RELATED-PARTY TRANSACTIONS - Due to Related Parties (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Related Party Transaction [Line Items]
Due to related parties	$ 10,632	$ 6,706
Asset management fees | Affiliated Entity
Related Party Transaction [Line Items]
Due to related parties	4,487	2,386
Property management fees and reimbursements | Affiliated Entity | CIM Management Entities
Related Party Transaction [Line Items]
Due to related parties	1,926	1,662
Expense reimbursements | Affiliated Entity | Non-segment
Related Party Transaction [Line Items]
Due to related parties	904	647
Expense reimbursements | Affiliated Entity | Operating Segments
Related Party Transaction [Line Items]
Due to related parties	1,685	690
Upfront dealer manager and trailing dealer manager fees | Affiliated Entity
Related Party Transaction [Line Items]
Due to related parties	655	493
Non-issuance specific offering costs | Affiliated Entity
Related Party Transaction [Line Items]
Due to related parties	969	668
Other amounts due to the CIM Management Entities and certain of its affiliates | Affiliated Entity | CIM Management Entities And Related Parties
Related Party Transaction [Line Items]
Due to related parties	$ 6	$ 160