Idaho Code § 50-230
If, upon the hearing, the court shall find that such tract or tracts of land are tracts containing at least five (5) acres and are included within the corporate limits of such city and the lands included within such tract or tracts are used exclusively for agricultural purposes, provided, however, if there is upon or over such tract or tracts of land a railroad or canal right of way, such tract or tracts shall, if no other reason exists, be deemed to be used exclusively for agricultural purposes, within the meaning of this section; that such lands do not receive sufficient special benefits to justify the retention of said lands within the corporate limits of such city, and that by the detachment of said lands the symmetry of the city would not be materially marred, then the judge of said court shall grant the prayer of said petition and shall enter judgment and decree accordingly: Provided, however, that if said petition prays for detaching several tracts of land the court may enter judgment granting the prayer of the petition as to such tract or tracts as come within his findings as aforesaid and deny such petition as to such tract or tracts which do not come within his findings as aforesaid.
And said tract or tracts of land sought to be detached and for which the said judgment is entered detaching the same shall, upon the entering of said judgment, become detached from such city and the corporate boundary line or limits of said city shall be deemed changed accordingly, and said tract or tracts so detached shall be free from the government of such corporation from said date.
It shall not be necessary for the judge of the court, prior to entering his judgment, or at any time, to make written findings of fact or conclusions of law. Within twenty (20) days after the filing of said decree the petitioner shall file or cause to be filed with the county recorder and with the city clerk a certified copy thereof.
Idaho Code § 50-230