SPRINGFIELD — Illinois already bans private, for-profit prisons for criminal offenses, but a bill before the General Assembly would block for-profit civil detention facilities as well.The bill’s target is a plan by the Livingston County village of Dwight, population 4,038, to host a for-profit Immigration and Customs Enforcement detention center.House Bill 2040, sponsored by Democratic Rep. Kelly Cassidy of Chicago, would prohibit the state or any unit of local government from operating private detention …