REGULATORY MATTERS (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Regulatory Assets and Liabilities [Roll Forward]
Net regulatory asset (liability) balance at beginning of period	$ (23.7)	$ 29.3	$ 11.9	$ 29.9
Current period under recovery revenue adjustments	28.8	6.4	1.8	20.0
Amortization of prior year regulatory asset	(1.6)	(7.9)	(10.2)	(22.1)
Net regulatory asset balance at end of period	$ 3.5	$ 27.8	$ 3.5	$ 27.8

Regulatory Assets and Liabilities [Roll Forward]

No definition available.

Name:	eep_RegulatoryAssetsandLiabilitiesRollForward
Namespace Prefix:	eep_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The expense charged against earnings during the period to allocate the capitalized costs of regulatory assets over the periods expected to benefit from such costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.3)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

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

- Definition

The increase (decrease) during the reporting period in the value of assets that are created when regulatory agencies permits public utilities to defer costs (revenues) to the balance sheet. This element is a the increase (decrease) of regulatory assets and liabilities combined.

+ References

+ Details

Name:	us-gaap_IncreaseDecreaseInRegulatoryAssetsAndLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The net amount of all regulatory assets less all regulatory liabilities as of the end of the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 340
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382

+ Details

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