Total costs accrued as of the balance sheet date for environmental loss contingencies.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 20
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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Name:	us-gaap_AccrualForEnvironmentalLossContingencies
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

COMMITMENTS AND CONTINGENCIES (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Loss Contingencies [Line Items]
Environmental liability	$ 136.7		$ 141.6
Environmental Issue [Member] \| Torrance Refinery [Member]
Loss Contingencies [Line Items]
Environmental liability	125.4	$ 130.8
Other Noncurrent Liabilities [Member]
Loss Contingencies [Line Items]
Environmental liability	$ 127.6		$ 135.1