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Investments in Marketable Securities - Additional Information (Details) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2023 | Dec. 31, 2022
Investments in and Advances to Affiliates [Line Items] |  |
Equity securities, FV-NI | $ 37.9 | $ 447.9
Unrealized gains on equity securities | 2.9 | 35.5
Proceeds from maturity of AFS securities | 511.1 | 0.0
Debt securities net unrealized (loss) gain | 0.8 | (2.2)
Variable Interest Entity, Primary Beneficiary |  |
Investments in and Advances to Affiliates [Line Items] |  |
Equity securities, FV-NI | $ 15.8 | 23.5
EQT AB (“EQT”) |  |
Investments in and Advances to Affiliates [Line Items] |  |
Equity securities, FV-NI |  | $ 405.1

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- Definition Amount of unrealized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in net income (trading). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 14 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481800/320-10-50-14 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481800/320-10-50-9 + Details
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- Definition Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(1)(b)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(2)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1A -Publisher FASB -URI https://asc.fasb.org//1943274/2147482736/825-10-45-1A + Details
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