Consolidated Statement of Changes in Members' Equity - USD ($) $ in Millions		Total		Common Units	Accumulated Other Comprehensive Loss	Non-Controlling Interest	Redeemable Non-Controlling Interest (Temporary Equity)
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				487,800,000
Increase (Decrease) in Members' Equity
Conversion of restricted units for common units, net of units withheld for taxes		(4.0)		$ (4.0)		0.0
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		0.0
Contributions from non-controlling interests		37.1				37.1
Distributions		(117.7)		(93.3)		(24.4)	$ (0.3)
Unrealized gain (loss) on designated cash flow hedge	[1]	(13.1)			(13.1)
Fair value adjustment related to redeemable non-controlling interest		0.7		0.7			(0.9)
Net income (loss)		(260.4)		(286.8)		26.4	0.0
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				489,100,000
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)
Fair value adjustment related to redeemable non-controlling interest		0.7		0.7			(0.9)
Redemption of non-controlling interest							(4.0)
Redeemable noncontrolling interest, ending balance at Mar. 31, 2020							0.0
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				487,800,000
Increase (Decrease) in Members' Equity
Unrealized gain (loss) on designated cash flow hedge	[2]	(11.6)
Member equity, end balance at Jun. 30, 2020		3,429.6		$ 1,728.5	(22.6)	1,723.7
Units outstanding, end balance (in shares) at Jun. 30, 2020				489,500,000
Redeemable noncontrolling interest, beginning balance at Dec. 31, 2019							5.2
Redeemable noncontrolling interest, ending balance at Jun. 30, 2020							0.0
Member equity, beginning balance at Mar. 31, 2020		3,461.0		$ 1,764.4	(24.1)	1,720.7
Units outstanding, beginning balance (in shares) at Mar. 31, 2020				489,100,000
Increase (Decrease) in Members' Equity
Conversion of restricted units for common units, net of units withheld for taxes		(0.3)		$ (0.3)		0.0
Conversion of restricted units for common units, net of units withheld for taxes (in shares)				400,000
Unit-based compensation		6.8		$ 6.8		0.0
Contributions from non-controlling interests		13.2				13.2
Distributions		(82.4)		(46.5)		(35.9)
Unrealized gain (loss) on designated cash flow hedge	[3]	1.5	[2]		1.5
Net income (loss)		29.8		4.1		25.7	0.0
Member equity, end balance at Jun. 30, 2020		3,429.6		$ 1,728.5	(22.6)	1,723.7
Units outstanding, end balance (in shares) at Jun. 30, 2020				489,500,000
Redeemable noncontrolling interest, beginning balance at Mar. 31, 2020							0.0
Increase (Decrease) in Temporary Equity
Distributions		(82.4)		$ (46.5)		(35.9)
Redeemable noncontrolling interest, ending balance at Jun. 30, 2020							0.0
Member equity, beginning balance at Dec. 31, 2020		$ 3,213.0		$ 1,508.8	(15.3)	1,719.5
Units outstanding, beginning balance (in shares) at Dec. 31, 2020		489,381,149		489,400,000
Increase (Decrease) in Members' Equity
Conversion of restricted units for common units, net of units withheld for taxes		$ (1.2)		$ (1.2)
Conversion of restricted units for common units, net of units withheld for taxes (in shares)				700,000
Unit-based compensation		6.5		$ 6.5
Contributions from non-controlling interests		0.9				0.9
Distributions		(72.9)		(47.1)		(25.8)	(0.2)
Unrealized gain (loss) on designated cash flow hedge	[4]	3.6			3.6
Fair value adjustment related to redeemable non-controlling interest		(0.1)		(0.1)			0.2
Net income (loss)		12.6		(12.7)		25.3
Member equity, end balance at Mar. 31, 2021		3,162.4		$ 1,454.2	(11.7)	1,719.9
Units outstanding, end balance (in shares) at Mar. 31, 2021				490,100,000
Redeemable noncontrolling interest, beginning balance at Dec. 31, 2020							0.0
Increase (Decrease) in Temporary Equity
Distributions		(72.9)		$ (47.1)		(25.8)	(0.2)
Fair value adjustment related to redeemable non-controlling interest		(0.1)		(0.1)			0.2
Redeemable noncontrolling interest, ending balance at Mar. 31, 2021							0.0
Member equity, beginning balance at Dec. 31, 2020		$ 3,213.0		$ 1,508.8	(15.3)	1,719.5
Units outstanding, beginning balance (in shares) at Dec. 31, 2020		489,381,149		489,400,000
Increase (Decrease) in Members' Equity
Unrealized gain (loss) on designated cash flow hedge	[2]	$ 7.3
Common units repurchased (in shares)		(317,751)
Member equity, end balance at Jun. 30, 2021		$ 3,098.0		$ 1,390.1	(8.0)	1,715.9
Units outstanding, end balance (in shares) at Jun. 30, 2021		489,854,915		489,900,000
Redeemable noncontrolling interest, beginning balance at Dec. 31, 2020							0.0
Redeemable noncontrolling interest, ending balance at Jun. 30, 2021							0.0
Member equity, beginning balance at Mar. 31, 2021		$ 3,162.4		$ 1,454.2	(11.7)	1,719.9
Units outstanding, beginning balance (in shares) at Mar. 31, 2021				490,100,000
Increase (Decrease) in Members' Equity
Conversion of restricted units for common units, net of units withheld for taxes		(0.2)		$ (0.2)
Conversion of restricted units for common units, net of units withheld for taxes (in shares)				100,000
Unit-based compensation		6.4		$ 6.4
Contributions from non-controlling interests		1.0				1.0
Distributions		(82.7)		(46.7)		(36.0)	0.0
Unrealized gain (loss) on designated cash flow hedge	[5]	3.7	[2]		3.7
Common units repurchased		$ (2.0)		$ (2.0)
Common units repurchased (in shares)		(317,751)		(300,000)
Net income (loss)		$ 9.4		$ (21.6)		31.0
Member equity, end balance at Jun. 30, 2021		$ 3,098.0		$ 1,390.1	$ (8.0)	1,715.9
Units outstanding, end balance (in shares) at Jun. 30, 2021		489,854,915		489,900,000
Redeemable noncontrolling interest, beginning balance at Mar. 31, 2021							0.0
Increase (Decrease) in Temporary Equity
Distributions		$ (82.7)		$ (46.7)		$ (36.0)	0.0
Redeemable noncontrolling interest, ending balance at Jun. 30, 2021							$ 0.0

[1] Includes a tax benefit of $4.0 million.

[2] Includes a tax expense of $1.1 million and a tax expense of $0.5 million for the three months ended June 30, 2021 and 2020, respectively, and a tax expense of $2.2 million and a tax benefit of $3.5 million for the six months ended June 30, 2021 and 2020, respectively.

[3] Includes a tax expense of $0.5 million.

[4] Includes a tax expense of $1.1 million.

[5] Includes a tax expense of $1.1 million.