ORGANIZATION (Details) $ / shares in Units, $ in Thousands									3 Months Ended		9 Months Ended		36 Months Ended	130 Months Ended
	Feb. 16, 2020 USD ($)	Nov. 01, 2019	Mar. 20, 2019 USD ($)	Mar. 08, 2016 USD ($)	Mar. 08, 2016 ILS (₪)	Mar. 08, 2016 ILS (₪)	Mar. 07, 2016 ILS (₪)	Mar. 01, 2016 ILS (₪)	Sep. 30, 2020 USD ($) shares	Sep. 30, 2019 USD ($) shares	Sep. 30, 2020 USD ($) shares	Sep. 30, 2019 USD ($) shares	Nov. 14, 2012 USD ($) shares	Sep. 30, 2020 USD ($) shares	Sep. 30, 2020 $ / shares	Sep. 30, 2020 USD ($)	Sep. 30, 2020 property	Sep. 30, 2020 a	Sep. 30, 2020 portfolio	Sep. 30, 2020 unit	Sep. 30, 2020 investment	Mar. 27, 2020 shares	Feb. 19, 2020	Feb. 16, 2020 ILS (₪)	Dec. 31, 2019 USD ($) $ / shares shares	Mar. 02, 2016 ILS (₪)	Dec. 18, 2015 shares	Oct. 23, 2012 USD ($) shares	Dec. 29, 2011 USD ($) shares	Jan. 08, 2009 shares
Organizational Structure [Line Items]
Common stock, shares authorized (in shares)									1,000,000,000		1,000,000,000			1,000,000,000											1,000,000,000
Common stock, shares issued (in shares)									69,225,016		69,225,016			69,225,016											65,866,765			55,249	220,994
Period of termination of advisory agreement without cause or penalty		60 days
Common stock, par value (in dollars per share) | $ / shares															$ 0.01										$ 0.01
Issuance of common stock | $										$ 271	$ 262	$ 835	$ 561,700
Shares of common stock sold under dividend reinvestment plan, value | $														$ 76,500
Redemptions of common stock | $			$ 8,600						$ 6	$ 2,326	$ 830	$ 7,433		$ 286,300
Common stock, value, issued | $																$ 693									$ 659			$ 500	$ 2,000
Preferred stock, shares issued (in shares)									0		0			0											0
Number of investments in unconsolidated joint venture | investment																					6
Number of investments in equity securities | investment																					3
Office Properties
Organizational Structure [Line Items]
Number of real estate properties consolidated | property																	6
Number of real estate properties | property																	6
Office Portfolio
Organizational Structure [Line Items]
Number of real estate properties consolidated | portfolio																			1
Office Buildings, Portfolio
Organizational Structure [Line Items]
Number of real estate properties consolidated | property																	4
Undeveloped Land, Portfolio
Organizational Structure [Line Items]
Real estate area of undeveloped land | a																		14
Apartment Property
Organizational Structure [Line Items]
Number of real estate properties consolidated | property																	1
Undeveloped Land
Organizational Structure [Line Items]
Real estate area of undeveloped land | a																		1,000
Number of investments in real estate | investment																					3
Residential Home Portfolio
Organizational Structure [Line Items]
Number of real estate properties																	1		1
Number of units in real estate property | unit																				1,769
Series A Debentures | Bonds Payable
Organizational Structure [Line Items]
Maximum borrowing capacity | ₪																										₪ 1,000,000,000
Contractual interest rate, percentage																										4.25%
Proceeds from issuance of debt				$ 249,200	₪ 970,200,000	₪ 970,200,000	₪ 127,700,000	₪ 842,500,000
Contractual Interest Rate																										4.25%
Series B Debentures | Bonds Payable
Organizational Structure [Line Items]
Maximum borrowing capacity	$ 74,100																							₪ 254,100,000
Contractual interest rate, percentage	3.93%																							3.93%
Contractual Interest Rate	3.93%																							3.93%
Principal of installment payments as percent of face amount	33.33%
Special Dividends
Organizational Structure [Line Items]
Common stock, shares issued (in shares)									25,976,746		25,976,746			25,976,746
Maximum | Series A Debentures | Bonds Payable
Organizational Structure [Line Items]
Contractual interest rate, percentage																										4.25%
Contractual Interest Rate																										4.25%
Common Stock
Organizational Structure [Line Items]
Shares registered in primary offering (in shares)																														100,000,000
Shares registered for sale under dividend reinvestment plan (in shares)																														40,000,000
Issuance of common stock (in shares)										27,434	24,645	84,248	56,584,976
Issuance of common stock | $												$ 1
Shares of common stock sold under dividend reinvestment plan, (in shares)														6,851,969
Redemptions of common stock (in shares)									601	245,571	78,131	782,391		23,897,205
Redemptions of common stock | $										$ 2		$ 8
Common Stock | Minimum
Organizational Structure [Line Items]
Stock offering, shares authorized for issuance (in shares)																														250,000
Common Stock | Maximum
Organizational Structure [Line Items]
Stock offering, shares authorized for issuance (in shares)																														140,000,000
POSOR II
Organizational Structure [Line Items]
Merger, common stock conversion ratio																							96.43%
KBS Capital Advisors LLC
Organizational Structure [Line Items]
Preferred stock, shares issued (in shares)																						3,411,737
Operating Partnership
Organizational Structure [Line Items]
Partnership interest in Operating Partnership											0.10%
Partnership interest in the Operating Partnership and is its sole limited partner											99.90%
Pacific Oak Strategic Opportunity BVI
Organizational Structure [Line Items]
Common stock, shares authorized (in shares)																											50,000
Pacific Oak Strategic Opportunity BVI | Operating Partnership
Organizational Structure [Line Items]
Common stock, shares issued (in shares)																											10,000