Common stock - Subscription Agreement (Details) $ / shares in Units, $ in Thousands		3 Months Ended
	Jan. 20, 2017 USD ($) $ / shares shares	Mar. 31, 2018 USD ($) item
Merger with Macrocure
Number of votes each common share is entitled to | item		1
Dividend declared		$ 0
HCV IX | Subscription Agreement
Merger with Macrocure
Issuance of stock (in shares) | shares	1,010,225
Purchase price	$ 10,000
Price per share (in dollars per share) | $ / shares	$ 9.90