I agree with "I remain detached", there is the possibility that "mi tiro fuori" contains another level of meaning though, in that the person "is" involved but is "pulling out", or "getting out" of what they are already involved in - so perhaps I detach myself or I exclude/extract myself, rather than remaining, which may indicate the person was never involved? "I keep myself out of it" would probably be good, but is much longer than the source. Just a possibility, would need confirmation!?! (Now I've even confused myself!)