Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value On Recurring Basis - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets measured at fair value	$ 1,138	$ 681
Total liabilities measured at fair value	17	5
Liability for Sale of Future Royalties
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total liabilities measured at fair value	17	5
Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets measured at fair value	169	148
U.S. Treasury Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets measured at fair value	314	112
Corporate Securities and Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets measured at fair value	631	421
U.S. Government Agency Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets measured at fair value	20
Certificates of Deposit
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets measured at fair value	4
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets measured at fair value	169	148
Level 1 | Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets measured at fair value	169	148
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets measured at fair value	969	533
Level 2 | U.S. Treasury Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets measured at fair value	314	112
Level 2 | Corporate Securities and Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets measured at fair value	631	421
Level 2 | U.S. Government Agency Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets measured at fair value	20
Level 2 | Certificates of Deposit
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets measured at fair value	4
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total liabilities measured at fair value	17	5
Level 3 | Liability for Sale of Future Royalties
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total liabilities measured at fair value	$ 17	$ 5