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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
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-Section 50
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-URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13531-108611

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

Name:	us-gaap_ConcentrationRiskPercentage1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Concentrations (Details)	12 Months Ended
Concentrations (Details)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Supplier Concentration Risk \| 2 Grain Suppliers
Concentration Risk [Line Items]
Concentration risk, percentage	29.00%	29.00%	31.00%
Supplier Concentration Risk \| Pacific Ethanol
Concentration Risk [Line Items]
Concentration risk, percentage	12.00%
Supplier Concentration Risk \| 10 Largest Suppliers
Concentration Risk [Line Items]
Concentration risk, percentage	68.00%	65.00%	63.00%
Net Sales \| Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	40.00%	39.00%	36.00%