The federal government plans to swap its historic downtown Coeur d'Alene courthouse for a larger, four-story building to be built in an office park near U.S. Highway 95 and Hanley Avenue. A lack of space, parking and security were cited as top reasons for the move. The existing courthouse, a 21,160-square-foot brick landmark, will likely be refitted for commercial office space, though no firm plans have been developed, said Bill Lesh, spokesman for the U.S. General Services Administration.