Basic and Diluted Net Loss per Share (Tables)

12 Months Ended

Dec. 31, 2015

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,
	2015		2014		2013
Stock options		8,300,819		5,423,741		3,822,887
Stock warrants		1,426,622		1,313,719		1,285,394
Nonvested restricted stock units		422,500		140,000		210,000
Total		10,149,941		6,877,460		5,318,281