Basic and Diluted Net Loss per Share (Tables)

12 Months Ended

Dec. 31, 2016

Earnings Per Share [Abstract]

Summary of Potential Common Shares

Potential common shares not included in calculating diluted net loss per share are as follows:

	December 31,
	2016		2015		2014
Stock options		12,488,551		8,300,819		5,423,741
Stock warrants		1,426,622		1,426,622		1,313,719
Nonvested restricted stock units		895,328		422,500		140,000
Total		14,810,501		10,149,941		6,877,460