XML 20 R50.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Derivatives (Details 3) (Discounted Cash Flow [Member], Level 3 Fair Value Measurements [Member], Series F Agreement [Member], USD $) In Thousands, unless otherwise specified | 6 Months Ended
--- | ---
Jun. 30, 2012
Quantitative information about Level 3 fair value measurements |
Fair Value of Liabilities | (1,433)
Maximum [Member] |
Quantitative information about Level 3 fair value measurements |
Fair value inputs, long dated treasuries | 2.88%
Fair value inputs, own credit risk | 2.78%
Minimum [Member] |
Quantitative information about Level 3 fair value measurements |
Fair value inputs, long dated treasuries | 2.72%
Fair value inputs, own credit risk | 1.55%

X
- Definition Fair value inputs long dated treasuries. + References No definition available. + Details
Name: | fr_FairValueInputsLongDatedTreasuries
Namespace Prefix: | fr_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value inputs own credit risk. + References No definition available. + Details
Name: | fr_FairValueInputsOwnCreditRisk
Namespace Prefix: | fr_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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

X
- Definition This element represents the aggregate of the liabilities reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258 + Details
Name: | us-gaap_LiabilitiesFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant