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

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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

CONCENTRATIONS (Details) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
CONCENTRATIONS (Details) $ in Thousands	Sep. 30, 2019 USD ($) property state	Sep. 30, 2018	Sep. 30, 2019 USD ($) property state	Sep. 30, 2018	Dec. 31, 2018 USD ($) property state
Concentrations
Number of states in which properties are owned \| state	2		2		2
Office properties
Concentrations
Number of real estate properties owned	8		8		16
Hotel properties
Concentrations
Number of real estate properties owned	1		1		1
Parking garages
Concentrations
Number of real estate properties owned	1		1		2
Development site
Concentrations
Number of real estate properties owned	1		1		2
Parking lot
Concentrations
Number of real estate properties owned	1		1		1
Revenues \| Tenant Revenue Concentrations \| Governmental Tenants
Concentrations
Amounts due from tenant revenue concentrations \| $	$ 768		$ 768		$ 2,899
Revenues \| Tenant Revenue Concentrations \| Kaiser Foundation Health Plan, Inc.
Concentrations
Amounts due from tenant revenue concentrations \| $	$ 132		$ 132		$ 331
Revenues \| Tenant Revenue Concentrations \| Kaiser Foundation Health Plan, Inc. \| California
Concentrations
Number of properties occupied by tenant revenue concentrations			2
Revenues \| Geographical concentrations
Concentrations
Concentration risk, percent	100.00%	100.00%	100.00%	100.00%
Revenues \| Geographical concentrations \| California
Concentrations
Concentration risk, percent	84.10%	76.20%	77.70%	76.90%
Revenues \| Geographical concentrations \| Texas
Concentrations
Concentration risk, percent	7.40%	3.50%	5.10%	3.30%
Revenues \| Geographical concentrations \| Washington, D.C.
Concentrations
Concentration risk, percent	8.50%	20.30%	17.20%	19.80%
Real Estate Investments \| Geographical concentrations
Concentrations
Concentration risk, percent			100.00%		100.00%
Real Estate Investments \| Geographical concentrations \| California
Concentrations
Concentration risk, percent			94.80%		70.60%
Real Estate Investments \| Geographical concentrations \| Texas
Concentrations
Concentration risk, percent			5.20%		2.20%
Real Estate Investments \| Geographical concentrations \| Washington, D.C.
Concentrations
Concentration risk, percent			0.00%		27.20%
Office Properties Segment \| Revenues \| Tenant Revenue Concentrations \| Governmental Tenants
Concentrations
Concentration risk, percent	11.20%	25.30%	20.00%	25.40%
Office Properties Segment \| Revenues \| Tenant Revenue Concentrations \| Kaiser Foundation Health Plan, Inc.
Concentrations
Concentration risk, percent	22.20%	13.10%	15.60%	13.00%