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Basis of Presentation - Narrative (Details) |  | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
Jul. 01, 2022 USD ($) | Sep. 30, 2022 USD ($) | Sep. 30, 2023 USD ($) partnership | Sep. 30, 2022 USD ($) | Dec. 31, 2018 partnership
Variable Interest Entity [Line Items] |  |  |  |  |
Number of partnerships consolidated | partnership |  |  | 2 |  | 2
Amortization of intangible assets |  |  | $ 9,000,000 | $ 11,000,000 |
Riverbend Funding, LLC |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |
Intangibles acquired | $ 95,000,000 |  |  |  |
Goodwill acquired during the period |  | $ 23,000,000 |  |  |
Change in amount of contingent consideration liability | $ 0 |  |  |  |
Contingent liability |  |  | $ 0 |  |
Variable Interest Entity, Primary Beneficiary |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |
Number of partnerships consolidated | partnership |  |  | 2 |  |
VIE, ownership interest rate (as a percent) |  |  | 80.00% |  |

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