Idaho Const. art. XX, § 3

Whenever two-thirds of the members elected to each branch of the legislature shall deem it necessary to call a convention to revise or amend this Constitution, they shall recommend to the electors to vote at the next general election, for or against a convention, and if a majority of all the electors voting at said election shall have voted for a convention, the legislature shall at the next session provide by law for calling the same; and such convention shall consist of a number of members, not less than double the number of the most numerous branch of the legislature.