Contingencies and Regulatory Matters: (Details) (USD $)	12 Months Ended		0 Months Ended
	Dec. 31, 2013 item	Dec. 31, 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	Mar. 13, 2014 Patronage Capital Litigation Subsequent event item
Nuclear Construction
Contractor's estimated adjustment attributable to the entity		$ 280,000,000
Number of defendant members			3
Number of excluded members against whom defendant class action is certified			1
Number of cooperative members	38		38
Number of former consumer members			4
Number of members in which the former consumer members filing the lawsuit belonged			3
Percentage of cooperatives total booked patronage capital			30.00%
Period of revolving plan			13 years
Percentage of total equity owed to former members			7.70%