Debt and Credit Arrangements Interest Expense, Net (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Debt Instrument
Interest expense, debt	$ 48.2
Interest expense, net	25.5	$ 3.2
Revolving Credit Facility
Debt Instrument
Interest expense, debt	8.1	3.3
Senior Secured And Unsecured Notes
Debt Instrument
Interest income	20.1
Senior Secured Notes Due 2030 | Secured Debt
Debt Instrument
Interest expense, debt	27.4
Senior Unsecured Notes Due 2031 | Unsecured Debt
Debt Instrument
Interest expense, debt	12.1
Term Loan Due 2030 | Revolving Credit Facility
Debt Instrument
Interest expense, debt	5.5	0.0
Convertible Notes, due 2024 | Convertible Debt
Debt Instrument
Interest expense, net	0.6	0.6
Senior secured revolving credit facility due October 2026 | Revolving Credit Facility
Debt Instrument
Interest expense, debt	$ 2.6	$ 3.3