Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net loss	$ (315.6)	$ (999.6)	$ (32.8)
Adjustments to reconcile net loss to net cash provided by operating activities:
Impairments	362.8	1,133.5	365.8
Depreciation and amortization	638.6	617.0	577.3
Loss on secured term loan receivable	0.0	52.9	0.0
Non-cash revenue from contract restructuring	0.0	0.0	(45.5)
(Gain) loss on disposition of assets	8.8	(1.9)	0.4
Non-cash unit-based compensation	28.4	39.4	41.1
Payments to terminate interest rate swaps	(10.9)	0.0	0.0
Deferred tax expense	142.1	6.9	16.3
(Gain) loss on derivative activity recognized in net loss	22.0	(14.4)	(5.2)
Cash settlements on derivatives	(7.2)	16.9	(7.0)
Gain on extinguishment of debt	(32.0)	0.0	0.0
Amortization of debt issuance costs, net (premium) discount of notes	4.6	4.9	4.3
Distribution of earnings from unconsolidated affiliates	1.6	16.5	15.8
(Income) loss from unconsolidated affiliates	(0.6)	16.8	(13.3)
Other operating activities	(0.3)	(2.2)	(2.6)
Changes in assets and liabilities:
Accounts receivable, accrued revenue, and other	(21.5)	337.1	(113.1)
Natural gas and NGLs inventory, prepaid expenses, and other	15.1	13.6	(12.2)
Accounts payable, accrued product purchases, and other accrued liabilities	(104.8)	(245.5)	58.3
Net cash provided by operating activities	731.1	991.9	847.6
Cash flows from investing activities:
Additions to property and equipment	(302.2)	(754.9)	(843.1)
Acquisition of assets	(32.3)	0.0	0.0
Proceeds from sale of property	17.6	14.3	1.9
Distribution from unconsolidated affiliates in excess of earnings	0.5	3.7	6.9
Other investing activities	(1.3)	(4.6)	8.0
Net cash used in investing activities	(317.7)	(741.5)	(826.3)
Cash flows from financing activities:
Proceeds from borrowings	1,650.0	3,310.0	3,946.8
Payments on borrowings	(1,786.0)	(2,971.4)	(3,060.0)
Payment of installment payable for EOGP acquisition	0.0	0.0	(250.0)
Debt financing costs	(7.7)	(10.0)	(1.9)
Distributions to non-controlling interests	(121.2)	(220.5)	(517.2)
Distribution to members	(232.7)	(467.2)	(194.8)
Conversion of restricted units, net of units withheld for taxes	(4.7)	(7.8)	(5.7)
Proceeds from issuance of ENLK common units	0.0	0.0	46.1
Contributions by non-controlling interests	52.6	97.5	90.2
Common units repurchased	(1.2)	0.0	0.0
Other financing activities	(0.3)	(4.0)	(5.6)
Net cash provided by (used in) financing activities	(451.2)	(273.4)	47.9
Net increase (decrease) in cash and cash equivalents	(37.8)	(23.0)	69.2
Cash and cash equivalents, beginning of period	77.4	100.4	31.2
Cash and cash equivalents, end of period	$ 39.6	$ 77.4	$ 100.4