Disinterested (8)
(Other definitions for detached that I've seen before include "Separate; aloof" , "being sent on special assignment" , "Clinical" , "Type of house" , "Separate, disconnected" .)
(Other definitions for unbiased that I've seen before include "Impartial" , "fair" , "Not partial or prejudiced" , "Not prejudiced or influenced" , "Not favouring one side or the other" .)
(Other definitions for cool that I've seen before include "Not hot or warm - just unexcited" , "Calm; not warm" , "Neither warm nor very cold" , "Super!" , "Rain heavily (colloq.)" .)