Annual report pursuant to Section 13 and 15(d)

Commitments and Contingencies (Details)

v2.4.1.9
Commitments and Contingencies (Details) (USD $)
1 Months Ended
Aug. 31, 2010
Dec. 31, 2014
Property
Tax incremental financing obligation    
The amount of tax incremental financing bonds issued by Anne Arundel County, Maryland $ 30,000,000ofc_TaxIncrementalFinancingBondsAmountIssuedByAnneArundelCountyMaryland  
Liability recognized with regard to tax incremental financing obligation at end of current period   1,300,000us-gaap_GuaranteeObligationsCurrentCarryingValue
Future minimum rental payments due:    
2015   905,000us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent
2016   839,000us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears
2017   768,000us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears
2018   735,000us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears
2019   728,000us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears
Thereafter   76,678,000us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter
Total   80,653,000us-gaap_OperatingLeasesFutureMinimumPaymentsDue
Environmental Indemnity Agreement    
Number of lease properties which were provided environmental indemnifications   3ofc_PropertySubjectToEnvironmentalIndemnityLeaseAgreementNumberOfProperties
Environmental indemnification to the tenant against losses covered under prior owner's indemnity agreement   5,000,000.0ofc_EnvironmentalIndemnificationToTenantAgainstLossesCoveredUnderPriorOwnerIndemnityAgreementMaximum
Maximum environmental indemnification to the tenant against consequential damages after acquisition of property   12,500,000.0ofc_EnvironmentalIndemnificationToTenantAgainstConsequentialDamagesAfterAcquisitionOfPropertyMaximum
Additional costs agreed to be paid by the entity related to construction and environmental regulatory activities (as a percent)   50.00%ofc_AdditionalCostsIncurredRelatedToConstructionAndEnvironmentalRegulatoryActivitiesPercentage
Maximum annual additional costs agreed to be paid by the entity related to construction and environmental regulatory activities   300,000ofc_AdditionalCostsIncurredRelatedToConstructionAndEnvironmentalRegulatoryActivitiesMaximumPerAnnum
Maximum additional costs agreed to be paid by the entity related to construction and environmental regulatory activities   $ 1,500,000.0ofc_MaximumAdditionalCostsIncurredRelatedToConstructionAndEnvironmentalRegulatoryActivities