I have an 01 Excursion 4x4 with the V-10. Is this normal?

When I start the truck it idles at about 1200 or so RPM untill it warms up then out of gear it settles in at around 1000 rpm. In gear it idles at around 850 or so once warmed up. Could this high idle be from the Idle control valve? I tried resetting the idle trim as discribed in the Manual by removeing the battery then going thru the steps listed. Seemed to smooth out the idle, but not drop it where it should be.

Also, what is the average "all working as it should" idle speed?

Thank you,