Condensed Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Statement Of Financial Position [Abstract]
Convertible Preferred stock, par value	$ 0.001	$ 0.001
Convertible Preferred stock, shares authorized	0	29,402,200
Convertible Preferred stock, shares issued	0	29,186,929
Convertible Preferred stock, shares outstanding	0	29,186,929
Convertible Preferred stock, aggregate liquidation preference	$ 0	$ 65,969
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	50,000,000
Common stock, shares issued	22,638,414	4,288,243
Common stock, shares outstanding	22,638,414	4,288,243