Idaho Code § 19-2131: Decision of questions of law and fact in other trials — Jury bound by instructions.

On the trial of an indictment for any other offense than libel, questions of law are to be decided by the court, questions of fact by the jury; and although the jury have the power to find a general verdict, which includes questions of law as well as of fact, they are bound, nevertheless, to receive as law what is laid down as such by the court.