Basis of Presentation Income Tax (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Federal Statutory Income Tax Rate, Percent						21.00%	35.00%
Proceeds from Income Tax Refunds	$ 170.7				$ 73.9
Income tax receivable	81.0		$ 81.0
Proceeds from Interest on AMT Credit Refunds	$ 5.6
Effective Income Tax Rate, Percent	52.90%	24.70%	46.50%	130.80%
Other Current Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Income tax receivable	$ 50.1		$ 50.1
Other Noncurrent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Income tax receivable	$ 30.9		$ 30.9