The transactions costs associated with the dispostion of assets.

No definition available.

Name:	cmct_DispositionOsAssetsTransactionCosts
Namespace Prefix:	cmct_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the gain (loss) on the sale of assets before transaction costs.

+ References

No definition available.

+ Details

Name:	cmct_GainLossOnSaleOfAssetsBeforeTransactionCosts
Namespace Prefix:	cmct_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of reductions in principal on mortgage loans due to sale of mortgage loans.

+ References

No definition available.

+ Details

Name:	cmct_MortgageLoansOnRealEstateOtherDeductionsSaleOfMortgageLoans
Namespace Prefix:	cmct_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The proceeds received from sale of mortgages.

+ References

No definition available.

+ Details

Name:	cmct_ProceedsFromSaleOfMortgages
Namespace Prefix:	cmct_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of difference between the carrying amount and the sales price of real estate properties sold as part of discontinued operations.

+ References

No definition available.

+ Details

Name:	us-gaap_GainLossOnDispositionOfRealEstateDiscontinuedOperations
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- 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_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=cmct_LendingDivisionSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

DISCONTINUED OPERATIONS - Gain on Sale (Details) - USD ($) $ in Thousands		12 Months Ended
	Dec. 29, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
DISCONTINUED OPERATIONS
Gain on disposition of assets held for sale		$ 0	$ 0	$ 0
Lending
DISCONTINUED OPERATIONS
Proceeds received				27,587
Less: Carrying value	$ (27,587)			(27,587)
Gain on sale before transaction costs				0
Transaction costs				0
Gain on disposition of assets held for sale				$ 0