SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020 USD ($) $ / shares	Jun. 30, 2019 USD ($) $ / shares	Jun. 30, 2020 USD ($) $ / shares	Jun. 30, 2019 USD ($) $ / shares	Dec. 31, 2019 USD ($) customer	Jul. 01, 2016
Accounting Policies [Line Items]
Inventory	$ 22,300		$ 22,300		$ 24,500
Debt issuance cost	25,204		25,204		$ 18,111
Amortization of deferred financing costs	1,900	$ 2,000	4,010	$ 4,043
Concentration risk, number of customers | customer					1
Provision for doubtful accounts	2,800		2,800		$ 1,300
Bad debt expense	$ 1,100	$ 0	$ 1,800	$ 3,000
Common stock dividends declared (in dollars per share) | $ / shares	$ 0.33	$ 0.33	$ 0.66	$ 0.66
Preferred stock dividends declared (in dollars per share) | $ / shares			$ 0.52	$ 0.50
Other Assets
Accounting Policies [Line Items]
Inventory	$ 400		$ 400		5,600
Debt fees	2,400		2,400		1,700
Capitalized costs, potential asset acquisitions	46,300		46,300		45,300
Prepaid expense	4,300		4,300		4,100
Derivative assets	$ 700		$ 700		$ 2,400
Customer Group Two | Customer Concentration Risk | Sales Revenue, Segment | Jefferson Terminal
Accounting Policies [Line Items]
Concentration risk	23.00%	23.00%	11.00%	23.00%
Major Accounts Receivable Customer, Customer One | Customer Concentration Risk | Accounts Receivable
Accounting Policies [Line Items]
Concentration risk			27.00%		16.00%
Major Accounts Receivable Customer, Customer Two | Customer Concentration Risk | Accounts Receivable
Accounting Policies [Line Items]
Concentration risk			14.00%
Delaware River Partners LLC | Variable Interest Entity, Primary Beneficiary
Accounting Policies [Line Items]
Ownership percentage						98.00%
Interest held in VIE, as a percentage			100.00%