2004 Ford Taurus Speed Control

I have a 2004 Ford Taurus and sometimes it idles itself up to high. I coudl be sitting at a red light and on the RPM side it is on the number 3. If I try to stop when its like this the car acts like it wants to keep going. Sometimes if i smash the gas hard it idles down to proper idleing speed. It does not do this on a constant bases just once in a while.

Could this be an speed control module problem? My transmission shifts fine no problems with that. Please help!

Tamara