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Investments in Marketable Securities - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Marketable Securities [Line Items]
Net unrealized gain (loss)	$ 2.0	$ (2.1)	$ 3.5	$ 1.3
Proceeds from maturity of AFS securities	100.0	178.4	825.2	280.1
Purchase of available-for-sale securities	0.0	245.3	413.9	420.3
Debt securities, net unrealized gain	0.8	$ 0.0	1.4	$ 0.0
Variable Interest Entity, Primary Beneficiary
Marketable Securities [Line Items]
Fair value of deconsolidated investment in affiliate, equity securities	$ 11.9		$ 11.9		$ 15.8

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Equity Securities, Fair Value, Consolidation

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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

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Amount of unrealized gain (loss) on 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 220
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Amount of cash outflow to acquire investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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