Summary of Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2013

Accounting Policies [Abstract]

Securities Excluded from Calculation of Weighted-Average Shares Outstanding

The following potentially dilutive securities have been excluded from the calculations of diluted net loss per share as their effect would be anti-dilutive:

	Three Months Ended June 30,				Six Months Ended June 30,
	2013		2012		2013		2012
Shares of convertible preferred stock		—		1,792,320		—		1,792,320
Shares underlying options outstanding		744,007		563,390		744,007		563,390
Shares underlying warrants outstanding		6,108,050		5,329,222		6,108,050		5,329,222