Organization and Basis of Presentation - Additional Information (Details) (USD $)	3 Months Ended	0 Months Ended
	Mar. 31, 2014	Sep. 02, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on disposal of discontinued operations	$ (1,667,000)
Alabama Gas Corporation
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Amount of consideration received		1,600,000,000
Amount of debt assumed		267,000,000
Proceeds from sale		1,320,000,000
Loss on disposal of discontinued operations		$ 726,500,000