Howdy AII, welcome to Boise!
Open carry without a permit is legal throughout the state, concealed carry by permit only or outside of city limits. Carrying concealed is prohibited while intoxicated.
If you have any valid CWP, Idaho will recognize it irrespective of any other states' formal reciprocity laws.
One may not carry open or concealed in any location K-12, courthouses, jails, or the sterile areas of airports (duh). I was perusing the Idaho statutes just today, and I can't remember anything else off hand.