Net loss per share (Tables)

12 Months Ended

Dec. 31, 2014

Earnings Per Share [Abstract]

Schedule of Computation of Basic and Diluted Earnings Per Share

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

	DECEMBER 31, 2014			DECEMBER 31, 2013			DECEMBER 31, 2012
Numerator
Net loss	$	(24,027,016	)	$	(8,729,371	)	$	(7,714,198	)
Accretion for liquidation preference on preferred stock		(1,132,893	)		(5,351,459	)		(3,860,140	)
Accretion for share issuance costs on preferred stock		(19,551	)		(123,074	)		(168,702	)
Tax expense on preferred stock		(100,291	)		(737,925	)		(394,908	)
Reversal of tax payable on preferred stock due to conversion of preferred stock		1,897,702			—			—
Extinguishment of remaining share issuance costs due to conversion of preferred stock		(439,227	)		—			—
Total loss attributable to common stockholders	$	(23,821,276	)	$	(14,941,829	)	$	(12,137,948	)
Denominator
Weighted average shares used to compute basic and diluted net loss per common share		8,667,387			301,745			301,745
Net loss per share attributable to common stockholders – basic and diluted	$	(2.75	)	$	(49.52	)	$	(40.23	)

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:

	DECEMBER 31, 2014		DECEMBER 31, 2013		DECEMBER 31, 2012
Convertible preferred stock		—		5,543,515		3,821,305
Outstanding stock options		824,608		628,754		551,584
Common stock warrants		11,363		11,363		—
Total		835,971		6,183,632		4,372,889