Name:	bdco_DeferredTaxAssetsStartupCosts
Namespace Prefix:	bdco_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible interest carryforward.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-6

Name:	us-gaap_DeferredTaxAssetInterestCarryforward
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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from deferred income.

Name:	us-gaap_DeferredTaxAssetsDeferredIncome
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Data Type:	xbrli:monetaryItemType
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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

Name:	us-gaap_DeferredTaxAssetsGross
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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Amount, after allocation of valuation allowances and deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, without jurisdictional netting.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards.

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Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences, classified as other.

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Data Type:	xbrli:monetaryItemType
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Amount of deferred tax liability attributable to taxable temporary differences from property, plant, and equipment.