Accrued expenses and other current liabilities - Narrative (Details)	1 Months Ended	3 Months Ended	6 Months Ended	13 Months Ended
	Jun. 30, 2018	Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($) employee
Restructuring Cost and Reserve [Line Items]
Restructuring charges (credit)		$ 0	$ (11,000)	$ 1,765,000
Number of retained employees | employee				7
One-time termination benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges (credit)			3,000	$ 97,000
Termination and retention benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges (credit)				1,355,000
Ongoing termination benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges (credit)			8,000	1,029,000
Employee retention benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges (credit)				214,000
Other
Restructuring Cost and Reserve [Line Items]
Restructuring charges (credit)				15,000
Research and development
Restructuring Cost and Reserve [Line Items]
Restructuring charges (credit)			(11,000)	957,000
Selling, general and administrative
Restructuring Cost and Reserve [Line Items]
Restructuring charges (credit)				808,000
Consumer Operations
Restructuring Cost and Reserve [Line Items]
Restructuring charges (credit)				94,000
Drug Development
Restructuring Cost and Reserve [Line Items]
Restructuring charges (credit)			(11,000)	957,000
Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring charges (credit)				714,000
Minimum
Restructuring Cost and Reserve [Line Items]
Restructuring charges (credit)				1,765,000
Maximum
Restructuring Cost and Reserve [Line Items]
Restructuring charges (credit)				3,343,000
Maximum | Consumer Operations
Restructuring Cost and Reserve [Line Items]
Restructuring charges (credit)				114,000
Maximum | Drug Development
Restructuring Cost and Reserve [Line Items]
Restructuring charges (credit)				1,024,000
Maximum | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring charges (credit)				2,205,000
Corporate restructuring plan, cost structure reduction
Restructuring Cost and Reserve [Line Items]
Percentage decrease in company workforce	60.00%
Retention bonus costs				51,000
Severance costs				889,000
Corporate restructuring plan, retention and severance increases
Restructuring Cost and Reserve [Line Items]
Retention bonus costs				214,000
Severance costs				185,000
Annual bonus cost				410,000
Cash retention bonuses payable		603,000	603,000	603,000
Severance benefits payable upon change in control and termination without cause		$ 928,000	$ 928,000	$ 928,000