XML 28 R67.htm IDEA: XBRL DOCUMENT v2.4.1.9
Schedule III - Real Estate Properties and Accumulated Depreciation (Detail) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]      
Gross Amount, Total $ 227,139us-gaap_RealEstateGrossAtCarryingValue $ 107,862us-gaap_RealEstateGrossAtCarryingValue  
Accumulated Amortization 15,311us-gaap_RealEstateAccumulatedDepreciation 7,735us-gaap_RealEstateAccumulatedDepreciation  
Predecessor [Member]      
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]      
Initial Cost to Company, Encumbrances 189,940us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Initial Cost to Company, Land 66,204us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Initial Cost to Company, Buildings and Improvements 146,399us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Costs Capitalized Subsequent to Acquisitions, Improvements 14,536us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Land 66,204us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Building and Improvements 160,935us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Total 227,139us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
107,862us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
46,256us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
Accumulated Amortization 15,311us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
7,735us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
4,084us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
Predecessor [Member] | AmberGlen [Member]      
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]      
Initial Cost to Company, Encumbrances 25,158us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_AmberGlenMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Initial Cost to Company, Land 8,790us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_AmberGlenMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Initial Cost to Company, Buildings and Improvements 5,705us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_AmberGlenMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Costs Capitalized Subsequent to Acquisitions, Improvements 3,187us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_AmberGlenMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Land 8,790us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_AmberGlenMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Building and Improvements 8,892us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_AmberGlenMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Total 17,682us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_AmberGlenMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Accumulated Amortization 3,592us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_AmberGlenMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Date Acquired 2009-12    
Depreciation Life for the Latest Income Statement 50 years    
Predecessor [Member] | AmberGlen [Member] | Minimum [Member]      
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]      
Date of Construction 1984    
Predecessor [Member] | AmberGlen [Member] | Maximum [Member]      
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]      
Date of Construction 1998    
Predecessor [Member] | City Center Property [Member]      
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]      
Initial Cost to Company, Encumbrances 24,500us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CityCenterPropertyMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Initial Cost to Company, Land 3,123us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CityCenterPropertyMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Initial Cost to Company, Buildings and Improvements 10,656us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CityCenterPropertyMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Costs Capitalized Subsequent to Acquisitions, Improvements 7,893us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CityCenterPropertyMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Land 3,123us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CityCenterPropertyMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Building and Improvements 18,549us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CityCenterPropertyMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Total 21,672us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CityCenterPropertyMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Accumulated Amortization 3,588us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CityCenterPropertyMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Date of Construction 1984    
Date Acquired 2010-12    
Depreciation Life for the Latest Income Statement 40 years    
Predecessor [Member] | Central Fairwinds [Member]      
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]      
Initial Cost to Company, Land 1,747us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CentralFairwindsMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Initial Cost to Company, Buildings and Improvements 9,751us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CentralFairwindsMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Costs Capitalized Subsequent to Acquisitions, Improvements 1,898us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CentralFairwindsMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Land 1,747us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CentralFairwindsMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Building and Improvements 11,649us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CentralFairwindsMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Total 13,396us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CentralFairwindsMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Accumulated Amortization 1,226us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CentralFairwindsMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Date of Construction 1982    
Date Acquired 2012-05    
Depreciation Life for the Latest Income Statement 40 years    
Predecessor [Member] | Corporate Parkway [Member]      
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]      
Initial Cost to Company, Encumbrances 20,500us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CorporateParkwayMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Initial Cost to Company, Land 3,757us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CorporateParkwayMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Initial Cost to Company, Buildings and Improvements 20,489us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CorporateParkwayMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Land 3,757us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CorporateParkwayMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Building and Improvements 20,489us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CorporateParkwayMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Total 24,246us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CorporateParkwayMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Accumulated Amortization 1,965us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CorporateParkwayMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Date of Construction 2006    
Date Acquired 2013-05    
Depreciation Life for the Latest Income Statement 43 years    
Predecessor [Member] | Washington Group Plaza [Member]      
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]      
Initial Cost to Company, Encumbrances 34,322us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_WashingtonGroupPlazaMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Initial Cost to Company, Land 12,748us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_WashingtonGroupPlazaMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Initial Cost to Company, Buildings and Improvements 20,716us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_WashingtonGroupPlazaMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Costs Capitalized Subsequent to Acquisitions, Improvements 1,345us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_WashingtonGroupPlazaMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Land 12,748us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_WashingtonGroupPlazaMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Building and Improvements 22,061us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_WashingtonGroupPlazaMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Total 34,809us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_WashingtonGroupPlazaMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Accumulated Amortization 2,426us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_WashingtonGroupPlazaMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Date Acquired 2013-06    
Depreciation Life for the Latest Income Statement 29 years    
Predecessor [Member] | Washington Group Plaza [Member] | Minimum [Member]      
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]      
Date of Construction 1970    
Predecessor [Member] | Washington Group Plaza [Member] | Maximum [Member]      
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]      
Date of Construction 1982    
Predecessor [Member] | Cherry Creek [Member]      
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]      
Initial Cost to Company, Encumbrances 50,000us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CherryCreekMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Initial Cost to Company, Land 25,745us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CherryCreekMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Initial Cost to Company, Buildings and Improvements 20,144us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CherryCreekMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Land 25,745us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CherryCreekMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Building and Improvements 20,144us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CherryCreekMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Total 45,889us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CherryCreekMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Accumulated Amortization 1,300us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_CherryCreekMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Date Acquired 2014-01    
Depreciation Life for the Latest Income Statement 36 years    
Predecessor [Member] | Cherry Creek [Member] | Minimum [Member]      
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]      
Date of Construction 1962    
Predecessor [Member] | Cherry Creek [Member] | Maximum [Member]      
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]      
Date of Construction 1980    
Predecessor [Member] | Plaza 25 [Member]      
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]      
Initial Cost to Company, Land 1,764us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_PlazaTwentyFiveMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Initial Cost to Company, Buildings and Improvements 20,563us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_PlazaTwentyFiveMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Costs Capitalized Subsequent to Acquisitions, Improvements 213us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_PlazaTwentyFiveMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Land 1,764us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_PlazaTwentyFiveMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Building and Improvements 20,776us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_PlazaTwentyFiveMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Total 22,540us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_PlazaTwentyFiveMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Accumulated Amortization 707us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_PlazaTwentyFiveMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Date of Construction 1981    
Date Acquired 2014-06    
Depreciation Life for the Latest Income Statement 30 years    
Predecessor [Member] | Lake Vista Pointe [Member]      
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]      
Initial Cost to Company, Encumbrances 18,460us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_LakeVistaPointeMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Initial Cost to Company, Land 4,115us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_LakeVistaPointeMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Initial Cost to Company, Buildings and Improvements 20,600us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_LakeVistaPointeMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Land 4,115us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_LakeVistaPointeMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Building and Improvements 20,600us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_LakeVistaPointeMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Total 24,715us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_LakeVistaPointeMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Accumulated Amortization 430us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_LakeVistaPointeMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Date of Construction 2007    
Date Acquired 2014-07    
Depreciation Life for the Latest Income Statement 45 years    
Predecessor [Member] | Florida Research Park [Member]      
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]      
Initial Cost to Company, Encumbrances 17,000us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_FloridaResearchParkMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Initial Cost to Company, Land 4,415us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_FloridaResearchParkMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Initial Cost to Company, Buildings and Improvements 17,775us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_FloridaResearchParkMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Land 4,415us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_FloridaResearchParkMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Building and Improvements 17,775us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_FloridaResearchParkMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Gross Amount, Total 22,190us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_FloridaResearchParkMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Accumulated Amortization $ 77us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= cio_FloridaResearchParkMember
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
   
Date of Construction 1999    
Date Acquired 2014-11    
Depreciation Life for the Latest Income Statement 40 years