Net loss per share (Tables)

9 Months Ended

Sep. 30, 2015

Earnings Per Share [Abstract]

Schedule of Computation of Basic and Diluted Net Loss Per Share

The detail of the computation of basic and diluted net loss per share is as follows:

	THREE MONTHS ENDED SEPTEMBER 30,						NINE MONTHS ENDED SEPTEMBER 30,
	2015			2014			2015			2014
Numerator
Net loss	$	(5,035	)	$	(6,284	)	$	(16,197	)	$	(15,937	)
Accretion for liquidation preference on preferred stock		—			—			—			(1,133	)
Accretion for share issuance costs on preferred stock		—			—			—			(20	)
Tax expense on preferred stock		—			—			—			(100	)
Reversal of tax payable on preferred stock due to conversion of preferred stock		—			—			—			1,898
Extinguishment of remaining share issuance costs due to conversion of preferred stock		—			—			—			(439	)
Total loss attributable to common stockholders	$	(5,035	)	$	(6,284	)	$	(16,197	)	$	(15,731	)
Denominator
Weighted average shares used to compute basic and diluted net loss per common share		11,841,147			10,695,042			11,096,369			7,984,052
Net loss per share attributable to common stockholders – basic and diluted	$	(0.43	)	$	(0.59	)	$	(1.46	)	$	(1.97	)

Schedule of Antidilutive Securities Excluded from Computation of Basic and Diluted Net Loss Per Share

The following have been excluded from the computation of basic and diluted net loss per share as their effect would have been antidilutive:

	THREE MONTHS ENDED SEPTEMBER 30,				NINE MONTHS ENDED SEPTEMBER 30,
	2015		2014		2015		2014
Outstanding stock options		858,957		813,358		858,957		813,358
Common stock warrants		11,363		11,363		11,363		11,363
		870,320		824,721		870,320		824,7212