NET INCOME PER LIMITED PARTNER UNIT (Basic and Diluted Net Income Per Limited Partner Unit) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Continuing operations:
Net income from continuing operations	[1]	$ 232.4	$ 240.7	$ 411.3	$ 443.4
Less: Net income attributable to: Noncontrolling interest		101.8	87.3	177.7	165.4
Series 1 preferred unit distributions		6.5	22.5	29.0	45.0
Accretion of discount on Series 1 preferred units		7.3	1.2	8.5	2.3
Net income attributable to general and limited partner interests in Enbridge Energy Partners, L.P. - continuing operations		116.8	129.7	196.1	230.7
Distributions:
Incentive distributions	[2]	(3.7)	(5.2)	(7.4)	(10.4)
Distributed earnings attributed to Class D and Class E units		(13.3)	(59.6)	(26.5)	(119.1)
Total distributed earnings attributed to our common units and i-units		(146.9)	(202.9)	(293.3)	(404.6)
Total distributed earnings		(160.2)	(262.5)	(319.8)	(523.7)
Overdistributed earnings		(43.4)	(132.8)	(123.7)	(293.0)
Discontinued operations:
Net loss	[1]	(35.4)	(63.0)	(56.8)	(93.3)
Less: Net loss attributable to Noncontrolling interest		(11.2)	(17.0)	(18.8)	(26.3)
Net loss attributable to general and limited partner interests in Enbridge Energy Partners, L.P. - discontinued operations		$ (24.2)	$ (46.0)	$ (38.0)	$ (67.0)
Weighted average common units and i-units outstanding		400.1	347.1	376.7	345.9
Basic and diluted earnings per unit:
Distributed earnings per common unit and i-unit - continuing operations	[3]	$ 0.37	$ 0.58	$ 0.78	$ 1.17
Overdistributed earnings per common unit and i-unit	[4]	(0.10)	(0.37)	(0.32)	(0.84)
Net income per common unit and i-unit (basic and diluted) - continuing operations	[5]	0.27	0.21	0.46	0.33
Net loss per common unit and i-unit (basic and diluted) - discontinued operations	[5]	(0.06)	(0.13)	(0.10)	(0.18)
Net income per common unit and i-unit (basic and diluted)		$ 0.21	$ 0.08	$ 0.36	$ 0.15
Class D and Class E Units [Member]
Distributions:
Distributed earnings attributed to Class D and Class E units		$ (6.4)	$ (49.1)	$ (12.7)	$ (98.2)
General Partner [Member]
Distributions:
Distributed earnings attributed to our General Partner		$ (3.2)	$ (5.3)	$ (6.4)	$ (10.5)

[1] Certain costs that are not allocated to individual segments, including Other, interest expense, allowance for equity used during construction, and income taxes are included in the consolidated total.

[2] For the three and six months ended June 30, 2017, Class D units and IDUs were not entitled to distributions as the wholly-owned subsidiary of our General Partner irrevocably waived its rights associated with the Class D and IDUs; for the three and six months ended June 30, 2017, incentive distributions were made to Class F units. For the three and six months ended June 30, 2016, incentive distributions were made to IDUs and Class D units.

[3] Represents the total distributed earnings to common units and i-units divided by the weighted average number of common units and i-units outstanding for the period.

[4] Represents the common units’ and i-units’ share (98%) of distributions in excess of earnings divided by the weighted average number of common units and i-units outstanding for the period and overdistributed earnings allocated to the common units and i-units based on the distribution waterfall that is outlined in our partnership agreement.

[5] For the three months ended June 30, 2017, there were no units excluded from the if-converted method of calculating diluted earnings per share. For the six months ended June 30, 2017 and the three and six months ended June 30, 2016, 43,201,310 anti-dilutive Preferred units and 18,114,975 anti-dilutive Class E units were excluded from the if-converted method of calculating diluted earnings per unit. For the six months ended June 30, 2017, 66,100,000 of Class D units were excluded from the if-converted method of calculating diluted earnings per unit as the General Partner irrevocably waived all of its rights associated with the Class D units effective April 27, 2017. For the three and six months ended June 30, 2016, 66,100,000 anti-dilutive Class D units were excluded from the if-converted method of calculating diluted earnings per unit.