Income Taxes Amounts and Expiration Dates of Net Operating Loss and Tax Credit Carryforwards (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
Taxable Income Limitation for Net Operating Loss Carryforward		80.00%
Net Operating Loss Subject to Taxable Income Limitation		$ 18.7
State NOL and tax credit carryforwards		121.1
State net operating loss valuation allowance		(101.9)	$ (98.8)
U.S. NOL(1)	[1]	181.3
Total NOL and tax credit carryforwards		306.2
Operating Loss Carryforwards			$ 75.7
State [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards		5,059.8
U.S. (Federal) [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards		863.5
General Business Tax Credit Carryforward [Member]
Operating Loss Carryforwards [Line Items]
Tax Credit Carryforward, Amount		$ 3.8

[1] Federal NOLs created in tax years beginning after December 31, 2017 can be carried forward indefinitely under the Tax Cuts and Jobs Act (limited to 80% of taxable income computed without the NOL deduction). Of the Company's U.S. NOL, $18.7 million has an indefinite carryforward period but its use is limited to 80% of taxable income.