Equity interest acquired.

No definition available.

Name:	fr_EquityInterestAcquired
Namespace Prefix:	fr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Fair Value Input Capitalization Rates

+ References

No definition available.

+ Details

Name:	fr_FairValueInputCapitalizationRates
Namespace Prefix:	fr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

In a Business combination, this element represents the amount of gain/loss recognized by the entity as a result of the change in control of the underlying real estate asset. This transaction was accounted for as a step acquisition utilizing the purchase method of accounting.

+ References

No definition available.

+ Details

Name:	fr_GainLossOnChangeInControlOfInterests
Namespace Prefix:	fr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Gross proceeds from the sale of industrial properties and land parcels

+ References

No definition available.

+ Details

Name:	fr_GrossProceedsFromSaleOfIndustrialPropertiesAndLandParcels
Namespace Prefix:	fr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number of Acquired Industrial Properties Vacant

+ References

No definition available.

+ Details

Name:	fr_NumberofAcquiredIndustrialPropertiesVacant
Namespace Prefix:	fr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of industrial properties acquired.

+ References

No definition available.

+ Details

Name:	fr_NumberOfIndustrialPropertiesAcquired
Namespace Prefix:	fr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of industrial properties sold.

+ References

No definition available.

+ Details

Name:	fr_NumberOfIndustrialPropertiesSold
Namespace Prefix:	fr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of Industrial Properties Transferred to Lender.

+ References

No definition available.

+ Details

Name:	fr_NumberOfIndustrialPropertiesTransferredToLender
Namespace Prefix:	fr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of Industrial Properties With Wholly Owned Equity Interest

+ References

No definition available.

+ Details

Name:	fr_NumberofIndustrialPropertiesWithWhollyOwnedEquityInterest
Namespace Prefix:	fr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number Of Land Parcels Sold

+ References

No definition available.

+ Details

Name:	fr_NumberOfLandParcelsSold
Namespace Prefix:	fr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of sold properties and the related gain or loss on sale of real estate included in discontinued operations.

+ References

No definition available.

+ Details

Name:	fr_NumberOfSoldPropertiesAndRelatedGainLossOnSaleOfRealEstateIncludedInDiscontinuedOperations
Namespace Prefix:	fr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	fr_RealEstateInvestmentsLineItems
Namespace Prefix:	fr_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Square footage of industrial properties sold.

+ References

No definition available.

+ Details

Name:	fr_SquareFootageOfIndustrialPropertiesSold
Namespace Prefix:	fr_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	duration

- Definition

Square Footage Of Industrial Property Transferred To Lender.

+ References

No definition available.

+ Details

Name:	fr_SquareFootageOfIndustrialPropertyTransferredToLender
Namespace Prefix:	fr_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	instant

- Definition

Square Footage of Real Estate Properties Acquired.

+ References

No definition available.

+ Details

Name:	fr_SquareFootageOfRealEstatePropertiesAcquired
Namespace Prefix:	fr_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of liabilities incurred by the acquirer as part of consideration transferred in a business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 25

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6405-128476

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 30

-Paragraph 7

-URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6578-128477

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 30

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6613-128477

+ Details

Name:	us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of assets acquired at the acquisition date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6910749&loc=d3e4845-128472

+ Details

Name:	us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of real estate acquired, at the acquisition date.

+ References

+ Details

Name:	us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLand
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The difference between the carrying value and the sale price of real estate or properties that were intended to be sold or held for capital appreciation or rental income. This element refers to the gain (loss) included in earnings and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

+ Details

Name:	us-gaap_GainLossOnSaleOfProperties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Fair value portion of an agreement for an unconditional promise by the maker to pay the holder a definite sum of money at a future date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.3(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 3

-Subparagraph b

-Article 5

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Net amount of the investment in a contractual right to receive money on demand or on fixed or determinable dates that is recognized as an asset in the creditor's statement of financial position. Examples include, but are not limited to, credit card receivables, notes receivable and receivables relating to lessor's rights to payments from leases other than operating leases that have been recorded as assets. Excludes trade accounts receivable with contractual maturity of one year or less and arose from the sale of goods or services.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.3)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 3

-Article 5

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 13

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3213-108585

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Disclosure of the unamortized amount of the discount on the note or receivable which is deducted from the face amount of the receivable or loan. The discount or premium is the difference between the present value and the face amount.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 1A

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399

+ Details

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Period Type:	instant

Investment in Real Estate - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended						0 Months Ended		2 Months Ended
	Dec. 31, 2013 sqft Property	Dec. 31, 2012 sqft Property Parcels	Dec. 31, 2011 Parcels Property sqft	Dec. 31, 2013 Discontinuing operations [Member]	Dec. 31, 2012 Discontinuing operations [Member]	Dec. 31, 2011 Discontinuing operations [Member]	Feb. 13, 2012 2003 Net Lease Joint Venture [Member] Property	May 26, 2011 2003 Net Lease Joint Venture [Member] Property	Feb. 28, 2014 2003 Net Lease Joint Venture [Member] sqft Property
Real Estate Investments [Line Items]
Number of industrial properties acquired	2	1	1				1	1
Number of industrial properties with 100% LLC interest acquired	1
Gross leasable area (GLA) of industrial properties acquired	1,100,000	400,000	700,000
Number of acquired industrial properties that are vacant	1
Equity interest acquired	100.00%						85.00%	85.00%
Carrying value of mortgage loan assumed from acquisition		$ 12,026	$ 24,417
Cash payment of acquisition		8,324	5,277
Approximate gain due to the difference between carrying value and fair value of acquisition	0	776	689
Purchase price of land parcels		46,695
Purchase price of acquisitions	72,812	21,819	30,625
Capitalization rate used for calculating estimated fair value of industrial properties acquired		7.30%	8.40%
Number of industrial properties sold	67	28	36						2
Gross leasable area (GLA) of industrial properties sold	3,000,000	4,200,000	2,900,000						1,600,000
Gain on sale of real estate	35,444	16,442	21,789	34,344	12,665	20,419
Number of sold properties included in discontinued operations	67	28	36
Number of land parcels sold		1	1
Gross proceeds from the sale of industrial properties and land parcels	144,628	85,561	86,643
Number of industrial properties transferred to lender			1
Square Footage Of Industrial Property Transferred To Lender			400,000
Notes receivable outstanding	52,605	40,771
Net discount of notes receivable outstanding	191	255
Fair value of notes receivable	$ 53,482	$ 44,352