Offsetting of Assets and Liabilities (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Offsetting Assets and Liabilities [Line Items]
Collateral received	$ 12.1	$ 2.8
Gross amounts not offset in the balance sheet	0.0	0.0
Aggregate fair value of all derivative instruments with credit-risk-related contingent features that are in a liability position	1,590.0	111.5
Collateral deposited with derivative counterparties for derivatives instruments with credit-risk-related contingent features that are in a liability position	1,470.0	84.2
Net maximum amount of termination payments that could have been required	115.4	27.3
Net Investment Hedges
Offsetting Assets and Liabilities [Line Items]
Collateral received	98.0
Gross amounts not offset in the balance sheet	$ 342.1
Cash collateral received from derivative counterparties and not offset against derivative assets		93.5
Cash collateral deposited with derivative counterparties not offset against derivative liabilities		$ 43.4