Concentration Risk, Number Of Properties Occupied

No definition available.

Name:	cmct_ConcentrationRiskNumberOfPropertiesOccupied
Namespace Prefix:	cmct_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- 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

Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(5))
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

+ Details

Name:	us-gaap_AccountsReceivableNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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
Period Type:	duration

- 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
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13531-108611

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13537-108611

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

+ Details

Name:	us-gaap_ConcentrationRiskPercentage1
Namespace Prefix:	us-gaap_
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:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_SalesRevenueNetMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	srt_MajorCustomersAxis=cmct_KaiserFoundationHealthPlanInc.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=stpr_CA
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MajorCustomersAxis=cmct_GovernmentalTenantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	srt_StatementGeographicalAxis=stpr_TX
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=stpr_DC
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_RealEstateInvestmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=cmct_OfficePropertiesSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

CONCENTRATIONS (Details) $ in Thousands	3 Months Ended		12 Months Ended
CONCENTRATIONS (Details) $ in Thousands	Mar. 31, 2020 USD ($) property	Mar. 31, 2019	Dec. 31, 2019 USD ($) property state
Concentration Risk [Line Items]
Number of states in which properties are owned \| state			2
Office properties
Concentration Risk [Line Items]
Number of real estate properties owned	8		8
Hotel properties
Concentration Risk [Line Items]
Number of real estate properties owned	1		1
Parking garages
Concentration Risk [Line Items]
Number of real estate properties owned	1		1
Development site
Concentration Risk [Line Items]
Number of real estate properties owned	1		1
Revenues \| Tenant Revenue Concentrations \| Kaiser Foundation Health Plan, Inc.
Concentration Risk [Line Items]
Amounts due from tenant revenue concentrations \| $	$ 11		$ 23
Revenues \| Tenant Revenue Concentrations \| Kaiser Foundation Health Plan, Inc. \| California
Concentration Risk [Line Items]
Number of properties occupied by tenant revenue concentrations	2
Revenues \| Tenant Revenue Concentrations \| Governmental Tenants
Concentration Risk [Line Items]
Amounts due from tenant revenue concentrations \| $	$ 101		$ 282
Revenues \| Geographical concentrations
Concentration Risk [Line Items]
Concentration risk, percent	100.00%	100.00%
Revenues \| Geographical concentrations \| California
Concentration Risk [Line Items]
Concentration risk, percent	91.90%	76.50%
Revenues \| Geographical concentrations \| Texas
Concentration Risk [Line Items]
Concentration risk, percent	7.70%	3.60%
Revenues \| Geographical concentrations \| Washington, D.C.
Concentration Risk [Line Items]
Concentration risk, percent	0.40%	19.90%
Real Estate Investments \| Geographical concentrations
Concentration Risk [Line Items]
Concentration risk, percent	100.00%		100.00%
Real Estate Investments \| Geographical concentrations \| California
Concentration Risk [Line Items]
Concentration risk, percent	93.90%		94.40%
Real Estate Investments \| Geographical concentrations \| Texas
Concentration Risk [Line Items]
Concentration risk, percent	6.10%		5.60%
Office Properties Segment \| Revenues \| Tenant Revenue Concentrations \| Kaiser Foundation Health Plan, Inc.
Concentration Risk [Line Items]
Concentration risk, percent	25.30%	11.30%
Office Properties Segment \| Revenues \| Tenant Revenue Concentrations \| Governmental Tenants
Concentration Risk [Line Items]
Concentration risk, percent	2.20%	23.30%