Idaho Code § 50-202
This act shall not impair or affect any act done, offense committed or right accruing, accrued, or acquired or liability, penalty, forfeiture or punishment incurred prior to the time this act takes effect, but the same may be enjoyed, asseted [asserted], enforced, prosecuted or inflicted, as fully and to the same extent as if this act has not been passed.
All cities of the first class and all cities of the second class, heretofore incorporated under the general laws of this state, and heretofore operating with a mayor and council, shall continue to operate with a mayor and a council under the provisions of this act. All villages, heretofore incorporated under the general laws of this state, and heretofore operating with a board of trustees, shall hereafter operate with a mayor and a council under the provisions of this act. All cities and villages, heretofore incorporated under the general laws of this state, and heretofore operating under chapters 36, 43 or 49, title 50, Idaho Code, shall hereafter operate under sections 50-805 [50-801] through 50-904 [50-812], and enjoy all powers and privileges given under the provisions of this act.
Idaho Code § 50-202