Fair Value of Financial Instruments - Fair Value of Financial Instruments (Detail) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021	Nov. 30, 2021
MidCap Credit Facility
Financial liabilities:
Financial liabilities fair value	$ 41.3	$ 40.8
Fair Value, Inputs, Level 3
Financial liabilities:
Financial liabilities fair value			$ 110.7
Carrying Value | MidCap Credit Facility
Financial liabilities:
Financial liabilities fair value	39.0	38.8
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3 | MidCap Credit Facility
Financial liabilities:
Financial liabilities fair value	41.3	40.8
Senior Convertible Notes
Financial liabilities:
Financial liabilities fair value	223.5	237.5
Senior Convertible Notes | Carrying Value
Financial liabilities:
Financial liabilities fair value	224.7	223.9
Senior Convertible Notes | Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3
Financial liabilities:
Financial liabilities fair value	223.5	237.5
Mann Group Convertible Note
Financial liabilities:
Financial liabilities fair value	15.8	37.8
Mann Group Convertible Note | Carrying Value
Financial liabilities:
Financial liabilities fair value	8.8	18.4
Mann Group Convertible Note | Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3
Financial liabilities:
Financial liabilities fair value	15.8	37.8
Milestone Rights Liability
Financial liabilities:
Financial liabilities fair value	13.2	18.1
Milestone Rights Liability | Carrying Value
Financial liabilities:
Financial liabilities fair value	5.9	5.9
Milestone Rights Liability | Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3
Financial liabilities:
Financial liabilities fair value	$ 13.2	$ 18.1