Idaho Code § 48-705
No merchant shall be entitled to immunity from liability provided for in this act unless there is displayed in a conspicuous place on his premises a notice not less than thirteen (13) inches wide and twenty-one (21) inches long, clearly legible and in substantially the following form:
ANY MERCHANT OR HIS AGENT WHO HAS REASON TO BELIEVE THAT MERCHANDISE HAS BEEN REMOVED OR CONCEALED BY A PERSON IN VIOLATION OF THIS ACT MAY DETAIN SUCH PERSON FOR THE PURPOSE OF RECOVERING THE PROPERTY OR NOTIFYING A PEACE OFFICER. A PERSON OR THE PARENTS OR LEGAL GUARDIAN OF A MINOR WHO KNOWINGLY REMOVES MERCHANDISE WITHOUT PAYING THEREFOR, OR CONCEALS MERCHANDISE TO AVOID PAYING THEREFOR, IS CIVILLY LIABLE FOR ITS VALUE, AND ADDITIONAL DAMAGES.
Idaho Code § 48-705