Derivative Financial Instruments, Investments and Fair Value Measurements - Additional Information (Details) derivative in Millions	Sep. 30, 2020 derivative
Commodity Swap Postions
Derivative [Line Items]
Outstanding positions (less than for commodity swap positions)	1
Forward Contracts \| Purchase Commitments
Derivative [Line Items]
Outstanding positions (less than for commodity swap positions)	3
Forward Contracts \| Sale Commitments
Derivative [Line Items]
Outstanding positions (less than for commodity swap positions)	2
RINs \| Sale Commitments
Derivative [Line Items]
Outstanding positions (less than for commodity swap positions)	62

The number of derivative instruments of a particular group held by the entity.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5579245-113959

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5580258-113959

Name:	us-gaap_DerivativeNumberOfInstrumentsHeld
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant