INVENTORIES (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Inventory [Line Items]
Crude oil and feedstocks	$ 1,107,700		$ 1,107,700			$ 1,044,800
Refined products and blendstocks	1,418,000		1,418,000			1,361,700
Warehouse stock and other	114,700		114,700			109,400
Inventory, Gross	2,640,400		2,640,400			2,515,900
Lower of cost or market adjustment	(327,800)	$ 54,800	(327,800)	$ 54,800		(651,800)	$ 212,800	$ 300,500
Total inventories	2,312,600		2,312,600			1,864,100
Income (Loss) from Operations	(25,600)	392,200	309,900	456,900
Scenario, Adjustment [Member]
Inventory [Line Items]
Lower of cost or market adjustment	(327,800)		(327,800)		$ (145,800)	(651,800)
Income (Loss) from Operations	(182,000)	$ 158,000	324,000	$ 245,700
Titled Inventory [Member]
Inventory [Line Items]
Crude oil and feedstocks	992,700		992,700			1,044,800
Refined products and blendstocks	1,082,900		1,082,900			1,026,900
Warehouse stock and other	114,700		114,700			109,400
Inventory, Gross	2,190,300		2,190,300			2,181,100
Lower of cost or market adjustment	(250,600)		(250,600)			(557,200)
Total inventories	1,939,700		1,939,700			1,623,900
Inventory Supply and Offtake Arrangements [Member]
Inventory [Line Items]
Crude oil and feedstocks	115,000		115,000			0
Refined products and blendstocks	335,100		335,100			334,800
Warehouse stock and other	0		0			0
Inventory, Gross	450,100		450,100			334,800
Lower of cost or market adjustment	(77,200)		(77,200)			(94,600)
Total inventories	$ 372,900		$ 372,900			$ 240,200