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Debt Instrument Interest Rate Change Due To Amendment

No definition available.

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Gross leasable area (GLA) of industrial properties acquired.

No definition available.

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Number of years of extension of line of credit facility at election.

No definition available.

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Unsecured debt gross.

No definition available.

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Amount of assets pledged to secure a debt instrument.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 942
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-Section 50
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Face (par) amount of debt instrument at time of issuance.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 835
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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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Contractual interest rate for funds borrowed, under the debt agreement.

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Description of the interest rate as being fixed or variable, and, if variable, identification of the index or rate on which the interest rate is based and the number of points or percentage added to that index or rate to set the rate, and other pertinent information, such as frequency of rate resets.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	us-gaap_DebtInstrumentTerm
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Gross amount of debt extinguished.

No definition available.

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Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

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Description of the interest rate for the amounts borrowed under the credit facility, including the terms and the method for determining the interest rate (for example, fixed or variable, LIBOR plus a percentage, increasing rate, timing of interest rate resets, remarketing provisions).

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

The fair value of loans assumed in noncash investing or financing activities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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The number of businesses acquired by the entity during the period.

No definition available.

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Name:	us-gaap_DebtInstrumentAxis=fr_SeniorNotesDueTwoThousandSeventeenNotesMember
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Name:	us-gaap_DebtInstrumentAxis=fr_UnsecuredDebtOneMember
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Name:	us-gaap_DebtInstrumentAxis=fr_UnsecuredDebtTwoMember
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Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_MortgagesMember
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Name:	us-gaap_DebtInstrumentAxis=fr_AssumedMortgageMember
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Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LineOfCreditMember
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