REVENUES (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Product Information [Line Items]
Revenues	$ 24,468.9	$ 27,164.0	$ 21,772.4
Deferred revenue	17.0	17.1
Gasoline and Distillates [Member]
Product Information [Line Items]
Revenues	21,278.4	23,032.6	18,316.1
Feedstocks and other [Member]
Product Information [Line Items]
Revenues	806.9	1,374.2	1,218.4
Asphalt and blackoils [Member]
Product Information [Line Items]
Revenues	1,426.4	1,592.9	1,162.3
Chemicals [Member]
Product Information [Line Items]
Revenues	682.3	842.8	770.5
Lubricants [Member]
Product Information [Line Items]
Revenues	$ 274.9	$ 321.5	$ 305.1

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130543-203045

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130539-203045

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130545-203045

Name:	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration