First, I want to thank everyone who has offered suggestions. I really appreciate the fact that you have taken time to try to help me with this problem.
Here's an update: I decided to do some more "research" last night and took the bike out. It started and ran fine. I rode around for awhile and got the engine good and warmed up. I had to come to a stop at an intersection and I could feel the idle start to drop. This was confirmed when I saw the needle on the tach slowly drift downward. "Ah-ha!, I thought, it's somehow related to the engine temperature!" I opened the throttle to keep the engine at 2,000 rpm and got through the intersection. I thought I would head for home and see what I could do.
I had several more intersections where I had to stop. No problems. I got the bike home and left it running in the driveway waiting for the idle to drop and then die. It kept running.
I parked the bike and let it cool off for about an hour and a half. I took it out again and rode for another hour covering 50 miles. Great ride - and no problems. Got it home, let it sit, idled fine, didn't die.
I am beginning to think that my bike may have Alzheimer's and may just forget how to idle on occasion. Beats me....