v2.4.1.9
INVENTORY AND LONG-TERM PARTS INVENTORY (Summary of Inventory) (Details) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Inventory Disclosure [Abstract]    
Finished goods product inventory, net $ 39,013us-gaap_InventoryFinishedGoods $ 44,137us-gaap_InventoryFinishedGoods
In-process mineral inventory 14,799us-gaap_InventoryWorkInProcess 19,584us-gaap_InventoryWorkInProcess
Total product inventory, net 53,812ipi_TotalProductInventory 63,721ipi_TotalProductInventory
Current parts inventory 20,634us-gaap_InventoryPartsAndComponentsNetOfReserves 20,373us-gaap_InventoryPartsAndComponentsNetOfReserves
Total current inventory, net 74,446us-gaap_InventoryNet 84,094us-gaap_InventoryNet
Long-term parts inventory 17,700ipi_LongTermPartsInventoryNoncurrent 16,366ipi_LongTermPartsInventoryNoncurrent
Total inventory, net $ 92,146ipi_InventoryCurrentAndNoncurrentNet $ 100,460ipi_InventoryCurrentAndNoncurrentNet