CONSOLIDATED STATEMENTS OF PARTNERS CAPITAL - USD ($) $ in Millions	Total	General Partner [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Series 1 Preferred units [Member]	Class D Unit [Member]	Class E Unit [Member]	Class A Common Units [Member]	Class B Common Unit [Member]	I Units [Member]	Incentive Distribution Unit [Member]
Beginning balance at Dec. 31, 2013		$ 301.5	$ (76.6)	$ 1,160.7	$ 0.0	$ 0.0	$ 2,979.0	$ 65.3	$ 1,291.9	$ 0.0
Beginning balance (in shares) at Dec. 31, 2013				48,000,000	0	0	254,208,428	7,825,500	63,743,099	0
Net income allocation	$ 371.8	38.4		$ 90.0	$ 106.5	$ 0.0	$ 165.8	$ 13.4	$ 43.6	$ 4.1
Allocation of proceeds and issuance costs from unit issuances		0.0					$ 0.0
Allocation of proceeds and issuance costs from unit issuances (in shares)							0
Allocation of fair value	0.0	(59.6)					$ (2,255.6)	(58.5)	(598.1)
Accretion of discount on preferred units	14.9			14.9
Transfer of interests in subsidiary to Midcoast Energy Partners, L.P.	125.4	(2.5)					(95.2)	(2.9)	(24.8)
Issuance of Units					$ 2,480.1	$ 0.0				$ 491.7
Issuance of Units (in shares)					66,100,000	0				1,000
Distributions	(154.0)	(79.5)		$ (90.0)	$ (69.8)	$ 0.0	$ (558.5)	$ (17.3)	$ 0.0	$ (2.8)
Distributions (in shares)				0	0	0	0	0	4,562,088	0
Net realized gains (losses) on changes in fair value of derivative financial instruments reclassified to earnings			22.0
Unrealized net gain (loss) on derivative financial instruments			(156.8)
Ending balance at Dec. 31, 2014		198.3	(211.4)	$ 1,175.6	$ 2,516.8	$ 0.0	$ 235.5	$ 0.0	$ 712.6	$ 493.0
Ending balance (in shares) at Dec. 31, 2014				48,000,000	66,100,000	0	254,208,428	7,825,500	68,305,187	1,000
Beginning balance at Dec. 31, 2013	1,975.6
Noncontrolling interest
Capital contributions	1,391.6
Other comprehensive income (loss), net of tax	7.1
Ending balance at Dec. 31, 2014	3,609.0
Total Enbridge Energy Partners, L.P. partners’ capital at December 31	8,729.4		5,120.4
Net income allocation	132.0	(31.9)		$ 90.0	$ 153.2	$ 42.0	$ 311.3	$ 18.1	$ (379.7)	$ 19.0
Allocation of proceeds and issuance costs from unit issuances		6.0					$ 288.8
Allocation of proceeds and issuance costs from unit issuances (in shares)							8,000,000
Allocation of fair value	(403.7)	(8.2)					$ (235.5)	0.0	(120.3)
Accretion of discount on preferred units	11.2			11.2
Transfer of interests in subsidiary to Midcoast Energy Partners, L.P.	0.0	0.0					0.0	0.0	0.0
Issuance of Units					$ 0.0	$ 767.7				$ 0.0
Issuance of Units (in shares)					0	18,114,975				0
Distributions	(339.4)	(16.8)		$ (90.0)	$ (152.4)	$ (31.5)	$ (600.1)	$ (18.1)	$ 0.0	$ (17.0)
Distributions (in shares)				0	0	0	0	0	4,980,552	0
Net realized gains (losses) on changes in fair value of derivative financial instruments reclassified to earnings			(3.1)
Unrealized net gain (loss) on derivative financial instruments			(155.5)
Ending balance at Dec. 31, 2015	4,967.6	$ 147.4	(370.0)	$ 1,186.8	$ 2,517.6	$ 778.2	$ 0.0	$ 0.0	$ 212.6	$ 495.0
Ending balance (in shares) at Dec. 31, 2015		195,124,456		48,000,000	66,100,000	18,114,975	262,208,428	7,825,500	73,285,739	1,000
Noncontrolling interest
Capital contributions	863.3
Other comprehensive income (loss), net of tax	(5.8)
Ending balance at Dec. 31, 2015	3,944.5
Total Enbridge Energy Partners, L.P. partners’ capital at December 31	8,912.1		4,967.6
Net income allocation	(162.4)	$ (796.9)		$ 90.0	$ 154.1	$ 42.2	$ 611.5	$ 18.2	$ (212.6)	$ 21.1
Allocation of proceeds and issuance costs from unit issuances		0.0					$ 0.0
Allocation of proceeds and issuance costs from unit issuances (in shares)							0
Allocation of fair value	0.0	0.0					$ 0.0	0.0	0.0
Accretion of discount on preferred units	4.7			4.7
Transfer of interests in subsidiary to Midcoast Energy Partners, L.P.	0.0	0.0					0.0	0.0	0.0
Issuance of Units					$ 0.0	$ 0.0				$ 0.0
Issuance of Units (in shares)					0	0				0
Distributions	(241.8)	(17.3)		$ (90.0)	$ (154.1)	$ (42.2)	$ (611.5)	$ (18.2)	$ 0.0	$ (20.9)
Distributions (in shares)				0	0	0	0	0	8,571,429	0
Net realized gains (losses) on changes in fair value of derivative financial instruments reclassified to earnings			39.4
Unrealized net gain (loss) on derivative financial instruments			(8.7)
Ending balance at Dec. 31, 2016	3,976.4	$ (666.8)	(339.3)	$ 1,191.5	$ 2,517.6	$ 778.2	$ 0.0	$ 0.0	$ 0.0	$ 495.2
Ending balance (in shares) at Dec. 31, 2016		196,126,169		48,000,000	66,100,000	18,114,975	262,208,428	7,825,500	81,857,168	1,000
Noncontrolling interest
Capital contributions	117.3
Other comprehensive income (loss), net of tax	(0.3)
Ending balance at Dec. 31, 2016	3,846.1
Total Enbridge Energy Partners, L.P. partners’ capital at December 31	$ 7,822.5		$ 3,976.4