Convertible Preferred Stock and Stockholders' Equity (Details) (USD $)	6 Months Ended			0 Months Ended			0 Months Ended
	Jun. 30, 2013	May 29, 2013 Pfizer note	Jul. 02, 2013 Common stock Warrant	Apr. 19, 2013 Series A preferred stock	Jul. 02, 2013 Series A-1 preferred stock Pfizer note	May 29, 2013 Series A-1 preferred stock Pfizer note	Jul. 02, 2013 IPO Common stock	Jul. 02, 2013 IPO Series A preferred stock	Jul. 02, 2013 IPO Series A-1 preferred stock
Convertible preferred stock and stockholders' deficit
Preferred stock, shares authorized				17,000,000		6,750,000
Share price of preferred stock (in dollars per share)			$ 6.99	$ 1.00		$ 1.1560
Proceeds from issuance of preferred stock, net of issuance costs	$ 16,827,000			$ 16,900,000
Stock issuance costs	1,067,000			100,000
Conversion rate				0.143		0.143
Outstanding principal amount		$ 7,800,000
Number of shares of convertible preferred stock converted into common stock					966,218		9,210,999	8,244,781	966,218