I'd say the difference is how long they're "resting". Taking a weekend or vacation? Wonderful. Haven't had a job in a year and not really trying to get one? Idle.
I would having a job is only a subset of what not being idle means.
I always divide my time into two basic phases: productive and consumptive. Either you are creating something or you are consuming something. Sitting around watching TV is consuming; creating a tv show would be producing.
I think both activities are valuable and have their place. Sometimes you need to relax and enjoy a passive activity, but what makes society great is the production of new things; be they art, science, entertainment, goods..
I tend not to judge the WHAT of the creative side. It doesn't matter what you create, but the creation of new ideas and things is what makes us human.