NET INCOME PER LIMITED PARTNER UNIT (Basic and Diluted Net Income Per Limited Partner Unit) (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income		$ 172.4	$ 217.8
Less: Net income attributable to noncontrolling interest		(68.8)	(51.3)
Less: Net income attributable to Series 1 preferred unit distributions		(22.5)	(22.5)
Less: Net income attributable to Accretion of discount on Series 1 preferred units		(1.1)	(3.9)
Net income attributable to general and limited partner interests in Enbridge Energy Partners, L.P.		80.0	140.1
Incentive distributions		(5.2)	(3.4)
Distributed earnings		(59.5)	(56.4)
Total distributed earnings attributed to our common units and i-units		(201.7)	(193.5)
Total distributed earnings		(261.2)	(249.9)
Overdistributed earnings		$ (181.2)	$ (109.8)
Weighted average common units and i-units outstanding (in shares)		344,700,000	332,600,000
Basic and diluted earnings per unit:
Distributed earnings per common unit and i-unit (in dollars per share)	[1]	$ 0.59	$ 0.58
Overdistributed earnings per common unit and i-unit (in dollars per share)	[2]	(0.52)	(0.32)
Net income per common unit and i-unit (basic and diluted) (in dollars per share)	[3]	$ 0.07	$ 0.26
Preferred Stock [Member]
Basic and diluted earnings per unit:
Anti-dilutive Preferred Units excluded (in shares)		43,201,310	43,201,310
Class D Units [Member]
Basic and diluted earnings per unit:
Anti-dilutive Preferred Units excluded (in shares)		66,100,000	66,100,000
Class E Units [Member]
Basic and diluted earnings per unit:
Anti-dilutive Preferred Units excluded (in shares)		18,114,975	18,114,975
General Partner [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Distributed earnings attributed to our General Partner		$ (5.2)	$ (5.0)
Class D and Class E Units [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Distributed earnings		$ (49.1)	$ (48.0)

[1] 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.

[2] 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.

[3] For the three months ended March 31, 2016 and 2015, 43,201,310 anti-dilutive Preferred units, 66,100,000 anti-dilutive Class D units and 18,114,975 anti-dilutive Class E units were excluded from the if-converted method of calculating diluted earnings per unit.