Net Loss per Share (Tables)

12 Months Ended

Dec. 31, 2020

Earnings Per Share [Abstract]

Common Stock Excluded from Calculation of Diluted Earnings Per Share

The following common stock equivalents were excluded from the calculation of diluted net loss per share applicable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect:

	Years ended December 31,
	2020	2019	2018
Stock options	6,143,046	6,201,485	5,416,069
Restricted stock units	1,284,378	766,953	532,144
Performance-based stock units	—	72,046	169,031
Employee Stock Purchase Plan shares	46,439	49,418	32,304
Total	7,473,863	7,089,902	6,149,548