Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2015

Accounting Policies [Abstract]

Summary of Common Stock Equivalents Excluded from Calculation of Diluted Net Loss 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 or the exercise prices were greater than the average market price of the common shares.

	As of June 30,
	2015	2014
Stock options	2,060,334	1,490,979
Unvested restricted stock	71,310	177,178
Restricted stock units	211,400	—
Common stock warrants	926,840	—
	3,269,884	1,668,157