2.4.0.8040050 - Disclosure - Repurchase Agreements - Narrative (Details)truefalsefalse1false USDfalsefalse$AS_OF_Jun30_2013http://www.sec.gov/CIK0001275477instant2013-06-30T00:00:000001-01-01T00:00:00PercentageStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false USDfalsefalse$AS_OF_Dec31_2012http://www.sec.gov/CIK0001275477instant2012-12-31T00:00:000001-01-01T00:00:00PercentageStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true 3bmnm_RepurchaseAgreementLineItemsbmnm_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Repurchase Agreement [Line Items]2false 4us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse346197338346197338USD$falsetruefalse2truefalsefalse150294174150294174USD$falsetruefalsexbrli:monetaryItemTypemonetaryThe carrying value as of the balance sheet date of securities that an institution sells and agrees to repurchase (the identical or substantially the same securities) as a seller-borrower at a specified date for a specified price, also known as a repurchase agreement, or repo. Most repos involve obligations of the federal government or its agencies, but other financial instruments, such as commercial paper, banker's acceptances, and negotiable certificates of deposit, are sometimes used in repos.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.13(1)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 13 -Subparagraph 1 -Article 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=7472769&loc=d3e9760-107771 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 140 -Paragraph 100 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(m)(1)(a)(i)) -URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Audit and Accounting Guide (AAG) -Number AAG-BRD -Paragraph 36 -IssueDate 2006-05-01 -Chapter 4 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Repurchase agreements3false 4bmnm_RepurchaseAgreementsWeightedAverageBorrowingRatesbmnm_falsenainstantfalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.00390.0039falsefalsefalse2truetruefalse0.00490.0049falsefalsefalsenum:percentItemTypepureThe weighted average borrowing rates on repurchase agreements.No definition available.false0Repurchase Agreements Weighted Average Borrowing Rates4false 4bmnm_CollateralHeldOnRepurchaseAgreementsbmnm_falsedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse357199000357199000USD$falsefalsefalse2truefalsefalse158765000158765000USD$falsefalsefalsexbrli:monetaryItemTypemonetaryThe fair value, including accrued interest, as of the balance sheet date of securities pledged as collateral that an institution holds on behalf of repurchases agreements.No definition available.false2Fair Value of securities pledged, including accrued interest receivable5false 4bmnm_RepurchaseAgreementMarginbmnm_falsedebitinstantfalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse66290006629000USD$falsefalsefalse2truefalsefalse614000614000USD$falsefalsefalsexbrli:monetaryItemTypemonetaryNo authoritative reference available.No definition available.false2Repurchase Agreement Margin6false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3false USDtruefalse$AS_OF_Jun30_2013_us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis_VariableInterestEntityPrimaryBeneficiaryMemberhttp://www.sec.gov/CIK0001275477instant2013-06-30T00:00:000001-01-01T00:00:00falsefalse[VariableInterestEntityPrimaryBeneficiaryMember]us-gaap_VariableInterestEntitiesByClassificationOfEntityAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_VariableInterestEntityPrimaryBeneficiaryMemberus-gaap_VariableInterestEntitiesByClassificationOfEntityAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0[VariableInterestEntityPrimaryBeneficiaryMember]7true 3bmnm_RepurchaseAgreementLineItemsbmnm_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Repurchase Agreement [Line Items]8false 4us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse308735338308735338USD$falsetruefalse2truefalsefalse00USD$falsetruefalsexbrli:monetaryItemTypemonetaryThe carrying value as of the balance sheet date of securities that an institution sells and agrees to repurchase (the identical or substantially the same securities) as a seller-borrower at a specified date for a specified price, also known as a repurchase agreement, or repo. Most repos involve obligations of the federal government or its agencies, but other financial instruments, such as commercial paper, banker's acceptances, and negotiable certificates of deposit, are sometimes used in repos.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.13(1)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 13 -Subparagraph 1 -Article 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=7472769&loc=d3e9760-107771 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 140 -Paragraph 100 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(m)(1)(a)(i)) -URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Audit and Accounting Guide (AAG) -Number AAG-BRD -Paragraph 36 -IssueDate 2006-05-01 -Chapter 4 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Repurchase agreementsfalseRepurchase Agreements - Narrative (Details) (USD $)NoRoundingUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.biminicapital.com/role/RepurchaseAgreementsNarrativeDetails28