Capital Structure - Warrants (Details) - Common Stock	Mar. 31, 2019 $ / shares shares
Common stock warrants, expiration date of October 2020
Common Stock Warrants
Number of shares available under warrant (in shares)	22,328
Exercise price per share (in dollars per share) \| $ / shares	$ 8.40
Common stock warrants, expiration date of May 2022
Common Stock Warrants
Number of shares available under warrant (in shares)	2,380
Exercise price per share (in dollars per share) \| $ / shares	$ 8.68
Common stock warrants, expiration date June 2024
Common Stock Warrants
Number of shares available under warrant (in shares)	4,000,000
Exercise price per share (in dollars per share) \| $ / shares	$ 12.50
Warrants on common stock
Common Stock Warrants
Number of shares available under warrant (in shares)	4,024,708