New fb chat is kind of confusing. How long do i have to not do anything to be idle? Help?

[Leva Mei]

Yeah so do i stop doing things for 10 mins or 30? some say i have been idle even after 5 mins of doing nothing. some say even after 10 mins nothing happens. what is it really? also, on my chat list the people i talk to all the time, sometimes when they are offline, they disappear from the list! is it just them being invisible then when they completely log out thats when they disappear? new fb sucks ball sacks.

[miniaturehorse036]

EDIT: Actually, I think the new facebook chat does not feature the idle symbol anymore.
There's only a green dot for availablity, and none if they are unavailable. It's unclear whether being idle for a set period of time (somewhere between 10~15 minutes) is considered being unavailable.
Idling seemed to have been taken out of the Facebook Help Centre, so there's no documentation on the feature anymore.

The new FB chat updates based on various unknown factors. Some of them disappear once they are unavailable, regardless of whether they are actually offline or just being invisible. It updates based on recency, amount of communication between you and them, and much more. You can search for any person at any time by typing their name into the search box on the chat window.