DISCONTINUED OPERATIONS - Gain on Sale (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
DISCONTINUED OPERATIONS
Mortgage Loans on Real Estate, Other Deductions, Sale of Mortgage Loans			$ (77,121)
Gain on disposition of assets held for sale (Note 8)	$ 0	$ 0	5,151
Commercial mortgage loans
DISCONTINUED OPERATIONS
Unamortized acquisition discounts			15,951
Lending division
DISCONTINUED OPERATIONS
Proceeds received		27,587	84,928
Mortgage Loans on Real Estate, Other Deductions, Sale of Mortgage Loans		(27,587)	(77,121)
Gain on sale before transaction costs		0	7,807
Transaction costs (2)		0	(2,656)
Gain on disposition of assets held for sale (Note 8)		$ 0	5,151
Unamortized acquisition discounts			15,951
Lending division \| CIM SBA
DISCONTINUED OPERATIONS
Reimbursement of costs			$ 1,638

Represents acquisition discounts.

No definition available.

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Balance Type:	debit
Period Type:	instant

- Definition

The transactions costs associated with the dispostion of assets.

+ References

No definition available.

+ Details

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

Represents the amount of compensation incurred for performing other services under related party transaction.

+ References

No definition available.

+ Details

Name:	cmct_RelatedPartyTransactionCompensationForOtherServices
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

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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

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Data Type:	xbrli:stringItemType
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- Details

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Namespace Prefix:
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- Details

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Namespace Prefix:
Data Type:	na
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- Details

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