XML 46 R75.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Debt (Details) (USD $) | 12 Months Ended | 1 Months Ended | 0 Months Ended | 12 Months Ended | 0 Months Ended |
--- | --- | --- | --- | --- | --- | ---
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2014 | Sep. 01, 2011 | Feb. 14, 2012 | Aug. 03, 2012 | Dec. 31, 2010 | May 06, 2013 | Sep. 16, 2013 | May 14, 2014 | Apr. 30, 2014
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt, net | $ 1,920,057,000 us-gaap_LongTermDebt |  | $ 1,927,703,000 us-gaap_LongTermDebt |  | $ 1,920,057,000 us-gaap_LongTermDebt |  |  |  |  |  |  |  |  |
Loss on early extinguishment of debt | 9,552,000 us-gaap_GainsLossesOnExtinguishmentOfDebt |  | 27,030,000 us-gaap_GainsLossesOnExtinguishmentOfDebt | 943,000 us-gaap_GainsLossesOnExtinguishmentOfDebt |  |  |  |  |  |  |  |  |  |
Principal amount of debt | 1,929,810,000 us-gaap_DebtInstrumentCarryingAmount | [1] |  |  | 1,929,810,000 us-gaap_DebtInstrumentCarryingAmount | [1] |  |  |  |  |  |  |  |
Interest expense associated with amortization of discount | 921,000 us-gaap_AmortizationOfDebtDiscountPremium |  | 1,159,000 us-gaap_AmortizationOfDebtDiscountPremium | 3,155,000 us-gaap_AmortizationOfDebtDiscountPremium |  |  |  |  |  |  |  |  |  |
Secured Loans Due November 2015 and January 2016 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loss on early extinguishment of debt |  |  |  |  | 9,100,000 us-gaap_GainsLossesOnExtinguishmentOfDebt / us-gaap_ExtinguishmentOfDebtAxis = ofc_SecuredLoansDueNovember2015AndJanuary2016Member |  |  |  |  |  |  |  |  |
Secured Loan Due January 2016 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stated interest rate (as a percent) | 5.56%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_ExtinguishmentOfDebtAxis = ofc_SecuredLoanDueJanuary2016Member |  |  |  | 5.56%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_ExtinguishmentOfDebtAxis = ofc_SecuredLoanDueJanuary2016Member |  |  |  |  |  |  |  |  |
Amount of loans repaid upon entry into Revolving Credit Facility and Term Loan Agreement |  |  |  |  | 108,500,000 us-gaap_ExtinguishmentOfDebtAmount / us-gaap_ExtinguishmentOfDebtAxis = ofc_SecuredLoanDueJanuary2016Member |  |  |  |  |  |  |  |  |
Secured Loan Due November 2015 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stated interest rate (as a percent) | 5.53%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_ExtinguishmentOfDebtAxis = ofc_SecuredLoanDueNovember2015Member |  |  |  | 5.53%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_ExtinguishmentOfDebtAxis = ofc_SecuredLoanDueNovember2015Member |  |  |  |  |  |  |  |  |
Amount of loans repaid upon entry into Revolving Credit Facility and Term Loan Agreement |  |  |  |  | 103,000,000 us-gaap_ExtinguishmentOfDebtAmount / us-gaap_ExtinguishmentOfDebtAxis = ofc_SecuredLoanDueNovember2015Member |  |  |  |  |  |  |  |  |
Mortgage and Other Secured Loans: |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt, net | 424,016,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = us-gaap_SecuredDebtMember |  | 712,751,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = us-gaap_SecuredDebtMember |  | 424,016,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = us-gaap_SecuredDebtMember |  |  |  |  |  |  |  |  |
Fixed rate mortgage loans |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt, net | 387,139,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_FixedRateSecuredDebtMember |  | 675,060,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_FixedRateSecuredDebtMember |  | 387,139,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_FixedRateSecuredDebtMember |  |  |  |  |  |  |  |  |
Stated Interest Rates, low end of range (as a percent) | 3.96%us-gaap_DebtInstrumentInterestRateStatedPercentageRateRangeMinimum / us-gaap_DebtInstrumentAxis = ofc_FixedRateSecuredDebtMember | [2] |  |  |  |  |  |  |  |  |  |  |  |
Stated Interest Rates, high end of range (as a percent) | 10.65%us-gaap_DebtInstrumentInterestRateStatedPercentageRateRangeMaximum / us-gaap_DebtInstrumentAxis = ofc_FixedRateSecuredDebtMember | [2] |  |  |  |  |  |  |  |  |  |  |  |
Unamortized premium included in carrying value | 42,000 us-gaap_DebtInstrumentUnamortizedPremium / us-gaap_DebtInstrumentAxis = ofc_FixedRateSecuredDebtMember |  | 69,000 us-gaap_DebtInstrumentUnamortizedPremium / us-gaap_DebtInstrumentAxis = ofc_FixedRateSecuredDebtMember |  | 42,000 us-gaap_DebtInstrumentUnamortizedPremium / us-gaap_DebtInstrumentAxis = ofc_FixedRateSecuredDebtMember |  |  |  |  |  |  |  |  |
Weighted average interest rate (as a percent) | 8.10%us-gaap_DebtWeightedAverageInterestRate / us-gaap_DebtInstrumentAxis = ofc_FixedRateSecuredDebtMember |  |  |  | 8.10%us-gaap_DebtWeightedAverageInterestRate / us-gaap_DebtInstrumentAxis = ofc_FixedRateSecuredDebtMember |  |  |  |  |  |  |  |  |
Weighted average interest rate excluding incremental rate | 6.16%ofc_DebtWeightedAverageInterestRateExcludingIncrementalRateOnDefaultRate / us-gaap_DebtInstrumentAxis = ofc_FixedRateSecuredDebtMember |  |  |  | 6.16%ofc_DebtWeightedAverageInterestRateExcludingIncrementalRateOnDefaultRate / us-gaap_DebtInstrumentAxis = ofc_FixedRateSecuredDebtMember |  |  |  |  |  |  |  |  |
Variable rate secured loans |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt, net | 36,877,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_VariableRateSecuredDebtMember |  | 37,691,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_VariableRateSecuredDebtMember |  | 36,877,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_VariableRateSecuredDebtMember |  |  |  |  |  |  |  |  |
Stated interest rate (as a percent) | 2.41%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = ofc_VariableRateSecuredDebtMember |  |  |  | 2.41%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = ofc_VariableRateSecuredDebtMember |  |  |  |  |  |  |  |  |
Description of variable rate basis | LIBOR | [3] |  |  |  |  |  |  |  |  |  |  |  |
Variable rate, spread (as a percent) | 2.25%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_DebtInstrumentAxis = ofc_VariableRateSecuredDebtMember | [3] |  |  |  |  |  |  |  |  |  |  |  |
Revolving Credit Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt, net | 83,000,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_CreditFacilityMember |  | 0 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_CreditFacilityMember |  | 83,000,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_CreditFacilityMember |  |  |  |  |  |  |  |  |
Description of variable rate basis | LIBOR |  |  |  |  |  |  |  |  |  |  |  |  |
Term Credit Facility Effective September 2011 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Additional borrowing capacity available provided there is no default under the agreement |  |  |  |  |  |  | 100,000,000 ofc_CreditFacilityAdditionalBorrowingCapacityAvailable / us-gaap_DebtInstrumentAxis = ofc_TermCreditFacilityEffectiveSeptember2011Member |  |  |  |  |  |  |
Extension option period (in years) |  |  |  |  |  |  | 1 year |  |  |  |  |  |  |
Initial amount borrowed |  |  |  |  |  |  | 400,000,000 us-gaap_ProceedsFromIssuanceOfDebt / us-gaap_DebtInstrumentAxis = ofc_TermCreditFacilityEffectiveSeptember2011Member |  |  |  |  |  |  |
Extension fee as a percentage of total availability of the facility |  |  |  |  |  |  | 0.15%ofc_CreditFacilityExtensionFeePercentageOfTotalAvailabilityOfFacility / us-gaap_DebtInstrumentAxis = ofc_TermCreditFacilityEffectiveSeptember2011Member |  |  |  |  |  |  |
Repayments of Debt | 100,000,000 us-gaap_RepaymentsOfDebt / us-gaap_DebtInstrumentAxis = ofc_TermCreditFacilityEffectiveSeptember2011Member |  | 150,000,000 us-gaap_RepaymentsOfDebt / us-gaap_DebtInstrumentAxis = ofc_TermCreditFacilityEffectiveSeptember2011Member |  |  |  |  |  |  |  |  |  |  |
Term Credit Facility Effective February 2012 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Extension option period (in years) |  |  |  |  |  |  |  | 1 year |  |  |  |  |  |
Initial amount borrowed |  |  |  |  |  |  |  | 250,000,000 us-gaap_ProceedsFromIssuanceOfDebt / us-gaap_DebtInstrumentAxis = ofc_TermCreditFacilityEffectiveFebruary2012Member |  |  |  |  |  |
Extension fee as a percentage of total availability of the facility |  |  |  |  |  |  |  | 0.15%ofc_CreditFacilityExtensionFeePercentageOfTotalAvailabilityOfFacility / us-gaap_DebtInstrumentAxis = ofc_TermCreditFacilityEffectiveFebruary2012Member |  |  |  |  |  |
Term Credit Facility Effective August 2012 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Additional borrowing capacity available provided there is no default under the agreement |  |  |  |  |  |  |  |  | 80,000,000 ofc_CreditFacilityAdditionalBorrowingCapacityAvailable / us-gaap_DebtInstrumentAxis = ofc_TermCreditFacilityEffectiveAugust2012Member |  |  |  |  |
Initial amount borrowed |  |  |  |  |  |  |  |  | 120,000,000 us-gaap_ProceedsFromIssuanceOfDebt / us-gaap_DebtInstrumentAxis = ofc_TermCreditFacilityEffectiveAugust2012Member |  |  |  |  |
Term Loan Facilities |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt, net | 520,000,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_TermLoanFacilitiesMember |  | 620,000,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_TermLoanFacilitiesMember |  | 520,000,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_TermLoanFacilitiesMember |  |  |  |  |  |  |  |  |
Description of variable rate basis | LIBOR | [4] |  |  |  |  |  |  |  |  |  |  |  |
Weighted average interest rate (as a percent) | 1.80%us-gaap_DebtWeightedAverageInterestRate / us-gaap_DebtInstrumentAxis = ofc_TermLoanFacilitiesMember |  |  |  | 1.80%us-gaap_DebtWeightedAverageInterestRate / us-gaap_DebtInstrumentAxis = ofc_TermLoanFacilitiesMember |  |  |  |  |  |  |  |  |
Additional borrowing capacity available provided there is no default under the agreement | 180,000,000 ofc_CreditFacilityAdditionalBorrowingCapacityAvailable / us-gaap_DebtInstrumentAxis = ofc_TermLoanFacilitiesMember |  |  |  | 180,000,000 ofc_CreditFacilityAdditionalBorrowingCapacityAvailable / us-gaap_DebtInstrumentAxis = ofc_TermLoanFacilitiesMember |  |  |  |  |  |  |  |  |
4.25% Exchangeable Senior Notes |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt, net | 572,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  | 563,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  | 572,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  |  |  |  |  |  |  |  |
Stated interest rate (as a percent) | 4.25%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  |  |  | 4.25%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  |  |  |  | 4.25%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  |  |  |
Interest rate on debt (as a percent) | 6.05%us-gaap_DebtInstrumentInterestRateEffectivePercentage / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  |  |  | 6.05%us-gaap_DebtInstrumentInterestRateEffectivePercentage / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  |  |  |  |  |  |  |  |
Unamortized discount included in carrying value | 3,000 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  | 12,000 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  | 3,000 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  |  |  |  |  |  |  |  |
Initial amount borrowed |  |  |  |  |  |  |  |  |  | 240,000,000 us-gaap_ProceedsFromIssuanceOfDebt / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  |  |  |
Exchange rate per $1000 principal amount (in common shares) | 20.8513 us-gaap_DebtInstrumentConvertibleConversionRatio1 / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  |  |  |  |  |  |  |  |  |  |  |  |
Convertible debt principal amount, basis for exchange | 1,000 ofc_DebtInstrumentExchangeRatePrincipalAmountUsedInCalculation / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  |  |  | 1,000 ofc_DebtInstrumentExchangeRatePrincipalAmountUsedInCalculation / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  |  |  |  |  |  |  |  |
Exchange price per common share based on exchange rate (in dollars per share) | $ 47.96 us-gaap_DebtInstrumentConvertibleConversionPrice1 / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  |  |  | $ 47.96 us-gaap_DebtInstrumentConvertibleConversionPrice1 / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  |  |  |  |  |  |  |  |
Percentage over the entity's common stock price at the time of issuance which was used to determine the initial exchange rate | 20.00%ofc_DebtInstrumentConvertibleExchangeRatePercentageOverEntityCommonStockPriceClosingPriceAtIssuance / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  |  |  |  |  |  |  |  |  |  |  |  |
Repurchase of notes, percentage of principal paid | 100.00%ofc_RepurchaseOfExchangeableSeniorNotesPercentageOfPrincipalPaid / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  |  |  | 100.00%ofc_RepurchaseOfExchangeableSeniorNotesPercentageOfPrincipalPaid / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  |  |  |  |  |  |  |  |
Amount of loans repaid upon entry into Revolving Credit Facility and Term Loan Agreement |  |  | 239,400,000 us-gaap_ExtinguishmentOfDebtAmount / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  |  |  |  |  |  |  |  |  |  |
Loss on early extinguishment of debt |  |  | 25,900,000 us-gaap_GainsLossesOnExtinguishmentOfDebt / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  |  |  |  |  |  |  |  |  |  |
Principal amount of debt | 575,000 us-gaap_DebtInstrumentCarryingAmount / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  | 575,000 us-gaap_DebtInstrumentCarryingAmount / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  | 575,000 us-gaap_DebtInstrumentCarryingAmount / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  |  |  |  |  |  |  |  |
Interest expense at stated interest rate | 24,000 us-gaap_InterestExpenseDebtExcludingAmortization / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  | 4,208,000 us-gaap_InterestExpenseDebtExcludingAmortization / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember | 10,200,000 us-gaap_InterestExpenseDebtExcludingAmortization / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  |  |  |  |  |  |  |  |  |
Interest expense associated with amortization of discount | 10,000 us-gaap_AmortizationOfDebtDiscountPremium / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  | 1,615,000 us-gaap_AmortizationOfDebtDiscountPremium / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember | 3,651,000 us-gaap_AmortizationOfDebtDiscountPremium / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  |  |  |  |  |  |  |  |  |
Total interest expenses | 34,000 us-gaap_InterestExpenseDebt / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  | 5,823,000 us-gaap_InterestExpenseDebt / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember | 13,851,000 us-gaap_InterestExpenseDebt / us-gaap_DebtInstrumentAxis = ofc_Exchangeable425PercentSeniorNotesMember |  |  |  |  |  |  |  |  |  |
Unsecured notes payable |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt, net | 1,607,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = us-gaap_UnsecuredDebtMember |  | 1,700,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = us-gaap_UnsecuredDebtMember |  | 1,607,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = us-gaap_UnsecuredDebtMember |  |  |  |  |  |  |  |  |
Stated interest rate (as a percent) | 0.00%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = us-gaap_UnsecuredDebtMember |  |  |  | 0.00%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = us-gaap_UnsecuredDebtMember |  |  |  |  |  |  |  |  |
Unamortized discount included in carrying value | 654,000 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = us-gaap_UnsecuredDebtMember |  | 761,000 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = us-gaap_UnsecuredDebtMember |  | 654,000 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = us-gaap_UnsecuredDebtMember |  |  |  |  |  |  |  |  |
Debt in Default of Payment Terms |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of real estate properties | 2 us-gaap_NumberOfRealEstateProperties / us-gaap_DebtInstrumentAxis = ofc_DebtinDefaultofPaymentTermsMember |  |  |  | 2 us-gaap_NumberOfRealEstateProperties / us-gaap_DebtInstrumentAxis = ofc_DebtinDefaultofPaymentTermsMember |  |  |  |  |  |  |  |  |
Senior Notes |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Redemption percentage within three months of maturity | 100.00%ofc_RedemptionPercentageWithinThreeMonthsofMaturity / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes | 3.60% Senior Notes |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt, net | 347,496,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_A3.60SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  | 347,244,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_A3.60SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  | 347,496,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_A3.60SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |  |  |  |  |  |  |  |
Stated interest rate (as a percent) | 3.60%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = ofc_A3.60SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |  |  | 3.60%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = ofc_A3.60SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |  |  |  |  | 3.60%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = ofc_A3.60SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |  |
Interest rate on debt (as a percent) | 3.70%us-gaap_DebtInstrumentInterestRateEffectivePercentage / us-gaap_DebtInstrumentAxis = ofc_A3.60SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |  |  | 3.70%us-gaap_DebtInstrumentInterestRateEffectivePercentage / us-gaap_DebtInstrumentAxis = ofc_A3.60SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |  |  |  |  |  |  |  |
Unamortized discount included in carrying value | 2,500,000 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = ofc_A3.60SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  | 2,800,000 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = ofc_A3.60SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  | 2,500,000 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = ofc_A3.60SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |  |  |  |  |  |  |  |
Initial amount borrowed |  |  |  |  |  |  |  |  |  |  | 347,100,000 us-gaap_ProceedsFromIssuanceOfDebt / us-gaap_DebtInstrumentAxis = ofc_A3.60SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |  |
Loan amount |  |  |  |  |  |  |  |  |  |  | 350,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = ofc_A3.60SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |  |
Debt issuance as a percentage of principal amount |  |  |  |  |  |  |  |  |  |  | 99.82%ofc_Debtissuanceasapercentageofprincipalamount / us-gaap_DebtInstrumentAxis = ofc_A3.60SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |  |
Senior Notes | 5.250% Senior Notes |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt, net | 245,797,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_A5.250SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  | 245,445,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_A5.250SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  | 245,797,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_A5.250SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |  |  |  |  |  |  |  |
Stated interest rate (as a percent) | 5.25%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = ofc_A5.250SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |  |  | 5.25%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = ofc_A5.250SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |  |  |  |  |  | 5.25%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = ofc_A5.250SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |
Interest rate on debt (as a percent) | 5.49%us-gaap_DebtInstrumentInterestRateEffectivePercentage / us-gaap_DebtInstrumentAxis = ofc_A5.250SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |  |  | 5.49%us-gaap_DebtInstrumentInterestRateEffectivePercentage / us-gaap_DebtInstrumentAxis = ofc_A5.250SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |  |  |  |  |  |  |  |
Unamortized discount included in carrying value | 4,200,000 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = ofc_A5.250SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  | 4,600,000 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = ofc_A5.250SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  | 4,200,000 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = ofc_A5.250SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |  |  |  |  |  |  |  |
Initial amount borrowed |  |  |  |  |  |  |  |  |  |  |  | 245,300,000 us-gaap_ProceedsFromIssuanceOfDebt / us-gaap_DebtInstrumentAxis = ofc_A5.250SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |
Loan amount |  |  |  |  |  |  |  |  |  |  |  | 250,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = ofc_A5.250SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |
Debt issuance as a percentage of principal amount |  |  |  |  |  |  |  |  |  |  |  | 98.78%ofc_Debtissuanceasapercentageofprincipalamount / us-gaap_DebtInstrumentAxis = ofc_A5.250SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |
Senior Notes | 3.70% Senior Notes |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt, net | 297,569,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_A3.70SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  | 0 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_A3.70SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  | 297,569,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = ofc_A3.70SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |  |  |  |  |  |  |  |
Stated interest rate (as a percent) |  |  |  |  |  |  |  |  |  |  |  |  | 3.70%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = ofc_A3.70SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |
Interest rate on debt (as a percent) | 3.85%us-gaap_DebtInstrumentInterestRateEffectivePercentage / us-gaap_DebtInstrumentAxis = ofc_A3.70SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |  |  | 3.85%us-gaap_DebtInstrumentInterestRateEffectivePercentage / us-gaap_DebtInstrumentAxis = ofc_A3.70SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |  |  |  |  |  |  |  |
Unamortized discount included in carrying value | 2,400,000 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = ofc_A3.70SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |  |  | 2,400,000 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = ofc_A3.70SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |  |  |  |  |  |  |  |  |
Initial amount borrowed |  |  |  |  |  |  |  |  |  |  |  |  | 297,300,000 us-gaap_ProceedsFromIssuanceOfDebt / us-gaap_DebtInstrumentAxis = ofc_A3.70SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |
Loan amount |  |  |  |  |  |  |  |  |  |  |  |  | 300,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = ofc_A3.70SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |
Debt issuance as a percentage of principal amount |  |  |  |  |  |  |  |  |  |  |  |  | 99.74%ofc_Debtissuanceasapercentageofprincipalamount / us-gaap_DebtInstrumentAxis = ofc_A3.70SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember |
London Interbank Offered Rate (LIBOR) | Term Credit Facility Effective September 2011 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Description of variable rate basis | LIBOR |  |  |  |  |  |  |  |  |  |  |  |  |
London Interbank Offered Rate (LIBOR) | Term Credit Facility Effective February 2012 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Description of variable rate basis | LIBOR |  |  |  |  |  |  |  |  |  |  |  |  |
London Interbank Offered Rate (LIBOR) | Term Credit Facility Effective August 2012 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Description of variable rate basis | LIBOR |  |  |  |  |  |  |  |  |  |  |  |  |
Adjusted Treasury | Senior Notes | 3.60% Senior Notes |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Basis points used in determining redemption price prior to maturity | 30.00%ofc_Basispointsusedindeterminingredemptionpricepriortomaturity / us-gaap_DebtInstrumentAxis = ofc_A3.60SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember / us-gaap_VariableRateAxis = ofc_AdjustedTreasuryMember |  |  |  | 30.00%ofc_Basispointsusedindeterminingredemptionpricepriortomaturity / us-gaap_DebtInstrumentAxis = ofc_A3.60SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember / us-gaap_VariableRateAxis = ofc_AdjustedTreasuryMember |  |  |  |  |  |  |  |  |
Adjusted Treasury | Senior Notes | 5.250% Senior Notes |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Basis points used in determining redemption price prior to maturity | 40.00%ofc_Basispointsusedindeterminingredemptionpricepriortomaturity / us-gaap_DebtInstrumentAxis = ofc_A5.250SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember / us-gaap_VariableRateAxis = ofc_AdjustedTreasuryMember |  |  |  | 40.00%ofc_Basispointsusedindeterminingredemptionpricepriortomaturity / us-gaap_DebtInstrumentAxis = ofc_A5.250SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember / us-gaap_VariableRateAxis = ofc_AdjustedTreasuryMember |  |  |  |  |  |  |  |  |
Adjusted Treasury | Senior Notes | 3.70% Senior Notes |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Basis points used in determining redemption price prior to maturity | 25.00%ofc_Basispointsusedindeterminingredemptionpricepriortomaturity / us-gaap_DebtInstrumentAxis = ofc_A3.70SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember / us-gaap_VariableRateAxis = ofc_AdjustedTreasuryMember |  |  |  | 25.00%ofc_Basispointsusedindeterminingredemptionpricepriortomaturity / us-gaap_DebtInstrumentAxis = ofc_A3.70SeniorNotesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_SeniorNotesMember / us-gaap_VariableRateAxis = ofc_AdjustedTreasuryMember |  |  |  |  |  |  |  |  |
Revolving Credit Facility | Revolving Credit Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maximum Availability | 800,000,000 us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_DebtInstrumentAxis = ofc_CreditFacilityMember |  |  |  | 800,000,000 us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_DebtInstrumentAxis = ofc_CreditFacilityMember |  |  |  |  |  |  |  |  |
Weighted average interest rate (as a percent) | 1.47%us-gaap_DebtWeightedAverageInterestRate / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_DebtInstrumentAxis = ofc_CreditFacilityMember |  | 1.74%us-gaap_DebtWeightedAverageInterestRate / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_DebtInstrumentAxis = ofc_CreditFacilityMember |  | 1.47%us-gaap_DebtWeightedAverageInterestRate / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_DebtInstrumentAxis = ofc_CreditFacilityMember |  |  |  |  |  |  |  |  |
Expansion right, maximum borrowing capacity | 1,300,000,000 ofc_LineOfCreditExpansionRightMaximumBorrowingAvailabiliity / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_DebtInstrumentAxis = ofc_CreditFacilityMember |  |  |  | 1,300,000,000 ofc_LineOfCreditExpansionRightMaximumBorrowingAvailabiliity / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_DebtInstrumentAxis = ofc_CreditFacilityMember |  |  |  |  |  |  |  |  |
Amount available as a percentage of unencumbered Asset value | 60.00%ofc_LineOfCreditFacilityPercentageOfUnencumberedAssetValue / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_DebtInstrumentAxis = ofc_CreditFacilityMember |  |  |  |  |  |  |  |  |  |  |  |  |
Extension option period (in years) | 1 year |  |  |  |  |  |  |  |  |  |  |  |  |
Line of credit facility, extension fee percentage | 0.15%ofc_LineofCreditFacilityExtensionFeePercentage / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_DebtInstrumentAxis = ofc_CreditFacilityMember |  |  |  |  |  |  |  |  |  |  |  |  |
Remaining borrowing capacity | 702,200,000 us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_DebtInstrumentAxis = ofc_CreditFacilityMember |  |  |  | 702,200,000 us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_DebtInstrumentAxis = ofc_CreditFacilityMember |  |  |  |  |  |  |  |  |
Weighted average borrowings | 15,900,000 us-gaap_LineOfCreditFacilityAverageOutstandingAmount / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_DebtInstrumentAxis = ofc_CreditFacilityMember |  | 55,500,000 us-gaap_LineOfCreditFacilityAverageOutstandingAmount / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_DebtInstrumentAxis = ofc_CreditFacilityMember |  |  |  |  |  |  |  |  |  |  |
Minimum | Revolving Credit Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable rate, spread (as a percent) | 0.975%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_DebtInstrumentAxis = ofc_CreditFacilityMember / us-gaap_RangeAxis = us-gaap_MinimumMember |  |  |  |  |  |  |  |  |  |  |  |  |
Minimum | Term Loan Facilities |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable rate, spread (as a percent) | 1.10%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_DebtInstrumentAxis = ofc_TermLoanFacilitiesMember / us-gaap_RangeAxis = us-gaap_MinimumMember | [4] |  |  |  |  |  |  |  |  |  |  |  |
Minimum | London Interbank Offered Rate (LIBOR) | Term Credit Facility Effective September 2011 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable rate, spread (as a percent) | 1.10%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_DebtInstrumentAxis = ofc_TermCreditFacilityEffectiveSeptember2011Member / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_VariableRateAxis = us-gaap_LondonInterbankOfferedRateLIBORMember |  |  |  |  |  |  |  |  |  |  |  |  |
Minimum | London Interbank Offered Rate (LIBOR) | Term Credit Facility Effective February 2012 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable rate, spread (as a percent) | 1.10%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_DebtInstrumentAxis = ofc_TermCreditFacilityEffectiveFebruary2012Member / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_VariableRateAxis = us-gaap_LondonInterbankOfferedRateLIBORMember |  |  |  |  |  |  |  |  |  |  |  |  |
Minimum | London Interbank Offered Rate (LIBOR) | Term Credit Facility Effective August 2012 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable rate, spread (as a percent) | 2.10%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_DebtInstrumentAxis = ofc_TermCreditFacilityEffectiveAugust2012Member / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_VariableRateAxis = us-gaap_LondonInterbankOfferedRateLIBORMember |  |  |  |  |  |  |  |  |  |  |  |  |
Minimum | Revolving Credit Facility | Revolving Credit Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Commitment fee percentage | 0.125%us-gaap_LineOfCreditFacilityCommitmentFeePercentage / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_DebtInstrumentAxis = ofc_CreditFacilityMember / us-gaap_RangeAxis = us-gaap_MinimumMember |  |  |  |  |  |  |  |  |  |  |  |  |
Minimum | Revolving Credit Facility | London Interbank Offered Rate (LIBOR) | Revolving Credit Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable rate, spread (as a percent) | 0.975%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_DebtInstrumentAxis = ofc_CreditFacilityMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_VariableRateAxis = us-gaap_LondonInterbankOfferedRateLIBORMember |  |  |  |  |  |  |  |  |  |  |  |  |
Maximum | Fixed rate mortgage loans |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stated interest rate excluding incremental rate on default rate | 7.87%ofc_DebtInstrumentInterestRateStatedPercentageExcludingIncrementalRateOnDefaultRate / us-gaap_DebtInstrumentAxis = ofc_FixedRateSecuredDebtMember / us-gaap_RangeAxis = us-gaap_MaximumMember |  |  |  | 7.87%ofc_DebtInstrumentInterestRateStatedPercentageExcludingIncrementalRateOnDefaultRate / us-gaap_DebtInstrumentAxis = ofc_FixedRateSecuredDebtMember / us-gaap_RangeAxis = us-gaap_MaximumMember |  |  |  |  |  |  |  |  |
Maximum | Revolving Credit Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable rate, spread (as a percent) | 1.75%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_DebtInstrumentAxis = ofc_CreditFacilityMember / us-gaap_RangeAxis = us-gaap_MaximumMember |  |  |  |  |  |  |  |  |  |  |  |  |
Maximum | Term Loan Facilities |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable rate, spread (as a percent) | 2.60%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_DebtInstrumentAxis = ofc_TermLoanFacilitiesMember / us-gaap_RangeAxis = us-gaap_MaximumMember | [4] |  |  |  |  |  |  |  |  |  |  |  |
Maximum | London Interbank Offered Rate (LIBOR) | Term Credit Facility Effective September 2011 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable rate, spread (as a percent) | 2.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_DebtInstrumentAxis = ofc_TermCreditFacilityEffectiveSeptember2011Member / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_VariableRateAxis = us-gaap_LondonInterbankOfferedRateLIBORMember |  |  |  |  |  |  |  |  |  |  |  |  |
Maximum | London Interbank Offered Rate (LIBOR) | Term Credit Facility Effective February 2012 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable rate, spread (as a percent) | 2.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_DebtInstrumentAxis = ofc_TermCreditFacilityEffectiveFebruary2012Member / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_VariableRateAxis = us-gaap_LondonInterbankOfferedRateLIBORMember |  |  |  |  |  |  |  |  |  |  |  |  |
Maximum | London Interbank Offered Rate (LIBOR) | Term Credit Facility Effective August 2012 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable rate, spread (as a percent) | 2.60%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_DebtInstrumentAxis = ofc_TermCreditFacilityEffectiveAugust2012Member / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_VariableRateAxis = us-gaap_LondonInterbankOfferedRateLIBORMember |  |  |  |  |  |  |  |  |  |  |  |  |
Maximum | Revolving Credit Facility | Revolving Credit Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Commitment fee percentage | 0.35%us-gaap_LineOfCreditFacilityCommitmentFeePercentage / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_DebtInstrumentAxis = ofc_CreditFacilityMember / us-gaap_RangeAxis = us-gaap_MaximumMember |  |  |  |  |  |  |  |  |  |  |  |  |
Maximum | Revolving Credit Facility | London Interbank Offered Rate (LIBOR) | Revolving Credit Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable rate, spread (as a percent) | 1.75%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_DebtInstrumentAxis = ofc_CreditFacilityMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_VariableRateAxis = us-gaap_LondonInterbankOfferedRateLIBORMember |  |  |  |  |  |  |  |  |  |  |  |  |
Wholly Owned Subsidiary |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt, net | $ 150,000,000 us-gaap_DebtDefaultLongtermDebtAmount / dei_LegalEntityAxis = ofc_WhollyOwnedSubsidiaryMember |  |  |  | $ 150,000,000 us-gaap_DebtDefaultLongtermDebtAmount / dei_LegalEntityAxis = ofc_WhollyOwnedSubsidiaryMember |  |  |  |  |  |  |  |  | $ 150,000,000 us-gaap_DebtDefaultLongtermDebtAmount / dei_LegalEntityAxis = ofc_WhollyOwnedSubsidiaryMember
Wholly Owned Subsidiary | Debt in Default of Payment Terms |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
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Northern Virginia | Wholly Owned Subsidiary | Debt in Default of Payment Terms |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |
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[1] | Represents scheduled principal amortization and maturities only and therefore excludes net discounts of $9.8 million.
[2] | The interest rate on the loan outstanding was 2.41% as of December 31, 2014.
[3] | Refer to the paragraphs below for further disclosure.
[4] | These notes carry interest rates that were below market rates upon assumption and therefore were recorded at their fair value based on applicable effective interest rates. The carrying value of these notes reflects an unamortized discount totaling $654,000 as of December 31, 2014 and $761,000 as of December 31, 2013.

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