UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (79,042)	$ (319,166)
Adjustments to reconcile net loss to net cash provided by operating activities -
Depreciation, depletion and amortization	200,975	222,210
Impairment expense	0	280,826
Amortization and write-off of debt issuance costs, premium and discount	9,242	17,515
Amortization of non-cash costs on previously owned direct financing leases	0	(8,217)
Payments received under previously owned direct financing leases (Note 4)	52,500	56,837
Equity in earnings of investments in equity investees	(45,183)	(41,216)
Cash distributions of earnings of equity investees	44,747	40,773
Non-cash effect of long-term incentive compensation plans	5,111	(2,806)
Deferred and other tax liabilities	630	25
Unrealized losses (gains) on derivative transactions	30,729	(19,582)
Cancellation of debt income	0	(20,534)
Other, net	16,191	16,817
Net changes in components of operating assets and liabilities (Note 14)	6,457	72,146
Net cash provided by operating activities	242,357	295,628
CASH FLOWS FROM INVESTING ACTIVITIES:
Payments to acquire fixed and intangible assets	(217,972)	(100,381)
Cash distributions received from equity investees - return of investment	24,126	14,943
Investments in equity investees	(129)	0
Proceeds from asset sales	223	447
Net cash used in investing activities	(193,752)	(84,991)
CASH FLOWS FROM FINANCING ACTIVITIES:
Borrowings on senior secured credit facility	553,100	814,100
Repayments on senior secured credit facility	(763,800)	(788,600)
Proceeds from issuance of senior unsecured notes (Note 9)	259,375	750,000
Net proceeds from issuance of preferred units (Note 10)	93,100	0
Repayment of senior unsecured notes (Note 9)	(80,859)	(827,031)
Debt issuance costs	(12,208)	(15,279)
Contributions from noncontrolling interests	557	2,163
Distributions to common unitholders	(55,161)	(104,192)
Distributions to preferred unitholders	(56,052)	(56,052)
Other, net	1,821	1,865
Net cash used in financing activities	(60,127)	(223,026)
Net decrease in cash, restricted cash, and cash equivalents	(11,522)	(12,389)
Cash, restricted cash and cash equivalents at beginning of period	27,018	56,405
Cash, restricted cash and cash equivalents at end of period	$ 15,496	$ 44,016