XML 119 R94.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Accounts Receivables-Allowance for doubtful accounts [Member] |  |  |
Movement in Valuation Allowances and Reserves [Roll Forward] |  |  |
Balance at Beginning of Year | $ 603 | $ 1,525 | $ 717
Charged to Costs and Expenses | 368 | (17) | 1,125
Charged to Other Accounts | (36) | 235 | 98
Deductions | (328) | (1,140) | (415)
Balance at End of Year | 607 | 603 | 1,525
Allowance for Deferred Rent Receivable [Member] |  |  |
Movement in Valuation Allowances and Reserves [Roll Forward] |  |  |
Balance at Beginning of Year | 373 | 1,962 | 1,418
Charged to Costs and Expenses | (9) | (1,589) | 0
Charged to Other Accounts | 0 | 0 | 544
Deductions | 0 | 0 | 0
Balance at End of Year | 364 | 373 | 1,962
Allowance for Deferred Tax Asset [Member] |  |  |
Movement in Valuation Allowances and Reserves [Roll Forward] |  |  |
Balance at Beginning of Year | 2,062 | 2,062 | 2,062
Charged to Costs and Expenses | (646) | 0 | 0
Charged to Other Accounts | 0 | 0 | 0
Deductions | 0 | 0 | 0
Balance at End of Year | $ 1,416 | $ 2,062 | $ 2,062

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | us-gaap_MovementInValuationAllowancesAndReservesRollForward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Total of 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. + 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_ValuationAllowancesAndReservesBalance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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 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 accounts other than 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_ValuationAllowancesAndReservesChargedToOtherAccounts
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=us-gaap_AllowanceForDoubtfulAccountsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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