Income Taxes - Carryforwards (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2021
Operating Loss Carryforwards
Net operating loss carryforwards with no expiration date			$ 293.8
Foreign pre-tax loss	$ 0.0	$ 0.0
Federal
Operating Loss Carryforwards
Net operating loss carryforwards			622.4
Federal | R&D credit
Operating Loss Carryforwards
Net operating loss carryforwards			37.6
State
Operating Loss Carryforwards
Net operating loss carryforwards			812.2
State | R&D credit
Operating Loss Carryforwards
Net operating loss carryforwards			$ 13.1
Australian Subsidiary
Operating Loss Carryforwards
Foreign Net Operating Loss written off		$ 14.9