Inventories (Details) $ in Thousands, bu in Millions	Sep. 30, 2018 USD ($)	Dec. 31, 2017 USD ($) bu	Sep. 30, 2017 USD ($) bu
Inventory, Net [Abstract]
Grain	$ 324,232	$ 505,217	$ 342,837
Ethanol and co-products	15,419	11,003	12,502
Plant nutrients and cob products	145,363	126,962	114,131
Retail merchandise	0	0	718
Railcar repair parts	5,317	5,521	5,414
Total inventories	$ 490,331	$ 648,703	$ 475,602
Bushels of grain held in storage for others and excluded from inventory calculations \| bu		1.0	1.0

Grain Held in Storage, Excluded from Inventory Calculations

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- Definition

Railcar repair parts inventory.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Carrying amount as of the balance sheet date of merchandise or supplies held which are related to plants and animals.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Carrying amount as of the balance sheet date of products that are used in the growth of plant goods (examples would include seeds, soil, fertilizers and other products).

+ References

+ Details

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- Definition

Carrying amount as of the balance sheet date of merchandise, goods, commodities, or supplies relating to a source of usable power held for future sale or future use in manufacturing or production process.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.6(a))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 330
-SubTopic 10
-Section 35
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=68049868&loc=d3e3927-108312

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82887183&loc=d3e6676-107765

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- References

No definition available.

+ Details

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- Definition

Carrying amount as of the balance sheet date of merchandise inventory purchased by a retailer, wholesaler or distributor and held for future sale.

+ References

+ Details

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