Derivative Financial Instruments (Derivative Instruments Offsetting Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Offsetting Derivative Liabilities [Abstract]
Gross Amount Recognized	$ 190.5	$ 194.0
Gross Amounts Not Offset Permitted Under Master Netting Agreements	(134.0)	(112.5)
Net Amount	$ 56.5	$ 81.5

Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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