Nature of Business (Details)	Sep. 30, 2014 regulated_gas_distributions_divisions customers
Schedule of Number of Customers, Discontinued Operations [Line Items]
Number Of Customers, Regulated Distribution	3,000,000
Number Of Divisions, Regulated Distribution	6
Georgia [Member]
Schedule of Number of Customers, Discontinued Operations [Line Items]
Number Of Customers, Regulated Distribution	64,000
Missouri, Illinois and Iowa [Member]
Schedule of Number of Customers, Discontinued Operations [Line Items]
Number Of Customers, Regulated Distribution	84,000