Business concentrations - Additional Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($)
Mayne Pharma [Member]
Concentration Risk [Line Items]
Customer license revenue percentage	100.00%
Royalty receivable short term portion	$ 2.0
Royalty receivable long term portion	20.3
Mayne Pharma [Member] | Accrued Expenses and Other Current Liabilities [Member]
Concentration Risk [Line Items]
Prepaid royalties received	$ 1.1
Theramex [Member]
Concentration Risk [Line Items]
Customer license revenue percentage	100.00%
Royalty receivable short term portion	$ 2.0