Stock Benefit Plans and Equity Transactions - Summary of Outstanding Warrants (Details)	Sep. 30, 2018 $ / shares shares
Class Of Warrant Or Right [Line Items]
Number of Warrants	20,931,515
2017 Common Stock Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	3,757,000
Exercise price of warrants per share | $ / shares	$ 2.00
2017 Banker Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	167,418
Exercise price of warrants per share | $ / shares	$ 2.50
2018 Common Stock Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	13,471,851
Exercise price of warrants per share | $ / shares	$ 3.50
Merger Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	2,200,000
Exercise price of warrants per share | $ / shares	$ 3.50
Executive Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	1,327,434
Exercise price of warrants per share | $ / shares	$ 5.00
Other Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	7,812
Exercise price of warrants per share | $ / shares	$ 19.20