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Fair Value Measurements - Changes in Level 3 Liabilities (Details) - Significant Unobservable Inputs (Level 3) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Contingent Payment Obligations
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	$ 23.4	$ 14.2	$ 21.0	$ 40.3
Purchases and issuances	0.0	0.0	0.0	0.0
Settlements and reductions	0.0	0.0	0.0	0.0
Net realized and unrealized gains	(5.2)	(0.3)	(2.8)	(26.4)
Balance, end of period	18.2	13.9	18.2	13.9
Net change in unrealized (gains) losses relating to instruments still held at the reporting date	(5.2)	(0.3)	(2.8)	(26.4)
Affiliate Equity Purchase Obligations
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	68.4	25.0	24.5	12.6
Purchases and issuances	4.7	6.6	75.7	55.1
Settlements and reductions	(25.4)	(4.8)	(49.7)	(37.0)
Net realized and unrealized gains	(2.5)	(1.4)	(5.3)	(5.3)
Balance, end of period	45.2	25.4	45.2	25.4
Net change in unrealized (gains) losses relating to instruments still held at the reporting date	$ (2.4)	$ (1.5)	$ (4.5)	$ (5.3)

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- Definition

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Purchases And Issuances

+ References

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- Definition

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Settlements And Reductions

+ References

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- Definition

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings and Other Comprehensive Income (Loss)

+ References

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- Definition

Amount of unrealized gain (loss) recognized in income from liability measured at fair value on recurring basis using unobservable input (level 3) and still held.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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- Definition

Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-SubTopic 10
-Topic 820
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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