Indebtedness (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Feb. 28, 2021	Mar. 31, 2022	Mar. 31, 2021
Debt Instrument [Line Items]
Repayments of Senior Debt	$ 151.8
Interest Expense		$ 66.1	$ 64.7
5.200% Senior Notes due 2045
Debt Instrument [Line Items]
Repayments of Senior Debt	12.1
Debt Instrument, Redemption, Amount	8.9
Long Term Debt, Exchanged, Amount	624.6
Gain (Loss) on Extinguishment of Debt		3.2
Repayments of borrowings and premiums paid on debt exchange		13.8
Interest Expense		$ 6.1
3.250% Senior Notes, Due February 15, 2051
Debt Instrument [Line Items]
Long Term Debt, Exchanged, Amount	$ 700.7