2.2.0.25truefalse00100 - Statement - Consolidated Balance SheetstruefalseIn Thousandsfalse1falsefalseUSDtruefalse{dei_LegalEntityAxis} : BIOMED REALTY TRUST, INC. [Member] 3/31/2011 USD ($) USD ($) / shares $As_Of_3_31_2011_dei_LegalEntityAxis_us-gaap_ParentCompanyMemberhttp://www.sec.gov/CIK0001289236instant2011-03-31T00:00:000001-01-01T00:00:00falsefalseus-gaap_ParentCompanyMemberdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ParentCompanyMemberdei_LegalEntityAxisexplicitMemberUnit1Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit13Standardhttp://www.xbrl.org/2003/instancesharesxbrli0Unit12Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0USDUSD$2falsefalseUSDtruefalse{dei_LegalEntityAxis} : BIOMED REALTY TRUST, INC. [Member] 12/31/2010 USD ($) USD ($) / shares $As_Of_12_31_2010_dei_LegalEntityAxis_us-gaap_ParentCompanyMemberhttp://www.sec.gov/CIK0001289236instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseus-gaap_ParentCompanyMemberdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ParentCompanyMemberdei_LegalEntityAxisexplicitMemberUnit1Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit12Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0Unit13Standardhttp://www.xbrl.org/2003/instancesharesxbrli0USDUSD$1false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.biomedrealty.com/role/statementconsolidatedbalancesheets1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse1falsefalseUSDtruefalse{dei_LegalEntityAxis} : BIOMED REALTY TRUST, INC. [Member] 3/31/2011 USD ($) USD ($) / shares $As_Of_3_31_2011_dei_LegalEntityAxis_us-gaap_ParentCompanyMemberhttp://www.sec.gov/CIK0001289236instant2011-03-31T00:00:000001-01-01T00:00:00falsefalseus-gaap_ParentCompanyMemberdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ParentCompanyMemberdei_LegalEntityAxisexplicitMemberUnit1Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit13Standardhttp://www.xbrl.org/2003/instancesharesxbrli0Unit12Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0USDUSD$2falsefalseUSDtruefalse{dei_LegalEntityAxis} : BIOMED REALTY TRUST, INC. [Member] 12/31/2010 USD ($) USD ($) / shares $As_Of_12_31_2010_dei_LegalEntityAxis_us-gaap_ParentCompanyMemberhttp://www.sec.gov/CIK0001289236instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseus-gaap_ParentCompanyMemberdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ParentCompanyMemberdei_LegalEntityAxisexplicitMemberUnit1Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit12Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0Unit13Standardhttp://www.xbrl.org/2003/instancesharesxbrli0USDUSD$3falsefalseUSDtruefalse{dei_LegalEntityAxis} : BIOMED REALTY TRUST, INC. [Member] 3/31/2010 USD ($) $As_Of_3_31_2010_dei_LegalEntityAxis_us-gaap_ParentCompanyMemberhttp://www.sec.gov/CIK0001289236instant2010-03-31T00:00:000001-01-01T00:00:00falsefalseus-gaap_ParentCompanyMemberdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ParentCompanyMemberdei_LegalEntityAxisexplicitMemberUnit1Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$4falsefalseUSDtruefalse{dei_LegalEntityAxis} : BIOMED REALTY TRUST, INC. [Member] 12/31/2009 USD ($) $As_Of_12_31_2009_dei_LegalEntityAxis_us-gaap_ParentCompanyMemberhttp://www.sec.gov/CIK0001289236instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseus-gaap_ParentCompanyMemberdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ParentCompanyMemberdei_LegalEntityAxisexplicitMemberUnit1Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalseBIOMED REALTY TRUST, INC. [Member]2true0us-gaap_AssetsAbstractus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalseASSETS3false0us-gaap_RealEstateInvestmentPropertyNetus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse35385600003538560falsetruefalsefalsefalse2truefalsefalse35361140003536114falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe net book value of real estate property held for investment purposes.No authoritative reference available.falsefalseInvestments in real estate, net4false0us-gaap_EquityMethodInvestmentsus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse5628700056287falsefalsefalsefalsefalse2truefalsefalse5726500057265falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment losses recognized.No authoritative reference available.falsefalseInvestments in unconsolidated partnerships5false0us-gaap_CashAndCashEquivalentsAtCarryingValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse1935100019351falsefalsefalsefalsefalse2truefalsefalse2146700021467falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryIncludes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 falsefalseCash and cash equivalents6false0us-gaap_RestrictedCashAndCashEquivalentsus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse66870006687falsefalsefalsefalsefalse2truefalsefalse99710009971falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe carrying amounts of cash and cash equivalent items which are restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. This element is for unclassified presentations; for classified presentations there is a separate and distinct element.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Audit and Accounting Guide (AAG) -Number AAG-BRD -Chapter 4 -Paragraph 80 -Subparagraph Exhibit 4-8, 3 -IssueDate 2006-05-01 falsefalseRestricted cash7false0us-gaap_AccountsReceivableNetus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse73580007358falsefalsefalsefalsefalse2truefalsefalse58740005874falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFor an unclassified balance sheet, the amount due from customers or clients for goods or services that have been delivered or sold in the normal course of business, reduced to their estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Article 5 falsefalseAccounts receivable, net8false0us-gaap_DeferredRentReceivablesNetus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse110981000110981falsefalsefalsefalsefalse2truefalsefalse106905000106905falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe cumulative difference between the rental payments required by a lease agreement and the rental income or expense recognized on a straight-line basis, or other systematic and rational basis more representative of the time pattern in which use or benefit is granted or derived from the leased property, expected to be recognized in income or expense over the term of the leased property, by the lessor or lessee, respectively. Such receivable should be reduced by allowances attributable to, for instance, credit risk associated with a lessee.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Technical Bulletin (FTB) -Number 85-3 -Paragraph 2 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 13 -Paragraph 19 -Subparagraph b falsefalseAccrued straight-line rents, net9false0bmr_AcquiredAboveMarketLeasesNetbmrfalsedebitinstantAcquired above-market leases, netfalsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse2806900028069falsefalsefalsefalsefalse2truefalsefalse3056600030566falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAcquired above-market leases, netNo authoritative reference available.falsefalseAcquired above-market leases, net10false0us-gaap_DeferredCostsLeasingNetus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse121658000121658falsefalsefalsefalsefalse2truefalsefalse125060000125060falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents costs incurred by the lessor that are (a) costs to originate a lease incurred in transactions with independent third parties that (i) result directly from and are essential to acquire that lease and (ii) would not have been incurred had that leasing transaction not occurred and (b) certain costs directly related to specified activities performed by the lessor for that lease. Those activities are: evaluating the prospective lessee's financial condition; evaluating and recording guarantees, collateral, and other security arrangements; negotiating lease terms; preparing and processing lease documents; and closing the transaction. This element is net of accumulated amortization.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 13 -Paragraph 5 -Subparagraph m Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 13 -Paragraph 19 -Subparagraph c falsefalseDeferred leasing costs, net11false0us-gaap_DeferredFinanceCostsNetus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse1347300013473falsefalsefalsefalsefalse2truefalsefalse1149900011499falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFor an unclassified balance sheet, the carrying amount (net of accumulated amortization) as of the balance sheet date of capitalized costs associated with the issuance of debt instruments (for example, legal, accounting, underwriting, printing, and registration costs) that will be charged against earnings over the life of the debt instruments to which such costs pertain.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 21 -Paragraph 16 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 17 -Article 5 falsefalseDeferred loan costs, net12false0us-gaap_OtherAssetsus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse5665600056656falsefalsefalsefalsefalse2truefalsefalse5503300055033falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying amount as of the balance sheet date of assets not otherwise specified in the taxonomy. Also serves as the sum of assets not individually reported in the financial statements, or not separately disclosed in notes.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 17 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 10 -Article 7 falsefalseOther assets13false0us-gaap_Assetsus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse39590800003959080falsefalsefalsefalsefalse2truefalsefalse39597540003959754falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetarySum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Concepts (CON) -Number 6 -Paragraph 25 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 18 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 12 -Article 7 truefalseTotal assets14true0us-gaap_LiabilitiesAndStockholdersEquityAbstractus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalseLIABILITIES AND EQUITY/CAPITAL15false0us-gaap_SecuredDebtus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse629640000629640falsefalsefalsefalsefalse2truefalsefalse657922000657922falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying value as of the balance sheet date , including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 20, 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 9 falsefalseMortgage notes payable, net16false0us-gaap_ConvertibleDebtus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse199613000199613falsefalsefalsefalsefalse2truefalsefalse199522000199522falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryIncluding the current and noncurrent portions, carrying amount of debt identified as being convertible into another form of financial instrument (typically the entity's common stock) as of the balance-sheet date, which originally required full repayment more than twelve months after issuance or greater than the normal operating cycle of the company.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 20, 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 9 falsefalseExchangeable senior notes, net17false0us-gaap_SeniorNotesus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse645081000645081falsefalsefalsefalsefalse2truefalsefalse247571000247571falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryIncluding the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 9 falsefalseUnsecured senior notes, net18false0us-gaap_LineOfCreditus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse5100000051000falsefalsefalsefalsefalse2truefalsefalse392450000392450falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 20, 22 -Article 5 falsefalseUnsecured line of credit19false0us-gaap_SecurityDepositLiabilityus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse1158500011585falsefalsefalsefalsefalse2truefalsefalse1174900011749falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents money paid in advance to protect the provider of a product or service, such as a lessor, against damage or nonpayment by the buyer or tenant (lessee) during the term of the agreement. Such damages may include physical damage to the property, theft of property, and other contractual breaches. Security deposits held may be interest or noninterest bearing.No authoritative reference available.falsefalseSecurity deposits20false0us-gaap_DividendsPayableCurrentAndNoncurrentus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse3108600031086falsefalsefalsefalsefalse2truefalsefalse2702900027029falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying value as of the balance sheet date of dividends declared but unpaid on equity securities issued by the entity and outstanding.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 15 -Subparagraph 5 -Article 9 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 15 -Subparagraph a -Article 7 falsefalseDividends and distributions payable21false0bmr_AccountsPayableAccruedExpensesAndOtherLiabilitiesbmrfalsecreditinstantAccounts payable, accrued expenses, and other liabilitiesfalsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse8811600088116falsefalsefalsefalsefalse2truefalsefalse9882600098826falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAccounts payable, accrued expenses, and other liabilitiesNo authoritative reference available.falsefalseAccounts payable, accrued expenses and other liabilities22false0us-gaap_DerivativeLiabilitiesus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse22310002231falsefalsefalsefalsefalse2truefalsefalse38260003826falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFair values as of the balance sheet date of all liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments, net of the effects of master netting arrangements.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FIN39-1 -Paragraph 10A, 10B Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 4, 17 falsefalseDerivative instruments23false0bmr_AcquiredBelowMarketLeasesNetbmrfalsecreditinstantAcquired below-market leases, netfalsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse75650007565falsefalsefalsefalsefalse2truefalsefalse79630007963falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAcquired below-market leases, netNo authoritative reference available.falsefalseAcquired below-market leases, net24false0us-gaap_Liabilitiesus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse16659170001665917falsefalsefalsefalsefalse2truefalsefalse16468580001646858falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetarySum of the carrying amounts as of the balance sheet date of all liabilities that are recognized. Liabilities are probable future sacrifices of economic benefits arising from present obligations of an entity to transfer assets or provide services to other entities in the future.No authoritative reference available.truefalseTotal liabilities25true0us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstractus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalseStockholders' equity/Partners' capital26false0us-gaap_PreferredStockValueus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse222413000222413falsefalsefalsefalsefalse2truefalsefalse222413000222413falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryDollar value of issued nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) whether issued at par value, no par or stated value. This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable preferred shares, par value and other disclosure concepts are in another section within stockholders' equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 129 -Paragraph 2, 3, 4, 5, 6, 7, 8 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 10 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29 -Article 5 falsefalsePreferred stock, $.01 par value, 15,000,000 shares authorized: 7.375% Series A cumulative redeemable preferred stock, $230,000,000 liquidation preference ($25.00 per share), 9,200,000 shares issued and outstanding at March 31, 2011 and December 31, 201027false0us-gaap_CommonStockValueus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse13120001312falsefalsefalsefalsefalse2truefalsefalse13100001310falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryDollar value of issued common stock whether issued at par value, no par or stated value. This item includes treasury stock repurchased by the entity. Note: elements for number of common shares, par value and other disclosure concepts are in another section within stockholders' equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 30 -Article 5 falsefalseCommon stock, $.01 par value, 200,000,000 shares authorized, 131,239,482 and 131,046,509 shares issued and outstanding at March 31, 2011 and December 31, 2010, respectively28false0us-gaap_AdditionalPaidInCapitalus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse23699220002369922falsefalsefalsefalsefalse2truefalsefalse23714880002371488falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryExcess of issue price over par or stated value of the entity's capital stock and amounts received from other transactions involving the entity's stock or stockholders. Includes adjustments to additional paid in capital. Some examples of such adjustments include recording the issuance of debt with a beneficial conversion feature and certain tax consequences of equity instruments awarded to employees. Use this element for the aggregate amount of APIC associated with common AND preferred stock. For APIC associated with only common stock, use the element Additional Paid In Capital, Common Stock. For APIC associated with only preferred stock, use the element Additional Paid In Capital, Preferred Stock.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 31 -Article 5 falsefalseAdditional paid-in capital29false0us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTaxus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse-68908000-68908falsefalsefalsefalsefalse2truefalsefalse-70857000-70857falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAccumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at fiscal year-end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, and unrealized gains and losses on certain investments in debt and equity securities as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 10 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 14, 17, 26 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 31 -Article 5 falsefalseAccumulated other comprehensive loss30false0us-gaap_RetainedEarningsAccumulatedDeficitus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse-241894000-241894falsefalsefalsefalsefalse2truefalsefalse-221176000-221176falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe cumulative amount of the reporting entity's undistributed earnings or deficit.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 10 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 31 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 falsefalseDividends in excess of earnings31false0us-gaap_StockholdersEquityus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse22828450002282845falsefalsefalsefalsefalse2truefalsefalse23031780002303178falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryTotal of all Stockholders' Equity (deficit) items, net of receivables from officers, directors owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A3 -Appendix A Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section E Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30, 31 -Article 5 truefalseTotal stockholders' equity32false0us-gaap_MinorityInterestus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse1031800010318falsefalsefalsefalsefalse2truefalsefalse97180009718falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryTotal of all Stockholders' Equity (deficit) items, net of receivables from officers, directors owners, and affiliates of the entity which is directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 27 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 20 -Article 7 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 26 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A3 -Appendix A falsefalseNoncontrolling interests /Noncontrolling interests deficit33false0us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse22931630002293163falsefalsefalsefalsefalse2truefalsefalse23128960002312896falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryTotal of Stockholders' Equity (deficit) items, net of receivables from officers, directors owners, and affiliates of the entity including portions attributable to both the parent and noncontrolling interests (previously referred to as minority interest), if any. The entity including portions attributable to the parent and noncontrolling interests is sometimes referred to as the economic entity. This excludes temporary equity and is sometimes called permanent equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 25 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 26 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A3 -Appendix A truefalseTotal equity/capital34false0us-gaap_LiabilitiesAndStockholdersEquityus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse39590800003959080falsefalsefalsefalsefalse2truefalsefalse39597540003959754falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryTotal of all Liabilities and Stockholders' Equity items.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 32 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 25 -Article 7 truefalseTotal liabilities and equity/capital35false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.biomedrealty.com/role/statementconsolidatedbalancesheets1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse5falsefalseUSDtruefalse{dei_LegalEntityAxis} : BIOMED REALTY, L.P. [Member] 3/31/2011 USD ($) USD ($) / shares $As_Of_3_31_2011_dei_LegalEntityAxis_bmr_BiomedRealtyLpMemberhttp://www.sec.gov/CIK0001289236instant2011-03-31T00:00:000001-01-01T00:00:00falsefalsebmr_BiomedRealtyLpMemberdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldibmr_BiomedRealtyLpMemberdei_LegalEntityAxisexplicitMemberUnit1Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit13Standardhttp://www.xbrl.org/2003/instancesharesxbrli0Unit12Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0USDUSD$6falsefalseUSDtruefalse{dei_LegalEntityAxis} : BIOMED REALTY, L.P. [Member] 12/31/2010 USD ($) USD ($) / shares $As_Of_12_31_2010_dei_LegalEntityAxis_bmr_BiomedRealtyLpMemberhttp://www.sec.gov/CIK0001289236instant2010-12-31T00:00:000001-01-01T00:00:00falsefalsebmr_BiomedRealtyLpMemberdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldibmr_BiomedRealtyLpMemberdei_LegalEntityAxisexplicitMemberUnit1Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit13Standardhttp://www.xbrl.org/2003/instancesharesxbrli0Unit12Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0USDUSD$7falsefalseUSDtruefalse{dei_LegalEntityAxis} : BIOMED REALTY, L.P. [Member] 3/31/2010 USD ($) $As_Of_3_31_2010_dei_LegalEntityAxis_bmr_BiomedRealtyLpMemberhttp://www.sec.gov/CIK0001289236instant2010-03-31T00:00:000001-01-01T00:00:00falsefalsebmr_BiomedRealtyLpMemberdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldibmr_BiomedRealtyLpMemberdei_LegalEntityAxisexplicitMemberUnit1Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$8falsefalseUSDtruefalse{dei_LegalEntityAxis} : BIOMED REALTY, L.P. [Member] 12/31/2009 USD ($) $As_Of_12_31_2009_dei_LegalEntityAxis_bmr_BiomedRealtyLpMemberhttp://www.sec.gov/CIK0001289236instant2009-12-31T00:00:000001-01-01T00:00:00falsefalsebmr_BiomedRealtyLpMemberdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldibmr_BiomedRealtyLpMemberdei_LegalEntityAxisexplicitMemberUnit1Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalseBIOMED REALTY, L.P. [Member]36true0us-gaap_AssetsAbstractus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalseASSETS37false0us-gaap_RealEstateInvestmentPropertyNetus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse35385600003538560falsefalsefalsefalsefalse2truefalsefalse35361140003536114falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe net book value of real estate property held for investment purposes.No authoritative reference available.falsefalseInvestments in real estate, net38false0us-gaap_EquityMethodInvestmentsus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse5628700056287falsefalsefalsefalsefalse2truefalsefalse5726500057265falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment losses recognized.No authoritative reference available.falsefalseInvestments in unconsolidated partnerships39false0us-gaap_CashAndCashEquivalentsAtCarryingValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse1935100019351falsefalsefalsefalsefalse2truefalsefalse2146700021467falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryIncludes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 falsefalseCash and cash equivalents40false0us-gaap_RestrictedCashAndCashEquivalentsus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse66870006687falsefalsefalsefalsefalse2truefalsefalse99710009971falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe carrying amounts of cash and cash equivalent items which are restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. This element is for unclassified presentations; for classified presentations there is a separate and distinct element.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Audit and Accounting Guide (AAG) -Number AAG-BRD -Chapter 4 -Paragraph 80 -Subparagraph Exhibit 4-8, 3 -IssueDate 2006-05-01 falsefalseRestricted cash41false0us-gaap_AccountsReceivableNetus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse73580007358falsefalsefalsefalsefalse2truefalsefalse58740005874falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFor an unclassified balance sheet, the amount due from customers or clients for goods or services that have been delivered or sold in the normal course of business, reduced to their estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Article 5 falsefalseAccounts receivable, net42false0us-gaap_DeferredRentReceivablesNetus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse110981000110981falsefalsefalsefalsefalse2truefalsefalse106905000106905falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe cumulative difference between the rental payments required by a lease agreement and the rental income or expense recognized on a straight-line basis, or other systematic and rational basis more representative of the time pattern in which use or benefit is granted or derived from the leased property, expected to be recognized in income or expense over the term of the leased property, by the lessor or lessee, respectively. Such receivable should be reduced by allowances attributable to, for instance, credit risk associated with a lessee.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Technical Bulletin (FTB) -Number 85-3 -Paragraph 2 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 13 -Paragraph 19 -Subparagraph b falsefalseAccrued straight-line rents, net43false0bmr_AcquiredAboveMarketLeasesNetbmrfalsedebitinstantAcquired above-market leases, netfalsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse2806900028069falsefalsefalsefalsefalse2truefalsefalse3056600030566falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAcquired above-market leases, netNo authoritative reference available.falsefalseAcquired above-market leases, net44false0us-gaap_DeferredCostsLeasingNetus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse121658000121658falsefalsefalsefalsefalse2truefalsefalse125060000125060falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents costs incurred by the lessor that are (a) costs to originate a lease incurred in transactions with independent third parties that (i) result directly from and are essential to acquire that lease and (ii) would not have been incurred had that leasing transaction not occurred and (b) certain costs directly related to specified activities performed by the lessor for that lease. Those activities are: evaluating the prospective lessee's financial condition; evaluating and recording guarantees, collateral, and other security arrangements; negotiating lease terms; preparing and processing lease documents; and closing the transaction. This element is net of accumulated amortization.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 13 -Paragraph 5 -Subparagraph m Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 13 -Paragraph 19 -Subparagraph c falsefalseDeferred leasing costs, net45false0us-gaap_DeferredFinanceCostsNetus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse1347300013473falsefalsefalsefalsefalse2truefalsefalse1149900011499falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFor an unclassified balance sheet, the carrying amount (net of accumulated amortization) as of the balance sheet date of capitalized costs associated with the issuance of debt instruments (for example, legal, accounting, underwriting, printing, and registration costs) that will be charged against earnings over the life of the debt instruments to which such costs pertain.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 21 -Paragraph 16 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 17 -Article 5 falsefalseDeferred loan costs, net46false0us-gaap_OtherAssetsus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse5665600056656falsefalsefalsefalsefalse2truefalsefalse5503300055033falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying amount as of the balance sheet date of assets not otherwise specified in the taxonomy. Also serves as the sum of assets not individually reported in the financial statements, or not separately disclosed in notes.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 17 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 10 -Article 7 falsefalseOther assets47false0us-gaap_Assetsus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse39590800003959080falsefalsefalsefalsefalse2truefalsefalse39597540003959754falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetarySum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Concepts (CON) -Number 6 -Paragraph 25 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 18 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 12 -Article 7 truefalseTotal assets48true0us-gaap_LiabilitiesAndStockholdersEquityAbstractus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalseLIABILITIES AND EQUITY/CAPITAL49false0us-gaap_SecuredDebtus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse629640000629640falsefalsefalsefalsefalse2truefalsefalse657922000657922falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying value as of the balance sheet date , including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 20, 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 9 falsefalseMortgage notes payable, net50false0us-gaap_ConvertibleDebtus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse199613000199613falsefalsefalsefalsefalse2truefalsefalse199522000199522falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryIncluding the current and noncurrent portions, carrying amount of debt identified as being convertible into another form of financial instrument (typically the entity's common stock) as of the balance-sheet date, which originally required full repayment more than twelve months after issuance or greater than the normal operating cycle of the company.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 20, 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 9 falsefalseExchangeable senior notes, net51false0us-gaap_SeniorNotesus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse645081000645081falsefalsefalsefalsefalse2truefalsefalse247571000247571falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryIncluding the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 9 falsefalseUnsecured senior notes, net52false0us-gaap_LineOfCreditus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse5100000051000falsefalsefalsefalsefalse2truefalsefalse392450000392450falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 20, 22 -Article 5 falsefalseUnsecured line of credit53false0us-gaap_SecurityDepositLiabilityus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse1158500011585falsefalsefalsefalsefalse2truefalsefalse1174900011749falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents money paid in advance to protect the provider of a product or service, such as a lessor, against damage or nonpayment by the buyer or tenant (lessee) during the term of the agreement. Such damages may include physical damage to the property, theft of property, and other contractual breaches. Security deposits held may be interest or noninterest bearing.No authoritative reference available.falsefalseSecurity deposits54false0us-gaap_DividendsPayableCurrentAndNoncurrentus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse3108600031086falsefalsefalsefalsefalse2truefalsefalse2702900027029falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying value as of the balance sheet date of dividends declared but unpaid on equity securities issued by the entity and outstanding.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 15 -Subparagraph 5 -Article 9 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 15 -Subparagraph a -Article 7 falsefalseDividends and distributions payable55false0bmr_AccountsPayableAccruedExpensesAndOtherLiabilitiesbmrfalsecreditinstantAccounts payable, accrued expenses, and other liabilitiesfalsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse8811600088116falsefalsefalsefalsefalse2truefalsefalse9882600098826falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAccounts payable, accrued expenses, and other liabilitiesNo authoritative reference available.falsefalseAccounts payable, accrued expenses and other liabilities56false0us-gaap_DerivativeLiabilitiesus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse22310002231falsefalsefalsefalsefalse2truefalsefalse38260003826falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFair values as of the balance sheet date of all liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments, net of the effects of master netting arrangements.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FIN39-1 -Paragraph 10A, 10B Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 4, 17 falsefalseDerivative instruments57false0bmr_AcquiredBelowMarketLeasesNetbmrfalsecreditinstantAcquired below-market leases, netfalsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse75650007565falsefalsefalsefalsefalse2truefalsefalse79630007963falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAcquired below-market leases, netNo authoritative reference available.falsefalseAcquired below-market leases, net58false0us-gaap_Liabilitiesus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse16659170001665917falsefalsefalsefalsefalse2truefalsefalse16468580001646858falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetarySum of the carrying amounts as of the balance sheet date of all liabilities that are recognized. Liabilities are probable future sacrifices of economic benefits arising from present obligations of an entity to transfer assets or provide services to other entities in the future.No authoritative reference available.truefalseTotal liabilities59true0us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstractus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalseStockholders' equity/Partners' capital60false0us-gaap_PreferredUnitsValueus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse222413000222413falsefalsefalsefalsefalse2truefalsefalse222413000222413falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCapital contributed by preferred partners. Preferred partners are partners in a publicly listed limited partnership or master limited partnership with preferential rights and privileges.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section F Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 8, 10, 15 falsefalsePreferred units, 7.375% Series A cumulative redeemable preferred units, $230,000,000 liquidation preference ($25.00 per unit), 9,200,000 units issued and outstanding at March 31, 2011 and December 31, 201061false0us-gaap_LimitedPartnersCapitalAccountus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse1053600010536falsefalsefalsefalsefalse2truefalsefalse99180009918falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe limited partner's ownership share in the capital account balance. The limited partners are partners of a publicly traded limited partnership or master limited partnership. Limited partners have limited liability and do not manage the partnership.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section F Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 2, 10, 15 falsefalseLimited partners' capital, 2,989,069 and 3,001,250 units issued and outstanding at March 31, 2011 and December 31, 2010, respectively62false0us-gaap_GeneralPartnersCapitalAccountus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse21279880002127988falsefalsefalsefalsefalse2truefalsefalse21503140002150314falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCapital account balance of the general partner. The general partner is a partner of a publicly traded limited partnership or master limited partnership who has unlimited liability and manages the partnership.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section F Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 10 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 falsefalseGeneral partner's capital, 131,239,482 and 131,046,509 units issued and outstanding at March 31, 2011 and December 31, 2010, respectively63false0us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTaxus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse-67556000-67556falsefalsefalsefalsefalse2truefalsefalse-69549000-69549falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAccumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at fiscal year-end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, and unrealized gains and losses on certain investments in debt and equity securities as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 10 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 14, 17, 26 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 31 -Article 5 falsefalseAccumulated other comprehensive loss64false0us-gaap_PartnersCapitalus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse22933810002293381falsefalsefalsefalsefalse2truefalsefalse23130960002313096falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryOwnership interest of different classes of partners in the publicly listed limited partnership or master limited partnership. Partners include general, limited and preferred partners. Limited liability partnerships (LLPs) are formed in accordance with the laws of the state in which such entities are organized. Because those laws are not uniform, the characteristics of LPCs vary from state to state. However, LLPs generally have the following characteristics: An LLP is an unincorporated association of two or more "persons"; Its members have limited personal liability for the obligations or debts of the entity; It is classified as a partnership for federal income tax purposes.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 15 truefalseTotal partners' capital65false0us-gaap_MinorityInterestus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse-218000-218falsefalsefalsefalsefalse2truefalsefalse-200000-200falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryTotal of all Stockholders' Equity (deficit) items, net of receivables from officers, directors owners, and affiliates of the entity which is directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 27 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 20 -Article 7 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 26 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A3 -Appendix A falsefalseNoncontrolling interests /Noncontrolling interests deficit66false0us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse22931630002293163falsefalsefalsefalsefalse2truefalsefalse23128960002312896falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryTotal of Stockholders' Equity (deficit) items, net of receivables from officers, directors owners, and affiliates of the entity including portions attributable to both the parent and noncontrolling interests (previously referred to as minority interest), if any. The entity including portions attributable to the parent and noncontrolling interests is sometimes referred to as the economic entity. This excludes temporary equity and is sometimes called permanent equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 25 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 26 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A3 -Appendix A truefalseTotal equity/capital67false0us-gaap_LiabilitiesAndStockholdersEquityus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse39590800003959080falsetruefalsefalsefalse2truefalsefalse39597540003959754falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryTotal of all Liabilities and Stockholders' Equity items.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 32 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 25 -Article 7 truefalseTotal liabilities and equity/capital267Consolidated Balance Sheets (USD $)ThousandsUnKnownUnKnownUnKnownfalsetrue