New Accounting Standards (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2021	[1]	Dec. 31, 2020	[1]	Dec. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Shareholders' deficit	$ 854.7		$ 867.2		$ 983.8	$ 896.8
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Shareholders' deficit	$ 404.2		$ 360.5		(2,138.9)	$ (2,234.3)
Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Shareholders' deficit					2.0
Cumulative Effect, Period of Adoption, Adjustment | Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Shareholders' deficit					2.0
Cumulative Effect, Period of Adoption, Adjustment | Retained Earnings | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Shareholders' deficit					$ 2.0

[1] The number of shares of Common Stock (par value $0.01 per share) outstanding at December 31, 2021 and 2020 was 101.34.