Annual report pursuant to Section 13 and 15(d)

Share-Based Compensation and Other Compensation Matters Share-Based Compensation and Other Compensation Matters (Details 4)

v2.4.1.9
Share-Based Compensation and Other Compensation Matters Share-Based Compensation and Other Compensation Matters (Details 4) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]      
Maximum percentage of compensation employees can contribute to the 401K plan 90.00%ofc_DefinedContributionPlanMaximumPercentageOfEmployeesCompensationContributionTo401KPlan    
Minimum age of participants who are eligible to contribute an additional portion of their annual compensation 50 years    
Employer matching contribution for the first 1% of the participants' eligible compensation (as a percent) 100.00%ofc_DefinedContributionPlanEmployerMatchingContributionForFirstOnePercentContributionByParticipant    
Maximum percentage of participants' compensation eligible for 100% employer matching contribution (as a percent) 1.00%ofc_DefinedContributionPlanMaximumPercentageOfParticipantCompensationEligibleFor100PercentEmployerMatchingContribution    
Employer matching contribution for the next 5% after first 1% of the participants' eligible compensation (as a percent) 50.00%ofc_DefinedContributionPlanEmployerMatchingConributionToEmployeePercentageUpToFivePercentAfterFirstOnePercentContributionByParticipant    
Maximum percentage of participants' compensation eligible for 50% employer matching contribution (as a percent) 5.00%ofc_DefinedContributionPlanPercentageOfParticipantCompensationMartchedFiftyPercentByEmployer    
Employer's aggregate matching contribution for the first 6% of the participants' eligible compensation (as a percent) 3.50%ofc_DefinedContributionPlanAggregateEmployerMatchingContribution    
Maximum percentage of participants' compensation eligible for 3.5% aggregate employer matching contribution 6.00%ofc_DefinedContributionPlanMaximumPercentageOfParticipantCompensationEligibleFor35PercentOfEmployerMatchingContribution    
Participants' vesting portion in employer matching contribution after one year of credited service (as a percent) 50.00%ofc_DefinedContributionPlanVestingPercentageAfterOneYearOfCreditService    
Period of credited service after which participants are 50% vested in employer matching contribution 1 year    
Participants' vesting portion in employer matching contribution after two years of credited service (as a percent) 100.00%ofc_DefinedContributionPlanVestingPercentageAfterTwoYearsOfCreditedService    
Period of credited service after which participants are 100% vested in employer matching contribution 2 years    
Matching contribution under the plan $ 1.2us-gaap_DefinedBenefitPlanContributionsByEmployer $ 1.1us-gaap_DefinedBenefitPlanContributionsByEmployer $ 1.1us-gaap_DefinedBenefitPlanContributionsByEmployer