Nature of Business (Details) customers in Thousands	Sep. 30, 2015 customers regulated_gas_distributions_divisions	Sep. 30, 2013 customers
Schedule of Number of Customers, Discontinued Operations [Line Items]
Number Of Customers, Regulated Distribution	3,000
Number Of Divisions, Regulated Distribution | regulated_gas_distributions_divisions	6
Georgia, Illinois, Iowa and Missouri [Member]
Schedule of Number of Customers, Discontinued Operations [Line Items]
Number Of Customers, Regulated Distribution		148