Nuclear Fuel Disposal Cost Litigation (Details) - Nuclear Fuel Disposal Cost Settlement, January 1, 2005 through December 31, 2010 - Plant Hatch and Plant Vogtle - USD ($)	1 Months Ended	3 Months Ended
	Apr. 30, 2015	Mar. 31, 2015	Dec. 14, 2014
Nuclear Fuel Disposal Cost Litigation
Settlement amount, all parties			$ 36,474,000
Settlement amount, entity share	$ 10,949,000
Reduction of total operating expenses		$ 7,320,000
Reduction to plant in service		$ 3,629,000