Fair Value Measurements - Fair Value of Investment Assets (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial Paper	$ 155	$ 164
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at amortized cost	162	156
Level 1 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial Paper	87	75
Level 1 | Fair Value | Fixed Income Mutual Funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial Paper	87	75
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	68	89
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	63
Level 2 | Fair Value | Government Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial Paper	19	26
Total | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial Paper	155	164
Total | Fair Value | Fixed Income Mutual Funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial Paper	87	75
Total | Fair Value | Corporate Bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial Paper	49	63
Total | Fair Value | Government Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial Paper	$ 19	$ 26