Concentration Risk, Number Of Properties Occupied

No definition available.

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Namespace Prefix:	cmct_
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- Definition

Represents the number of states in which the entity owns real estate properties as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	cmct_NumberofStatesinwhichRealEstatePropertiesareOwned
Namespace Prefix:	cmct_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

For an unclassified balance sheet, the amount due from customers or clients for goods or services that have been delivered or sold in the normal course of business, reduced to their estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.

+ References

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-Section S99
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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ConcentrationRiskLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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+ Details

Name:	us-gaap_ConcentrationRiskPercentage1
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of real estate properties owned as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfRealEstateProperties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	cmct_InvestmentsInRealEstateTypeAxis=cmct_RealEstateOfficePropertyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	cmct_InvestmentsInRealEstateTypeAxis=cmct_RealEstateHotelPropertyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	cmct_InvestmentsInRealEstateTypeAxis=cmct_RealEstateParkingGarageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	cmct_InvestmentsInRealEstateTypeAxis=cmct_RealEstateDevelopmentSiteMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	cmct_InvestmentsInRealEstateTypeAxis=cmct_RealEstateParkingLotMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_SalesRevenueNetMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	us-gaap_ConcentrationRiskByTypeAxis=us-gaap_CustomerConcentrationRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MajorCustomersAxis=cmct_GovernmentalTenantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	srt_MajorCustomersAxis=cmct_KaiserFoundationHealthPlanInc.Member
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Balance Type:
Period Type:

- Details

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- Details

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- Details

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- Details

Name:	srt_StatementGeographicalAxis=stpr_TX
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- Details

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CONCENTRATIONS (Details) $ in Thousands	3 Months Ended		12 Months Ended
CONCENTRATIONS (Details) $ in Thousands	Mar. 31, 2019 USD ($) property state	Mar. 31, 2018	Dec. 31, 2018 USD ($) property state
Concentrations
Number of states in which properties are owned \| state	2		2
Office properties
Concentrations
Number of real estate properties owned	11		16
Hotel properties
Concentrations
Number of real estate properties owned	1		1
Parking garages
Concentrations
Number of real estate properties owned	1		2
Development site
Concentrations
Number of real estate properties owned	2		2
Parking lot
Concentrations
Number of real estate properties owned	1		1
Revenues \| Tenant Revenue Concentrations \| Governmental Tenants
Concentrations
Concentration risk, percent	23.00%	25.10%
Amount due from governmental tenants \| $	$ 1,928		$ 2,899
Revenues \| Tenant Revenue Concentrations \| Kaiser Foundation Health Plan, Inc.
Concentrations
Concentration risk, percent	12.90%	13.10%
Amount due from governmental tenants \| $	$ 1		$ 331
Revenues \| Tenant Revenue Concentrations \| Kaiser Foundation Health Plan, Inc. \| California
Concentrations
Number of properties occupied	2
Revenues \| Geographical concentrations
Concentrations
Concentration risk, percent	100.00%	100.00%
Revenues \| Geographical concentrations \| California
Concentrations
Concentration risk, percent	76.50%	76.80%
Revenues \| Geographical concentrations \| Washington, D.C.
Concentrations
Concentration risk, percent	19.90%	19.90%
Revenues \| Geographical concentrations \| Texas
Concentrations
Concentration risk, percent	3.60%	3.30%
Real Estate Investments \| Geographical concentrations
Concentrations
Concentration risk, percent	100.00%		100.00%
Real Estate Investments \| Geographical concentrations \| California
Concentrations
Concentration risk, percent	74.30%		70.60%
Real Estate Investments \| Geographical concentrations \| Washington, D.C.
Concentrations
Concentration risk, percent	22.40%		27.20%
Real Estate Investments \| Geographical concentrations \| Texas
Concentrations
Concentration risk, percent	3.30%		2.20%