Drunk driver drove a car not insured or registered to them,got in an accident with another car. Is the registered owner liable?

I am not an Idaho lawyer but in most states, unless there is a statute that says otherwise, the owner of a car that he/she was not driving, is not liable to a victim of an accident that happened when the car was used by somebody else. If the drunk driver was a car thief, the owner is certainly not liable. If the drunk driver had permission from the owner of a non-registered, uninsured vehicle, the owner may not be the cause of the accident but there should be penalties for allowing an unregistered, uninsured vehicle to be operated on the streets. The penalties could include restitution for any harm done. The owner may also be liable for damages under a negligent entrustment theory if the owner was aware of past drunk driving, alchoholism or poor driving skills when the owner allowed the driver to take the car. The question says the car was registered, just not to the driver. The drunk driver does not have to be listed on the policy. If the car is insured, the insurance would cover anyone who the owner gives permission to drive. Check with a local lawyer to find out if the specific facts of your situation are treated differently in your state.