Income Taxes - NOLs (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Income Taxes
Net operating losses subject to Section 382 and other restrictions	$ 652.6
Federal
Income Taxes
Net operating loss carryforwards	850.0
Net operating loss carryforward, Indefinite lived	197.4
Net operating loss carryforward subject to expiration	652.6
State
Income Taxes
Net operating loss carryforwards	931.0
Net operating loss carryforward, Indefinite lived	158.4
Net operating loss carryforward subject to expiration	772.6
Net operating loss carryforward subject to utilization limitations due to ownership change	$ 646.0