797)	(111,373,608)	(101,400,797)
Series C dividend				(413,214)		(58,670)
Net loss			(4,806,460)	(3,325,717)	(2,281,289)	(2,119,397)
Ending Balances			$ (119,918,999)	$ (115,112,539)	$ (105,860,153)	$ (103,578,864)	$ (119,918,999)	$ (105,860,153)