Debt and Warrants - Long-term Debt (Details) - USD ($)						1 Months Ended		4 Months Ended	12 Months Ended
	Aug. 01, 2018	Mar. 23, 2018	Jul. 07, 2017	Apr. 21, 2016	Aug. 31, 2015	Oct. 31, 2017	Aug. 31, 2015	Apr. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Mar. 01, 2016
Long-term debt
Current portion of long-term debt										$ 1,609,244
Interest expense on convertible debt									$ 934,214	634,276
Balloon amount payable on August 1, 2018	$ 600,000
Interest-only payments, term						3 months		4 months
Long Term Debt [Member]
Long-term debt
Interest expense on convertible debt									$ 99,300	526,069
Loan And Security Agreement [Member]
Long-term debt
Debt and unpaid accrued end-of-term payment										1,636,639
Unamortized note discount					$ 134,433		$ 134,433			6,615
Unamortized debt issuance costs										(20,780)
Total										1,609,244
Current portion of long-term debt										$ 1,609,244
Stand-by line of credit					8,000,000		$ 8,000,000
Initial loan commitment					$ 6,000,000
Term of agreement							3 years
Interest rate (as a percent)											9.90%
Effective interest rate					15.00%		15.00%
Repayment of loan from restricted cash				$ 1,500,000
Debt Agreement Third Amendment [Member]
Long-term debt
Repayment of loan from restricted cash			$ 1,000,000
Principal paid		$ 689,345
Interest paid		4,471
Cash proceeds		$ 600,000