Basis of presentation and significant accounting policies (Tables)

6 Months Ended

Jun. 30, 2017

Accounting Policies [Abstract]

Schedule of amounts excluded from the calculation of diluted net loss per share

The amounts in the table below were excluded from the calculation of diluted net loss per share due to their anti-dilutive effect (in thousands):

	As of June 30,
	2017	2016
Outstanding stock options and restricted stock units	7,469	5,598