Accumulated Other Comprehensive Income (Loss) Reclassification Adjustments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Interest Expense	$ 51.3	$ 144.3	$ 149.7	$ 240.6
Total reclassifications for the period	2.2	1.7	5.2	16.1
Reclassification out of Accumulated Other Comprehensive Income [Member]
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	2.6	2.1	6.4	11.2
Accumulated Net Gain (Loss) from Interest Rate Hedge [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Interest Expense	$ 0.4	$ 0.4	$ 1.2	$ (4.9)