For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

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Data Type:	num:percentItemType
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Period Type:	duration

Nature of Ops and Sign. Acctg Policies (Major Customers) (Details Textuals 3)	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2020	Sep. 18, 2020	Dec. 31, 2019	Dec. 31, 2018
Plains Marketing LP
Product Information [Line Items]
Revenue from major customer (percentage)	30.00%	30.00%	32.00%	24.00%
Marathon Petroleum Company
Product Information [Line Items]
Revenue from major customer (percentage)	13.00%	12.00%
Hunt Crude Oil Company
Product Information [Line Items]
Revenue from major customer (percentage)	12.00%	12.00%	11.00%	10.00%
Sunoco Inc
Product Information [Line Items]
Revenue from major customer (percentage)			11.00%