v3.8.0.1
BUSINESS SEGMENT (Information by Segment) (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Segment Reporting Information [Line Items]        
Sales $ 32,060 $ 43,643 $ 124,302 $ 168,760
Less: Freight costs 6,160 8,187 22,867 27,450
Warehousing and handling costs 2,046 2,616 7,013 7,818
Cost of goods sold 19,395 35,272 84,981 136,899
Lower-of-cost-or-market inventory adjustments 667 5,192 4,808 17,129
Costs associated with abnormal production and other 0 0 0 1,707
Gross Margin (Deficit) 3,792 (7,624) 4,633 (22,243)
Depreciation, depletion and amortization expense [1] 8,270 8,756 25,890 32,965
Operating Segments | Potash        
Segment Reporting Information [Line Items]        
Sales 20,711 35,357 75,745 128,248
Less: Freight costs 2,864 6,722 9,401 20,156
Warehousing and handling costs 1,173 2,072 4,051 6,358
Cost of goods sold 11,534 29,027 50,776 108,816
Lower-of-cost-or-market inventory adjustments 113 4,856 146 16,793
Costs associated with abnormal production and other       650
Gross Margin (Deficit) 5,027 (7,320) 11,371 (24,525)
Depreciation, depletion and amortization expense [1] 6,567 8,090 20,685 28,970
Operating Segments | Trio        
Segment Reporting Information [Line Items]        
Sales 11,349 8,286 48,557 40,512
Less: Freight costs 3,296 1,465 13,466 7,294
Warehousing and handling costs 873 544 2,962 1,460
Cost of goods sold 7,861 6,245 34,205 28,083
Lower-of-cost-or-market inventory adjustments 554 336 4,662 336
Costs associated with abnormal production and other       1,057
Gross Margin (Deficit) (1,235) (304) (6,738) 2,282
Depreciation, depletion and amortization expense [1] 1,687 597 5,091 3,150
Corporate/Other        
Segment Reporting Information [Line Items]        
Sales 0 0 0 0
Less: Freight costs 0 0 0 0
Warehousing and handling costs 0 0 0 0
Cost of goods sold 0 0 0 0
Lower-of-cost-or-market inventory adjustments 0 0 0 0
Costs associated with abnormal production and other       0
Gross Margin (Deficit) 0 0 0 0
Depreciation, depletion and amortization expense [1] $ 16 $ 69 $ 114 $ 845
[1] Depreciation, depletion and amortization incurred for potash and Trio® excludes depreciation, depletion and amortization amounts absorbed in or relieved from inventory.