CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
CURRENT ASSETS:
Cash and cash equivalents	$ 21,282	$ 29,128
Restricted cash	5,736	27,277
Accounts receivable—trade, net	392,465	417,002
Inventories	99,877	65,137
Other	60,809	54,530
Total current assets	580,169	593,074
FIXED ASSETS, at cost	5,173,475	5,540,596
Less: Accumulated depreciation	(1,322,141)	(1,246,121)
Net fixed assets	3,851,334	4,294,475
MINERALS LEASEHOLDS, net of accumulated depletion	552,575	555,825
NET INVESTMENT IN DIRECT FINANCING LEASES, net of unearned income	0	107,702
EQUITY INVESTEES	319,068	334,523
INTANGIBLE ASSETS, net of amortization	128,742	138,927
GOODWILL	301,959	301,959
RIGHT OF USE ASSETS, net	153,925	177,071
OTHER ASSETS, net of amortization	45,847	94,085
TOTAL ASSETS	5,933,619	6,597,641
CURRENT LIABILITIES:
Accounts payable—trade	198,433	218,737
Accrued liabilities	184,978	196,758
Total current liabilities	383,411	415,495
SENIOR SECURED CREDIT FACILITY	643,700	959,300
SENIOR UNSECURED NOTES, net of debt issuance costs	2,750,016	2,469,937
DEFERRED TAX LIABILITIES	13,317	12,640
OTHER LONG-TERM LIABILITIES	393,018	393,850
Total liabilities	4,183,462	4,251,222
MEZZANINE CAPITAL
Class A Convertible Preferred Units, 25,336,778 issued and outstanding at December 31, 2020 and 2019	790,115	790,115
Redeemable noncontrolling interests, 141,249 and 130,000 preferred units issued and outstanding at December 31, 2020 and 2019, respectively	141,194	125,133
COMMITMENTS AND CONTINGENCIES (Note 21)
PARTNERS’ CAPITAL:
Common unitholders, 122,579,218 and 122,579,218 units issued and outstanding at December 31, 2020 and 2019, respectively	829,326	1,443,320
Accumulated other comprehensive loss	(9,365)	(8,431)
Noncontrolling interests	(1,113)	(3,718)
Total partners' capital	818,848	1,431,171
TOTAL LIABILITIES, MEZZANINE CAPITAL AND PARTNERS’ CAPITAL	$ 5,933,619	$ 6,597,641