My car just started overheating only in idle

What is the temp reading, in degrees F, when it overheats? Does the radiator fan work?

Check the cooling fan fuses in the power distribution box (underhood fuse box)
Make sure the cooliing fan relays are well connected in their sockets.
With the engine cool, check the coolant level at the radiator. Once the that is established, Allow the engine to run until it reaches "normal operational temperature" to physically see if the cooling fans come on (or not). Remeber this may take a while because the engine takes some time to heat-up at idle
If the fans are not running, use a test light (or multi-meter) to check for battery voltage (12v) at the cooling fan electrical connection. (Allow the fan to runs with the test light connected to see if eventually the light comes on--if it doesn't come on before the engine starts to overheat the fans aren't getting power).

In that case, swap the cooling fan relay with another identical relay from the power distribution box (underhood fuse box). Run the engine to see if the fans now come on.
Keep the test light in place to see if it comes on (or the fans come on). If so, replace the ren felay.
Keep us abreast of the results.

Let us know what you find.