Fair Value Measurements (Details Textuals) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Fair Value of Financial Instruments [Line Items]
Cash balance excluded from available for sale securities	$ 130	$ 193
Investment excludes Receivables, Payables and Accrued income	6	(7)
Fair Value of Financial Instruments (Textuals) [Abstract]
Investments not required to be disclosed	345	259
Debt assumed-carrying value	4,530
Debt assumed- Fair value	4,127
FES
Fair Value of Financial Instruments [Line Items]
Cash balance excluded from available for sale securities	39	153
Investment excludes Receivables, Payables and Accrued income		7
OE
Fair Value of Financial Instruments [Line Items]
Cash balance excluded from available for sale securities	3	3
Investment excludes Receivables, Payables and Accrued income	2	1
TE
Fair Value of Financial Instruments [Line Items]
Cash balance excluded from available for sale securities		34
Investment excludes Receivables, Payables and Accrued income	(1)	2
JCP&L
Fair Value of Financial Instruments [Line Items]
Cash balance excluded from available for sale securities	19	3
Investment excludes Receivables, Payables and Accrued income	5	(3)
Met-Ed
Fair Value of Financial Instruments [Line Items]
Cash balance excluded from available for sale securities	14	(3)
Investment excludes Receivables, Payables and Accrued income	(1)	(9)
Penelec
Fair Value of Financial Instruments [Line Items]
Cash balance excluded from available for sale securities	55	4
Investment excludes Receivables, Payables and Accrued income	$ 1	$ (3)