It seems to be normal. Even on idle mode, the Operating System runs different processes within its back ground and will always need the processor resources.
Furthermore, differences between the core temperatures can be from 15 to 20 °C.
I hope u are right , i still don't like my temperatures thought . I don't want my cpu hit 90c in the summer.
I saw similar overclocked cpus to hit my temps but they are overclocked to 4ghz.
I ll do a better research and i ll post again.