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Fair Value Measurements - Changes in Level 3 Assets and Liabilities (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018
Contingent Payment Arrangements |  |  |  |  |
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |  |  |  |
Balance, beginning of period |  | $ 0.0 | $ 4.2 | $ 1.9 | $ 9.4
Net realized and unrealized losses | [1] | 0.0 | 0.1 | 0.1 | (0.3)
Purchases and issuances | [2] | 0.0 | 0.0 | 0.0 | 0.0
Settlements and reductions |  | 0.0 | 0.0 | (2.0) | (4.8)
Balance, end of period |  | 0.0 | 4.3 | 0.0 | 4.3
Net change in unrealized losses relating to instruments still held at the reporting date |  | 0.0 | 0.1 | 0.0 | 0.4
Affiliate Equity Repurchase Obligations |  |  |  |  |
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |  |  |  |
Balance, beginning of period |  | 57.4 | 36.9 | 36.2 | 49.2
Net realized and unrealized losses | [1] | 0.7 | 0.0 | 0.6 | 0.0
Purchases and issuances | [2] | 12.1 | 40.1 | 85.1 | 86.0
Settlements and reductions |  | (33.4) | (48.3) | (85.1) | (106.5)
Balance, end of period |  | 36.8 | 28.7 | 36.8 | 28.7
Net change in unrealized losses relating to instruments still held at the reporting date |  | $ 0.0 | $ 0.0 | $ 0.0 | $ 0.0
[1] | Accretion expense for these arrangements is recorded in Interest expense.
[2] | Includes transfers from Redeemable non-controlling interests.

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- Definition Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Purchases And Issuances + References No definition available. + Details
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- Definition Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Settlements And Reductions + References No definition available. + Details
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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 No definition available. + Details
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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 -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
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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. + References No definition available. + Details
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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 -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
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