UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
ASSETS
Cash and cash equivalents	$ 16,233	$ 15,544
Restricted cash	8,067
Accounts receivable, net	54,301	61,932
Other current assets	12,167	4,623
Total current assets	90,768	82,099
Property, plant and equipment, net	1,788,222	1,817,546
Intangible assets, net	192,378	199,566
Investment in equity method investees	394,405	392,740
Other noncurrent assets	6,792	7,866
TOTAL ASSETS	2,472,565	2,499,817
LIABILITIES AND CAPITAL
Trade accounts payable	15,873	11,878
Accrued expenses	11,666	13,036
Deferred revenue	10,017	9,988
Ad valorem taxes payable	7,589	9,086
Accrued compensation and employee benefits	4,481	9,658
Accrued interest	8,512	8,007
Accrued environmental remediation	1,885	1,392
Other current liabilities	14,682	5,363
Total current liabilities	74,705	68,408
Long-term debt	1,304,918	1,347,326
Noncurrent deferred revenue	47,644	48,250
Noncurrent accrued environmental remediation	1,368	1,537
Other noncurrent liabilities	21,700	21,747
Total liabilities	1,450,335	1,487,268
Commitments and contingencies (Note 13)
Mezzanine Capital
Subsidiary Series A Preferred Units (86,802 and 85,308 units issued and outstanding at March 31, 2021 and December 31, 2020, respectively)	93,590	89,658
Partners' Capital
Series A Preferred Units (162,109 units issued and outstanding at March 31, 2021 and December 31, 2020)	178,712	174,425
Common limited partner capital (6,206,021 and 6,110,092 units issued and outstanding at March 31, 2021 and December 31, 2020, respectively)	749,928	748,466
Total partners' capital	928,640	922,891
TOTAL LIABILITIES AND CAPITAL	$ 2,472,565	$ 2,499,817