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Commitment and contingencies variable interest entities (Details 4) - USD ($) $ in Thousands | Mar. 31, 2017 | Jun. 27, 2016 | Mar. 31, 2016 | Feb. 07, 2013
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Dakota Prairie Refining, LLC [Member] |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |
Total project costs | $ 300,000 |  |  |
Portion of capital commitment | 150,000 |  |  |
Partner portion of capital commitment | 75,000 |  |  |
Excess capital commitments | 300,000 |  |  |
Term loan for project debt financing | 75,000 |  |  |
Dakota Prairie Refining, LLC [Member] | Cash and cash equivalents [Member] |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |
Limited liability entity, consolidated, carrying amount, assets |  |  | $ 478 |
Dakota Prairie Refining, LLC [Member] | Accounts receivable [Member] |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |
Limited liability entity, consolidated, carrying amount, assets |  |  | 11,169 |
Dakota Prairie Refining, LLC [Member] | Inventories [Member] |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |
Limited liability entity, consolidated, carrying amount, assets |  |  | 17,056 |
Dakota Prairie Refining, LLC [Member] | Other current assets [Member] |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |
Limited liability entity, consolidated, carrying amount, assets |  |  | 6,124 |
Dakota Prairie Refining, LLC [Member] | Total current assets [Member] |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |
Limited liability entity, consolidated, carrying amount, assets |  |  | 34,827 |
Dakota Prairie Refining, LLC [Member] | Net property, plant and equipment [Member] |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |
Limited liability entity, consolidated, carrying amount, assets |  |  | 419,492 |
Dakota Prairie Refining, LLC [Member] | Other [Member] |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |
Limited liability entity, consolidated, carrying amount, assets |  |  | 8,941 |
Dakota Prairie Refining, LLC [Member] | Total deferred charges and other assets [Member] |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |
Limited liability entity, consolidated, carrying amount, assets |  |  | 8,941 |
Dakota Prairie Refining, LLC [Member] | Total assets [Member] |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |
Limited liability entity, consolidated, carrying amount, assets |  |  | 463,260 |
Dakota Prairie Refining, LLC [Member] | Short-term borrowings [Member] |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |
Limited liability entity, consolidated, carrying amount, liabilities |  |  | 63,200 |
Dakota Prairie Refining, LLC [Member] | Long-term debt due within one year [Member] |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |
Limited liability entity, consolidated, carrying amount, liabilities |  |  | 6,375 |
Dakota Prairie Refining, LLC [Member] | Accounts payable [Member] |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |
Limited liability entity, consolidated, carrying amount, liabilities |  |  | 27,697 |
Dakota Prairie Refining, LLC [Member] | Taxes payable [Member] |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |
Limited liability entity, consolidated, carrying amount, liabilities |  |  | 1,001 |
Dakota Prairie Refining, LLC [Member] | Accrued compensation [Member] |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |
Limited liability entity, consolidated, carrying amount, liabilities |  |  | 717 |
Dakota Prairie Refining, LLC [Member] | Other accrued liabilities [Member] |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |
Limited liability entity, consolidated, carrying amount, liabilities |  |  | 7,155 |
Dakota Prairie Refining, LLC [Member] | Total current liabilities [Member] |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |
Limited liability entity, consolidated, carrying amount, liabilities |  |  | 106,145 |
Dakota Prairie Refining, LLC [Member] | Long-term debt [Member] |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |
Limited liability entity, consolidated, carrying amount, liabilities |  |  | 62,625 |
Dakota Prairie Refining, LLC [Member] | Total liabilities [Member] |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |
Limited liability entity, consolidated, carrying amount, liabilities |  |  | $ 168,770 |
Fuel contract [Member] |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |
Variable interest entity, reporting entity involvement, maximum loss exposure, amount | $ 42,700 |  |  |
Calumet [Member] | Dakota Prairie Refining, LLC [Member] |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |
Previous percentage of ownership |  |  |  | 50.00%
WBI Energy [Member] | Dakota Prairie Refining, LLC [Member] |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |
Previous percentage of ownership |  |  |  | 50.00%
Percentage of ownership acquired |  | 50.00% |  |

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