Cash, Cash Equivalents, and Marketable Debt Securities - Schedule of Marketable Debt Securities in Continuous Loss Position (Details) $ in Millions	Sep. 30, 2024 USD ($) Security		Dec. 31, 2023 USD ($) Security
Schedule Of Available For Sale Securities [Line Items]
Fair Value of Marketable Debt Securities in a Loss Position Less Than 12 Months	$ 10.3		$ 47.8
Number of Marketable Debt Securities in a Loss Position Less Than 12 Months | Security	15		60
Unrealized Losses Less Than 12 Months	$ 0.0	[1]	$ 0.1
Fair Value of Marketable Debt Securities in a Loss Position 12 Months Or Longer	$ 13.0		$ 43.9
Number of Marketable Debt Securities in a Loss Position 12 Months Or Longer | Security	15		61
Unrealized Losses 12 Months Or Longer	$ 0.0	[1]	$ 0.4
Corporate Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Fair Value of Marketable Debt Securities in a Loss Position Less Than 12 Months	$ 8.3		$ 27.9
Number of Marketable Debt Securities in a Loss Position Less Than 12 Months | Security	12		35
Unrealized Losses Less Than 12 Months	$ 0.0	[1]	$ 0.1
Fair Value of Marketable Debt Securities in a Loss Position 12 Months Or Longer	$ 4.0		$ 36.2
Number of Marketable Debt Securities in a Loss Position 12 Months Or Longer | Security	7		49
Unrealized Losses 12 Months Or Longer	$ 0.0	[1]	$ 0.3
U.S. Treasury Securities
Schedule Of Available For Sale Securities [Line Items]
Fair Value of Marketable Debt Securities in a Loss Position Less Than 12 Months	$ 0.0		$ 11.4
Number of Marketable Debt Securities in a Loss Position Less Than 12 Months | Security	0		11
Unrealized Losses Less Than 12 Months	$ 0.0	[1]	$ 0.0
Fair Value of Marketable Debt Securities in a Loss Position 12 Months Or Longer	$ 9.0		$ 6.2
Number of Marketable Debt Securities in a Loss Position 12 Months Or Longer | Security	8		10
Unrealized Losses 12 Months Or Longer	$ 0.0	[1]	$ 0.1
U.S. Government Agency Securities
Schedule Of Available For Sale Securities [Line Items]
Fair Value of Marketable Debt Securities in a Loss Position Less Than 12 Months	$ 2.0		$ 8.5
Number of Marketable Debt Securities in a Loss Position Less Than 12 Months | Security	3		14
Unrealized Losses Less Than 12 Months	$ 0.0	[1]	$ 0.0
Fair Value of Marketable Debt Securities in a Loss Position 12 Months Or Longer	$ 0.0		$ 1.5
Number of Marketable Debt Securities in a Loss Position 12 Months Or Longer | Security	0		2
Unrealized Losses 12 Months Or Longer	$ 0.0	[1]	$ 0.0

[1] Unrealized losses were insignificant for both debt securities in a continuous loss position less than 12 months and debt securities in a continuous loss position greater than or equal to 12 months for the period ended September 30, 2024.