SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Fees and Segments) (Details)	12 Months Ended
	Dec. 31, 2019 segment market
Summary of Significant Accounting Policies [Line Items]
Number of reportable segments	2
KBS Capital Advisors LLC
Summary of Significant Accounting Policies [Line Items]
Acquisition advisory fee, percent	1.00%
Monthly asset management fee, percent of acquisition expense	0.00063%
KBS Capital Advisors LLC or Affiliates
Summary of Significant Accounting Policies [Line Items]
Selling commissions fees paid, percent of sales price	1.00%
Maximum | KBS Capital Advisors LLC, Affiliates or Unaffiliated Third Parties
Summary of Significant Accounting Policies [Line Items]
Selling commissions fees paid, percent of sales price	6.00%
Strategic Opportunistic Properties
Summary of Significant Accounting Policies [Line Items]
Number of reportable segments	1
Single-Family Homes
Summary of Significant Accounting Policies [Line Items]
Number of reportable segments	1
Number of markets in which the Company owns single-family homes | market	6