The common meaning of imprisonment is incarceration in a prison, jail, or other penal institution, including work furlough from a custody sentence. See, e.g., United States v. Miller, 547 F.3d 1207, 1213 (9th Cir. 2008) (incarceration in county jail work release program constituted part of defendants term of imprisonment where defendant remained under the authority of the Bureau of Prisons).