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Fair Value Measurements - Fair Value of Investment Assets (Details) - USD ($) $ in Millions | Sep. 30, 2023 | Dec. 31, 2022
--- | --- | ---
Fair Value |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Commercial Paper | $ 141 | $ 196
Carrying Value |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total investments at amortized cost | 147 | 201
Level 1 | Fair Value |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Commercial Paper | 78 | 89
Level 1 | Fair Value | Fixed Income Mutual Funds |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Commercial Paper | 78 | 89
Level 1 | Fair Value | Corporate Bonds |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Commercial Paper | 0 | 0
Level 1 | Fair Value | Government Securities |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Commercial Paper | 0 | 0
Level 2 | Fair Value |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Commercial Paper | 63 | 107
Level 2 | Fair Value | Fixed Income Mutual Funds |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Commercial Paper | 0 | 0
Level 2 | Fair Value | Corporate Bonds |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Commercial Paper | 47 | 49
Level 2 | Fair Value | Government Securities |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Commercial Paper | 16 | 58
Total | Fair Value |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Commercial Paper | 141 | 196
Total | Fair Value | Fixed Income Mutual Funds |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Commercial Paper | 78 | 89
Total | Fair Value | Corporate Bonds |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Commercial Paper | 47 | 49
Total | Fair Value | Government Securities |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Commercial Paper | $ 16 | $ 58

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