v3.19.1

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES DISAGGREGATION OF REVENUE (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Mineral [Member]
Disaggregation of Revenue [Line Items]
Sales	$ 54,364	$ 41,410	$ 55,176	$ 57,320	$ 42,582	$ 36,484	$ 47,347	$ 51,502	$ 208,270	[1]	$ 177,915	[1]	$ 212,097	[1]
Potash [Member]
Disaggregation of Revenue [Line Items]
Sales									107,471		95,540		149,335
Trio [Member]
Disaggregation of Revenue [Line Items]
Sales									64,139		63,338		52,884
Water [Member]
Disaggregation of Revenue [Line Items]
Sales									19,797		7,042		0
Salt [Member]
Disaggregation of Revenue [Line Items]
Sales									6,877		6,334		2,947
Magnesium Chloride [Member]
Disaggregation of Revenue [Line Items]
Sales									6,804		5,432		6,931
Brines [Member]
Disaggregation of Revenue [Line Items]
Sales									1,777		229		0
Other [Member]
Disaggregation of Revenue [Line Items]
Sales									$ 1,405		$ 0		$ 0
[1] Segment sales include the sales of byproducts generated during the production of potash and Trio®. Prior to the adoption of ASC 606, sales of byproducts were accounted for as a credit to cost of goods sold for potash and Trio®.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130539-203045

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
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-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130545-203045

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-Topic 606
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