Co-Promotion Agreement - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2018	Dec. 31, 2019
Co Promotion Agreement [Line Items]
Accrued expenses and other current liabilities	$ 170,731		$ 139,826
Co-Promotion Agreement | Kowa Pharmaceuticals America, Inc.
Co Promotion Agreement [Line Items]
Agreement amended date	Jul. 25, 2017
Promotion fee as a percentage of gross margin		18.50%
Maximum co-promotion tail payments receive period	3 years
Co-promotion tail payments receivable		$ 17,800
Accrued co- promotion tail payments		$ 16,600
Accrued expenses and other liabilities	$ 7,700		10,000
Accrued expenses and other current liabilities	$ 5,300		$ 6,500