Yes, that's normal ... I asked the same question about my car a few years ago. Apparently it goes along with the computer in your car and will idle it higher when it's cold and lower when the engine is hot. Hope this helps.
It's the engine management system compensating for not having a choke. In older cars with manual choke you manually reduced the amount of air into the carb and increased the revs by virtue of a lever under the dash until the engine was warm enough to tick over on it's own. These days cars compensate for cold starting in the same way but it's managed electronically. It's only a problem if it's not doing it!