idle temp doesnt matter, it varies a lot depending on the fan profile and really isnt too important to the processor, as long as your load temp is okay its fine.
Whats your room temperature? 17C seems to low to be possible so i would ignore those numbers. Get HW Monitor, and Speedfan see if they match up. Sometimes BIOS readings are higher because it hasnt engaged the power saving features on the CPU yet so its running full speed but doing very little, its often higher than idling on your desktop.