Derivatives - Notional and Fair Value Amounts of Derivative Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Derivative
Notional Amount	$ 305.7	$ 287.1
Fair Value	10.7	16.8
Bank of America, N.A.
Derivative
Notional Amount	193.0	205.2
Fair Value	6.3	14.0
Barclays Bank PLC
Derivative
Notional Amount	98.7	81.9
Fair Value	4.1	2.8
Citigroup Inc.
Derivative
Notional Amount	0.0	0.0
Fair Value	0.0	0.0
Credit Suisse International
Derivative
Notional Amount	14.0	0.0
Fair Value	0.3	0.0
Societe Generale
Derivative
Notional Amount	0.0	0.0
Fair Value	$ 0.0	$ 0.0

Fair value, after the effects of master netting arrangements, of a financial asset or other 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 assets not subject to a master netting arrangement and not elected to be offset.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226052-175313

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=123594938&loc=d3e13433-108611

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant