Idaho Code § 26-2604

Except as authorized in this chapter, chapter 16, title 26, Idaho Code, and by the laws of the United States, no out-of-state financial institution or out-of-state financial institution holding company, nor any subsidiary or affiliate thereof, may establish or maintain an office of, or conduct the business of, a financial institution in this state; nor may such out-of-state financial institutions or out-of-state financial institution holding companies, or any subsidiaries or affiliates thereof, directly or indirectly, acquire control of, acquire substantially all of the assets of, merge with, consolidate with, or assume the deposit liabilities of an Idaho financial institution or an Idaho financial institution holding company.