Shareholders' Equity (Schedule of Accumulated Other Comprehensive (Loss) Activity) (Parenthetical) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Accumulated Other Comprehensive Income Loss [Line Items]
Other comprehensive income (loss) before reclassifications, tax (benefit) expense	$ (0.5)	$ 3.8
Derivative Gain (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Other comprehensive income (loss) before reclassifications, tax (benefit) expense	2.5	5.2
Pension And Postretirement Adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Other comprehensive income (loss) before reclassifications, tax (benefit) expense	$ (3.0)	$ (1.4)