Preferred Stock and Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2015

Equity [Abstract]

Summary of Common Stock Reserved for Future Issuance

Common stock reserved for future issuance is as follows (in thousands):

	December 31,
	2015	2014
Stock options and restricted stock units outstanding	2,714	2,114
Warrants to purchase common stock	1,975	2,029
Shares authorized for future issuance under equity and purchase plans	678	603
	5,367	4,746