FAIR VALUE DISCLOSURES - Schedule of Face Value, Carrying Amounts and Fair Value (Details) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes and bond payable, Face Value	$ 754,039,000	$ 846,101,000
Series A Debentures | Pacific Oak SOR (BVI) Holdings, Ltd. Series A Debentures | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes and bond payable, Face Value	197,901,000	181,198,000
Series B Debentures | Pacific Oak SOR (BVI) Holdings, Ltd. Series B Debentures | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes and bond payable, Face Value	78,794,000	79,078,000
Carrying Amount | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes and bond payable, Value	751,064,000	842,112,000
Carrying Amount | Series A Debentures | Pacific Oak SOR (BVI) Holdings, Ltd. Series A Debentures | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes and bond payable, Value	195,428,000	179,786,000
Carrying Amount | Series B Debentures | Pacific Oak SOR (BVI) Holdings, Ltd. Series B Debentures | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes and bond payable, Value	77,286,000	77,170,000
Fair Value | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes and bond payable, Value	752,417,000	846,608,000
Fair Value | Series A Debentures | Pacific Oak SOR (BVI) Holdings, Ltd. Series A Debentures | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes and bond payable, Value	197,437,000	178,450,000
Fair Value | Series B Debentures | Pacific Oak SOR (BVI) Holdings, Ltd. Series B Debentures | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes and bond payable, Value	$ 76,899,000	$ 69,433,000