Fair Value of Financial Instruments - Fair Value of Financial Instruments (Detail) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Carrying Amount | MidCap Credit Facility
Financial liabilities:
Total financial liabilities fair value		$ 33.0
Carrying Amount | Senior Convertible Notes
Financial liabilities:
Total financial liabilities fair value	$ 36.1	226.9
Carrying Amount | Mann Group Convertible Note
Financial liabilities:
Total financial liabilities fair value		8.8
Carrying Amount | Milestone Rights
Financial liabilities:
Total financial liabilities fair value	3.2	3.9
Carrying Amount | Contingent Milestone Liability
Financial liabilities:
Total financial liabilities fair value		0.3
Carrying Amount | Financing Liability
Financial liabilities:
Total financial liabilities fair value	103.9	104.1
Carrying Amount | Liability for Sale of Future Royalties
Financial liabilities:
Total financial liabilities fair value	149.6
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3 | MidCap Credit Facility
Financial liabilities:
Total financial liabilities fair value		35.5
Estimate of Fair Value Measurement | Senior Convertible Notes | Fair Value, Inputs, Level 3
Financial liabilities:
Total financial liabilities fair value	46.9	231.3
Estimate of Fair Value Measurement | Mann Group Convertible Note | Fair Value, Inputs, Level 3
Financial liabilities:
Total financial liabilities fair value		14.4
Estimate of Fair Value Measurement | Milestone Rights | Fair Value, Inputs, Level 3
Financial liabilities:
Total financial liabilities fair value	19.2	11.9
Estimate of Fair Value Measurement | Contingent Milestone Liability | Fair Value, Inputs, Level 3
Financial liabilities:
Total financial liabilities fair value		0.3
Estimate of Fair Value Measurement | Financing Liability | Fair Value, Inputs, Level 3
Financial liabilities:
Total financial liabilities fair value	117.4	$ 106.8
Estimate of Fair Value Measurement | Liability for Sale of Future Royalties | Fair Value, Inputs, Level 3
Financial liabilities:
Total financial liabilities fair value	$ 156.7