I agree with the safe idea. I would be worried about "Scanning" important documents. I don't trust electronic / computer stuff to much and it seems to me that scanning important stuff on to a thumb drive would make it really easy to loose it and, easier to steal it.
Thumb drive gets wet, thumb drive gets to close to a Electro Magnet, thumb drive is small and gets lost easily, you use thumb drive and accidently hit the wrong key and it's all erased, lightening hits the house and thumb drive gets shorted out, and the list goes on and on.