Idaho Code § 18-111: Felony, misdemeanor and infraction defined.

A felony is a crime which is punishable with death or by imprisonment in the state prison. An infraction is a civil public offense, not constituting a crime, which is punishable only by a penalty not exceeding three hundred dollars ($300) and for which no period of incarceration may be imposed. Every other crime is a misdemeanor. When a crime punishable by imprisonment in the state prison is also punishable by fine or imprisonment in a county jail, in the discretion of the court, it shall be deemed a misdemeanor for all purposes after a judgment imposing a punishment other than imprisonment in the state prison.