It is the policy of the state of Idaho to allow out-of-state banks, chartered either by other states or by the federal government, to branch within the state of Idaho on the terms and conditions set out in this chapter, chapter 3, title 26, Idaho Code, and federal law; further, it is the policy of the state of Idaho to allow banks chartered by or located in this state to establish, operate, and maintain branches in other states in any manner authorized by this act, the law of such other states, and federal law. It is an express purpose of this chapter to authorize mergers between banks in Idaho and banks located in other states.