Organization and Formation of Company - Additional Information (Detail)	Mar. 31, 2013 State Province sqft Jointventures Property
Organization And Formation Of Company [Line Items]
Ownership interest of sole general partner	95.80%
Ownership interest of limited partners	4.20%
Number of industrial properties owned	710
Number of Joint Ventures	2
Number of states in which industrial properties are located	26
Number of provinces in which industrial properties are located	1
Gross Leasable Area (GLA) of industrial properties owned	63,200,000
2007 Europe Joint Venture
Organization And Formation Of Company [Line Items]
Number of industrial properties owned	0

The number of joint ventures that the entity owns a non-controlling interest in as of the balance sheet date.

No definition available.

The number of provinces in Canada in which the entity operates as of the balance sheet date.

No definition available.

Name:	fr_NumberOfProvincesInWhichEntityOperates
Namespace Prefix:	fr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

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

Area of a real estate property.

No definition available.

Name:	us-gaap_AreaOfRealEstateProperty
Namespace Prefix:	us-gaap_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	instant

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

No definition available.

Name:	us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

No definition available.

Name:	us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

The number of real estate properties owned as of the balance sheet date.

No definition available.

Name:	us-gaap_NumberOfRealEstateProperties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

The number of states the entity operates in as of the balance sheet date.

No definition available.

Name:	us-gaap_NumberOfStatesInWhichEntityOperates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant