Idaho R. App. P. 46
The time prescribed by these rules for any act, except the physical filing of a notice of appeal, a notice of cross-appeal, petition for rehearing, or a challenge to a final redistricting plan may be enlarged by the Court or any Justice thereof for good cause shown upon the motion of a party. Applications for extensions of time for filing briefs shall also be subject to the requirements of Rule 34(D). Any motion for the extension of time to do an act must be served upon all parties, but the order enlarging the time for performance may be issued immediately and ex parte in the discretion of the Court or any Justice thereof, subject to review upon any written objection filed within seven (7) days of service of the motion. Any order of extension of time to do an act shall be served by the Clerk on all parties.
Id. App. R. 46