Summary of Significant Accounting Policies - Prepaids and other current assets and other long-term assets (Details)	9 Months Ended
	Sep. 30, 2018 USD ($)
Deferred costs	$ 1,255,554
Cash and non-cash increase in prepaids and other current assets	1,267,861
Raw materials included in prepaids and other current assets	777,380
Cash and non-cash increase in other long-term assets	501,120
Raw materials included in other long-term assets	289,828
Deferred rent included in other long-term assets	211,292
Office lease extension agreement
Fair market value of the short-term portion of the warrant	$ 225,147