UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net income (loss)	$ (53,758)	$ 10,663
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation and amortization	53,160	56,955
Amortization of debt issuance costs	2,086	2,072
Deferred Purchase Price Obligation	90,963	15,825
Unit-based and noncash compensation	4,223	3,999
Loss from equity method investees	2,534	4,041
Distributions from equity method investees	17,124	18,003
Loss (gain) on asset sales, net	(12)	70
Long-lived asset impairment	587	287
Early extinguishment of debt	0	22,020
Write-off of debt issuance costs	0	302
Changes in operating assets and liabilities:
Accounts receivable	(6,265)	41,527
Trade accounts payable	(3,483)	(4,372)
Accrued expenses	6,934	(3,111)
Due (to) from affiliate	(997)	212
Deferred revenue, net	3,281	(39,671)
Ad valorem taxes payable	(1,825)	(3,293)
Accrued interest	(51)	(468)
Accrued environmental remediation, net	(1,805)	(924)
Other, net	(2,647)	(2,796)
Net cash provided by operating activities	110,049	121,341
Cash flows from investing activities:
Capital expenditures	(90,394)	(45,912)
Proceeds from asset sale	496	0
Contributions to equity method investees	0	(15,649)
Other, net	(306)	(521)
Net cash provided by (used in) investing activities	(90,204)	(62,082)
Cash flows from financing activities:
Distributions to unitholders		(89,029)
Borrowings under Revolving Credit Facility	148,000	112,500
Repayments under Revolving Credit Facility	(53,000)	(269,500)
Debt issuance costs	(121)	(15,613)
Payment of redemption and call premiums on senior notes	0	(17,913)
Proceeds from ATM Program common unit issuances, net of costs	0	17,259
Contribution from General Partner	0	465
Issuance of senior notes	0	500,000
Tender and redemption of senior notes	0	(300,000)
Other, net	(3,423)	(2,268)
Net cash provided by (used in) financing activities	(13,063)	(64,099)
Net change in cash and cash equivalents	6,782	(4,840)
Cash and cash equivalents, beginning of period	1,430	7,428
Cash and cash equivalents, end of period	8,212	2,588
Supplemental cash flow disclosures:
Cash interest paid	30,962	33,382
Less capitalized interest	3,085	918
Interest paid (net of capitalized interest)	27,877	32,464
Cash paid for taxes	175	0
Noncash investing and financing activities
Capital expenditures in trade accounts payable (period-end accruals)	20,598	6,869
Capital expenditures relating to contributions in aid of construction for Topic 606 day 1 adoption	33,123	0
Common units
Cash flows from financing activities:
Distributions to unitholders	(90,269)	(89,029)
Series A Preferred Units
Cash flows from financing activities:
Distributions to unitholders	$ (14,250)	$ 0