Merger (Details 5) (USD $) In Millions, except Per Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Summary of consolidated results of operations
Revenue	$ 4,062	$ 4,401	$ 8,848	$ 9,086
Earnings available to FirstEnergy	$ 186	$ 389	$ 323	$ 644
Basic Earnings Per Share	$ 0.44	$ 0.93	$ 0.77	$ 1.54
Diluted Earnings Per Share	$ 0.44	$ 0.93	$ 0.77	$ 1.53