Net Loss Per Share Attributable to Common Stockholders (Tables)

12 Months Ended

Dec. 31, 2018

Earnings Per Share [Abstract]

Computation of basic and diluted net loss per share

The following table sets forth the computation of basic and diluted net loss per share attributable to common stockholders:

	Year Ended December 31,
(in thousands, except per share data)	2018			2017			2016
Net loss attributable to common stockholders	$	(73,955	)	$	(41,785	)	$	(37,971	)
Weighted-average shares used to compute net loss per share attributable to common stockholders, basic and diluted	53,669			22,211			20,974
Net loss per share attributable to common stockholders, basic and diluted	$	(1.38	)	$	(1.88	)	$	(1.81	)

Potentially dilutive securities

The following potentially dilutive securities have been excluded from the diluted per share calculations because they would have been antidilutive:

	Year Ended December 31,
(in thousands)	2018	2017	2016
Stock options	19,219	14,573	9,336
Restricted stock units	1,129	—	—
Restricted shares	890	1,583	—
Shares to be issued under ESPP	320	—	—
Redeemable convertible preferred stock	—	55,386	55,386
Total	21,558	71,542	64,722