Commitments, Guarantees and Contingencies (Details) $ in Millions	Dec. 31, 2017 USD ($)
Guarantor Obligations [Line Items]
Potential additional collateral obligations	$ 407
Regulated Distribution
Guarantor Obligations [Line Items]
Potential additional collateral obligations	148
FE
Guarantor Obligations [Line Items]
Potential additional collateral obligations	237
FES
Guarantor Obligations [Line Items]
Potential additional collateral obligations	20
AE Supply
Guarantor Obligations [Line Items]
Potential additional collateral obligations	2
At Current Credit Rating
Guarantor Obligations [Line Items]
Potential additional collateral obligations	5
At Current Credit Rating | Regulated Distribution
Guarantor Obligations [Line Items]
Potential additional collateral obligations	0
At Current Credit Rating | FE
Guarantor Obligations [Line Items]
Potential additional collateral obligations	0
At Current Credit Rating | FES
Guarantor Obligations [Line Items]
Potential additional collateral obligations	4
At Current Credit Rating | AE Supply
Guarantor Obligations [Line Items]
Potential additional collateral obligations	1
Upon Further Downgrade
Guarantor Obligations [Line Items]
Potential additional collateral obligations	41
Upon Further Downgrade | Regulated Distribution
Guarantor Obligations [Line Items]
Potential additional collateral obligations	41
Upon Further Downgrade | FE
Guarantor Obligations [Line Items]
Potential additional collateral obligations	0
Upon Further Downgrade | FES
Guarantor Obligations [Line Items]
Potential additional collateral obligations	0
Upon Further Downgrade | AE Supply
Guarantor Obligations [Line Items]
Potential additional collateral obligations	0
Surety Bond
Guarantor Obligations [Line Items]
Potential additional collateral obligations	361
Surety Bond | Regulated Distribution
Guarantor Obligations [Line Items]
Potential additional collateral obligations	107
Surety Bond | FE
Guarantor Obligations [Line Items]
Potential additional collateral obligations	237
Surety Bond | FES
Guarantor Obligations [Line Items]
Potential additional collateral obligations	16
Surety Bond | AE Supply
Guarantor Obligations [Line Items]
Potential additional collateral obligations	$ 1