Idaho Code § 66-355
The incompetency of a mentally ill person shall be determined in the same manner that incompetency is determined in any other person and shall be a separate judicial proceeding. Any guardian appointed in the case of a mentally ill incompetent person, is subject to all the provisions of the general laws of the state of Idaho in relation to guardians and wards. Whenever a mentally ill person is receiving care and treatment in a facility in the event that incompetency is adjudicated and a guardian appointed, the court on determining the incompetency must inquire into the ability of the mentally ill person to pay for his or her expenses which arise in connection with his or her care and treatment, if any, transportation to the facility, court costs for incompetency proceedings, and for the care and treatment for such person for such time as he remains in such facility, and when there are sufficient assets in the hands of the guardian, the court may order a sale of property or such part thereof as may be necessary, and from the proceeds of such sale the guardian must pay for all expenses and reasonable charges for the patient's care and treatment, or such part as it is possible to pay, to the director of the facility in which said mentally ill person is a patient.
Idaho Code § 66-355