REVENUE FROM CONTRACTS WITH CUSTOMERS - Contract Revenue (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated future ASC 606 revenue	$ 19,454
Estimated revenue in accordance with ASC 842, 2020	158,700
Estimated revenue in accordance with ASC 842, 2021	119,800
Estimated revenue in accordance with ASC 842, 2022	86,300
Estimated revenue in accordance with ASC 842, 2023	72,000
Estimated revenue in accordance with ASC 840, 2024	47,000
Estimated revenue in accordance with ASC 842, thereafter	489,800
Gulf Coast Terminals
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated future ASC 606 revenue	7,135
Midwest Terminals and Pipeline System
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated future ASC 606 revenue	623
River terminals
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated future ASC 606 revenue	1,612
West Coast terminals
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated future ASC 606 revenue	10,084
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated future ASC 606 revenue	$ 11,128
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01 | Gulf Coast Terminals
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated future ASC 606 revenue	$ 4,658
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01 | Midwest Terminals and Pipeline System
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated future ASC 606 revenue	$ 576
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01 | River terminals
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated future ASC 606 revenue	$ 1,090
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01 | West Coast terminals
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated future ASC 606 revenue	$ 4,804
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated future ASC 606 revenue	$ 6,104
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | Gulf Coast Terminals
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated future ASC 606 revenue	$ 1,513
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | Midwest Terminals and Pipeline System
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated future ASC 606 revenue	$ 47
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | River terminals
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated future ASC 606 revenue	$ 522
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | West Coast terminals
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated future ASC 606 revenue	$ 4,022
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated future ASC 606 revenue	$ 2,222
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | Gulf Coast Terminals
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated future ASC 606 revenue	$ 964
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | West Coast terminals
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated future ASC 606 revenue	$ 1,258
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months