Organization and Basis of Presentation (Details) (Alabama Gas Corporation, USD $)	1 Months Ended
	Apr. 30, 2014
Alabama Gas Corporation
Schedule of Quantifying Prior Year Misstatement Not Corrected Due to Materiality [Line Items]
Expected amount of consideration to be received	$ 1,600,000,000
Expected proceeds from sale of Alagasco	1,280,000,000
Expected amount of debt to be assigned	$ 320,000,000