Idaho Code § 43-2404
The secretary must cause the notice of the filing of such petition to be published three (3) weeks in the manner of notices of special elections. The notice shall state the filing of such petition, the names of the petitioners, a description of the lands mentioned in said petition, and that domestic annexation thereof has been requested, and it shall notify all persons interested in or that may be affected by such domestic annexation to appear at the office of said board, at a time named in said notice, and show cause in writing, if any they have, why the petition for domestic annexation should not be granted. The petitioners shall advance to the secretary sufficient money to pay the estimated cost of all proceedings in connection with all such domestic annexations.
Idaho Code § 43-2404