Stock Benefit Plans and Equity Transactions - Summary of Outstanding Warrants (Details)	Jun. 30, 2019 $ / shares shares
Class Of Warrant Or Right [Line Items]
Number of Warrants	26,885,361
2017 Common Stock Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	3,657,000
Strike Price | $ / shares	$ 2.00
2017 Banker Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	148,554
Strike Price | $ / shares	$ 2.50
2018 Common Stock Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	13,860,851
Strike Price | $ / shares	$ 3.50
Merger Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	2,200,000
Strike Price | $ / shares	$ 3.50
Executive Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	1,327,434
Strike Price | $ / shares	$ 5.00
Squadron Capital Warrant Exercise Price at $3.15
Class Of Warrant Or Right [Line Items]
Number of Warrants	845,000
Strike Price | $ / shares	$ 3.15
Squadron Capital Warrant Exercise Price at $2.17
Class Of Warrant Or Right [Line Items]
Number of Warrants	4,838,710
Strike Price | $ / shares	$ 2.17
Other Warrants
Class Of Warrant Or Right [Line Items]
Number of Warrants	7,812
Strike Price | $ / shares	$ 19.20