Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

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Income Taxes (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
Unrecognized tax benefits (less than)	$ 0.1	$ 0.1
Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards		160.9
State
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards		347.1
R&D credit
Operating Loss Carryforwards [Line Items]
Credit carryforwards		$ 2.5