Idaho Code § 61-622A
For any telephone corporation which provides telecommunication services pursuant to both title 61, Idaho Code, and title 62, Idaho Code, the commission may, or at the request of a telephone corporation shall, establish procedures for allocation of costs between telecommunication services provided pursuant to title 61, Idaho Code, and telecommunication services provided pursuant to title 62, Idaho Code. Such allocations shall reasonably reflect how joint-use facilities are utilized, provide reasonable stability for telephone corporations to do business planning and pricing and minimize the cost of accounting and record keeping to the extent possible. In developing such allocation methods, the commission may adopt procedures which are based on gross allocation factors derived from relative changes in total intrastate telecommunication service revenues or expenses or other measures of relative change between the provision of telecommunication services subject to title 61, Idaho Code, and telecommunication services subject to title 62, Idaho Code. The commission shall have authority to establish just and reasonable rates for all telecommunication services which remain subject to title 61, Idaho Code, and for basic local service in accordance with the provisions of chapter 6, title 62, Idaho Code.
Idaho Code § 61-622A