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Commitment and contingencies variable interest entities (Details 4) (USD $) | Jun. 30, 2013
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Dakota Prairie Refining, LLC [Member] |
Variable Interest Entities [Line Items] |
Percent of ownership | 50.00%
Portion of capital commitment | $ 150,000,000
Partner portion of capital commitment | 75,000,000
Term loan for project debt financing | 75,000,000
Dakota Prairie Refining, LLC [Member] | Cash and Cash Equivalents [Member] |
Variable Interest Entities [Line Items] |
Limited liability entity, consolidated, carrying amount, assets | 63,089,000
Dakota Prairie Refining, LLC [Member] | Accounts receivable [Member] |
Variable Interest Entities [Line Items] |
Limited liability entity, consolidated, carrying amount, assets | 5,000
Dakota Prairie Refining, LLC [Member] | Total current assets [Member] |
Variable Interest Entities [Line Items] |
Limited liability entity, consolidated, carrying amount, assets | 63,094,000
Dakota Prairie Refining, LLC [Member] | Net property, plant and equipment [Member] |
Variable Interest Entities [Line Items] |
Limited liability entity, consolidated, carrying amount, assets | 75,216,000
Dakota Prairie Refining, LLC [Member] | Total assets [Member] |
Variable Interest Entities [Line Items] |
Limited liability entity, consolidated, carrying amount, assets | 138,310,000
Dakota Prairie Refining, LLC [Member] | Accounts Payable [Member] |
Variable Interest Entities [Line Items] |
Limited liability entity, consolidated, carrying amount, liabilities | 21,057,000
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 | 3,000,000
Dakota Prairie Refining, LLC [Member] | Other accrued liabilities [Member] |
Variable Interest Entities [Line Items] |
Limited liability entity, consolidated, carrying amount, liabilities | 300,000
Dakota Prairie Refining, LLC [Member] | Total current liabilities [Member] |
Variable Interest Entities [Line Items] |
Limited liability entity, consolidated, carrying amount, liabilities | 24,357,000
Dakota Prairie Refining, LLC [Member] | Long-term debt [Member] |
Variable Interest Entities [Line Items] |
Limited liability entity, consolidated, carrying amount, liabilities | 72,000,000
Dakota Prairie Refining, LLC [Member] | Total liabilities [Member] |
Variable Interest Entities [Line Items] |
Limited liability entity, consolidated, carrying amount, liabilities | 96,357,000
Fuel contract [Member] |
Variable Interest Entities [Line Items] |
Percent of ownership | 25.00%
Variable interest entity, reporting entity involvement, maximum loss exposure, amount | $ 7,100,000

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- Definition Partner portion of capital commitment. + References No definition available. + Details
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Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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- Definition Percent of ownership. + References No definition available. + Details
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Balance Type: | na
Period Type: | instant

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- Definition Percent of ownership - fule contract. + References No definition available. + Details
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Balance Type: | na
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- Definition Portion of capital commitment. + References No definition available. + Details
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Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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- Definition Amount of term loan entered into to finance the project. + References No definition available. + Details
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Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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- Details
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- Definition The carrying amount of the consolidated Variable Interest Entity's assets included in the reporting entity's statement of financial position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (bb) -URI http://asc.fasb.org/extlink&oid=28200181&loc=d3e5710-111685 + Details
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Balance Type: | debit
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- Definition The carrying amount of the consolidated Variable Interest Entity's liabilities included in the reporting entity's statement of financial position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (bb) -URI http://asc.fasb.org/extlink&oid=28200181&loc=d3e5710-111685 + Details
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- Definition The reporting entity's maximum amount of exposure to loss as a result of its involvement with the Variable Interest Entity (VIE). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph b -URI http://asc.fasb.org/extlink&oid=28200181&loc=d3e5728-111685 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=28200181&loc=d3e5747-111685 + Details
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