Fair Value Measurements - Fair Value of Investment Assets (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial Paper	$ 143	$ 196
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at amortized cost	148	201
Level 1 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial Paper	77	89
Level 1 | Fair Value | Fixed Income Mutual Funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial Paper	77	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	66	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	49	49
Level 2 | Fair Value | Government Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial Paper	17	58
Total | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial Paper	143	196
Total | Fair Value | Fixed Income Mutual Funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial Paper	77	89
Total | Fair Value | Corporate Bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial Paper	49	49
Total | Fair Value | Government Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial Paper	$ 17	$ 58