REVENUES (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Product Information [Line Items]
Revenues	$ 15,045.0	$ 24,468.9	$ 27,164.0
Deferred revenue	45.1	17.0
Gasoline and Distillates [Member]
Product Information [Line Items]
Revenues	12,799.4	21,278.4	23,032.6
Feedstocks and other [Member]
Product Information [Line Items]
Revenues	935.5	806.9	1,374.2
Asphalt and blackoils [Member]
Product Information [Line Items]
Revenues	777.9	1,426.4	1,592.9
Chemicals [Member]
Product Information [Line Items]
Revenues	351.5	682.3	842.8
Lubricants [Member]
Product Information [Line Items]
Revenues	$ 180.7	$ 274.9	$ 321.5