Represents Consideration transferred to Shareholders on account of Business combination

No definition available.

Name:	ede_BusinessCombinationConsiderationTransferredToShareholders
Namespace Prefix:	ede_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the period with in which either the party can exercise the right to terminate contract.

+ References

No definition available.

+ Details

Name:	ede_MaximumPeriodForExercisingTerminationRight
Namespace Prefix:	ede_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the extension period to obtain certain required regulatory approvals.

+ References

No definition available.

+ Details

Name:	ede_MaximumPeriodForExtendingRegulatoryApprovals
Namespace Prefix:	ede_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage payable on the transaction costs.

+ References

No definition available.

+ Details

Name:	ede_PercentagePayableOfTransactionCosts
Namespace Prefix:	ede_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount payable on cancellation of merger either due to non approval from shareholders or government authorities.

+ References

No definition available.

+ Details

Name:	ede_TerminationFeePayableOnCancellationOfMerger
Namespace Prefix:	ede_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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.

+ References

No definition available.

+ Details

Name:	us-gaap_BusinessAcquisitionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 23
-URI http://asc.fasb.org/extlink&oid=34752592&loc=d3e1043-128460

+ Details

Name:	us-gaap_BusinessCombinationAcquisitionRelatedCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_BusinessAcquisitionAxis=ede_LibertyUtilitiesCentralCoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=us-gaap_ScenarioForecastMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
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Period Type:

Mergers and Acquisitions (Details) - USD ($)		3 Months Ended	12 Months Ended
Mergers and Acquisitions (Details) - USD ($)	Feb. 09, 2016	Mar. 31, 2016	Dec. 31, 2016	Mar. 31, 2016
Mergers and Acquisitions
Termination fee	$ 53,000,000
Maximum period for extending regulatory approvals	6 months
Maximum period for exercising termination right	9 months
Transaction costs		$ 4,248,000		$ 4,499,000
Liberty Utilities (Central) Co
Mergers and Acquisitions
Right to receive in cash without interest	$ 34.00
Termination fee	$ 65,000,000
Forecast
Mergers and Acquisitions
Percentage payable of transaction costs			50.00%
Forecast \| High end of range
Mergers and Acquisitions
Transaction costs			$ 17,000,000
Forecast \| Low end of range
Mergers and Acquisitions
Transaction costs			$ 15,000,000