XML 52 R37.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Significant Accounting Policies - Rent Receivables (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Tenant Rent Receivables and Straight-line Rent Receivable |  |  |
Period within which tenant rent receivables are expected to be collected | 1 year |  |
Straight-line rent receivable | $ 53,194,000 | $ 50,930,000 |
Allowance for doubtful accounts - Tenant rent receivables |  |  |
Tenant Rent Receivables and Straight-line Rent Receivable |  |  |
Increase (decrease) in allowance | 178,000 | 78,000 | $ (106,000)
Receivables written-off | $ 28,000 | $ 108,000 | 89,000
Allowance for doubtful accounts - Straight-line rent receivable |  |  |
Tenant Rent Receivables and Straight-line Rent Receivable |  |  |
Increase (decrease) in allowance |  |  | (112,000)
Receivables written-off |  |  | $ 112,000

X
- Definition Represents deferred rent receivables net including amounts for assets held for sale. + References No definition available. + Details
Name: | fsp_DeferredRentReceivableNetIncludingAmountsForAssetsHeldForSale
Namespace Prefix: | fsp_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Represents the maximum period within which receivables are expected to be collected. + References No definition available. + Details
Name: | fsp_TenantRentReceivablesCollectionPeriodMaximum
Namespace Prefix: | fsp_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_ReceivablesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of increase in the allowances and reserves, which consist of the valuation and qualifying accounts that are either netted against the cost of an asset or that reflect a liability established to represent expected future costs, from charges to costs and expenses. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690 + Details
Name: | us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Total of the deductions in a given period to allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs, representing receivables written off as uncollectible and portions of the reserves utilized, respectively. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690 + Details
Name: | us-gaap_ValuationAllowancesAndReservesDeductions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_ValuationAllowancesAndReservesTypeAxis=fsp_AllowanceForTenantRentReceivablesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationAllowancesAndReservesTypeAxis=fsp_AllowanceForStraightLineRentReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |