Consolidated Balance Sheets - USD ($) $ in Thousands		Sep. 30, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents		$ 99,862	$ 444,922
Accounts receivable, net		583,652	452,880
Other current assets		73,196	45,262
Total current assets		756,710	943,064
Property, plant, and equipment
Cost		12,732,926	12,641,745
Less accumulated depreciation		4,208,845	3,931,800
Net property, plant, and equipment		8,524,081	8,709,945
Goodwill		4,783	4,783
Other intangible assets		752,659	776,409
Equity investments		1,181,181	1,224,813
Other assets	[1]	199,964	171,013
Total assets	[2]	11,419,378	11,830,027
Current liabilities
Accounts and imbalance payables		341,220	210,691
Short-term debt		726,429	438,870
Accrued ad valorem taxes		49,065	41,427
Accrued liabilities		190,628	269,947
Total current liabilities		1,307,342	960,935
Long-term liabilities
Long-term debt		6,399,874	7,415,832
Deferred income taxes		24,470	22,195
Asset retirement obligations		271,022	260,283
Other liabilities		320,224	275,570
Total long-term liabilities		7,015,590	7,973,880
Total liabilities	[3]	8,322,932	8,934,815
Equity and partners' capital
Common units (408,610,916 and 413,839,863 units issued and outstanding at September 30, 2021, and December 31, 2020, respectively)		2,965,944	2,778,339
General partner units (9,060,641 units issued and outstanding at September 30, 2021, and December 31, 2020)		(11,286)	(17,208)
Total partners' capital		2,954,658	2,761,131
Noncontrolling interests		141,788	134,081
Total equity and partners' capital		3,096,446	2,895,212
Total liabilities, equity, and partners' capital		$ 11,419,378	$ 11,830,027
Common units issued		408,610,916	413,839,863
Common units outstanding		408,610,916	413,839,863
General partner units issued		9,060,641	9,060,641
General partner units outstanding		9,060,641	9,060,641

[1] Other assets includes $11.2 million and $4.2 million of NGLs line-fill inventory as of September 30, 2021, and December 31, 2020, respectively. Other assets also includes $63.1 million and $71.9 million of materials and supplies inventory as of September 30, 2021, and December 31, 2020, respectively.

[2] Total assets includes related-party amounts of $1.6 billion as of September 30, 2021, and December 31, 2020, which includes related-party Accounts receivable, net of $289.4 million and $291.3 million as of September 30, 2021, and December 31, 2020, respectively. See Note 6.

[3] Total liabilities includes related-party amounts of $250.7 million and $164.7 million as of September 30, 2021, and December 31, 2020, respectively. See Note 6.