XML 23 R46.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Properties, net (Details) (USD $) |  |  | 3 Months Ended |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 Greater Philadelphia | Mar. 31, 2014 Operating properties, net | Dec. 31, 2013 Operating properties, net | Mar. 31, 2014 Operating properties, net Land | Dec. 31, 2013 Operating properties, net Land | Mar. 31, 2014 Operating properties, net Buildings and improvements | Dec. 31, 2013 Operating properties, net Buildings and improvements
Properties |  |  |  |  |  |  |  |  |
Gross |  |  |  |  |  | $ 436,381,000 | $ 430,472,000 | $ 2,927,800,000 | $ 2,869,870,000
Less: accumulated depreciation |  |  |  | (635,178,000) | (597,649,000) |  |  |  |
Operating properties, net | 2,729,003,000 | 2,702,693,000 |  |  |  |  |  |  |
Depreciation Expense on Reclassified Assets |  |  | $ 12,900,000 |  |  |  |  |  |

X
- Definition Additional depreciation expense recognized resulting from a change in the useful life of the disclosed asset. + References No definition available. + Details
Name: | ofc_DepreciationExpenseResultingFromUsefulLifeChange
Namespace Prefix: | ofc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, before accumulated depreciation, of real estate investments for entities with a substantial portion of business acquiring and holding investment real estate. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 10 -Section S99 -Paragraph 6 -Subparagraph (SX 210.5-04.(c) Schedule III) -URI http://asc.fasb.org/extlink&oid=27047687&loc=d3e5864-122674 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 28 -Article 12 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph c -Subparagraph Schedule III -Article 5 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 970 -SubTopic 360 -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-28.4) -URI http://asc.fasb.org/extlink&oid=6590653&loc=d3e638233-123024 + Details
Name: | us-gaap_RealEstateGrossAtCarryingValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The cumulative amount of depreciation for real estate property held for investment purposes. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.1(3)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Article 7 + Details
Name: | us-gaap_RealEstateInvestmentPropertyAccumulatedDepreciation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_RealEstatePropertiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Carrying amount of income producing properties held for rental. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.1(d)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
Name: | us-gaap_RentalProperties
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant