Consolidated Statements of Changes in Members' Equity - USD ($) $ in Millions		Total		Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjusted Balance	Common Units	Common Units Cumulative Effect, Period of Adoption, Adjustment	Common Units Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss Cumulative Effect, Period of Adoption, Adjusted Balance	Non-Controlling Interest	Non-Controlling Interest Cumulative Effect, Period of Adoption, Adjusted Balance	Redeemable Non-Controlling Interest (Temporary Equity)	Redeemable Non-Controlling Interest (Temporary Equity) Cumulative Effect, Period of Adoption, Adjusted Balance
Member equity, beginning balance at Dec. 31, 2017		$ 5,556.7				$ 1,924.2			$ (2.0)		$ 3,634.5
Units outstanding, beginning balance (in shares) at Dec. 31, 2017						180,600,000
Increase (Decrease) in Members' Equity
Issuance of common units by ENLK		46.1									46.1
Conversion of restricted units for common units, net of units withheld for taxes		(11.3)				$ (5.7)					(5.6)
Conversion of restricted units for common units, net of units withheld for taxes (in shares)						700,000
Unit-based compensation		41.9				$ 20.5					21.4
Change in equity due to issuance of units by ENLK		0.1				0.7					(0.6)
Contributions from non-controlling interests		90.2									90.2
Distributions		(712.0)				(194.8)					(517.2)
Loss on designated cash flow hedge	[1]	0.0
Fair value adjustment related to redeemable non-controlling interest		(4.1)				(0.8)					(3.3)		$ 4.1
Net income (loss)		(33.4)				(13.2)					(20.2)		0.6
Member equity, end balance at Dec. 31, 2018		4,974.2		$ 0.3	$ 4,974.5	$ 1,730.9	$ 0.3	$ 1,731.2	(2.0)	$ (2.0)	3,245.3	$ 3,245.3
Units outstanding, end balance (in shares) at Dec. 31, 2018						181,300,000		181,300,000
Redeemable noncontrolling interest, beginning balance at Dec. 31, 2017													4.6
Increase (Decrease) in Temporary Equity
Fair value adjustment related to redeemable non-controlling interest		(4.1)				$ (0.8)					(3.3)		4.1
Net income (loss)		(33.4)				(13.2)					(20.2)		0.6
Redeemable noncontrolling interest, ending balance at Dec. 31, 2018													9.3	$ 9.3
Increase (Decrease) in Members' Equity
Issuance of common units for ENLK public common units related to the Merger		399.0				$ 1,958.1					(1,559.1)
Issuance of common units for ENLK public common units related to the Merger (in shares)						304,900,000
Conversion of restricted units for common units, net of units withheld for taxes		(10.6)				$ (7.8)					(2.8)
Conversion of restricted units for common units, net of units withheld for taxes (in shares)						1,600,000
Unit-based compensation		38.9				$ 37.5					1.4
Contributions from non-controlling interests		97.5									97.5
Distributions		(687.4)				(467.2)					(220.2)		(0.3)
Loss on designated cash flow hedge	[2],[3]	(9.0)	[1]						(9.0)
Fair value adjustment related to redeemable non-controlling interest		3.0				3.0							(4.0)
Net income (loss)		(999.8)				(1,119.3)					119.5		0.2
Member equity, end balance at Dec. 31, 2019		$ 3,806.1				$ 2,135.5			(11.0)		1,681.6
Units outstanding, end balance (in shares) at Dec. 31, 2019		487,791,612				487,800,000
Increase (Decrease) in Temporary Equity
Fair value adjustment related to redeemable non-controlling interest		$ 3.0				$ 3.0							(4.0)
Net income (loss)		(999.8)				(1,119.3)					119.5		0.2
Redeemable noncontrolling interest, ending balance at Dec. 31, 2019													5.2
Increase (Decrease) in Members' Equity
Issuance of common units for ENLK public common units related to the Merger		399.0
Conversion of restricted units for common units, net of units withheld for taxes		(4.7)				$ (4.7)
Conversion of restricted units for common units, net of units withheld for taxes (in shares)						2,000,000.0
Unit-based compensation		33.0				$ 33.0
Contributions from non-controlling interests		52.6									52.6
Distributions		(353.3)				(232.7)					(120.6)		(0.6)
Loss on designated cash flow hedge		(4.3)	[1]						(4.3)
Fair value adjustment related to redeemable non-controlling interest		0.4				0.4							(0.6)
Redemption of non-controlling interest		0.0				0.0							(4.0)
Common units repurchased		$ (1.2)				$ (1.2)
Common units repurchased (in shares)		(383,614)				(400,000)
Net income (loss)		$ (315.6)				$ (421.5)					105.9
Member equity, end balance at Dec. 31, 2020		$ 3,213.0				$ 1,508.8			$ (15.3)		1,719.5
Units outstanding, end balance (in shares) at Dec. 31, 2020		489,381,149				489,400,000
Increase (Decrease) in Temporary Equity
Fair value adjustment related to redeemable non-controlling interest		$ 0.4				$ 0.4							(0.6)
Net income (loss)		$ (315.6)				$ (421.5)					$ 105.9
Redeemable noncontrolling interest, ending balance at Dec. 31, 2020													$ 0.0

[1] The loss on designated cash flow hedge recorded in accumulated other comprehensive loss for the years ended December 31, 2020 and 2019 was net of a tax benefit of $1.3 million and $3.4 million, respectively

[2] Includes a tax benefit of $1.3 million.

[3] Includes a tax benefit of $3.4 million.