Shareholders' Equity (Schedule of Accumulated Other Comprehensive (Loss) Activity) (Parenthetical) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Accumulated Other Comprehensive Income Loss [Line Items]
Other comprehensive income (loss) before reclassifications, tax benefit (expense)	$ (1.7)	$ 1.1
Derivative Gain (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Other comprehensive income (loss) before reclassifications, tax benefit (expense)	$ (1.7)	4.0
Pension And Postretirement Adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Other comprehensive income (loss) before reclassifications, tax benefit (expense)		$ (2.9)