Company Posted Collateral Related To Net Liability Positions.

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- Definition

Coverage of Decontamination Costs As Per Property Damage Insurance

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No definition available.

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- Definition

Decommissioning Costs Coverage, Retrospective Premium Assessment, Annual Amount

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No definition available.

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- Definition

Investment, Ownership Percentage Pledged as Collateral

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No definition available.

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- Definition

Public Utilities, Liability Assessed with Respect to Single Nuclear Incident Based On Act

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No definition available.

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- Definition

Face (par) amount of debt instrument at time of issuance.

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- Definition

The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

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- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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Commitments, Guarantees and Contingencies - Nuclear Insurance, Commitments and Collateral (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Jun. 30, 2018
Loss Contingencies [Line Items]
Coverage of decontamination costs	$ 150,000,000
Liability assessed with respect to single nuclear incident	560,000,000
Outstanding guarantees and other assurances aggregated	1,700,000,000
Potential additional collateral obligations	369,000,000
FE
Loss Contingencies [Line Items]
Outstanding guarantees and other assurances aggregated	345,000,000
Subsidiaries' Guarantees
Loss Contingencies [Line Items]
Outstanding guarantees and other assurances aggregated	1,000,000,000
Other Guarantees
Loss Contingencies [Line Items]
Outstanding guarantees and other assurances aggregated	190,000,000
Other Assurances
Loss Contingencies [Line Items]
Outstanding guarantees and other assurances aggregated	140,000,000
Regulated Distribution
Loss Contingencies [Line Items]
Company posted collateral related to net liability positions	2,000,000
Potential additional collateral obligations	121,000,000
JCP& L, ME and PE
Loss Contingencies [Line Items]
Annual retrospective premium assessments	$ 1,200,000
FEV \| Signal Peak \| Senior Secured Term Loan \| Senior Loans \| Global Holding
Loss Contingencies [Line Items]
Investment ownership percentage	33.33%
WMB Marketing Ventures, LLC \| Signal Peak \| Senior Secured Term Loan \| Senior Loans \| Global Holding
Loss Contingencies [Line Items]
Investment ownership percentage	33.33%
Global Holding \| Senior Secured Term Loan \| Senior Loans
Loss Contingencies [Line Items]
Long-term debt and other long-term obligations	$ 190,000,000
Global Holding \| Signal Peak, Global Rail and Affiliates \| Senior Secured Term Loan \| Senior Loans
Loss Contingencies [Line Items]
Investment ownership percentage	69.99%
AE Supply
Loss Contingencies [Line Items]
Potential additional collateral obligations	$ 2,000,000
Surety Bond \| Little Bull Run \| Line of Credit
Loss Contingencies [Line Items]
Maximum amount borrowed under revolving credit facility	169,000,000
Surety Bond \| Hatfield Ferry \| Line of Credit
Loss Contingencies [Line Items]
Maximum amount borrowed under revolving credit facility	31,000,000
Term Loan Facility Due March 2020 \| Line of Credit \| Global Holding
Loss Contingencies [Line Items]
Face amount of loan	$ 300,000,000	$ 300,000,000