ORGANIZATION AND BASIS OF PRESENTATION - Additional Information (Details) $ / shares in Units, mi in Thousands, bbl in Millions		9 Months Ended
	Nov. 01, 2019 USD ($)	Sep. 30, 2019 USD ($) terminal mi bbl	May 10, 2019 $ / shares
Business Acquisition [Line Items]
Length of refined petroleum products pipelines (in miles) | mi		6
Number of terminals (more than) | terminal		115
Storage capacity of refined petroleum product terminals (in bbl) | bbl		118
Hercules Merger Sub LLC
Business Acquisition [Line Items]
Right to receive cash (in dollars per share) | $ / shares			$ 41.50
Line of Credit | Subsequent event
Business Acquisition [Line Items]
Maximum borrowing capacity	$ 2,850,000,000
Prior Credit Facility | Line of Credit
Business Acquisition [Line Items]
Maximum borrowing capacity		$ 1,500,000,000
Prior Credit Facility | Line of Credit | Subsequent event
Business Acquisition [Line Items]
Debt terminated	1,500,000,000
Revolving Credit Facility | Line of Credit | Subsequent event
Business Acquisition [Line Items]
Maximum borrowing capacity	600,000,000
Term Loan Credit Facility | Line of Credit | Subsequent event
Business Acquisition [Line Items]
Maximum borrowing capacity	$ 2,250,000,000