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Investment Securities - Investments Held on Deposit or as Collateral (Details) - USD ($) $ in Millions | Jun. 30, 2022 | Dec. 31, 2021
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Debt and Equity Securities, FV-NI [Line Items] |  |
Investments held in trusts | $ 461.5 | $ 479.5
Assets held by insurance regulators | 4.8 | 4.8
Other long-term investments | 1,468.7 | 1,377.8
Lloyd’s trust deposits |  |
Debt and Equity Securities, FV-NI [Line Items] |  |
Other long-term investments | 113.4 | 113.8
Short-term investments | Asset Pledged as Collateral | Citibank LOC Facility |  |
Debt and Equity Securities, FV-NI [Line Items] |  |
Investments pledged as collateral | 49.8 | 50.0
Lloyds Bank |  |
Debt and Equity Securities, FV-NI [Line Items] |  |
Investments held in trusts | 113.4 |
Fair value investments | $ 304.8 | $ 342.8

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- Definition Carrying amount of cash and investment securities on deposit with state regulatory authorities in connection with capital requirements. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 825 -Section 50 -Paragraph 1A -URI https://asc.fasb.org/extlink&oid=123600598&loc=SL75763979-209797 + Details
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- Definition The aggregate fair value as of the balance sheet date of financial instruments and other positions owned by the entity including: (1) mortgages, mortgage-backed and asset backed securities; (2) US government and agency obligations; (3) state and municipal government obligations; (4) other sovereign government debt; (5) corporate obligations; (6) corporate equities; (7) principal investments; (8) derivative contracts; and (9) physical commodities. Includes both pledged and unpledged holdings. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 940 -SubTopic 320 -Section 45 -Paragraph 2 -URI https://asc.fasb.org/extlink&oid=35711157&loc=d3e42546-110969 + Details
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- Definition Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258 + Details
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