Engine idles high

I have a 2002 Mazda 626 4 cylinder 2.0 with about 46000 miles on it. When I first start it up after its been sitting for at least 6-8 hours its very loud and idles high at about 2 and 1/2. Then after it warms up after about 5 minutes the idling gradually goes down to about 1 and 1/2 where it should be and is nice and quiet. If the car is sitting for only a bit, it doesnt do this as much, maybe only for a couple of seconds depending on how long its been sitting. But when its been sitting for a while its quite loud.
If I drive it right after I start it up after its been sitting, it seems to take the loudness away.

Thanks, Ryan of Cortland NY