Contingencies and Regulatory Matters (Details) (USD $)	12 Months Ended	9 Months Ended
	Dec. 31, 2013 item	Sep. 30, 2013 Vogtle Units No.3 and No.4 item MW	Sep. 30, 2013 Costs associated with design changes, delays in the project schedule and issuance of the combined construction permits and operating licenses Vogtle Units No.3 and No.4
Nuclear Construction
Number of Westinghouse AP1000 nuclear generating units		2
Nominally rated generating capacity for each unit		1,100
Contractor's estimated adjustment attributable to the entity			$ 280,000,000
Number of plaintiffs	150