Revenues, Significant Customers and Concentrations of Risk - Summary of Significant Customers from which the Company Derived 10% or More of Total Revenue (Detail) - Customer Concentration Risk - Revenue from Contract with Customer Benchmark	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Teva
Concentration Risk [Line Items]
Total revenue by customer, percentage	42.00%	40.00%	41.00%
McKesson
Concentration Risk [Line Items]
Total revenue by customer, percentage	13.00%	12.00%	10.00%
AmerisourceBergen Corporation
Concentration Risk [Line Items]
Total revenue by customer, percentage	12.00%	12.00%
Cardinal Health
Concentration Risk [Line Items]
Total revenue by customer, percentage	11.00%	11.00%
Covis
Concentration Risk [Line Items]
Total revenue by customer, percentage			20.00%