Fair Value of Financial Instruments - Fair Value of Financial Instruments (Parenthetical) (Detail) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)
Senior Convertible Notes
Fair Value Of Financial Instruments [Line Items]
Note payable, percentage of hypothetical yield	7.5	7.5
Note payable, percentage of interest rate increases (decreases)	2.00%	2.00%
Senior Convertible Notes | Volatility
Fair Value Of Financial Instruments [Line Items]
Note payable, fair value key inputs	37.6	49.5
Senior Convertible Notes | Minimum
Fair Value Of Financial Instruments [Line Items]
Financial liabilities fair value	$ 38.8	$ 46.2
Senior Convertible Notes | Maximum
Fair Value Of Financial Instruments [Line Items]
Financial liabilities fair value	$ 40.0	$ 47.6
Milestone Rights | Risk-Free Rate
Fair Value Of Financial Instruments [Line Items]
Note payable, fair value key inputs	4.1	4.5
Milestone Rights | Dividend Yield
Fair Value Of Financial Instruments [Line Items]
Note payable, fair value key inputs	0	0
Milestone Rights | Volatility
Fair Value Of Financial Instruments [Line Items]
Note payable, fair value key inputs	45	45
Milestone Rights | Period
Fair Value Of Financial Instruments [Line Items]
Note payable, fair value key inputs	6.75	7
Milestone Rights | Credit Risk
Fair Value Of Financial Instruments [Line Items]
Note payable, fair value key inputs	11	11
Financing Liability
Fair Value Of Financial Instruments [Line Items]
Note payable, percentage of hypothetical yield	8	8
Note payable, percentage of interest rate increases (decreases)	2.00%	2.00%
Financing Liability | Minimum
Fair Value Of Financial Instruments [Line Items]
Financial liabilities fair value	$ 103.0	$ 103.1
Financing Liability | Maximum
Fair Value Of Financial Instruments [Line Items]
Financial liabilities fair value	$ 134.5	$ 135.2
Liability for Sale of Future Royalties
Fair Value Of Financial Instruments [Line Items]
Note payable, percentage of hypothetical yield	9	9
Note payable, percentage of interest rate increases (decreases)	2.00%	2.00%
Liability for Sale of Future Royalties | Minimum
Fair Value Of Financial Instruments [Line Items]
Financial liabilities fair value	$ 138.9	$ 137.9
Liability for Sale of Future Royalties | Maximum
Fair Value Of Financial Instruments [Line Items]
Financial liabilities fair value	$ 180.4	$ 180.0