Name:	us-gaap_LesseeLeaseDescriptionLineItems
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Data Type:	xbrli:stringItemType
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Period Type:	duration

Amount of lessee's right to use underlying asset under operating lease.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977

Name:	us-gaap_OperatingLeaseRightOfUseAsset
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount before accumulated depreciation, depletion and amortization of other physical assets used in the normal conduct of business to produce goods and services and not intended for resale.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Amount of accumulated depreciation of long-lived, physical assets used to produce goods and services and not intended for resale, classified as other.

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount after depreciation of long-lived, physical assets used to produce goods and services and not intended for resale, classified as other.

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

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Namespace Prefix:
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Balance Type:
Period Type:

Name:	wep_LeaseAxis=wep_PowerPurchaseContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	wep_LeaseAxis=wep_PortWashingtonGeneratingStationUnits1And2Member
Namespace Prefix:
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