BUSINESS SEGMENTS - Revenue by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue:
Total revenue from contracts with customers	$ 658,747	$ 768,823	$ 2,142,813	$ 2,532,281
Revenue from leases	61,265	52,000	172,450	156,777
Commodity derivative contracts, net	91,403	88,725	316,826	344,434
Total revenue	811,415	909,548	2,632,089	3,033,492
United States
Revenue:
Total revenue	759,146	846,390	2,477,464	2,847,217
International
Revenue:
Total revenue	52,269	63,158	154,625	186,275
Domestic Pipelines & Terminals
Revenue:
Total revenue from contracts with customers	254,415	246,959	724,755	736,128
Revenue from leases	12,543	9,199	32,558	28,254
Commodity derivative contracts, net	698	330	(4,540)	(2,579)
Total revenue	267,656	256,488	752,773	761,803
Global Marine Terminals
Revenue:
Total revenue from contracts with customers	88,845	98,625	265,745	300,131
Revenue from leases	48,870	42,943	140,334	128,665
Commodity derivative contracts, net	0	0	0	0
Total revenue	137,715	141,568	406,079	428,796
Merchant Services
Revenue:
Total revenue from contracts with customers	329,187	435,140	1,193,809	1,538,653
Revenue from leases	0	0	0	0
Commodity derivative contracts, net	90,705	88,395	321,366	344,923
Total revenue	419,892	523,535	1,515,175	1,883,576
Intersegment
Revenue:
Total revenue from contracts with customers	(13,700)	(11,901)	(41,496)	(42,631)
Revenue from leases	(148)	(142)	(442)	(142)
Commodity derivative contracts, net	0	0	0	2,090
Total revenue	(13,848)	(12,043)	(41,938)	(40,683)
Pipeline transportation
Revenue:
Total revenue from contracts with customers	134,185	125,908	371,023	369,535
Pipeline transportation | Domestic Pipelines & Terminals
Revenue:
Total revenue from contracts with customers	137,065	127,846	379,078	377,276
Pipeline transportation | Global Marine Terminals
Revenue:
Total revenue from contracts with customers	0	0	0	0
Pipeline transportation | Merchant Services
Revenue:
Total revenue from contracts with customers	0	0	0	0
Pipeline transportation | Intersegment
Revenue:
Total revenue from contracts with customers	(2,880)	(1,938)	(8,055)	(7,741)
Terminalling and storage services
Revenue:
Total revenue from contracts with customers	186,146	191,234	553,146	591,012
Terminalling and storage services | Domestic Pipelines & Terminals
Revenue:
Total revenue from contracts with customers	108,244	106,537	316,383	323,493
Terminalling and storage services | Global Marine Terminals
Revenue:
Total revenue from contracts with customers	85,778	92,948	261,546	294,093
Terminalling and storage services | Merchant Services
Revenue:
Total revenue from contracts with customers	0	0	0	0
Terminalling and storage services | Intersegment
Revenue:
Total revenue from contracts with customers	(7,876)	(8,251)	(24,783)	(26,574)
Product sales
Revenue:
Total revenue from contracts with customers	327,923	436,700	1,186,069	1,530,171
Product sales | Domestic Pipelines & Terminals
Revenue:
Total revenue from contracts with customers	0	0	0	0
Product sales | Global Marine Terminals
Revenue:
Total revenue from contracts with customers	2,631	5,243	2,893	5,263
Product sales | Merchant Services
Revenue:
Total revenue from contracts with customers	328,222	433,156	1,191,788	1,531,849
Product sales | Intersegment
Revenue:
Total revenue from contracts with customers	(2,930)	(1,699)	(8,612)	(6,941)
Other services
Revenue:
Total revenue from contracts with customers	10,493	14,981	32,575	41,563
Other services | Domestic Pipelines & Terminals
Revenue:
Total revenue from contracts with customers	9,106	12,576	29,294	35,359
Other services | Global Marine Terminals
Revenue:
Total revenue from contracts with customers	436	434	1,306	775
Other services | Merchant Services
Revenue:
Total revenue from contracts with customers	965	1,984	2,021	6,804
Other services | Intersegment
Revenue:
Total revenue from contracts with customers	$ (14)	$ (13)	$ (46)	$ (1,375)