XML 78 R93.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Commitments and Contingencies Commitments and Contingencies - Future Minimum Rental Payments Under Terms of all Non-Cancelable Ground and Operating Leases (Parenthetical) (Details) (USD $) | 12 Months Ended
--- | ---
Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract] |
Minimum rental payments have not been reduced by minimum sublease rentals due in the future under non-cancelable subleases. | $ 6,832

X
- Definition Operating Leases Future Minimum Sublease Income + References No definition available. + Details
Name: | fr_OperatingLeasesFutureMinimumSubleaseIncome
Namespace Prefix: | fr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_CommitmentsAndContingenciesDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration