Organization, Basis of Presentation and Significant Accounting Policies (Details 4)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
FGCO
Annual Composite Depreciation Rate
Annual Composite Depreciation Rate	3.10%	4.00%	4.60%
NGC
Annual Composite Depreciation Rate
Annual Composite Depreciation Rate	3.20%	3.10%	3.00%
OE
Annual Composite Depreciation Rate
Annual Composite Depreciation Rate	2.90%	2.90%	3.10%
CEI
Annual Composite Depreciation Rate
Annual Composite Depreciation Rate	3.20%	3.20%	3.30%
TE
Annual Composite Depreciation Rate
Annual Composite Depreciation Rate	3.20%	3.30%	3.30%
JCP&L
Annual Composite Depreciation Rate
Annual Composite Depreciation Rate	2.80%	2.40%	2.40%
Met-Ed
Annual Composite Depreciation Rate
Annual Composite Depreciation Rate	2.50%	2.50%	2.50%
Penelec
Annual Composite Depreciation Rate
Annual Composite Depreciation Rate	2.30%	2.50%	2.60%
ATSI
Annual Composite Depreciation Rate
Annual Composite Depreciation Rate	2.40%	2.40%	2.40%
Penn
Annual Composite Depreciation Rate
Annual Composite Depreciation Rate	2.20%	2.20%	2.40%
AE Supply
Annual Composite Depreciation Rate
Annual Composite Depreciation Rate	3.40%
MP
Annual Composite Depreciation Rate
Annual Composite Depreciation Rate	2.50%
PE
Annual Composite Depreciation Rate
Annual Composite Depreciation Rate	2.80%
WP
Annual Composite Depreciation Rate
Annual Composite Depreciation Rate	2.50%
TrAIL
Annual Composite Depreciation Rate
Annual Composite Depreciation Rate	2.70%