INVENTORIES (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Inventory [Line Items]
Crude oil and feedstocks	$ 1,226,100		$ 1,044,800
Refined products and blendstocks	1,375,100		1,361,700
Warehouse stock and other	109,400		109,400
Inventory, Gross	2,710,600		2,515,900
Lower of cost or market adjustment	(145,800)	$ 212,800	(651,800)	$ 300,500
Total inventories	2,564,800		1,864,100
Income (Loss) from Operations	335,500	64,700
Scenario, Adjustment [Member]
Inventory [Line Items]
Lower of cost or market adjustment	(145,800)		(651,800)
Income (Loss) from Operations	506,000	$ 87,700
Titled Inventory [Member]
Inventory [Line Items]
Crude oil and feedstocks	1,156,200		1,044,800
Refined products and blendstocks	1,067,100		1,026,900
Warehouse stock and other	109,400		109,400
Inventory, Gross	2,332,700		2,181,100
Lower of cost or market adjustment	(76,800)		(557,200)
Total inventories	2,255,900		1,623,900
Inventory Supply and Offtake Arrangements [Member]
Inventory [Line Items]
Crude oil and feedstocks	69,900		0
Refined products and blendstocks	308,000		334,800
Warehouse stock and other	0		0
Inventory, Gross	377,900		334,800
Lower of cost or market adjustment	(69,000)		(94,600)
Total inventories	$ 308,900		$ 240,200