Capital Stock - Stock Offerings (Details) - USD ($) $ / shares in Units, $ in Millions	Jun. 26, 2020	Jan. 09, 2020	Apr. 22, 2019
Capital Stock
Net proceeds	$ 90.2
IPO
Capital Stock
Issuance of common stock in stock offering, net of offering costs (in shares)			6,468,750
Share price (in dollars per share)			$ 15.00
Net proceeds			$ 87.4
Secondary Offering
Capital Stock
Issuance of common stock in stock offering, net of offering costs (in shares)	1,150,000
Share price (in dollars per share)	$ 82.00	$ 49.00
Net proceeds		$ 35.5
Selling stockholders
Capital Stock
Issuance of common stock in stock offering, net of offering costs (in shares)		5,000,000
Underwriter option
Capital Stock
Issuance of common stock in stock offering, net of offering costs (in shares)		750,000