CONSOLIDATED STATEMENTS OF CHANGES IN PARTNERS' CAPITAL (UNAUDITED) - USD ($) $ in Millions	Total	Class A Shares	Noncontrolling Interest	Accumulated Other Comprehensive Income
Balance, beginning of period at Dec. 31, 2019	$ 1,332.1	$ 131.1	$ 1,200.6	$ 0.4
Net income	129.0	6.5	122.5
Equity-based compensation	0.5	0.5
Distributions to unitholders	(121.0)	(7.6)	(113.4)
Other comprehensive income (loss)	(0.2)			(0.2)
Balance, end of period at Mar. 31, 2020	1,340.4	130.5	1,209.7	0.2
Balance, beginning of period at Dec. 31, 2019	1,332.1	131.1	1,200.6	0.4
Net income	236.8
Other comprehensive income (loss)	(0.4)
Balance, end of period at Jun. 30, 2020	1,327.2	128.2	1,199.0
Balance, beginning of period at Mar. 31, 2020	1,340.4	130.5	1,209.7	0.2
Net income	107.8	5.3	102.5
Equity-based compensation	0.3	0.3
Distributions to unitholders	(122.7)	(7.9)	(114.8)
Other comprehensive income (loss)	(0.2)			$ (0.2)
Hess Water Services Acquisition Final Settlement	1.6		1.6
Balance, end of period at Jun. 30, 2020	1,327.2	128.2	1,199.0
Balance, beginning of period at Dec. 31, 2020	1,326.0	125.0	1,201.0
Net income	159.6	8.6	151.0
Equity-based compensation	0.4	0.4
Distributions to unitholders	(127.3)	(8.2)	(119.1)
Recognition of deferred tax asset	26.4	26.4
Sales of shares held by Sponsors		31.8	(31.8)
Balance, end of period at Mar. 31, 2021	1,385.1	184.0	1,201.1
Balance, beginning of period at Dec. 31, 2020	1,326.0	125.0	1,201.0
Net income	321.6
Balance, end of period at Jun. 30, 2021	1,418.6	184.0	1,234.6
Balance, beginning of period at Mar. 31, 2021	1,385.1	184.0	1,201.1
Net income	162.0	11.0	151.0
Equity-based compensation	0.3	0.3
Distributions to unitholders	(128.8)	(11.3)	(117.5)
Balance, end of period at Jun. 30, 2021	$ 1,418.6	$ 184.0	$ 1,234.6