Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Millions	Oct. 17, 2019	Apr. 26, 2019	Sep. 30, 2019	Apr. 23, 2019	Dec. 31, 2018
Subsequent Event [Line Items]
Common stock, shares issued			70,850,000		62,083,000
Payment of offering costs		$ 0.6
Proceeds from issuance of common stock		$ 108.1
Subsequent Event
Subsequent Event [Line Items]
Payment of offering costs	$ 0.4
Proceeds from issuance of common stock	$ 216.2
Equity offering
Subsequent Event [Line Items]
Common stock, shares issued				5,263,158
Stock issued (in dollars per share)				$ 19
Equity offering | Subsequent Event
Subsequent Event [Line Items]
Common stock, shares issued	5,714,286
Stock issued (in dollars per share)	$ 35
Option for additional shares
Subsequent Event [Line Items]
Common stock, shares issued		789,473
Option for additional shares | Subsequent Event
Subsequent Event [Line Items]
Common stock, shares issued	857,142