INVENTORIES (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Inventory [Line Items]
Crude oil and feedstocks	$ 1,158,700		$ 1,074,100
Refined products and blendstocks	1,380,400		1,328,900
Warehouse stock and other	134,600		120,800
Inventory, Gross	2,673,700		2,523,800
Lower of cost or market adjustment	(1,687,200)		(401,600)
Total inventories	986,500		2,122,200
Income (Loss) from Operations	(1,414,400)	$ 335,500
Scenario, Adjustment [Member]
Inventory [Line Items]
Lower of cost or market adjustment	(1,687,200)	(145,800)	(401,600)	$ (651,800)
Income (Loss) from Operations	(1,285,600)	$ 506,000
Titled Inventory [Member]
Inventory [Line Items]
Crude oil and feedstocks	1,158,700		1,071,400
Refined products and blendstocks	1,109,600		976,000
Warehouse stock and other	134,600		120,800
Inventory, Gross	2,402,900		2,168,200
Lower of cost or market adjustment	(1,521,500)		(324,800)
Total inventories	881,400		1,843,400
Inventory Supply and Offtake Arrangements [Member]
Inventory [Line Items]
Crude oil and feedstocks	0		2,700
Refined products and blendstocks	270,800		352,900
Warehouse stock and other	0		0
Inventory, Gross	270,800		355,600
Lower of cost or market adjustment	(165,700)		(76,800)
Total inventories	$ 105,100		$ 278,800