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Fair Value Measurements (Details) - USD ($) $ in Millions | Mar. 31, 2024 | Dec. 31, 2023
--- | --- | ---
6.7% Senior Notes |  |
Financial Instruments |  |
Interest rate | 6.70% |
Institutional and Other | Minimum |  |
Financial Instruments |  |
Interest rate | 6.68% | 6.48%
Institutional and Other | Maximum |  |
Financial Instruments |  |
Interest rate | 7.93% | 7.96%
Book Value | Retail |  |
Financial Instruments |  |
Long-term debt | $ 1,500 | $ 1,500
Book Value | Institutional |  |
Financial Instruments |  |
Long-term debt | 536 | 536
Book Value | Other |  |
Financial Instruments |  |
Long-term debt | 1,048 | 1,063
Fair Value | Level 2 | Retail |  |
Financial Instruments |  |
Long-term debt | 1,109 | 1,097
Fair Value | Level 2 | Institutional |  |
Financial Instruments |  |
Long-term debt | 435 | 451
Fair Value | Level 2 | Other |  |
Financial Instruments |  |
Long-term debt | $ 1,048 | $ 1,063

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