Other Comprehensive Income (Loss) and Accumulated Other Comprehensive Income - Reclassification out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Impairment Losses	$ (4.0)	$ (12.0)
Income Tax Benefit (Expense)	1.6	(13.7)
Net Income	123.2	64.0
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Net Income	6.8	2.4
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Interest and Other Expenses	(0.1)	(0.1)
Income Tax Benefit (Expense)	0.0	0.0
Net Income	$ (0.1)	$ (0.1)