Derivative Liability - Additional Information (Detail) - Product Approval Payment Derivative - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Valeant Pharmaceuticals International, Inc.
Settlement And Termination [Line Items]
Nonrecurring milestone payment	$ 4.0
Medicis Pharmaceutical Corporation
Settlement And Termination [Line Items]
Fair value of derivative	$ 3.1	$ 3.0
Measurement Input, Expected Term | Medicis Pharmaceutical Corporation
Settlement And Termination [Line Items]
Fair value, measurement input, duration	4 months 24 days	10 months 24 days
Measurement Input, Entity Credit Risk | Medicis Pharmaceutical Corporation
Settlement And Termination [Line Items]
Fair value, measurement input (percent)	7.50%	7.50%
Measurement Input, Risk Free Interest Rate | Medicis Pharmaceutical Corporation
Settlement And Termination [Line Items]
Fair value, measurement input (percent)	0.20%	1.60%