According to Sunday's Ann Arbor News, Idlewild, the new film opening this week, is named after the famous Lake County Michigan resort, otherwise known as the Black Eden of Michigan in the 1920s and '30s and the Summer Apollo of Michigan in the 1950s and '60s. Idlewild, Michigan, hosted great jazz acts in its day, including Duke Ellington, and was the vacation spot of choice for such black luminaries as Langston Hughes and Zora Neale Hurston. Even W.E.B. Du Bois owned a home there. But the film itself is set in Georgia and its "Idlewild" is a small-town speakeasy. It does take place during the same period and features the music of OutKast (a bit of a historical stretch, but oh well). So far, reviews are mixed but Owen Gleiberman of Entertainment Weekly gives it an A-.
You can read more about the real Idlewild in Idlewild: the Black Eden of Michigan by Ronald J. Stephens.