Overheating at idle sounds like your T-stat is stuck. I'd r&r that just to be sure.

Oh, yeah, like Admin said, check your coolant level. Check the pressure cap, too. That's always a cheap fix.

Get the vehicle up to ot and feel the cores of the radiator. They should be evenly warm/hot. If you've got cold spots then you've got a clog.

Man, I hope it's not the pump. When you start to overheat, turn the heater on full blast. If that cools it down, then the pump should be ok. If the pump's bad, then it's time to do the timing belt, also.

My money's on a clogged radiator, or stuck T-stat. Check this site out for radiators: radiatorbarn