CONDENSED BALANCE SHEETS (Parenthetical) - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
CONDENSED BALANCE SHEETS    
Convertible preferred stock, par value (in dollars per share) $ 0.0001 $ 0.0001
Convertible preferred stock, shares authorized 0 14,274,741
Convertible preferred stock, shares issued 0 14,274,741
Convertible preferred stock, shares outstanding 0 14,274,741
Convertible preferred stock, liquidation preference (in dollars)   $ 108,500
Preferred stock, par value (in dollars per share) $ 0.0001 $ 0.0001
Preferred stock, shares authorized 10,000,000 0
Preferred stock, shares issued 0 0
Preferred stock, shares outstanding 0 0
Common stock, par value (in dollars per share) $ 0.0001 $ 0.0001
Common stock, shares authorized 290,000,000 20,000,000
Common stock, shares issued 20,922,428 1,431,615
Common stock, shares outstanding 20,922,428 1,431,615