Consolidated Statement of Changes in Members' Equity - USD ($) $ in Millions		Total	Redeemable Non-Controlling Interest (Temporary Equity)	Common Units	Accumulated Other Comprehensive Loss	Non-Controlling Interest	Redeemable Non-Controlling Interest (Temporary Equity)
Member equity, beginning balance at Dec. 31, 2018		$ 4,974.2		$ 1,730.9	$ (2.0)	$ 3,245.3
Units outstanding, beginning balance (in shares) at Dec. 31, 2018				181,300,000
Increase (Decrease) in Members' Equity
Conversion of restricted units for common units, net of units withheld for taxes		(8.4)		$ (5.6)		(2.8)
Conversion of restricted units for common units, net of units withheld for taxes (in shares)				1,000,000.0
Unit-based compensation		13.6		$ 12.2		1.4
Contributions from non-controlling interests		15.7				15.7
Distributions		(178.6)		(51.0)		(127.6)
Fair value adjustment related to redeemable non-controlling interest		2.5		2.5			$ (2.1)
Loss on designated cash flow hedge	[1]	0.0
Net income (loss)		(134.8)		(176.3)		41.5	0.0
Member equity, end balance at Mar. 31, 2019		5,083.5		$ 3,471.1	(2.0)	1,614.4
Units outstanding, end balance (in shares) at Mar. 31, 2019				487,200,000
Redeemable noncontrolling interest, beginning balance at Dec. 31, 2018							9.3
Increase (Decrease) in Temporary Equity
Distributions		(178.6)		$ (51.0)		(127.6)
Redemption of non-controlling interest		0.0
Fair value adjustment related to redeemable non-controlling interest		2.5		2.5			(2.1)
Redeemable noncontrolling interest, ending balance at Mar. 31, 2019							7.2
Member equity, beginning balance at Dec. 31, 2019		$ 3,806.1		$ 2,135.5	(11.0)	1,681.6
Units outstanding, beginning balance (in shares) at Dec. 31, 2019		487,791,612		487,800,000
Increase (Decrease) in Members' Equity
Conversion of restricted units for common units, net of units withheld for taxes		$ (4.0)		$ (4.0)
Conversion of restricted units for common units, net of units withheld for taxes (in shares)				1,300,000
Unit-based compensation		12.3		$ 12.3
Contributions from non-controlling interests		37.1				37.1
Distributions		(117.7)		(93.3)		(24.4)	(0.3)
Fair value adjustment related to redeemable non-controlling interest		0.7		0.7			(0.9)
Loss on designated cash flow hedge	[1]	(13.1)			(13.1)
Net income (loss)		(260.4)		(286.8)		26.4
Member equity, end balance at Mar. 31, 2020		$ 3,461.0		$ 1,764.4	$ (24.1)	1,720.7
Units outstanding, end balance (in shares) at Mar. 31, 2020		489,137,038		489,100,000
Redeemable noncontrolling interest, beginning balance at Dec. 31, 2019							5.2
Increase (Decrease) in Temporary Equity
Distributions		$ (117.7)		$ (93.3)		$ (24.4)	(0.3)
Redemption of non-controlling interest		4.0	$ (4.0)
Fair value adjustment related to redeemable non-controlling interest		$ 0.7		$ 0.7			(0.9)
Redeemable noncontrolling interest, ending balance at Mar. 31, 2020							$ 0.0

[1] Includes a tax benefit of $4.0 million for the three months ended March 31, 2020.