Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income (loss)	$ (32,800,000)	$ 320,000,000	$ (888,200,000)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Impairments	365,800,000	17,100,000	873,300,000
Depreciation and amortization	577,300,000	545,300,000	503,900,000
Loss on disposition of assets	400,000	0	13,200,000
Non-cash unit-based compensation	41,100,000	48,100,000	30,300,000
Deferred tax expense (benefit)	16,300,000	(197,200,000)	2,100,000
(Gain) loss on derivatives recognized in net income (loss)	(5,200,000)	4,200,000	11,100,000
Cash settlements on derivatives	(7,000,000)	(11,200,000)	10,500,000
Gain on extinguishment of debt	0	(9,000,000)	0
Amortization of debt issue costs, net (premium) discount of notes and installment payable	4,300,000	29,300,000	53,400,000
Distribution of earnings from unconsolidated affiliates	15,800,000	13,300,000	3,100,000
(Income) loss from unconsolidated affiliates	(13,300,000)	(9,600,000)	19,900,000
Non-cash revenue from contract restructuring	(45,500,000)	0	0
Other operating activities	(2,600,000)	600,000	900,000
Changes in assets and liabilities net of assets acquired and liabilities assumed:
Accounts receivable, accrued revenue and other	(113,100,000)	(189,400,000)	(118,100,000)
Natural gas and NGLs inventory, prepaid expenses, and other	(12,200,000)	(23,500,000)	18,700,000
Accounts payable, accrued gas and crude oil purchases, and other accrued liabilities	58,300,000	162,100,000	132,300,000
Net cash provided by operating activities	847,600,000	700,100,000	666,400,000
Cash flows from investing activities:
Additions to property and equipment	(843,100,000)	(790,800,000)	(663,000,000)
Acquisition of business, net of cash acquired	0	0	(791,500,000)
Proceeds from sale of unconsolidated affiliate investment	0	189,700,000	0
Proceeds from sale of property	1,900,000	2,300,000	93,100,000
Investment in unconsolidated affiliates	(100,000)	(12,600,000)	(73,800,000)
Distribution from unconsolidated affiliates in excess of earnings	6,900,000	200,000	54,600,000
Other investing activities	8,100,000	400,000	300,000
Net cash used in investing activities	(826,300,000)	(610,800,000)	(1,380,300,000)
Cash flows from financing activities:
Proceeds from borrowings	3,946,800,000	2,381,800,000	2,150,400,000
Payments on borrowings	(3,060,000,000)	(2,123,400,000)	(1,917,500,000)
Payment of installment payable for EOGP acquisition	(250,000,000)	(250,000,000)	0
Debt financing costs	(1,900,000)	(5,500,000)	(4,700,000)
Proceeds from issuance of ENLK common units	46,100,000	106,900,000	167,500,000
Distributions to non-controlling interest	(517,200,000)	(433,700,000)	(384,200,000)
Distribution to members	(194,800,000)	(186,000,000)	(185,400,000)
Contributions by non-controlling interest	90,200,000	57,300,000	167,900,000
Other financing activities	(11,300,000)	(11,200,000)	(10,500,000)
Net cash provided by (used in) financing activities	47,900,000	(69,800,000)	707,600,000
Net increase (decrease) in cash and cash equivalents	69,200,000	19,500,000	(6,300,000)
Cash and cash equivalents, beginning of period	31,200,000	11,700,000	18,000,000
Cash and cash equivalents, end of period	100,400,000	31,200,000	11,700,000
Series B Preferred Units
Cash flows from financing activities:
Proceeds from issuance of ENLK Preferred Units	0	0	724,100,000
Series C Preferred Units
Cash flows from financing activities:
Proceeds from issuance of ENLK Preferred Units	$ 0	$ 394,000,000	$ 0