Idaho Code § 22-2627

When the board of directors of an association shall consist of five (5) or more members, in lieu of electing the whole number of directors annually, the articles of incorporation or by laws may provide that the directors be divided into either two (2) or three (3) classes, each class to be as nearly equal in number as possible, the term of office of directors of the first class to expire at the first annual meeting of members after their election, that of the second class to expire at the second annual meeting after their election, and that of the third class, if any, to expire at the third annual meeting after their election. At each annual meeting after such classification the number of directors equal to the number of the class whose term expires at the time of such meeting shall be elected to hold office until the second succeeding annual meeting, if there be two (2) classes, or until the third succeeding annual meeting, if there be three (3) classes. No classification of directors shall be effective prior to the first annual meeting of members.