Alliant Energy Corporation operates as a regulated investor-owned public utility holding company. The Company's segments include Utility and Non-regulated and Parent. The Utility segment includes the operations of Interstate Power and Light Company (IPL) and Wisconsin Power and Light Company (WPL), which serve retail customers in Iowa and Wisconsin. The Utility segment includes utility electric operations and utility gas operations, which includes steam operations and the unallocated portions of the utility business. Its Non-regulated and Parent segment includes the operations of Alliant Energy Finance, LLC (AEF) and its subsidiaries, the Alliant Energy parent company and any Alliant Energy parent company consolidating adjustments. AEF consists of its interest in ATC Holdings, Travero, a non-utility wind farm, the Sheboygan Falls Energy Facility and other non-utility holdings. IPL and WPL own a portfolio of electric generating units located in Iowa, Wisconsin and Minnesota.