Pacific Oak Strategic Opportunity REIT (PCOK) 10-Q 9 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Nov. 05, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	KBS Strategic Opportunity REIT, Inc.
Entity Central Index Key	1,452,936
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		54,207,256

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Assets
Real estate held for investment, net	$ 804,079	$ 502,222
Real estate held for sale, net	0	30,645
Real estate equity securities	98,735	90,063
Real estate debt securities, net	17,855	17,751
Total real estate and real estate-related investments, net	920,669	640,681
Cash and cash equivalents	93,357	366,512
Restricted cash	12,525	10,670
Investments in unconsolidated joint ventures	47,304	55,577
Rents and other receivables, net	14,103	8,755
Above-market leases, net	3,485	10
Assets related to real estate held for sale, net	0	1,965
Prepaid expenses and other assets	18,056	17,404
Total assets	1,109,499	1,101,574
Notes and bonds payable, net
Notes and bonds payable related to real estate held for investment, net	741,129	575,528
Note payable related to real estate held for sale, net	0	27,515
Notes and bonds payable, net	741,129	603,043
Accounts payable and accrued liabilities	17,788	16,686
Due to affiliate	65	26
Distribution payable	0	187,914
Below-market leases, net	5,554	2,843
Other liabilities	16,538	16,966
Redeemable common stock payable	4,442	8,595
Total liabilities	785,516	836,073
Commitments and contingencies (Note 14)
Redeemable common stock	0	4,518
Equity
Preferred stock, $.01 par value; 10,000,000 shares authorized, no shares issued and outstanding	0	0
Common stock, $.01 par value; 1,000,000,000 shares authorized, 54,231,264 and 52,053,817 shares issued and outstanding as of September 30, 2018 and December 31, 2017, respectively	542	521
Additional paid-in capital	428,622	388,800
Cumulative distributions and net income	(107,770)	(155,454)
Accumulated other comprehensive income	0	25,146
Total KBS Strategic Opportunity REIT, Inc. stockholders’ equity	321,394	259,013
Noncontrolling interests	2,589	1,970
Total equity	323,983	260,983
Total liabilities and equity	$ 1,109,499	$ 1,101,574

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, shares issued (in shares)	54,231,264	52,053,817
Common stock, shares outstanding (in shares)	54,231,264	52,053,817

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues:
Rental income	$ 19,585	$ 27,850	$ 53,681	$ 90,200
Interest income from real estate debt securities	513	511	1,525	1,271
Dividend income from real estate equity securities	2,885	1,015	5,146	1,505
Total revenues	27,156	36,414	72,082	114,648
Expenses:
Operating, maintenance, and management	8,336	11,431	21,395	33,638
Real estate taxes and insurance	3,208	4,780	8,982	14,932
Asset management fees to affiliate	2,299	2,800	6,342	8,404
General and administrative expenses	1,488	1,168	6,037	4,115
Foreign currency transaction loss (gain), net	8	4,356	(9,106)	11,454
Depreciation and amortization	9,826	13,228	26,133	43,136
Interest expense	8,404	9,618	22,814	29,327
Total expenses	33,569	47,381	82,597	145,006
Other income:
Income from unconsolidated joint venture	244	0	428	1,869
Equity in loss of unconsolidated joint ventures	(2,644)	(2,152)	(7,394)	(3,928)
Other interest income	253	340	1,602	536
Gain (loss) on real estate equity securities	741	0	(6,546)	0
Gain on sale of real estate	44,692	2,239	45,340	36,267
Loss on extinguishment of debt	(26)	0	(26)	0
Total other income, net	43,260	427	33,404	34,744
Net income (loss) before income taxes	36,847	(10,540)	22,889	4,386
Income tax provision	(426)	(2)	(178)	(176)
Net income (loss)	36,421	(10,542)	22,711	4,210
Net loss attributable to noncontrolling interests	76	8	141	10
Net income (loss) attributable to common stockholders	$ 36,497	$ (10,534)	$ 22,852	$ 4,220
Net income (loss) per common share, basic and diluted (in dollars per share)	$ 0.67	$ (0.19)	$ 0.38	$ 0.07
Weighted-average number of common shares outstanding, basic and diluted (in shares)	54,599,254	56,643,160	59,649,846	56,712,752
Tenant reimbursements
Revenues:
Revenue from contract with customer	$ 3,345	$ 6,094	$ 9,729	$ 18,188
Other operating income
Revenues:
Revenue from contract with customer	$ 828	$ 944	$ 2,001	$ 3,484

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 36,421	$ (10,542)	$ 22,711	$ 4,210
Other comprehensive income:
Unrealized gain on real estate securities	0	2,865	0	3,714
Total other comprehensive income	0	2,865	0	3,714
Total comprehensive income (loss)	36,421	(7,677)	22,711	7,924
Total comprehensive loss attributable to noncontrolling interests	76	8	141	10
Total comprehensive income (loss) attributable to common stockholders	$ 36,497	$ (7,669)	$ 22,852	$ 7,934

CONSOLIDATED STATEMENTS OF EQUI

CONSOLIDATED STATEMENTS OF EQUITY (unaudited) - USD ($) $ in Thousands	Total	Total Stockholders' Equity	Common Stock	Additional Paid-in Capital	Cumulative Distributions and Net Income	Accumulated Other Comprehensive Income	Noncontrolling Interests
Balance (in shares) at Dec. 31, 2016			56,775,767
Balance at Dec. 31, 2016	$ 295,550	$ 293,652	$ 568	$ 455,373	$ (162,289)	$ 0	$ 1,898
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	210,580	210,644			210,644		(64)
Other comprehensive income	25,146	25,146				25,146
Issuance of common stock (in shares)			585,192
Issuance of common stock	8,666	8,666	$ 6	8,660
Transfers to redeemable common stock	(498)	(498)		(498)
Redemptions of common stock (in shares)			(5,307,142)
Redemptions of common stock	(74,780)	(74,780)	$ (53)	(74,727)
Distributions declared	(203,809)	(203,809)			(203,809)
Other offering costs	(8)	(8)		(8)
Noncontrolling interests contributions	158	0					158
Distributions to noncontrolling interests	$ (22)	0					(22)
Balance (in shares) at Dec. 31, 2017	52,053,817		52,053,817
Balance at Dec. 31, 2017	$ 260,983	259,013	$ 521	388,800	(155,454)	25,146	1,970
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect adjustments to retained earnings	2,472	2,472			27,618	(25,146)
Net income (loss)	22,711	22,852			22,852		(141)
Other comprehensive income	0
Issuance of common stock (in shares)			123,288
Issuance of common stock	1,418	1,418	$ 1	1,417
Stock distribution issued (in shares)			13,069,487
Stock distribution issued	150,299	150,299	$ 130	150,169
Transfers from redeemable common stock	8,671	8,671		8,671
Redemptions of common stock (in shares)			(11,015,328)
Redemptions of common stock	(120,544)	(120,544)	$ (110)	(120,434)
Distributions declared	(2,786)	(2,786)			(2,786)
Other offering costs	(1)	(1)		(1)
Noncontrolling interests contributions	$ 760	0					760
Balance (in shares) at Sep. 30, 2018	54,231,264		54,231,264
Balance at Sep. 30, 2018	$ 323,983	$ 321,394	$ 542	$ 428,622	$ (107,770)	$ 0	$ 2,589

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Cash Flows from Operating Activities:
Net income	$ 36,421	$ (10,542)	$ 22,711	$ 4,210	$ 210,580
Adjustments to reconcile net income to net cash provided by operating activities:
Loss due to property damages			964	668
Equity in loss of unconsolidated joint ventures	2,644	2,152	7,394	3,928
Depreciation and amortization	9,826	13,228	26,133	43,136
Loss on real estate equity securities	(741)	0	6,546	0
Gain on sale of real estate	(44,692)	(2,239)	(45,340)	(36,267)
Loss on extinguishment of debt	26	0	26	0
Unrealized loss on interest rate caps			21	102
Deferred rent			(3,508)	(1,678)
Bad debt (recovery) expense			(5)	66
Amortization of above- and below-market leases, net			(853)	(2,253)
Amortization of deferred financing costs	1,000	1,000	2,675	3,578
Interest accretion on real estate debt securities			(104)	(456)
Net amortization of discount and (premium) on bond and notes payable			45	36
Foreign currency transaction (gain) loss, net	8	4,356	(9,106)	11,454
Changes in assets and liabilities:
Rents and other receivables			(1,744)	(2,245)
Prepaid expenses and other assets			(5,901)	(6,368)
Accounts payable and accrued liabilities			37	1,575
Due to affiliates			39	(22)
Other liabilities			409	261
Net cash provided by operating activities			439	19,725
Cash Flows from Investing Activities:
Acquisitions of real estate			(312,348)	(165,465)
Improvements to real estate			(21,147)	(28,775)
Proceeds from sales of real estate, net			85,615	130,580
Reimbursement of construction costs			1,636	0
Insurance proceeds received for property damages			0	744
Proceeds from termination of foreign currency collars			0	6,557
Contributions to unconsolidated joint venture			(1,320)	0
Distributions of capital from unconsolidated joint venture			2,199	59,157
Investment in real estate equity securities			(15,851)	(43,308)
Proceeds from the sale of real estate equity securities			633	0
Proceeds for future development obligations			0	(12,514)
Proceeds for future development obligations			1,055	1,367
Funding of development obligations			(1,162)	(926)
Net cash used in investing activities			(260,853)	(56,124)
Cash Flows from Financing Activities:
Proceeds from notes and bonds payable			184,351	176,777
Principal payments on notes and bonds payable			(34,348)	(73,907)
Payments of deferred financing costs			(2,791)	(2,339)
Payments to redeem common stock			(120,544)	(8,050)
Payments of prepaid other offering costs			(458)	(376)
Distributions paid			(38,983)	(7,229)
Noncontrolling interests contributions			760	150
Distributions to noncontrolling interests			0	(18)
Net cash (used in) provided by financing activities			(12,013)	85,008
Effect of exchange rate changes on cash, cash equivalents and restricted cash			1,127	514
Net (decrease) increase in cash, cash equivalents and restricted cash			(271,300)	49,123
Cash, cash equivalents and restricted cash, beginning of period			377,182	64,450	64,450
Cash, cash equivalents and restricted cash, end of period	$ 105,882	$ 113,573	105,882	113,573	$ 377,182
Interest Rate Cap
Cash Flows from Investing Activities:
Purchase of derivatives			(163)	(107)
Foreign currency option
Cash Flows from Investing Activities:
Purchase of derivatives			$ 0	$ (3,434)

ORGANIZATION

ORGANIZATION	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
ORGANIZATION	ORGANIZATION KBS Strategic Opportunity REIT, Inc. (the “Company”) was formed on October 8, 2008 as a Maryland corporation and elected to be taxed as a real estate investment trust (“REIT”) beginning with the taxable year ended December 31, 2010. The Company conducts its business primarily through KBS Strategic Opportunity (BVI) Holdings, Ltd. (“KBS Strategic Opportunity BVI”), a private company limited by shares according to the British Virgin Islands Business Companies Act, 2004, which was incorporated on December 18, 2015 and is authorized to issue a maximum of 50,000 common shares with no par value. Upon incorporation, KBS Strategic Opportunity BVI issued one certificate containing 10,000 common shares with no par value to KBS Strategic Opportunity Limited Partnership (the “Operating Partnership”), a Delaware limited partnership formed on December 10, 2008. The Company is the sole general partner of, and owns a 0.1% partnership interest in the Operating Partnership. KBS Strategic Opportunity Holdings LLC (“REIT Holdings”), a Delaware limited liability company formed on December 9, 2008, owns the remaining 99.9% interest in the Operating Partnership and is its sole limited partner. The Company is the sole member and manager of REIT Holdings. Subject to certain restrictions and limitations, the business of the Company is externally managed by KBS Capital Advisors LLC (the “Advisor”), an affiliate of the Company, pursuant to an advisory agreement the Company renewed with the Advisor on October 8, 2018 (the “Advisory Agreement”). The Advisor conducts the Company’s operations and manages its portfolio of real estate, real estate-related debt securities and other real estate-related investments. On January 8, 2009, the Company filed a registration statement on Form S-11 with the Securities and Exchange Commission (the “SEC”) to offer a minimum of 250,000 shares and a maximum of 140,000,000 shares of common stock for sale to the public (the “Offering”), of which 100,000,000 shares were registered in a primary offering and 40,000,000 shares were registered to be sold under the Company’s dividend reinvestment plan. The SEC declared the Company’s registration statement effective on November 20, 2009. The Company ceased offering shares of common stock in its primary offering on November 14, 2012 and continues to offer shares under its dividend reinvestment plan. The Company sold 56,584,976 shares of common stock in its primary offering for gross offering proceeds of $561.7 million . As of September 30, 2018 , the Company had sold 6,743,649 shares of common stock under its dividend reinvestment plan for gross offering proceeds of $75.5 million . Also, as of September 30, 2018 , the Company had redeemed 22,463,092 shares for $272.3 million . As of September 30, 2018 , the Company had issued 13,069,487 shares of common stock in connection with the December 2017 special dividend. Additionally, on December 29, 2011 and October 23, 2012, the Company issued 220,994 shares and 55,249 shares of common stock, respectively, for $2.0 million and $0.5 million , respectively, in private transactions exempt from the registration requirements pursuant to Section 4(2) of the Securities Act of 1933. On March 2, 2016, KBS Strategic Opportunity BVI filed a final prospectus with the Israel Securities Authority for a proposed offering of up to 1,000,000,000 Israeli new Shekels of Series A debentures (the “Debentures”) at an annual interest rate not to exceed 4.25% . On March 1, 2016, KBS Strategic Opportunity BVI commenced the institutional tender of the Debentures and accepted application for 842.5 million Israeli new Shekels. On March 7, 2016, KBS Strategic Opportunity BVI commenced the public tender of the Debentures and accepted 127.7 million Israeli new Shekels. In the aggregate, KBS Strategic Opportunity BVI accepted 970.2 million Israeli new Shekels (approximately $249.2 million as of March 8, 2016) in both the institutional and public tenders at an annual interest rate of 4.25% . KBS Strategic Opportunity BVI issued the Debentures on March 8, 2016. The terms of the Debentures require principal installment payments equal to 20% of the face value of the Debentures on March 1st of each year from 2019 to 2023. In connection with the above-referenced offering, on March 8, 2016, the Operating Partnership assigned to KBS Strategic Opportunity BVI all of its interests in the subsidiaries through which the Company indirectly owns all of its real estate and real estate-related investments. The Operating Partnership owns all of the issued and outstanding equity of KBS Strategic Opportunity BVI. As a result of these transactions, the Company now holds all of its real estate and real estate-related investments indirectly through KBS Strategic Opportunity BVI. As of September 30, 2018 , the Company consolidated six office properties, one office portfolio consisting of four office buildings and 14 acres of undeveloped land, one office/flex/industrial portfolio consisting of 21 buildings, one retail property, two apartment properties and three investments in undeveloped land with approximately 1,000 developable acres. The Company also owned three investments in unconsolidated joint ventures, an investment in real estate debt securities and three investments in real estate equity securities.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES There have been no significant changes to the Company’s accounting policies since it filed its audited financial statements in its Annual Report on Form 10-K for the year ended December 31, 2017 , except for the Company’s adoption of the revenue recognition and financial instruments standards issued by the Financial Accounting Standards Board (“FASB”) effective on January 1, 2018. For further information about the Company’s accounting policies, refer to the Company’s consolidated financial statements and notes thereto for the year ended December 31, 2017 included in the Company’s Annual Report on Form 10-K filed with the SEC. Principles of Consolidation and Basis of Presentation The accompanying unaudited consolidated financial statements and condensed notes thereto have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information as contained within the FASB Accounting Standards Codification (“ASC”) and the rules and regulations of the SEC, including the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, the unaudited consolidated financial statements do not include all of the information and footnotes required by GAAP for audited financial statements. In the opinion of management, the financial statements for the unaudited interim periods presented include all adjustments, which are of a normal and recurring nature, necessary for a fair and consistent presentation of the results for such periods. Operating results for the three and nine months ended September 30, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018 . The consolidated financial statements include the accounts of the Company, REIT Holdings, the Operating Partnership, KBS Strategic Opportunity BVI and their direct and indirect wholly owned subsidiaries, and joint ventures in which the Company has a controlling interest. All significant intercompany balances and transactions are eliminated in consolidation. Use of Estimates The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could materially differ from those estimates. Redeemable Common Stock The Company has adopted a share redemption program that may enable stockholders to sell their shares to the Company in limited circumstances. Pursuant to the share redemption program there are several limitations on the Company’s ability to redeem shares: • Unless the shares are being redeemed in connection with a stockholder’s death, “qualifying disability” or “determination of incompetence” (each as defined under the share redemption program), the Company may not redeem shares until the stockholder has held the shares for one year. • During each calendar year, redemptions are limited to the amount of net proceeds from the sale of shares under the dividend reinvestment plan during the prior calendar year. • The Company may not redeem more than $3.0 million of shares in a given quarter (excluding shares redeemed in connection with a stockholder’s death, “qualifying disability” or “determination of incompetence”). To the extent that the Company redeems less than $3.0 million of shares (excluding shares redeemed in connection with a stockholder’s death, “qualifying disability” or “determination of incompetence”) in a given fiscal quarter, any remaining excess capacity to redeem shares in such fiscal quarter will be added to the Company’s capacity to otherwise redeem shares (excluding shares redeemed in connection with a stockholder’s death, “qualifying disability” or “determination of incompetence”) during succeeding fiscal quarters. The last $1.0 million of net proceeds from the dividend reinvestment plan during the prior year is reserved exclusively for shares redeemed in connection with a stockholder’s death, “qualifying disability,” or “determination of incompetence”. The share redemption plan also provides that, to the extent that in the last month of any calendar year the amount of redemption requests in connection with a stockholder’s death, “qualifying disability or “determination of incompetence” is less than the $1.0 million reserved for such redemptions under the share redemption plan, any excess funds may be used to redeem shares not requested in connection with a stockholder’s death, “qualifying disability or “determination of incompetence” during such month. The Company may increase or decrease this limit upon ten business days’ notice to stockholders. The Company’s board of directors may approve an increase in this limit to the extent that the Company has received proceeds from asset sales or the refinancing of debt or for any other reason deemed appropriate by the board of directors. On August 9, 2018, the Company’s board of directors approved an additional $6.0 million of funds available for the redemption of shares in 2018. Based on the amount of net proceeds raised from the sale of shares under the dividend reinvestment plan during 2017 and the additional $6.0 million made available by the Company’s board of directors, the Company had $3.0 million available for all share redemption requests for the remainder of 2018 as of September 30, 2018 . • During any calendar year, the Company may redeem no more than 5% of the weighted-average number of shares outstanding during the prior calendar year. • The Company has no obligation to redeem shares if the redemption would violate the restrictions on distributions under Maryland law, which prohibits distributions that would cause a corporation to fail to meet statutory tests of solvency. Effective December 30, 2016, pursuant to the tenth amended and restated share redemption program, except for redemptions made upon a stockholder’s death, “qualifying disability” or “determination of incompetence”, the price at which the Company began to redeem shares is 95% of the Company’s most recent estimated value per share as of the applicable redemption date. Upon the death, “qualifying disability” or “determination of incompetence” of a stockholder, the redemption price continued to be equal to the Company’s most recent estimated value per share. The Company’s board of directors may amend, suspend or terminate the share redemption program with ten business days’ notice to its stockholders. The Company may provide this notice by including such information in a Current Report on Form 8-K or in the Company’s annual or quarterly reports, all publicly filed with the SEC, or by a separate mailing to its stockholders. In anticipation of a self-tender offer in order to make liquidity available to stockholders in excess of that permitted under the share redemption program, on March 14, 2018 , the Company’s board of directors approved a temporary suspension of the share redemption program starting with the March 2018 redemption period, including any unsatisfied requests from prior redemption periods. In connection with its approval of the Self-Tender (defined below), the Company’s board of directors approved the reopening of the share redemption program for the June 2018 redemption period, meaning no redemptions were made in March, April or May 2018 (including those requested following a stockholder’s death, qualifying disability or determination of incompetence). On April 23, 2018 , the Company commenced a self-tender offer (the “Self-Tender”) for up to 8,234,217 shares of common stock at a price of $10.93 per share, or approximately $90.0 million of shares. The Company increased the number of shares accepted for payment in the Self-Tender by up to 1,294,910 shares at a price of $10.93 per share, or approximately $14.1 million of shares. On June 1, 2018 , the Company accepted for purchase 9,527,724 shares at a purchase price of $10.93 per share, or approximately $104.1 million of shares, excluding fees and expenses related to the Self-Tender. The Company records amounts that are redeemable under the share redemption program as redeemable common stock in its consolidated balance sheets because the shares will be redeemable at the option of the holder and therefore their redemption will be outside the control of the Company. However, because the amounts that can be redeemed will be determinable and only contingent on an event that is likely to occur (e.g., the passage of time), the Company presents the net proceeds from the current year and prior year DRP, net of current year redemptions, as redeemable common stock in its consolidated balance sheets. The Company classifies as liabilities financial instruments that represent a mandatory obligation of the Company to redeem shares. The Company’s redeemable common shares are redeemable at the option of the holder. When the Company determines it has a mandatory obligation to repurchase shares under the share redemption program, it will reclassify such obligations from temporary equity to a liability based upon their respective settlement values. The Company limits the dollar value of shares that may be redeemed under the program as described above. During the nine months ended September 30, 2018 , the Company had redeemed $16.1 million of common stock, of which $4.4 million relates to delayed December 2017 redemptions. The Company recorded $4.4 million and $8.6 million of other liabilities on the Company’s balance sheet as of September 30, 2018 and December 31, 2017 , respectively, related to unfulfilled redemption requests received in good order under the share redemption program. Based on the amount of net proceeds raised from the sale of shares under the dividend reinvestment plan during 2017 and the additional $6.0 million made available by the Company’s board of directors, the Company has $3.0 million available for redemptions in the remainder of 2018 as of September 30, 2018 , including shares that are redeemed in connection with a stockholders’ death, “qualifying disability” or “determination of incompetence,” subject to the limitations described above. Revenue Recognition Effective January 1, 2018, the Company adopted ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) (“ASU No. 2014-09”), using the modified retrospective approach, which requires a cumulative effect adjustment as of the date of the Company’s adoption. Under the modified retrospective approach, an entity may also elect to apply this standard to either (i) all contracts as of January 1, 2018 or (ii) only to contracts that were not completed as of January 1, 2018. A completed contract is a contract for which all (or substantially all) of the revenue was recognized under legacy GAAP that was in effect before the date of initial application. The Company elected to apply this standard only to contracts that were not completed as of January 1, 2018. Based on the Company’s evaluation of contracts within the scope of ASU No. 2014-09, revenue that is impacted by ASU No. 2014-09 includes revenue generated by sales of real estate, other operating income and tenant reimbursements for substantial services earned at the Company’s properties. The recognition of such revenue will occur when the services are provided and the performance obligations are satisfied. For the three and nine months ended September 30, 2018 , tenant reimbursements for substantial services accounted for under ASU No. 2014-09 were $0.5 million and $1.4 million , respectively, which were included in tenant reimbursements on the accompanying statements of operations. Sale of Real Estate Prior to January 1, 2018, gains on real estate sold were recognized using the full accrual method at closing when collectibility of the sales price was reasonably assured, the Company was not obligated to perform additional activities that may be considered significant, the initial investment from the buyer was sufficient and other profit recognition criteria had been satisfied. Gain on sales of real estate may have been deferred in whole or in part until the requirements for gain recognition had been met. Effective January 1, 2018, the Company adopted the guidance of ASC 610-20, Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (“ASC 610-20”), which applies to sales or transfers to noncustomers of nonfinancial assets or in substance nonfinancial assets that do not meet the definition of a business. Generally, the Company’s sales of real estate would be considered a sale of a nonfinancial asset as defined by ASC 610-20. ASC 610-20 refers to the revenue recognition principles under ASU No. 2014-09. Under ASC 610-20, if the Company determines it does not have a controlling financial interest in the entity that holds the asset and the arrangement meets the criteria to be accounted for as a contract, the Company would derecognize the asset and recognize a gain or loss on the sale of the real estate when control of the underlying asset transfers to the buyer. As a result of the adoption of ASC 610-20 on January 1, 2018, the Company recorded a cumulative effect adjustment to increase retained earnings by $2.5 million to recognize the deferred gain from the sale of 102 developable acres at Park Highlands that closed on May 1, 2017, as control of the sold acres had transferred to the buyers at closing. As of January 1, 2018 and September 30, 2018 , the Company had recorded contract liabilities of $1.7 million and $3.1 million , respectively, related to deferred proceeds received from the buyers of the Park Highlands land sales and another developer for the value of land that was contributed to a master association that is consolidated by the Company, which was included in other liabilities on the accompanying consolidated balance sheets. Real Estate Equity Securities The Company’s real estate equity securities are carried at their estimated fair value based on quoted market prices for the security, net of any discounts for restrictions on the sale of the security. Any discount for lack of marketability is estimated using an option pricing model. Transaction costs that are directly attributable to the acquisition of real estate equity securities are capitalized to its cost basis. Prior to the Company’s adoption of ASU No. 2016-01, Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU No. 2016-01”) on January 1, 2018, the Company classified its investments in real estate equity securities as available-for-sale and unrealized gains and losses were reported in accumulated other comprehensive income (loss). Upon the sale of a security, the previously recognized unrealized gain (loss) would be reversed out of accumulated other comprehensive income (loss) and the actual realized gain (loss) recognized in earnings. Effective January 1, 2018, unrealized gains and losses on real estate equity securities are recognized in earnings. Upon adoption of ASU No. 2016-01 on January 1, 2018, the Company recorded a $25.1 million cumulative effect adjustment to retained earnings related to the unrealized gain on real estate equity securities previously reported in accumulated other comprehensive income prior to January 1, 2018. Investment in Unconsolidated Joint Ventures Equity Investment Without Readily Determinable Value Prior to the adoption of ASU No. 2016-01 on January 1, 2018, the Company accounted for investments in unconsolidated joint venture entities in which the Company did not have the ability to exercise significant influence and had virtually no influence over partnership operating and financial policies using the cost method of accounting. Under the cost method, income distributions from the partnership were recognized in other income. Distributions that exceed the Company’s share of earnings were applied to reduce the carrying value of the Company’s investment and any capital contributions increased the carrying value of the Company’s investment. On a quarterly basis, the Company evaluated its cost method investment in an unconsolidated joint venture for other-than-temporary impairments. The fair value of a cost method investment was not estimated if there were no identified events or changes in circumstances that indicated a significant adverse effect on the fair value of the investment. In accordance with ASU No. 2016-01, the Company may elect to measure an equity investment without a readily determinable value that does not qualify for the practical expedient to estimate fair value using the net asset value per share, at its cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer. The Company elected to measure its investment in the NIP Joint Venture (defined in Note 12 ) in accordance with the above guidance, applying it prospectively, and as of January 1, 2018 and September 30, 2018 , recorded its investment in the NIP Joint Venture at a cost basis of $3.7 million and $1.5 million , respectively. Distributions of income from the NIP Joint Venture are recognized in other income. Distributions that exceed the Company’s share of earnings are applied to reduce the carrying value of the Company’s investment and any capital contributions would increase the carrying value of the Company’s investment. Reclassifications Certain amounts in the Company’s prior period consolidated financial statements have been reclassified to conform to the current period presentation. These reclassifications have not changed the results of operations of the prior period. During the nine months ended September 30, 2018 , the Company disposed of one office building. As a result, certain assets and liabilities were reclassified as held for sale on the consolidated balance sheets for all periods presented. Segments The Company has invested in opportunistic real estate and other real estate-related assets. In general, the Company intends to hold its investments in opportunistic real estate and other real estate‑related assets for capital appreciation. Traditional performance metrics of opportunistic real estate and other real estate-related assets may not be meaningful as these investments are generally non-stabilized and do not provide a consistent stream of interest income or rental revenue. These investments exhibit similar long-term financial performance and have similar economic characteristics. These investments typically involve a higher degree of risk and do not provide a constant stream of ongoing cash flows. As a result, the Company’s management views opportunistic real estate and other real estate-related assets as similar investments. Substantially all of its revenue and net income (loss) is from opportunistic real estate and other real estate-related assets, and therefore, the Company currently aggregates its operating segments into one reportable business segment. Per Share Data Basic net income (loss) per share of common stock is calculated by dividing net income (loss) attributable to common stockholders by the weighted-average number of shares of common stock issued and outstanding during such period. Diluted net income (loss) per share of common stock equals basic net income (loss) per share of common stock as there were no potentially dilutive securities outstanding during the three and nine months ended September 30, 2018 and 2017 . Distributions declared per share were $0.01597500 and $0.04792500 during the three and nine months ended September 30, 2018 , respectively, and $0.09452055 and $0.28047945 during the three and nine months ended September 30, 2017 , respectively. Square Footage, Occupancy and Other Measures Any references to square footage, occupancy or annualized base rent are unaudited and outside the scope of the Company’s independent registered public accounting firm’s review of the Company’s financial statements in accordance with the standards of the United States Public Company Accounting Oversight Board. Recently Issued Accounting Standards Updates In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (“ASU No. 2016-02”). The amendments in ASU No. 2016-02 change the existing accounting standards for lease accounting, including requiring lessees to recognize most leases on their balance sheets and making targeted changes to lessor accounting. ASU No. 2016-02 is effective for annual periods beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption of ASU No. 2016-02 as of its issuance is permitted. ASU No. 2016-02 requires a modified retrospective transition approach for all leases existing at, or entered into after, the date of initial application, with an option to use certain transition relief. Upon adoption of ASU No. 2016-02, the Company expects to adopt the package of practical expedients for all leases that commenced before the effective date of January 1, 2019. Accordingly, the Company will 1) not reassess whether any expired or existing contracts are or contain leases, 2) not reassess the lease classification for any expired or existing lease, and 3) not reassess initial direct costs for any existing leases. The Company does not expect to elect the practical expedient related to using hindsight to reevaluate the lease term. In addition, the Company expects to adopt the practical expedient for land easements to not assess whether existing or expired land easements that were not previously accounted for as leases under the current lease accounting standards of Topic 840 are or contain a lease under Topic 842. In July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842), Targeted Improvements (“ASU No. 2018-11”), which provides lessors with a practical expedient, by class of underlying asset, to not separate nonlease components from the associated lease component and, instead to account for those components as a single component if the nonlease components otherwise would be accounted for under the new revenue recognition standard (Topic 606) and if certain conditions are met. Upon adoption of the lease accounting standard under Topic 842, the Company expects to adopt this practical expedient, specifically related to its tenant reimbursements which would otherwise be accounted for under the new revenue recognition standard. The Company believes the two conditions have been met for tenant reimbursements as 1) the timing and pattern of transfer of the nonlease components and associated lease components are the same and 2) the lease component would be classified as an operating lease. In addition, ASU No. 2018-11 provides an additional optional transition method to allow entities to apply the new lease accounting standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings. An entity’s reporting for the comparative periods presented in the financial statements in which it adopts the new lease accounting standard will continue to be reported under the current lease accounting standards of Topic 840. The Company expects to adopt this transition method upon adoption of the lease accounting standard of Topic 842 on January 1, 2019. The Company is currently evaluating the impact of adopting the new lease accounting standards on its consolidated financial statements. The Company is in process of creating an inventory of its leases where the Company may be a lessee to assess the potential impact to the Company’s financial statements upon adoption of the new lease accounting standards. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses of Financial Instruments (“ASU No. 2016-13”). ASU No. 2016-13 affects entities holding financial assets and net investments in leases that are not accounted for at fair value through net income. The amendments in ASU No. 2016-13 require a financial asset (or a group of financial assets) measured at amortized cost basis to be presented at the net amount expected to be collected. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial asset(s) to present the net carrying value at the amount expected to be collected on the financial asset. ASU No. 2016-13 also amends the impairment model for available-for-sale debt securities. An entity will recognize an allowance for credit losses on available-for-sale debt securities as a contra-account to the amortized cost basis rather than as a direct reduction of the amortized cost basis of the investment, as is currently required. ASU No. 2016-13 also requires new disclosures. For financial assets measured at amortized cost, an entity will be required to disclose information about how it developed its allowance for credit losses, including changes in the factors that influenced management’s estimate of expected credit losses and the reasons for those changes. For financing receivables and net investments in leases measured at amortized cost, an entity will be required to further disaggregate the information it currently discloses about the credit quality of these assets by year of the asset’s origination for as many as five annual periods. For available-for-sale debt securities, an entity will be required to provide a roll-forward of the allowance for credit losses and an aging analysis for securities that are past due. ASU No. 2016-13 is effective for annual periods beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company is still evaluating the impact of adopting ASU No. 2016-13 on its financial statements. In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework -Changes to the Disclosure Requirements for Fair Value Measurement (“ASU No. 2018-13”). The primary focus of ASU 2018-13 is to improve the effectiveness of the disclosure requirements for fair value measurements. ASU No. 2018-13 removes the requirement to disclose the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, the policy for the timing of transfers between levels and the valuation processes for Level 3 fair value measurements. It also adds a requirement to disclose changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period and to disclose the range and weighted average of significant unobservable inputs used to develop recurring and nonrecurring Level 3 fair value measurements. For certain unobservable inputs, entities may disclose other quantitative information in lieu of the weighted average if the other quantitative information would be a more reasonable and rational method to reflect the distribution of unobservable inputs used to develop the Level 3 fair value measurement. In addition, public entities are required to provide information about the measurement uncertainty of recurring Level 3 fair value measurements from the use of significant unobservable inputs if those inputs reasonably could have been different at the reporting date. ASU No. 2018-13 is effective for annual periods beginning after December 15, 2019, including interim periods within those fiscal years. Entities are permitted to early adopt either the entire standard or only the provisions that eliminate or modify the requirements. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. The Company is still evaluating the impact of adopting ASU No. 2018-13 on its financial statements, but does not expect the adoption of ASU No. 2018-13 to have a material impact on its financial statements.

REAL ESTATE HELD FOR INVESTMENT

REAL ESTATE HELD FOR INVESTMENT	9 Months Ended
	Sep. 30, 2018
Real Estate [Abstract]
REAL ESTATE FOR INVESTMENT	REAL ESTATE HELD FOR INVESTMENT As of September 30, 2018 , the Company owned six office properties, one office portfolio consisting of four office buildings and 14 acres of undeveloped land, one office/flex/industrial portfolio consisting of 21 buildings and one retail property, encompassing, in the aggregate, approximately 3.8 million rentable square feet. As of September 30, 2018 , these properties were 76% occupied. In addition, the Company owned two apartment properties, containing 383 units and encompassing approximately 0.3 million rentable square feet, which were 94% occupied. The Company also owned three investments in undeveloped land with approximately 1,000 developable acres. The following table summarizes the Company’s real estate held for investment as of September 30, 2018 and December 31, 2017 , respectively (in thousands): September 30, 2018 December 31, 2017 Land $ 192,765 $ 155,046 Buildings and improvements 628,748 361,118 Tenant origination and absorption costs 39,315 23,212 Total real estate, cost 860,828 539,376 Accumulated depreciation and amortization (56,749 ) (37,154 ) Total real estate, net $ 804,079 $ 502,222 The following table provides summary information regarding the Company’s real estate held for investment as of September 30, 2018 (in thousands): Property Date Acquired or Foreclosed on City State Property Type Land Building Tenant Origination and Absorption Total Real Estate, at Cost Accumulated Depreciation and Amortization Total Real Estate, Net Ownership % Richardson Portfolio: Palisades Central I 11/23/2011 Richardson TX Office $ 1,037 $ 10,714 $ — $ 11,751 $ (2,646 ) $ 9,105 90.0 % Palisades Central II 11/23/2011 Richardson TX Office 810 17,954 — 18,764 (4,115 ) 14,649 90.0 % Greenway I 11/23/2011 Richardson TX Office 561 2,084 — 2,645 (711 ) 1,934 90.0 % Greenway III 11/23/2011 Richardson TX Office 702 4,068 559 5,329 (1,953 ) 3,376 90.0 % Undeveloped Land 11/23/2011 Richardson TX Undeveloped Land 3,134 — — 3,134 — 3,134 90.0 % Total Richardson Portfolio 6,244 34,820 559 41,623 (9,425 ) 32,198 Park Highlands (1) 12/30/2011 North Las Vegas NV Undeveloped Land 29,845 — — 29,845 — 29,845 (1) Burbank Collection 12/12/2012 Burbank CA Retail 4,175 12,544 725 17,444 (2,960 ) 14,484 90.0 % Park Centre 03/28/2013 Austin TX Office 3,251 27,841 — 31,092 (4,361 ) 26,731 100.0 % 1180 Raymond 08/20/2013 Newark NJ Apartment 8,292 38,372 — 46,664 (6,305 ) 40,359 100.0 % Park Highlands II 12/10/2013 North Las Vegas NV Undeveloped Land 25,532 — — 25,532 — 25,532 100.0 % 424 Bedford 01/31/2014 Brooklyn NY Apartment 8,860 25,909 — 34,769 (3,405 ) 31,364 90.0 % Richardson Land II 09/04/2014 Richardson TX Undeveloped Land 3,418 — — 3,418 — 3,418 90.0 % Westpark Portfolio 05/10/2016 Redmond WA Office/Flex/Industrial 36,085 93,362 6,352 135,799 (11,681 ) 124,118 100.0 % Crown Pointe 02/14/2017 Dunwoody GA Office 22,590 63,662 5,528 91,780 (6,855 ) 84,925 100.0 % 125 John Carpenter 09/15/2017 Irving TX Office 2,755 76,368 8,840 87,963 (4,636 ) 83,327 100.0 % Marquette Plaza 03/01/2018 Minneapolis MN Office 10,387 72,094 4,405 86,886 (2,265 ) 84,621 100.0 % City Tower 03/06/2018 Orange CA Office 13,930 129,713 8,120 151,763 (3,964 ) 147,799 100.0 % Eight & Nine Corporate Centre 06/08/2018 Franklin TN Office 17,401 54,063 4,786 76,250 (892 ) 75,358 100.0 % $ 192,765 $ 628,748 $ 39,315 $ 860,828 $ (56,749 ) $ 804,079 _____________________ (1) On September 7, 2016, a subsidiary of the Company that owns a portion of Park Highlands, sold 820 units of 10% Class A non-voting preferred membership units for $0.8 million to accredited investors. The amount of the Class A non-voting preferred membership units raised, net of offering costs, is included in other liabilities on the accompanying consolidated balance sheets. Operating Leases Certain of the Company’s real estate properties are leased to tenants under operating leases for which the terms and expirations vary. As of September 30, 2018 , the leases, excluding options to extend and apartment leases (which have terms that are generally one year or less), had remaining terms of up to 13.7 years with a weighted-average remaining term of 4.6 years. Some of the leases have provisions to extend the lease agreements, options for early termination after paying a specified penalty and other terms and conditions as negotiated. The Company retains substantially all of the risks and benefits of ownership of the real estate assets leased to tenants. Generally, upon the execution of a lease, the Company requires a security deposit from tenants in the form of a cash deposit and/or a letter of credit. The amount required as a security deposit varies depending upon the terms of the respective leases and the creditworthiness of the tenant, but generally are not significant amounts. Therefore, exposure to credit risk exists to the extent that a receivable from a tenant exceeds the amount of its security deposit. Security deposits received in cash and assumed in real estate acquisitions related to tenant leases are included in other liabilities in the accompanying consolidated balance sheets and totaled $5.1 million and $4.3 million as of September 30, 2018 and December 31, 2017 , respectively. During the nine months ended September 30, 2018 and 2017 , the Company recognized deferred rent from tenants of $3.5 million and $1.7 million , respectively, net of lease incentive amortization. As of September 30, 2018 and December 31, 2017 , the cumulative deferred rent receivable balance, including unamortized lease incentive receivables, was $10.9 million and $6.6 million , respectively, and is included in rents and other receivables on the accompanying balance sheets. The cumulative deferred rent balance included $1.5 million and $0.8 million of unamortized lease incentives as of September 30, 2018 and December 31, 2017 , respectively. As of September 30, 2018 , the future minimum rental income from the Company’s properties, excluding apartment leases, under non-cancelable operating leases was as follows (in thousands): October 1, 2018 through December 31, 2018 $ 15,168 2019 61,898 2020 56,312 2021 49,918 2022 42,432 Thereafter 138,775 $ 364,503 As of September 30, 2018 , the Company’s commercial real estate properties were leased to approximately 350 tenants over a diverse range of industries and geographic areas. The Company’s highest tenant industry concentrations (greater than 10% of annualized base rent) were as follows: Industry Number of Tenants Annualized Base Rent (1) (in thousands) Percentage of Annualized Base Rent Health Care and Social Services 15 $ 6,659 10.1 % _____________________ (1) Annualized base rent represents annualized contractual base rental income as of September 30, 2018 , adjusted to straight-line any contractual tenant concessions (including free rent), rent increases and rent decreases from the lease’s inception through the balance of the lease term. No other tenant industries accounted for more than 10% of annualized base rent. No material tenant credit issues have been identified at this time. Geographic Concentration Risk As of September 30, 2018 , the Company’s real estate investments in California , Texas and Washington represented 14.6% , 13.1% and 11.2% , respectively, of the Company’s total assets. As a result, the geographic concentration of the Company’s portfolio makes it particularly susceptible to adverse economic developments in the California , Texas and Washington real estate markets. Any adverse economic or real estate developments in these markets, such as business layoffs or downsizing, industry slowdowns, relocations of businesses, changing demographics and other factors, or any decrease in demand for office space resulting from the local business climate, could adversely affect the Company’s operating results and its ability to make distributions to stockholders. Recent Real Estate Acquisitions Marquette Plaza On March 1, 2018 , the Company, through an indirect wholly owned subsidiary, acquired an office property containing 522,656 rentable square feet located on 2.5 acres of land in Minneapolis, Minnesota (“Marquette Plaza”). The seller is not affiliated with the Company or the Advisor. The purchase price (net of closing credits) of Marquette Plaza was $88.3 million plus $1.1 million of capitalized acquisition costs. The Company recorded this acquisition as an asset acquisition and recorded $10.4 million to land, $71.4 million to building and improvements, $4.5 million to tenant origination and absorption costs, $3.7 million to above-market lease assets and $0.6 million to below-market lease liabilities. The intangible assets and liabilities acquired in connection with this acquisition have weighted-average amortization periods as of the date of acquisition of 6.6 years for tenant origination and absorption costs, 11.7 years for above-market lease assets and 2.4 years for below-market lease liabilities. City Tower On March 6, 2018 , the Company, through an indirect wholly owned subsidiary, acquired an office building containing 431,007 rentable square feet located on approximately 4.9 acres of land in Orange, California (“City Tower”). The seller is not affiliated with the Company or the Advisor. The purchase price (net of closing credits) of City Tower was $147.1 million plus $1.6 million of capitalized acquisition costs. The Company recorded this acquisition as an asset acquisition and recorded $13.9 million to land, $127.9 million to building and improvements, $8.1 million to tenant origination and absorption costs and $1.2 million to below-market lease liabilities. The intangible assets and liabilities acquired in connection with this acquisition have weighted-average amortization periods as of the date of acquisition of 5.2 years for tenant origination and absorption costs and 6.6 years for below-market lease liabilities. Eight & Nine Corporate Centre On June 8, 2018 , the Company, through an indirect wholly owned subsidiary, acquired an office building consisting of two buildings containing an aggregate of 311,864 rentable square feet located on approximately 27.6 acres of land in Franklin, Tennessee (“Eight & Nine Corporate Centre”). The seller is not affiliated with the Company or the Advisor. The purchase price (net of closing credits) of Eight & Nine Corporate Centre was $73.0 million plus $1.2 million of capitalized acquisition costs. The Company recorded this acquisition as an asset acquisition and recorded $17.4 million to land, $54.0 million to building and improvements, $4.8 million to tenant origination and absorption costs and $2.0 million to below-market lease liabilities. The intangible assets and liabilities acquired in connection with this acquisition have weighted-average amortization periods as of the date of acquisition of 6.4 years for tenant origination and absorption costs and 7.4 years for below-market lease liabilities. Recent Real Estate Land Sales Park Highlands On February 28, 2018, the Company sold approximately 26 developable acres of Park Highlands undeveloped land for an aggregate sales price, net of closing credits, of $2.5 million , excluding closing costs. The purchasers are not affiliated with the Company or the Advisor. The Company recognized a gain on sale of $0.7 million related to the land sale, which is net of deferred profit of $0.3 million related to proceeds received from the purchaser for the value of land that was contributed to a master association which is consolidated by the Company. On July 2, 2018, the Company sold approximately 83 developable acres of Park Highlands undeveloped land for an aggregate sales price, net of closing credits, of $18.7 million , excluding closing costs. The purchaser is not affiliated with the Company or the Advisor. The Company recognized a gain on sale of $12.6 million related to the land sale, which is net of deferred profit of $1.1 million related to proceeds received from the purchaser for the value of land that was contributed to a master association which is consolidated by the Company. Potential Real Estate Disposition Westpark Portfolio On May 10, 2016, the Company, through an indirect wholly owned subsidiary (the “Owner”), purchased a portfolio of 21 office/flex/industrial buildings containing a total of 778,472 rentable square feet located on approximately 41 acres of land in Redmond, Washington (the “Westpark Portfolio”). On September 23, 2018, the Owner entered into a Purchase and Sale Agreement and Escrow Instructions (the “Agreement”) for the sale of the Westpark Portfolio to Keppel-KBS Westpark, LLC, a wholly owned subsidiary of Keppel-KBS US REIT (the “SREIT”), subject to certain closing conditions. Pursuant to the Agreement, the contractual purchase price of the Westpark Portfolio is $169.4 million . The sale of the Westpark Portfolio is scheduled to close on or before December 31, 2018. However, closing of the sale is contingent upon, among other things, the SREIT receiving sufficient funds necessary to fund the acquisition of the Westpark Portfolio through (i) a public offering on the Singapore Stock Exchange and (ii) any financing obtained in connection with the acquisition of the Westpark Portfolio. There can be no assurance that the Company will complete the sale of the Westpark Portfolio on or before December 31, 2018, or at all. The SREIT is externally managed by a joint venture between (i) an entity in which Keith D. Hall, the Company’s Chief Executive Officer and a director, and Peter McMillan III, the Company’s President and Chairman of the board of directors, have an indirect ownership interest and (ii) Keppel Capital Holding Pte. Ltd., which is not affiliated with the Company. See note 11 , “Related Party Transactions” for a further discussion on this joint venture. As of September 30, 2018 , the Company owned 43,999,500 common units of the SREIT, representing a 6.97% ownership interest. A portion of the purchase price shall be paid to the Company by the SREIT in the form of additional common units, in lieu of cash, in an amount sufficient to cause the Company to maintain a 6.97% ownership interest.

TENANT ORIGINATION AND ABSORPTI

TENANT ORIGINATION AND ABSORPTION COSTS, ABOVE-MARKET LEASE ASSETS AND BELOW-MARKET LEASE LIABILITIES	9 Months Ended
	Sep. 30, 2018
Tenant Origination and Absorption Costs, Above-Market Lease Assets and Below-Market Lease Liabilities [Abstract]
TENANT ORIGINATION AND ABSORPTION COSTS, ABOVE-MARKET LEASE ASSETS AND BELOW-MARKET LEASE LIABILITIES	TENANT ORIGINATION AND ABSORPTION COSTS, ABOVE-MARKET LEASE ASSETS AND BELOW-MARKET LEASE LIABILITIES As of September 30, 2018 and December 31, 2017 , the Company’s tenant origination and absorption costs, above-market lease assets and below-market lease liabilities (excluding fully amortized assets and liabilities and accumulated amortization) were as follows (in thousands): Tenant Origination and Absorption Costs Above-Market Lease Assets Below-Market Lease Liabilities September 30, 2018 December 31, 2017 September 30, 2018 December 31, 2017 September 30, 2018 December 31, 2017 Cost $ 39,315 $ 23,212 $ 3,731 $ 17 $ (7,222 ) $ (3,636 ) Accumulated Amortization (10,281 ) (5,733 ) (246 ) (7 ) 1,668 793 Net Amount $ 29,034 $ 17,479 $ 3,485 $ 10 $ (5,554 ) $ (2,843 ) Increases (decreases) in net income as a result of amortization of the Company’s tenant origination and absorption costs, above-market lease assets and below-market lease liabilities for the three and nine months ended September 30, 2018 and 2017 were as follows (in thousands): Tenant Origination and Above-Market Below-Market For the Three Months Ended September 30, For the Three Months Ended September 30, For the Three Months Ended September 30, 2018 2017 2018 2017 2018 2017 Amortization $ (2,312 ) $ (2,190 ) $ (104 ) $ (62 ) $ 457 $ 278 Tenant Origination and Above-Market Below-Market For the Nine Months Ended For the Nine Months Ended For the Nine Months Ended 2018 2017 2018 2017 2018 2017 Amortization $ (5,937 ) $ (8,268 ) $ (259 ) $ (229 ) $ 1,112 $ 2,482 Additionally, as of September 30, 2018 and December 31, 2017 , the Company had recorded tax abatement intangible assets, net of amortization, which are included in prepaid expenses and other assets in the accompanying balance sheets, of $4.6 million and $5.3 million , respectively. During the three and nine months ended September 30, 2018 , the Company recorded amortization expense of $0.2 million and $0.7 million , respectively, related to tax abatement intangible assets. During the three and nine months ended September 30, 2017 , the Company recorded amortization expense of $0.2 million and $0.7 million , respectively, related to tax abatement intangible assets.

REAL ESTATE EQUITY SECURITIES

REAL ESTATE EQUITY SECURITIES	9 Months Ended
	Sep. 30, 2018
Investments, Debt and Equity Securities [Abstract]
REAL ESTATE EQUITY SECURITIES	REAL ESTATE EQUITY SECURITIES As of September 30, 2018 , the Company owned three investments in real estate equity securities. The following table sets forth the number of shares owned by the Company and the related carrying value of the shares as of September 30, 2018 and December 31, 2017 (dollars in thousands): September 30, 2018 December 31, 2017 Real Estate Equity Security Number of Shares Owned Total Carrying Value Number of Shares Owned Total Carrying Value Whitestone REIT 3,722,019 $ 51,662 3,603,189 $ 51,922 Keppel-KBS US REIT 43,999,500 34,474 43,999,500 38,141 Franklin Street Properties Corp. 1,576,809 12,599 — — 49,298,328 $ 98,735 47,602,689 $ 90,063 During the nine months ended September 30, 2018 , the Company purchased 1,576,809 shares of common stock of Franklin Street Properties Corp. (NYSE Ticker: FSP) for an aggregate purchase price of $14.0 million . During the nine months ended September 30, 2018 , the Company purchased 165,000 shares of common stock of Whitestone REIT (NYSE Ticker: WSR) for an aggregate purchase price of $1.9 million . Also during the nine months ended September 30, 2018 , the Company sold 46,170 shares of common stock of Whitestone REIT for an aggregate sale price of $0.6 million . On November 8, 2017, the Company acquired 43,999,500 shares of common units of Keppel-KBS US REIT (SGX Ticker: CMOU) in connection with the sale of 11 properties to Keppel-KBS US REIT. The Company agreed not to sell, transfer or assign 21,999,750 units of the Keppel-KBS US REIT issued to the Company at closing of the transaction until May 8, 2018 and the remaining 21,999,750 units until November 8, 2018 (the “Unit Lockout Periods”). As of September 30, 2018 and December 31, 2017 , the Company recorded a lack of marketability discount of $0.3 million and $1.7 million , respectively, as a result of the Unit Lockout Periods. The following summarizes the activity related to real estate equity securities for the nine months ended September 30, 2018 (in thousands): Amortized Cost Basis Unrealized Gain (Loss) (1) Total Real estate equity securities - December 31, 2017 $ 64,917 $ 25,146 $ 90,063 Acquisition of real estate equity securities 15,676 — 15,676 Acquisition fee to affiliate and purchase commission 175 — 175 Disposition of real estate equity securities (554 ) (79 ) (633 ) Loss on real estate equity securities — (6,546 ) (6,546 ) Real estate equity securities - September 30, 2018 $ 80,214 $ 18,521 $ 98,735 _____________________ (1) As of December 31, 2017 , unrealized gain (loss) due to the change in market value of real estate equity securities was recorded to accumulated other comprehensive income. Effective January 1, 2018, upon the adoption of ASU No. 2016-01, unrealized gain (losses) on real estate equity securities are recorded in earnings on the accompanying consolidated statement of operations. The following summarizes the portion of gain and loss for the period related to real estate equity securities held during the three and nine months ended September 30, 2018 (in thousands): For the Three Months Ended September 30, 2018 For the Nine Months Ended September 30, 2018 Net gain (loss) recognized during the period on real estate equity securities $ 741 $ (6,546 ) Less: Net gain (loss) recognized during the period on real estate equity securities sold during the period 57 (32 ) Unrealized gain (loss) recognized during the reporting period on real estate equity securities still held at September 30, 2018 $ 684 $ (6,514 ) During the three and nine months ended September 30, 2018 , the Company recognized $2.9 million and $5.1 million , respectively, of dividend income from real estate equity securities. During the three and nine months ended September 30, 2017 , the Company recognized $1.0 million and $1.5 million of dividend income from real estate equity securities. REAL ESTATE DEBT SECURITIES As of September 30, 2018 , the Company owned an investment in real estate debt securities. The Company’s investment in real estate debt securities is classified as held to maturity, as the Company has the intent and ability to hold its investment until maturity, and it is not more likely than not that the Company would be required to sell its investment before recovery of the Company’s amortized cost basis. The information for those real estate debt securities as of September 30, 2018 and December 31, 2017 is set forth below (in thousands): Debt Securities Name Dates Acquired Debt Securities Type Outstanding Principal Balance as of September 30, 2018 (1) Book Value as of September 30, 2018 (2) Book Value as of December 31, 2017 (2) Contractual Interest Rate (3) Annualized Effective Interest Rate (3) Maturity Date Battery Point Series B Preferred Units (4) 10/28/2016 / 03/30/2017 / 05/12/2017 Series B Preferred Units $ 17,500 $ 17,855 $ 17,751 12.0 % 11.1 % 10/28/2019 _____________________ (1) Outstanding principal balance as of September 30, 2018 represents principal balance outstanding under the real estate debt securities. (2) Book value of the real estate debt securities represents outstanding principal balance adjusted for unamortized acquisition discounts, origination fees and direct origination and acquisition costs and additional interest accretion. (3) Contractual interest rate is the stated interest rate on the face of the real estate securities. Annualized effective interest rate is calculated as the actual interest income recognized in 2018 , using the interest method, annualized (if applicable) and divided by the average amortized cost basis of the investment. The annualized effective interest rate and contractual interest rate presented are as of September 30, 2018 . (4) On October 31, 2018 , the Company received a partial principal prepayment of the real estate debt securities in the amount of $4.5 million . The following summarizes the activity related to real estate debt securities for the nine months ended September 30, 2018 (in thousands): Real estate debt securities - December 31, 2017 $ 17,751 Deferred interest receivable and interest accretion 68 Accretion of commitment fee, net of closing costs 36 Real estate debt securities - September 30, 2018 $ 17,855 For the three and nine months ended September 30, 2018 and 2017 , interest income from real estate debt securities consisted of the following (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Contractual interest income $ 537 $ 403 $ 1,421 $ 815 Interest (amortization) accretion (37 ) 97 68 218 Accretion of commitment fee, net of closing costs and acquisition fee 13 11 36 238 Interest income from real estate debt securities $ 513 $ 511 $ 1,525 $ 1,271

REAL ESTATE DEBT SECURITIES

REAL ESTATE DEBT SECURITIES	9 Months Ended
	Sep. 30, 2018
Investments, Debt and Equity Securities [Abstract]
REAL ESTATE DEBT SECURITIES	REAL ESTATE EQUITY SECURITIES As of September 30, 2018 , the Company owned three investments in real estate equity securities. The following table sets forth the number of shares owned by the Company and the related carrying value of the shares as of September 30, 2018 and December 31, 2017 (dollars in thousands): September 30, 2018 December 31, 2017 Real Estate Equity Security Number of Shares Owned Total Carrying Value Number of Shares Owned Total Carrying Value Whitestone REIT 3,722,019 $ 51,662 3,603,189 $ 51,922 Keppel-KBS US REIT 43,999,500 34,474 43,999,500 38,141 Franklin Street Properties Corp. 1,576,809 12,599 — — 49,298,328 $ 98,735 47,602,689 $ 90,063 During the nine months ended September 30, 2018 , the Company purchased 1,576,809 shares of common stock of Franklin Street Properties Corp. (NYSE Ticker: FSP) for an aggregate purchase price of $14.0 million . During the nine months ended September 30, 2018 , the Company purchased 165,000 shares of common stock of Whitestone REIT (NYSE Ticker: WSR) for an aggregate purchase price of $1.9 million . Also during the nine months ended September 30, 2018 , the Company sold 46,170 shares of common stock of Whitestone REIT for an aggregate sale price of $0.6 million . On November 8, 2017, the Company acquired 43,999,500 shares of common units of Keppel-KBS US REIT (SGX Ticker: CMOU) in connection with the sale of 11 properties to Keppel-KBS US REIT. The Company agreed not to sell, transfer or assign 21,999,750 units of the Keppel-KBS US REIT issued to the Company at closing of the transaction until May 8, 2018 and the remaining 21,999,750 units until November 8, 2018 (the “Unit Lockout Periods”). As of September 30, 2018 and December 31, 2017 , the Company recorded a lack of marketability discount of $0.3 million and $1.7 million , respectively, as a result of the Unit Lockout Periods. The following summarizes the activity related to real estate equity securities for the nine months ended September 30, 2018 (in thousands): Amortized Cost Basis Unrealized Gain (Loss) (1) Total Real estate equity securities - December 31, 2017 $ 64,917 $ 25,146 $ 90,063 Acquisition of real estate equity securities 15,676 — 15,676 Acquisition fee to affiliate and purchase commission 175 — 175 Disposition of real estate equity securities (554 ) (79 ) (633 ) Loss on real estate equity securities — (6,546 ) (6,546 ) Real estate equity securities - September 30, 2018 $ 80,214 $ 18,521 $ 98,735 _____________________ (1) As of December 31, 2017 , unrealized gain (loss) due to the change in market value of real estate equity securities was recorded to accumulated other comprehensive income. Effective January 1, 2018, upon the adoption of ASU No. 2016-01, unrealized gain (losses) on real estate equity securities are recorded in earnings on the accompanying consolidated statement of operations. The following summarizes the portion of gain and loss for the period related to real estate equity securities held during the three and nine months ended September 30, 2018 (in thousands): For the Three Months Ended September 30, 2018 For the Nine Months Ended September 30, 2018 Net gain (loss) recognized during the period on real estate equity securities $ 741 $ (6,546 ) Less: Net gain (loss) recognized during the period on real estate equity securities sold during the period 57 (32 ) Unrealized gain (loss) recognized during the reporting period on real estate equity securities still held at September 30, 2018 $ 684 $ (6,514 ) During the three and nine months ended September 30, 2018 , the Company recognized $2.9 million and $5.1 million , respectively, of dividend income from real estate equity securities. During the three and nine months ended September 30, 2017 , the Company recognized $1.0 million and $1.5 million of dividend income from real estate equity securities. REAL ESTATE DEBT SECURITIES As of September 30, 2018 , the Company owned an investment in real estate debt securities. The Company’s investment in real estate debt securities is classified as held to maturity, as the Company has the intent and ability to hold its investment until maturity, and it is not more likely than not that the Company would be required to sell its investment before recovery of the Company’s amortized cost basis. The information for those real estate debt securities as of September 30, 2018 and December 31, 2017 is set forth below (in thousands): Debt Securities Name Dates Acquired Debt Securities Type Outstanding Principal Balance as of September 30, 2018 (1) Book Value as of September 30, 2018 (2) Book Value as of December 31, 2017 (2) Contractual Interest Rate (3) Annualized Effective Interest Rate (3) Maturity Date Battery Point Series B Preferred Units (4) 10/28/2016 / 03/30/2017 / 05/12/2017 Series B Preferred Units $ 17,500 $ 17,855 $ 17,751 12.0 % 11.1 % 10/28/2019 _____________________ (1) Outstanding principal balance as of September 30, 2018 represents principal balance outstanding under the real estate debt securities. (2) Book value of the real estate debt securities represents outstanding principal balance adjusted for unamortized acquisition discounts, origination fees and direct origination and acquisition costs and additional interest accretion. (3) Contractual interest rate is the stated interest rate on the face of the real estate securities. Annualized effective interest rate is calculated as the actual interest income recognized in 2018 , using the interest method, annualized (if applicable) and divided by the average amortized cost basis of the investment. The annualized effective interest rate and contractual interest rate presented are as of September 30, 2018 . (4) On October 31, 2018 , the Company received a partial principal prepayment of the real estate debt securities in the amount of $4.5 million . The following summarizes the activity related to real estate debt securities for the nine months ended September 30, 2018 (in thousands): Real estate debt securities - December 31, 2017 $ 17,751 Deferred interest receivable and interest accretion 68 Accretion of commitment fee, net of closing costs 36 Real estate debt securities - September 30, 2018 $ 17,855 For the three and nine months ended September 30, 2018 and 2017 , interest income from real estate debt securities consisted of the following (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Contractual interest income $ 537 $ 403 $ 1,421 $ 815 Interest (amortization) accretion (37 ) 97 68 218 Accretion of commitment fee, net of closing costs and acquisition fee 13 11 36 238 Interest income from real estate debt securities $ 513 $ 511 $ 1,525 $ 1,271

REAL ESTATE SALES

REAL ESTATE SALES	9 Months Ended
	Sep. 30, 2018
Discontinued Operations and Disposal Groups [Abstract]
REAL ESTATE SALES	REAL ESTATE SALES During the three and nine months ended September 30, 2018 , the Company disposed of one office building. During the year ended December 31, 2017, the Company disposed of 12 office properties. On July 10, 2013, the Company, through an indirect wholly owned subsidiary, acquired an office building containing 191,784 rentable square feet located on approximately 0.6 acres of land in Seattle, Washington (the “Central Building”). On July 17, 2018, the Company sold the Central Building to a purchaser unaffiliated with the Company or the Advisor for $67.5 million before closing costs and credits. The carrying value of the Central Building as of the disposition date was $32.6 million , which was net of $5.6 million of accumulated depreciation and amortization. The Company recognized a gain on sale of $32.1 million related to the disposition of the Central Building. The following summary presents the major components of assets and liabilities related to real estate held for sale as of September 30, 2018 and December 31, 2017 (in thousands): September 30, 2018 December 31, 2017 Assets related to real estate held for sale Real estate, cost $ — $ 35,308 Accumulated depreciation and amortization — (4,663 ) Real estate, net — 30,645 Other assets — 1,965 Total assets related to real estate held for sale $ — $ 32,610 Liabilities related to real estate held for sale Notes payable, net — 27,515 Total liabilities related to real estate held for sale $ — $ 27,515 The operations of properties sold and related gain on sales are included in continuing operations on the accompanying statements of operations. The following table summarizes certain revenue and expenses related to these properties for the three and nine months ended September 30, 2018 and 2017 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Revenues Rental income $ 185 $ 17,129 $ 2,255 $ 53,262 Tenant reimbursements and other operating income 16 5,028 267 15,511 Total revenues $ 201 $ 22,157 $ 2,522 $ 68,773 Expenses Operating, maintenance, and management $ 20 $ 6,702 $ 453 $ 19,453 Real estate taxes and insurance (137 ) 3,170 150 9,649 Asset management fees to affiliate 79 1,371 351 4,197 Depreciation and amortization — 8,064 483 24,296 Interest expense 83 3,843 623 10,843 Total expenses $ 45 $ 23,150 $ 2,060 $ 68,438

NOTES AND BOND PAYABLE

NOTES AND BOND PAYABLE	9 Months Ended
	Sep. 30, 2018
Notes and Bonds Payable [Abstract]
NOTES AND BOND PAYABLE	NOTES AND BONDS PAYABLE As of September 30, 2018 and December 31, 2017 , the Company’s notes and bonds payable, including notes payable related to real estate held for sale, consisted of the following (dollars in thousands): Book Value as of September 30, 2018 Book Value as of December 31, 2017 Contractual Interest Rate as of September 30, 2018 (1) Effective Interest Rate at September 30, 2018 (1) Payment Type Maturity Date (2) Richardson Portfolio Mortgage Loan $ 32,435 $ 36,886 One-Month LIBOR + 2.10% 4.20% Principal & Interest 11/01/2018 (3) Portfolio Mortgage Loan (4) 8,772 9,877 One-Month LIBOR + 2.25% 4.36% Principal & Interest 07/01/2019 Burbank Collection Mortgage Loan 10,777 10,958 One-Month LIBOR + 2.35% 4.48% Principal & Interest 09/30/2019 1180 Raymond Bond Payable 6,325 6,460 6.50% 6.50% Principal & Interest 09/01/2036 Central Building Mortgage Loan (5) — 27,600 (5) (5) (5) (5) 424 Bedford Mortgage Loan 23,856 24,282 3.91% 3.91% Principal & Interest 10/01/2022 1180 Raymond Mortgage Loan 30,730 31,000 One-Month LIBOR + 2.25% 4.36% Principal & Interest 12/01/2018 KBS SOR (BVI) Holdings, Ltd. Series A Debentures (6) 266,854 278,801 4.25% 4.25% (6) 03/01/2023 Westpark Portfolio Mortgage Loan 85,020 85,200 One-Month LIBOR + 2.50% 4.60% Interest Only (7) 07/01/2020 Crown Pointe Mortgage Loan 51,171 50,500 One-Month LIBOR + 2.60% 4.70% Interest Only 02/13/2020 125 John Carpenter Mortgage Loan 50,130 50,130 (8) 3.86% Interest Only 10/01/2022 City Tower Mortgage Loan 89,000 — One-Month LIBOR + 1.55% 3.65% Interest Only 03/05/2021 Marquette Plaza Mortgage Loan 50,800 — One-Month LIBOR + 1.55% 3.65% Interest Only 06/06/2021 Eight & Nine Corporate Centre Mortgage Loan 43,880 — One-Month LIBOR + 1.60% 3.70% Interest Only 06/08/2021 Total Notes and Bonds Payable principal outstanding 749,750 611,694 Net Premium/(Discount) on Notes and Bonds Payable (9) 182 137 Deferred financing costs, net (8,803 ) (8,788 ) Total Notes and Bonds Payable, net $ 741,129 $ 603,043 _____________________ (1) Contractual interest rate represents the interest rate in effect under the loan as of September 30, 2018 . Effective interest rate is calculated as the actual interest rate in effect as of September 30, 2018 (consisting of the contractual interest rate and contractual floor rates), using interest rate indices at September 30, 2018 , where applicable. (2) Represents the initial maturity date or the maturity date as extended as of September 30, 2018 ; subject to certain conditions, the maturity dates of certain loans may be extended beyond the date shown. (3) Subsequent to September 30, 2018 , the Richardson Portfolio Mortgage Loan was refinanced. The maturity date of the loan was extended to November 1, 2021, with two one -year extension options, subject to certain conditions contained in the loan documents and the payment of an extension fee. The refinanced loan bears interest at a floating rate of 2.5% over one-month LIBOR. (4) The Portfolio Mortgage Loan is secured by Park Centre. (5) On July 17, 2018, in connection with the disposition of the Central Building, the Company repaid the $27.6 million outstanding principal balance due under the Central Building Mortgage Loan. (6) See “ – Israeli Bond Financing” below. (7) Represents the payment type required under the loan as of September 30, 2018 . Certain future monthly payments due under this loan also include amortizing principal payments. For more information of the Company’s contractual obligations under its notes and bonds payable, see five-year maturity table below. (8) The 125 John Carpenter Mortgage Loan bears interest at a floating rate of the greater of (a) 2.0% or (b) 175 basis points over one-month LIBOR. (9) Represents the unamortized premium/discount on notes and bonds payable due to the above- and below-market interest rates when the debt was assumed. The discount/premium is amortized over the remaining life of the notes and bonds payable. During the three and nine months ended September 30, 2018 , the Company incurred $8.4 million and $22.8 million , respectively, of interest expense. Included in interest expense for the three and nine months ended September 30, 2018 was $1.0 million and $2.7 million , respectively, of amortization of deferred financing costs. Additionally, during the three and nine months ended September 30, 2018 , the Company capitalized $0.6 million and $1.9 million , respectively, of interest related to its investments in undeveloped land. During the three and nine months ended September 30, 2017 , the Company incurred $9.6 million and $29.3 million , respectively, of interest expense. Included in interest expense for the three and nine months ended September 30, 2017 was $1.0 million and $3.6 million , respectively, of amortization of deferred financing costs. Additionally, during the three and nine months ended September 30, 2017 , the Company capitalized $0.6 million and $1.7 million , respectively, of interest related to its investments in undeveloped land. As of September 30, 2018 and December 31, 2017 , the Company’s interest payable was $2.6 million and $5.1 million , respectively. The following is a schedule of maturities, including principal amortization payments, for all notes and bonds payable outstanding as of September 30, 2018 (in thousands): October 1, 2018 through December 31, 2018 $ 64,024 2019 74,414 2020 189,056 2021 237,929 2022 125,546 Thereafter 58,781 $ 749,750 The Company’s notes payable contain financial debt covenants. As of September 30, 2018 , the Company was in compliance with all of these debt covenants. Israeli Bond Financing On March 2, 2016, KBS Strategic Opportunity BVI, a wholly owned subsidiary of the Company, filed a final prospectus with the Israel Securities Authority for a proposed offering of up to 1,000,000,000 Israeli new Shekels of Series A debentures (the “Debentures”) at an annual interest rate not to exceed 4.25% . On March 1, 2016, KBS Strategic Opportunity BVI commenced the institutional tender of the Debentures and accepted application for 842.5 million Israeli new Shekels. On March 7, 2016, KBS Strategic Opportunity BVI commenced the public tender of the Debentures and accepted 127.7 million Israeli new Shekels. In the aggregate, KBS Strategic Opportunity BVI accepted 970.2 million Israeli new Shekels (approximately $249.2 million as of March 8, 2016 ) in both the institutional and public tenders at an annual interest rate of 4.25% . KBS Strategic Opportunity BVI issued the Debentures on March 8, 2016. The terms of the Debentures require principal installment payments equal to 20% of the face value of the Debentures on March 1st of each year from 2019 to 2023. As of September 30, 2018 , the Company has one foreign currency collar for an aggregate notional amount of 776.2 million Israeli new Shekels to hedge its exposure to foreign currency exchange rate movements. See note 9 , “Derivative Instruments” for a further discussion on the Company’s foreign currency collar. The deed of trust that governs the terms of the Debentures contains various financial covenants. As of September 30, 2018 , the Company was in compliance with all of these financial debt covenants.

DERIVATIVE INSTRUMENTS

DERIVATIVE INSTRUMENTS	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE INSTRUMENTS	DERIVATIVE INSTRUMENTS The Company enters into derivative instruments for risk management purposes to hedge its exposure to cash flow variability caused by changing interest rates and foreign currency exchange rate movements. The primary goal of the Company’s risk management practices related to interest rate risk is to prevent changes in interest rates from adversely impacting the Company’s ability to achieve its investment return objectives. The Company does not enter into derivatives for speculative purposes. The Company enters into foreign currency options and foreign currency collars to mitigate its exposure to foreign currency exchange rate movements on its bonds payable outstanding denominated in Israeli new Shekels. A foreign currency collar consists of a purchased call option to buy and a sold put option to sell Israeli new Shekels. A foreign currency collar guarantees that the exchange rate of the currency will not fluctuate beyond the range of the options’ strike prices. A foreign currency option consists of a call option to buy Israeli new Shekels. The following table summarizes the notional amount and other information related to the Company’s foreign currency collar and foreign currency option as of September 30, 2018 and December 31, 2017 . The notional amount is an indication of the extent of the Company’s involvement in each instrument at that time, but does not represent exposure to credit, interest rate or market risks (currency in thousands): September 30, 2018 December 31, 2017 Strike Price Trade Date Maturity Date Derivative Instruments Number of Instruments Notional Amount Number of Instruments Notional Amount Derivative instruments not designated as hedging instruments Foreign currency collar 1 776,182 ILS — — 3.54 - 3.66 ILS - USD 08/20/2018 02/28/2019 Foreign currency option — $ — 1 $285,361 3.40 ILS-USD 08/03/2017 08/03/2018 The Company enters into interest rate caps to mitigate its exposure to rising interest rates on its variable rate notes payable. The values of interest rate caps are primarily impacted by interest rates, market expectations about interest rates, and the remaining life of the instrument. In general, increases in interest rates, or anticipated increases in interest rates, will increase the value of interest rate caps. As the remaining life of an interest rate cap decreases, the value of the instrument will generally decrease towards zero. As of September 30, 2018 , the Company had entered into two interest rate caps, which were not designated as a hedging instruments. The following table summarizes the notional amounts and other information related to the Company’s derivative instruments as of September 30, 2018 . The notional amount is an indication of the extent of the Company’s involvement in the instrument at that time, but does not represent exposure to credit, interest rate or market risks (dollars in thousands): Derivative Instrument Effective Date Maturity Date Notional Value Reference Rate Interest rate cap 02/21/2017 02/13/2020 $ 46,875 One-month LIBOR at 3.00% Interest rate cap 04/02/2018 03/05/2021 $ 77,513 One-month LIBOR at 3.50% The following table sets forth the fair value of the Company’s derivative instruments as well as their classification on the consolidated balance sheets as of September 30, 2018 and December 31, 2017 (dollars in thousands): September 30, 2018 December 31, 2017 Derivative Instruments Balance Sheet Location Number of Instruments Fair Value Number of Instruments Fair Value Derivative instruments not designated as hedging instruments Interest rate caps Prepaid expenses and other assets 2 $ 156 1 $ 14 Foreign currency option Prepaid expenses and other assets — — 1 4,243 Foreign currency collar Prepaid expenses and other assets 1 171 — — The change in fair value of foreign currency options and collars that are not designated as cash flow hedges are recorded as foreign currency transaction gains or losses in the accompanying consolidated statements of operations. During the three months ended September 30, 2018 , the Company recognized a $0.2 million gain related to the foreign currency option and collar, which is shown net against $0.2 million of foreign currency transaction loss in the accompanying consolidated statements of operations as foreign currency transaction loss , net. During the nine months ended September 30, 2018 , the Company recognized a $4.1 million loss related to the foreign currency option and collar, which is shown net against $13.2 million of foreign currency transaction gain in the accompanying consolidated statements of operations as foreign currency transaction gain , net. During the three months ended September 30, 2017 , the Company recognized a $8.1 million loss related to the foreign currency option and collars, which is shown net against $3.7 million of foreign currency transaction gain in the accompanying consolidated statements of operations as foreign currency transaction loss, net. During the nine months ended September 30, 2017 , the Company recognized a $10.9 million gain related to the foreign currency option and collars, which is shown net against $22.4 million of foreign currency transaction loss in the accompanying consolidated statements of operations as foreign currency transaction loss, net. During the three months ended September 30, 2018 , the Company recorded an unrealized gain of $10,000 on interest rate caps, which was included as an offset to interest expense on the accompanying consolidated statements of operations. During the nine months ended September 30, 2018 , the Company recorded an unrealized loss of $21,000 on interest rate caps, which was included in interest expense on the accompanying consolidated statements of operations. During the three and nine months ended September 30, 2017 , the Company recorded unrealized losses of $14,000 and $102,000 , respectively, on interest rate caps, which were included in interest expense on the accompanying consolidated statements of operations.

FAIR VALUE DISCLOSURES

FAIR VALUE DISCLOSURES	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
FAIR VALUE DISCLOSURES	FAIR VALUE DISCLOSURES Under GAAP, the Company is required to measure certain financial instruments at fair value on a recurring basis. In addition, the Company is required to measure other non-financial and financial assets at fair value on a non-recurring basis (e.g., carrying value of impaired real estate loans receivable and long-lived assets). Fair value is defined as the price that would be received upon the sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The GAAP fair value framework uses a three-tiered approach. Fair value measurements are classified and disclosed in one of the following three categories: • Level 1: unadjusted quoted prices in active markets that are accessible at the measurement date for identical assets or liabilities; • Level 2: quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-derived valuations in which significant inputs and significant value drivers are observable in active markets; and • Level 3: prices or valuation techniques where little or no market data is available that requires inputs that are both significant to the fair value measurement and unobservable. The fair value for certain financial instruments is derived using valuation techniques that involve significant management judgment. The price transparency of financial instruments is a key determinant of the degree of judgment involved in determining the fair value of the Company’s financial instruments. Financial instruments for which actively quoted prices or pricing parameters are available and for which markets contain orderly transactions will generally have a higher degree of price transparency than financial instruments for which markets are inactive or consist of non-orderly trades. The Company evaluates several factors when determining if a market is inactive or when market transactions are not orderly. The following is a summary of the methods and assumptions used by management in estimating the fair value of each class of financial instruments for which it is practicable to estimate the fair value: Cash and cash equivalents, restricted cash, rent and other receivables and accounts payable and accrued liabilities: These balances approximate their fair values due to the short maturities of these items. Real estate equity securities : The Company’s Whitestone REIT and Franklin Street Properties Corp. real estate equity securities are presented at fair value on the accompanying consolidated balance sheet. The fair values of Whitestone REIT and Franklin Street Properties Corp. real estate equity securities were based on quoted prices in an active market on a major stock exchange. The Company classifies these inputs as Level 1 inputs. As of December 31, 2017, the Company owned 43,999,500 shares of common units of Keppel-KBS US REIT. The fair value measurement of these shares was based on a quoted price in an active market, adjusted for the lack of marketability during the Unit Lockout Periods. On May 8, 2018, 21,999,750 shares of common units of Keppel-KBS US REIT were transfered from Level 2 to Level 1 inputs as a result of the Unit Lockout Period expiring. As of September 30, 2018 , the Company owned 43,999,500 shares of common units of Keppel-KBS US REIT. The fair value measurement on 21,999,750 shares are based on a quoted price in an active market on a major stock exchange. The Company classifies these inputs as Level 1 inputs. The fair value measurement on the remaining 21,999,750 shares are based on a quoted price in an active market on a major stock exchange, adjusted for the lack of marketability during the remaining Unit Lockout Period. The Company utilized inputs, all of which were deemed to be significant, including the quoted stock price, risk-free rate and expected volatility, in determining the value of the shares and the Company notes that the most significant input in its valuation model is the quoted price in an active market. However, as the valuation of the stock is adjusted for the lack of marketability using market-corroborated inputs, the Company categorizes the measurement of such securities as Level 2 inputs. Real estate debt securities : The Company’s real estate debt securities are presented in the accompanying consolidated balance sheets at their amortized cost net of recorded loss reserves (if any) and not at fair value. The fair value of real estate debt securities was estimated using an internal valuation model that considers the expected cash flows for the loans, underlying collateral values (for collateral dependent loans) and estimated yield requirements of institutional investors for real estate debt securities with similar characteristics, including remaining loan term, loan-to-value, type of collateral and other credit enhancements. The Company classifies these inputs as Level 3 inputs. Notes and bonds payable: The fair values of the Company’s notes and bonds payable are estimated using a discounted cash flow analysis based on management’s estimates of current market interest rates for instruments with similar characteristics, including remaining loan term, loan-to-value ratio, type of collateral and other credit enhancements. Additionally, when determining the fair value of liabilities in circumstances in which a quoted price in an active market for an identical liability is not available, the Company measures fair value using (i) a valuation technique that uses the quoted price of the identical liability when traded as an asset or quoted prices for similar liabilities or similar liabilities when traded as assets or (ii) another valuation technique that is consistent with the principles of fair value measurement, such as the income approach or the market approach. The Company classifies these inputs as Level 3 inputs. The Company’s bonds issued in Israel are publicly traded on the Tel-Aviv Stock Exchange. The Company used the quoted price as of September 30, 2018 for the fair value of its bonds issued in Israel. The Company classifies this input as a Level 1 input. Derivative instruments : The Company’s derivative instruments are presented at fair value on the accompanying consolidated balance sheets. The valuation of these instruments is determined using a proprietary model that utilizes observable inputs. As such, the Company classifies these inputs as Level 2 inputs. The fair value of interest rate caps (floors) are determined using the market standard methodology of discounting the future expected cash payments (receipts) which would occur if variable interest rates rise above (below) the strike rate of the caps (floors). The variable interest rates used in the calculation of projected payments (receipts) on the cap (floor) are based on an expectation of future interest rates derived from observed market interest rate curves and volatilities. The fair value of foreign currency option and collar is based on a Black-Scholes model tailored for currency derivatives. The following were the face values, carrying amounts and fair values of the Company’s financial instruments as of September 30, 2018 and December 31, 2017 , which carrying amounts do not approximate the fair values (in thousands): September 30, 2018 December 31, 2017 Face Value Carrying Amount Fair Value Face Value Carrying Amount Fair Value Financial asset: Real estate debt securities $ 17,500 $ 17,855 $ 17,459 $ 17,500 $ 17,751 $ 17,386 Financial liabilities: Notes and bond payable $ 482,896 $ 479,296 $ 487,215 $ 332,893 $ 330,727 $ 335,212 KBS SOR (BVI) Holdings, Ltd. Series A Debentures $ 266,854 $ 261,833 $ 271,353 $ 278,801 $ 272,316 $ 296,069 Disclosure of the fair value of financial instruments is based on pertinent information available to the Company as of the period end and requires a significant amount of judgment. This has made the estimation of fair values difficult and, therefore, both the actual results and the Company’s estimate of value at a future date could be materially different. As of September 30, 2018 , the Company measured the following assets at fair value (in thousands): Fair Value Measurements Using Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Recurring Basis: Real estate equity securities $ 98,735 $ 81,641 $ 17,094 $ — Asset derivative - interest rate caps $ 156 $ — $ 156 $ — Asset derivative - foreign currency collar $ 171 $ — $ 171 $ —

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS	9 Months Ended
	Sep. 30, 2018
Related Party Transactions [Abstract]
RELATED PARTY TRANSACTIONS	RELATED PARTY TRANSACTIONS The Advisory Agreement entitles the Advisor to specified fees upon the provision of certain services with regard to the investment of funds in real estate and real estate-related investments and the disposition of real estate and real estate-related investments (including the discounted payoff of non-performing loans) among other services, as well as reimbursement of certain costs incurred by the Advisor in providing services to the Company. The Advisory Agreement may also entitle the Advisor to certain back-end cash flow participation fees. The Company also entered into a fee reimbursement agreement (the “AIP Reimbursement Agreement”) with KBS Capital Markets Group LLC, the dealer manager for the Company’s initial public offering (the “Dealer Manager”), pursuant to which the Company agreed to reimburse the Dealer Manager for certain fees and expenses it incurs for administering the Company’s participation in the Depository Trust & Clearing Corporation Alternative Investment Product Platform with respect to certain accounts of the Company’s investors serviced through the platform. The Advisor and Dealer Manager also serve as, or previously served as, the advisor and dealer manager, respectively, for KBS Real Estate Investment Trust, Inc. (“KBS REIT I”), KBS Real Estate Investment Trust II, Inc. (“KBS REIT II”), KBS Real Estate Investment Trust III, Inc. (“KBS REIT III”), KBS Legacy Partners Apartment REIT, Inc. (“KBS Legacy Partners Apartment REIT”), KBS Strategic Opportunity REIT II, Inc. (“KBS Strategic Opportunity REIT II”) and KBS Growth & Income REIT, Inc. (“KBS Growth & Income REIT”). On January 6, 2014, the Company, together with KBS REIT I, KBS REIT II, KBS REIT III, KBS Legacy Partners Apartment REIT, KBS Strategic Opportunity REIT II, the Dealer Manager, the Advisor and other KBS-affiliated entities, entered into an errors and omissions and directors and officers liability insurance program where the lower tiers of such insurance coverage are shared. The cost of these lower tiers is allocated by the Advisor and its insurance broker among each of the various entities covered by the program, and is billed directly to each entity. The allocation of these shared coverage costs is proportionate to the pricing by the insurance marketplace for the first tiers of directors and officers liability coverage purchased individually by each REIT. The Advisor’s and the Dealer Manager’s portion of the shared lower tiers’ cost is proportionate to the respective entities’ prior cost for the errors and omissions insurance. In June 2015, KBS Growth & Income REIT was added to the insurance program at terms similar to those described above. KBS REIT I elected to cease participation in the program at the June 2017 renewal and obtained separate insurance coverage. At renewal in June 2018, the Company, KBS Strategic Opportunity REIT II and KBS Legacy Partners Apartment REIT elected to cease participation in the program and obtain separate insurance coverage. The Company, together with KBS Strategic Opportunity REIT II, entered into an errors and omissions and directors and officers liability insurance program where the lower tiers of such insurance coverage are shared. The cost of these lower tiers is allocated by the Advisor and its insurance broker among each REIT covered by the program, and is billed directly to each REIT. The program is effective through June 30, 2019. During the three and nine months ended September 30, 2018 and 2017 , no other business transactions occurred between the Company and these other KBS-sponsored programs. Pursuant to the terms of these agreements, summarized below are the related-party costs incurred by the Company for the three and nine months ended September 30, 2018 and 2017 , respectively, and any related amounts payable as of September 30, 2018 and December 31, 2017 (in thousands): Incurred Payable as of Three Months Ended September 30, Nine Months Ended September 30, September 30, 2018 December 31, 2017 2018 2017 2018 2017 Expensed Asset management fees $ 2,299 $ 2,800 $ 6,342 $ 8,404 $ — $ — Reimbursable operating expenses (1) 90 51 288 184 65 26 Disposition fees (2) 860 — 860 785 — — Capitalized Acquisition fees on real estate — 71 3,094 907 — — Acquisition fees on real estate equity securities — 43 157 429 — — $ 3,249 $ 2,965 $ 10,741 $ 10,709 $ 65 $ 26 _____________________ (1) The Advisor may seek reimbursement for certain employee costs under the Advisory Agreement. The Company has reimbursed the Advisor for the Company’s allocable portion of the salaries, benefits and overhead of internal audit department personnel providing services to the Company. These amounts totaled $74,000 and $235,000 for the three and nine months ended September 30, 2018 , respectively, and $49,000 and $168,000 for the three and nine months ended September 30, 2017 , respectively, and were the only employee costs reimbursed under the Advisory Agreement during these periods. The Company will not reimburse for employee costs in connection with services for which the Advisor earns acquisition, origination or disposition fees (other than reimbursement of travel and communication expenses) or for the salaries or benefits the Advisor or its affiliates may pay to the Company’s executive officers. In addition to the amounts above, the Company reimburses the Advisor for certain of the Company’s direct costs incurred from third parties that were initially paid by the Advisor on behalf of the Company. (2) Disposition fees with respect to real estate sold are included in the gain on sale of real estate in the accompanying consolidated statements of operations. During the nine months ended September 30, 2018 , the Advisor reimbursed the Company $0.1 million for a property insurance rebate. During the nine months ended September 30, 2017 , the Advisor reimbursed the Company $0.4 million for expenses incurred to evaluate certain strategic transactions for which the Advisor has agreed to reimburse the Company and $0.1 million for a property insurance rebate. On November 8, 2017, the Company sold 11 properties to Keppel-KBS US REIT. Keppel-KBS US REIT is externally managed by a joint venture (the “Manager”) between (i) an entity in which Keith D. Hall, the Company’s Chief Executive Officer and a director, and Peter McMillan III, the Company’s President and Chairman of the board of directors, have an indirect ownership interest and (ii) Keppel Capital Holding Pte. Ltd., which is not affiliated with the Company. Keppel-KBS US REIT is expected to pay certain purchase and sale commissions and asset management fees to the Manager in exchange for the provision of certain management services.

INVESTMENT IN UNCONSOLIDATED JO

INVESTMENT IN UNCONSOLIDATED JOINT VENTURES	9 Months Ended
	Sep. 30, 2018
Equity Method Investments and Joint Ventures [Abstract]
INVESTMENT IN UNCONSOLIDATED JOINT VENTURES	INVESTMENT IN UNCONSOLIDATED JOINT VENTURES As of September 30, 2018 and December 31, 2017 , the Company’s investments in unconsolidated joint ventures were composed of the following (dollars in thousands): Investment Balance at Joint Venture Number of Properties Location Ownership % September 30, 2018 December 31, 2017 NIP Joint Venture 2 Various Less than 5.0% $ 1,476 $ 3,674 110 William Joint Venture 1 New York, New York 60.0% 2,414 7,160 353 Sacramento Joint Venture 1 San Francisco, California 55.0% 43,414 44,743 $ 47,304 $ 55,577 Investment in National Industrial Portfolio Joint Venture On May 18, 2012, the Company, through an indirect wholly owned subsidiary, entered into a joint venture (the “NIP Joint Venture”) with OCM NIP JV Holdings, L.P. and HC KBS NIP JV, LLC (“HC-KBS”). The NIP Joint Venture has invested in a portfolio of industrial properties. The Company made an initial capital contribution of $8.0 million which represents less than a 5.0% ownership interest in the NIP Joint Venture as of September 30, 2018 . Prior to the Company’s adoption of ASU No. 2016-01 on January 1, 2018, the Company accounted for its investment in the NIP Joint Venture using the cost method of accounting. Effective January 1, 2018, the Company elected to measure its investment in the NIP Joint Venture, which is an equity investment without a readily determinable value, at its cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for an identical or similar investment of the same issuer. Prior to January 17, 2018, KBS REIT I, an affiliate of the Advisor, was a member of HC-KBS and had a participation interest in certain future potential profits generated by the NIP Joint Venture. However, KBS REIT I did not have any equity interest in the NIP Joint Venture. On January 17, 2018, KBS REIT I assigned its participation interest in the NIP Joint Venture to one of the other joint venture partners in the NIP Joint Venture. None of the other joint venture partners are affiliated with the Company or the Advisor. As of September 30, 2018 and December 31, 2017 , the book value of the Company’s investment in the NIP Joint Venture was $1.5 million and $3.7 million , respectively. During the three months ended September 30, 2018 , the Company received a distribution of $1.2 million related to its investment in the NIP Joint Venture. The Company recognized $0.2 million of income distributions and $1.0 million of return of capital from the NIP Joint Venture. During the nine months ended September 30, 2018 , the Company received aggregate distributions of $2.6 million related to its investment in the NIP Joint Venture. The Company recognized $0.4 million of income distributions and $2.2 million of return of capital from the NIP Joint Venture. During the three months ended September 30, 2017 , the Company did not receive any distributions related to its investment in the NIP Joint Venture. During the nine months ended September 30, 2017 , the Company received a distribution of $2.9 million related to its investment in the NIP Joint Venture. The Company recognized $1.9 million of income distributions and $1.0 million of return of capital from the NIP Joint Venture. Investment in 110 William Joint Venture On December 23, 2013, the Company, through an indirect wholly owned subsidiary, entered into an agreement with SREF III 110 William JV, LLC (the “110 William JV Partner”) to form a joint venture (the “110 William Joint Venture”). On May 2, 2014, the 110 William Joint Venture acquired an office property containing 928,157 rentable square feet located on approximately 0.8 acres of land in New York, New York (“110 William Street”). Each of the Company and the 110 William JV Partner hold a 60% and 40% ownership interest in the 110 William Joint Venture, respectively. The Company exercises significant influence over the operations, financial policies and decision making with respect to the 110 William Joint Venture but significant decisions require approval from both members. Accordingly, the Company has accounted for its investment in the 110 William Joint Venture under the equity method of accounting. Income, losses, contributions and distributions are generally allocated based on the members’ respective equity interests. As of September 30, 2018 and December 31, 2017 , the book value of the Company’s investment in the 110 William Joint Venture was $2.4 million and $7.2 million , respectively, which includes $1.5 million of unamortized acquisition fees and expenses incurred directly by the Company. During the nine months ended September 30, 2017 , the 110 William Joint Venture made a $58.2 million return of capital distribution to the Company and a $38.8 million return of capital distribution to the 110 William JV Partner funded with proceeds from the 110 William refinancing. Summarized financial information for the 110 William Joint Venture follows (in thousands): September 30, 2018 December 31, 2017 Assets: Real estate assets, net of accumulated depreciation and amortization $ 237,302 $ 248,269 Other assets 39,484 32,331 Total assets $ 276,786 $ 280,600 Liabilities and equity: Notes payable, net $ 266,326 $ 260,108 Other liabilities 8,843 11,016 Partners’ capital 1,617 9,476 Total liabilities and equity $ 276,786 $ 280,600 Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Revenues $ 10,137 $ 9,614 $ 29,897 $ 27,328 Expenses: Operating, maintenance, and management 2,550 2,577 7,313 7,343 Real estate taxes and insurance 1,715 1,637 5,005 4,725 Depreciation and amortization 4,075 4,664 12,420 12,277 Interest expense 4,557 3,951 13,092 9,150 Total expenses 12,897 12,829 37,830 33,495 Other income 37 14 75 42 Net loss $ (2,723 ) $ (3,201 ) $ (7,858 ) $ (6,125 ) Company’s equity in loss of unconsolidated joint venture $ (1,644 ) $ (1,930 ) $ (4,746 ) $ (3,706 ) Investment in 353 Sacramento Joint Venture On July 6, 2017, the Company, through an indirect wholly owned subsidiary, entered into an agreement with the Migdal Members to form the 353 Sacramento Joint Venture. On July 6, 2017, the Company sold a 45% equity interest in an entity that owns 353 Sacramento to the Migdal Members. The sale resulted in 353 Sacramento being owned by the 353 Sacramento Joint Venture, in which the Company indirectly owns 55% of the equity interests and the Migdal Members indirectly own 45% in the aggregate of the equity interests. The Company exercises significant influence over the operations, financial policies and decision making with respect to the 353 Sacramento Joint Venture but significant decisions require approval from both members. Accordingly, the Company has accounted for its investment in the 353 Sacramento Joint Venture under the equity method of accounting. Income, losses, contributions and distributions are generally allocated based on the members’ respective equity interests. As of September 30, 2018 and December 31, 2017 , the book value of the Company’s investment in the 353 Sacramento Joint Venture was $43.4 million and $44.7 million , respectively. During the nine months ended September 30, 2018 , the Company made a $1.3 million contribution to the 353 Sacramento Joint Venture. Summarized financial information for the 353 Sacramento Joint Venture follows (in thousands): September 30, 2018 December 31, 2017 Assets: Real estate assets, net of accumulated depreciation and amortization $ 179,420 $ 171,066 Other assets 9,219 6,472 Total assets $ 188,639 $ 177,538 Liabilities and equity: Notes payable, net $ 96,562 $ 89,423 Other liabilities 13,625 7,313 Partners’ capital 78,452 80,802 Total liabilities and equity $ 188,639 $ 177,538 For the Three Months Ended September 30, 2018 For the Nine Months Ended September 30, 2018 For the Period from July 6, 2017 to September 30, 2017 Revenues $ 2,475 $ 7,771 $ 3,507 Expenses: Operating, maintenance, and management 906 2,675 936 Real estate taxes and insurance 611 1,828 603 Depreciation and amortization 1,408 4,245 1,724 Interest expense 1,426 4,013 1,138 Total expenses 4,351 12,761 4,401 Net loss $ (1,876 ) $ (4,990 ) $ (894 ) Company’s equity in loss of unconsolidated joint venture $ (1,000 ) $ (2,648 ) $ (222 )

SUPPLEMENTAL CASH FLOW AND SIGN

SUPPLEMENTAL CASH FLOW AND SIGNIFICANT NONCASH TRANSACTION DISCLOSURES	9 Months Ended
	Sep. 30, 2018
Supplemental Cash Flow and Significant Noncash Transaction Disclosures [Abstract]
SUPPLEMENTAL CASH FLOW AND SIGNIFICANT NONCASH TRANSACTION DISCLOSURES	SUPPLEMENTAL CASH FLOW AND SIGNIFICANT NONCASH TRANSACTION DISCLOSURES Supplemental cash flow and significant noncash transaction disclosures were as follows (in thousands): Nine Months Ended September 30, 2018 2017 Supplemental Disclosure of Cash Flow Information: Interest paid, net of capitalized interest of $1,916 and $1,732 for the nine months ended September 30, 2018 and 2017 , respectively $ 22,485 $ 27,732 Supplemental Disclosure of Significant Noncash Transactions: Assets and liabilities deconsolidated in connection with the 353 Sacramento partial sale: Real estate, net — 170,586 Rents and other receivables, net — 1,244 Prepaid expenses and other assets — 555 Notes payable, net — 87,132 Accounts payable and accrued liabilities — 1,574 Below-market leases, net — 2,960 Other liabilities — 924 Application of escrow deposits to acquisition of real estate — 2,000 Increase in accrued improvements to real estate 1,179 1,319 Distributions paid to common stockholders through common stock issuances pursuant to the dividend reinvestment plan 1,418 8,666 Distributions paid to common stockholders through common stock issuances pursuant to the December 2017 special dividend 150,299 —

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Economic Dependency The Company is dependent on the Advisor for certain services that are essential to the Company, including the identification, evaluation, negotiation, origination, acquisition and disposition of investments; management of the daily operations of the Company’s investment portfolio; and other general and administrative responsibilities. In the event that the Advisor is unable to provide these services, the Company will be required to obtain such services from other sources. Environmental As an owner of real estate, the Company is subject to various environmental laws of federal, state and local governments. Although there can be no assurance, the Company is not aware of any environmental liability that could have a material adverse effect on its financial condition or results of operations as of September 30, 2018 . However, changes in applicable environmental laws and regulations, the uses and conditions of properties in the vicinity of the Company’s properties, the activities of its tenants and other environmental conditions of which the Company is unaware with respect to the properties could result in future environmental liabilities. Legal Matters From time to time, the Company is a party to legal proceedings that arise in the ordinary course of its business. Management is not aware of any legal proceedings of which the outcome is probable or reasonably possible to have a material adverse effect on the Company’s results of operations or financial condition, which would require accrual or disclosure of the contingency and the possible range of loss. Additionally, the Company has not recorded any loss contingencies related to legal proceedings in which the potential loss is deemed to be remote. Participation Fee Liability Pursuant to the Advisory Agreement currently in effect with the Advisor, the Advisor is due a subordinated participation in the Company’s net cash flows (the “Incentive Fee”) if, after the stockholders have received, together as a collective group, aggregate distributions (including distributions that may constitute a return of capital for federal income tax purposes) sufficient to provide (i) a return of their net invested capital, or the amount calculated by multiplying the total number of shares purchased by stockholders by the issue price, reduced by any amounts to repurchase shares pursuant to the share redemption program, and (ii) a 7.0% per year cumulative, noncompounded return on such net invested capital, the Advisor is entitled to receive 15.0% of the Company’s net cash flows, whether from continuing operations, net sale proceeds or otherwise. Net sales proceeds means the net cash proceeds realized by the Company after deduction of all expenses incurred in connection with a sale, including disposition fees paid to the Advisor. The 7.0% per year cumulative, noncompounded return on net invested capital is calculated on a daily basis. In making this calculation, the net invested capital is reduced to the extent distributions in excess of a cumulative, noncompounded, annual return of 7.0% are paid (from whatever source), except to the extent such distributions would be required to supplement prior distributions paid in order to achieve a cumulative, noncompounded, annual return of 7.0% (invested capital is only reduced as described in this sentence; it is not reduced simply because a distribution constitutes a return of capital for federal income tax purposes). The 7.0% per year cumulative, noncompounded return is not based on the return provided to any individual stockholder. Accordingly, it is not necessary for each of the stockholders to have received any minimum return in order for the Advisor to participate in the Company’s net cash flows. In fact, if the Advisor is entitled to participate in the Company’s net cash flows, the returns of the stockholders will differ, and some may be less than a 7.0% per year cumulative, noncompounded return. This fee is payable only if we are not listed on an exchange. On April 4, 2018, the Company’s stockholders approved the acceleration of the payment of such incentive compensation, subject to certain conditions. Such accelerated payment would require approval by a special committee of the Company’s board of directors in connection with the anticipated conversion of the Company into a net asset value REIT. The Advisor estimated the fair value of this liability to be as much as $43 million as of September 30, 2018 , based on a hypothetical liquidation of the assets and liabilities at their estimated fair values, after considering the impact of any potential closing costs and fees related to the disposition of real estate properties. The fair value of the Incentive Fee liability as of September 30, 2018 is based on the estimated fair values of the Company’s assets and liabilities as of that date and changes to the fair values of assets and liabilities could have a material impact to the Incentive Fee calculation. The Incentive Fee is not currently payable to the Advisor, as it remains subject to further approval by the special committee and the Company’s conversion to a perpetual-life NAV REIT, and there is no guarantee that it will ever be payable.

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	9 Months Ended
	Sep. 30, 2018
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS The Company evaluates subsequent events up until the date the consolidated financial statements are issued. Partial Real Estate Land Sale Subsequent to September 30, 2018 Park Highlands On October 16, 2018 , the Company sold approximately 15 developable acres of Park Highlands undeveloped land for an aggregate sales price of $3.5 million , excluding closing costs. The purchasers are not affiliated with the Company or the Advisor.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Basis of Presentation	The accompanying unaudited consolidated financial statements and condensed notes thereto have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information as contained within the FASB Accounting Standards Codification (“ASC”) and the rules and regulations of the SEC, including the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, the unaudited consolidated financial statements do not include all of the information and footnotes required by GAAP for audited financial statements. In the opinion of management, the financial statements for the unaudited interim periods presented include all adjustments, which are of a normal and recurring nature, necessary for a fair and consistent presentation of the results for such periods. Operating results for the three and nine months ended September 30, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018 .
Principles of Consolidation	The consolidated financial statements include the accounts of the Company, REIT Holdings, the Operating Partnership, KBS Strategic Opportunity BVI and their direct and indirect wholly owned subsidiaries, and joint ventures in which the Company has a controlling interest. All significant intercompany balances and transactions are eliminated in consolidation.
Use of Estimates	The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could materially differ from those estimates.
Redeemable Common Stock	The Company has adopted a share redemption program that may enable stockholders to sell their shares to the Company in limited circumstances. Pursuant to the share redemption program there are several limitations on the Company’s ability to redeem shares: • Unless the shares are being redeemed in connection with a stockholder’s death, “qualifying disability” or “determination of incompetence” (each as defined under the share redemption program), the Company may not redeem shares until the stockholder has held the shares for one year. • During each calendar year, redemptions are limited to the amount of net proceeds from the sale of shares under the dividend reinvestment plan during the prior calendar year. • The Company may not redeem more than $3.0 million of shares in a given quarter (excluding shares redeemed in connection with a stockholder’s death, “qualifying disability” or “determination of incompetence”). To the extent that the Company redeems less than $3.0 million of shares (excluding shares redeemed in connection with a stockholder’s death, “qualifying disability” or “determination of incompetence”) in a given fiscal quarter, any remaining excess capacity to redeem shares in such fiscal quarter will be added to the Company’s capacity to otherwise redeem shares (excluding shares redeemed in connection with a stockholder’s death, “qualifying disability” or “determination of incompetence”) during succeeding fiscal quarters. The last $1.0 million of net proceeds from the dividend reinvestment plan during the prior year is reserved exclusively for shares redeemed in connection with a stockholder’s death, “qualifying disability,” or “determination of incompetence”. The share redemption plan also provides that, to the extent that in the last month of any calendar year the amount of redemption requests in connection with a stockholder’s death, “qualifying disability or “determination of incompetence” is less than the $1.0 million reserved for such redemptions under the share redemption plan, any excess funds may be used to redeem shares not requested in connection with a stockholder’s death, “qualifying disability or “determination of incompetence” during such month. The Company may increase or decrease this limit upon ten business days’ notice to stockholders. The Company’s board of directors may approve an increase in this limit to the extent that the Company has received proceeds from asset sales or the refinancing of debt or for any other reason deemed appropriate by the board of directors. On August 9, 2018, the Company’s board of directors approved an additional $6.0 million of funds available for the redemption of shares in 2018. Based on the amount of net proceeds raised from the sale of shares under the dividend reinvestment plan during 2017 and the additional $6.0 million made available by the Company’s board of directors, the Company had $3.0 million available for all share redemption requests for the remainder of 2018 as of September 30, 2018 . • During any calendar year, the Company may redeem no more than 5% of the weighted-average number of shares outstanding during the prior calendar year. • The Company has no obligation to redeem shares if the redemption would violate the restrictions on distributions under Maryland law, which prohibits distributions that would cause a corporation to fail to meet statutory tests of solvency. Effective December 30, 2016, pursuant to the tenth amended and restated share redemption program, except for redemptions made upon a stockholder’s death, “qualifying disability” or “determination of incompetence”, the price at which the Company began to redeem shares is 95% of the Company’s most recent estimated value per share as of the applicable redemption date. Upon the death, “qualifying disability” or “determination of incompetence” of a stockholder, the redemption price continued to be equal to the Company’s most recent estimated value per share. The Company’s board of directors may amend, suspend or terminate the share redemption program with ten business days’ notice to its stockholders. The Company may provide this notice by including such information in a Current Report on Form 8-K or in the Company’s annual or quarterly reports, all publicly filed with the SEC, or by a separate mailing to its stockholders. In anticipation of a self-tender offer in order to make liquidity available to stockholders in excess of that permitted under the share redemption program, on March 14, 2018 , the Company’s board of directors approved a temporary suspension of the share redemption program starting with the March 2018 redemption period, including any unsatisfied requests from prior redemption periods. In connection with its approval of the Self-Tender (defined below), the Company’s board of directors approved the reopening of the share redemption program for the June 2018 redemption period, meaning no redemptions were made in March, April or May 2018 (including those requested following a stockholder’s death, qualifying disability or determination of incompetence). On April 23, 2018 , the Company commenced a self-tender offer (the “Self-Tender”) for up to 8,234,217 shares of common stock at a price of $10.93 per share, or approximately $90.0 million of shares. The Company increased the number of shares accepted for payment in the Self-Tender by up to 1,294,910 shares at a price of $10.93 per share, or approximately $14.1 million of shares. On June 1, 2018 , the Company accepted for purchase 9,527,724 shares at a purchase price of $10.93 per share, or approximately $104.1 million of shares, excluding fees and expenses related to the Self-Tender. The Company records amounts that are redeemable under the share redemption program as redeemable common stock in its consolidated balance sheets because the shares will be redeemable at the option of the holder and therefore their redemption will be outside the control of the Company. However, because the amounts that can be redeemed will be determinable and only contingent on an event that is likely to occur (e.g., the passage of time), the Company presents the net proceeds from the current year and prior year DRP, net of current year redemptions, as redeemable common stock in its consolidated balance sheets. The Company classifies as liabilities financial instruments that represent a mandatory obligation of the Company to redeem shares. The Company’s redeemable common shares are redeemable at the option of the holder. When the Company determines it has a mandatory obligation to repurchase shares under the share redemption program, it will reclassify such obligations from temporary equity to a liability based upon their respective settlement values. The Company limits the dollar value of shares that may be redeemed under the program as described above. During the nine months ended September 30, 2018 , the Company had redeemed $16.1 million of common stock, of which $4.4 million relates to delayed December 2017 redemptions. The Company recorded $4.4 million and $8.6 million of other liabilities on the Company’s balance sheet as of September 30, 2018 and December 31, 2017 , respectively, related to unfulfilled redemption requests received in good order under the share redemption program. Based on the amount of net proceeds raised from the sale of shares under the dividend reinvestment plan during 2017 and the additional $6.0 million made available by the Company’s board of directors, the Company has $3.0 million available for redemptions in the remainder of 2018 as of September 30, 2018 , including shares that are redeemed in connection with a stockholders’ death, “qualifying disability” or “determination of incompetence,” subject to the limitations described above.
Revenue Recognition	Effective January 1, 2018, the Company adopted ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) (“ASU No. 2014-09”), using the modified retrospective approach, which requires a cumulative effect adjustment as of the date of the Company’s adoption. Under the modified retrospective approach, an entity may also elect to apply this standard to either (i) all contracts as of January 1, 2018 or (ii) only to contracts that were not completed as of January 1, 2018. A completed contract is a contract for which all (or substantially all) of the revenue was recognized under legacy GAAP that was in effect before the date of initial application. The Company elected to apply this standard only to contracts that were not completed as of January 1, 2018. Based on the Company’s evaluation of contracts within the scope of ASU No. 2014-09, revenue that is impacted by ASU No. 2014-09 includes revenue generated by sales of real estate, other operating income and tenant reimbursements for substantial services earned at the Company’s properties. The recognition of such revenue will occur when the services are provided and the performance obligations are satisfied. For the three and nine months ended September 30, 2018 , tenant reimbursements for substantial services accounted for under ASU No. 2014-09 were $0.5 million and $1.4 million , respectively, which were included in tenant reimbursements on the accompanying statements of operations.
Revenue Recognition, Sale of Real Estate	Prior to January 1, 2018, gains on real estate sold were recognized using the full accrual method at closing when collectibility of the sales price was reasonably assured, the Company was not obligated to perform additional activities that may be considered significant, the initial investment from the buyer was sufficient and other profit recognition criteria had been satisfied. Gain on sales of real estate may have been deferred in whole or in part until the requirements for gain recognition had been met. Effective January 1, 2018, the Company adopted the guidance of ASC 610-20, Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (“ASC 610-20”), which applies to sales or transfers to noncustomers of nonfinancial assets or in substance nonfinancial assets that do not meet the definition of a business. Generally, the Company’s sales of real estate would be considered a sale of a nonfinancial asset as defined by ASC 610-20. ASC 610-20 refers to the revenue recognition principles under ASU No. 2014-09. Under ASC 610-20, if the Company determines it does not have a controlling financial interest in the entity that holds the asset and the arrangement meets the criteria to be accounted for as a contract, the Company would derecognize the asset and recognize a gain or loss on the sale of the real estate when control of the underlying asset transfers to the buyer. As a result of the adoption of ASC 610-20 on January 1, 2018, the Company recorded a cumulative effect adjustment to increase retained earnings by $2.5 million to recognize the deferred gain from the sale of 102 developable acres at Park Highlands that closed on May 1, 2017, as control of the sold acres had transferred to the buyers at closing. As of January 1, 2018 and September 30, 2018 , the Company had recorded contract liabilities of $1.7 million and $3.1 million , respectively, related to deferred proceeds received from the buyers of the Park Highlands land sales and another developer for the value of land that was contributed to a master association that is consolidated by the Company, which was included in other liabilities on the accompanying consolidated balance sheets.
Real Estate Equity Securities	The Company’s real estate equity securities are carried at their estimated fair value based on quoted market prices for the security, net of any discounts for restrictions on the sale of the security. Any discount for lack of marketability is estimated using an option pricing model. Transaction costs that are directly attributable to the acquisition of real estate equity securities are capitalized to its cost basis. Prior to the Company’s adoption of ASU No. 2016-01, Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU No. 2016-01”) on January 1, 2018, the Company classified its investments in real estate equity securities as available-for-sale and unrealized gains and losses were reported in accumulated other comprehensive income (loss). Upon the sale of a security, the previously recognized unrealized gain (loss) would be reversed out of accumulated other comprehensive income (loss) and the actual realized gain (loss) recognized in earnings. Effective January 1, 2018, unrealized gains and losses on real estate equity securities are recognized in earnings. Upon adoption of ASU No. 2016-01 on January 1, 2018, the Company recorded a $25.1 million cumulative effect adjustment to retained earnings related to the unrealized gain on real estate equity securities previously reported in accumulated other comprehensive income prior to January 1, 2018.
Investment in Unconsolidated Joint Ventures	Equity Investment Without Readily Determinable Value Prior to the adoption of ASU No. 2016-01 on January 1, 2018, the Company accounted for investments in unconsolidated joint venture entities in which the Company did not have the ability to exercise significant influence and had virtually no influence over partnership operating and financial policies using the cost method of accounting. Under the cost method, income distributions from the partnership were recognized in other income. Distributions that exceed the Company’s share of earnings were applied to reduce the carrying value of the Company’s investment and any capital contributions increased the carrying value of the Company’s investment. On a quarterly basis, the Company evaluated its cost method investment in an unconsolidated joint venture for other-than-temporary impairments. The fair value of a cost method investment was not estimated if there were no identified events or changes in circumstances that indicated a significant adverse effect on the fair value of the investment. In accordance with ASU No. 2016-01, the Company may elect to measure an equity investment without a readily determinable value that does not qualify for the practical expedient to estimate fair value using the net asset value per share, at its cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer. The Company elected to measure its investment in the NIP Joint Venture (defined in Note 12 ) in accordance with the above guidance, applying it prospectively, and as of January 1, 2018 and September 30, 2018 , recorded its investment in the NIP Joint Venture at a cost basis of $3.7 million and $1.5 million , respectively. Distributions of income from the NIP Joint Venture are recognized in other income. Distributions that exceed the Company’s share of earnings are applied to reduce the carrying value of the Company’s investment and any capital contributions would increase the carrying value of the Company’s investment.
Reclassifications	Certain amounts in the Company’s prior period consolidated financial statements have been reclassified to conform to the current period presentation. These reclassifications have not changed the results of operations of the prior period. During the nine months ended September 30, 2018 , the Company disposed of one office building. As a result, certain assets and liabilities were reclassified as held for sale on the consolidated balance sheets for all periods presented.
Segments	The Company has invested in opportunistic real estate and other real estate-related assets. In general, the Company intends to hold its investments in opportunistic real estate and other real estate‑related assets for capital appreciation. Traditional performance metrics of opportunistic real estate and other real estate-related assets may not be meaningful as these investments are generally non-stabilized and do not provide a consistent stream of interest income or rental revenue. These investments exhibit similar long-term financial performance and have similar economic characteristics. These investments typically involve a higher degree of risk and do not provide a constant stream of ongoing cash flows. As a result, the Company’s management views opportunistic real estate and other real estate-related assets as similar investments. Substantially all of its revenue and net income (loss) is from opportunistic real estate and other real estate-related assets, and therefore, the Company currently aggregates its operating segments into one reportable business segment.
Per Share Data	Basic net income (loss) per share of common stock is calculated by dividing net income (loss) attributable to common stockholders by the weighted-average number of shares of common stock issued and outstanding during such period. Diluted net income (loss) per share of common stock equals basic net income (loss) per share of common stock as there were no potentially dilutive securities outstanding during the three and nine months ended September 30, 2018 and 2017 .
Square Footage, Occupancy and Other Measures	Any references to square footage, occupancy or annualized base rent are unaudited and outside the scope of the Company’s independent registered public accounting firm’s review of the Company’s financial statements in accordance with the standards of the United States Public Company Accounting Oversight Board.
Recently Issued Accounting Standards Updates	In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (“ASU No. 2016-02”). The amendments in ASU No. 2016-02 change the existing accounting standards for lease accounting, including requiring lessees to recognize most leases on their balance sheets and making targeted changes to lessor accounting. ASU No. 2016-02 is effective for annual periods beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption of ASU No. 2016-02 as of its issuance is permitted. ASU No. 2016-02 requires a modified retrospective transition approach for all leases existing at, or entered into after, the date of initial application, with an option to use certain transition relief. Upon adoption of ASU No. 2016-02, the Company expects to adopt the package of practical expedients for all leases that commenced before the effective date of January 1, 2019. Accordingly, the Company will 1) not reassess whether any expired or existing contracts are or contain leases, 2) not reassess the lease classification for any expired or existing lease, and 3) not reassess initial direct costs for any existing leases. The Company does not expect to elect the practical expedient related to using hindsight to reevaluate the lease term. In addition, the Company expects to adopt the practical expedient for land easements to not assess whether existing or expired land easements that were not previously accounted for as leases under the current lease accounting standards of Topic 840 are or contain a lease under Topic 842. In July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842), Targeted Improvements (“ASU No. 2018-11”), which provides lessors with a practical expedient, by class of underlying asset, to not separate nonlease components from the associated lease component and, instead to account for those components as a single component if the nonlease components otherwise would be accounted for under the new revenue recognition standard (Topic 606) and if certain conditions are met. Upon adoption of the lease accounting standard under Topic 842, the Company expects to adopt this practical expedient, specifically related to its tenant reimbursements which would otherwise be accounted for under the new revenue recognition standard. The Company believes the two conditions have been met for tenant reimbursements as 1) the timing and pattern of transfer of the nonlease components and associated lease components are the same and 2) the lease component would be classified as an operating lease. In addition, ASU No. 2018-11 provides an additional optional transition method to allow entities to apply the new lease accounting standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings. An entity’s reporting for the comparative periods presented in the financial statements in which it adopts the new lease accounting standard will continue to be reported under the current lease accounting standards of Topic 840. The Company expects to adopt this transition method upon adoption of the lease accounting standard of Topic 842 on January 1, 2019. The Company is currently evaluating the impact of adopting the new lease accounting standards on its consolidated financial statements. The Company is in process of creating an inventory of its leases where the Company may be a lessee to assess the potential impact to the Company’s financial statements upon adoption of the new lease accounting standards. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses of Financial Instruments (“ASU No. 2016-13”). ASU No. 2016-13 affects entities holding financial assets and net investments in leases that are not accounted for at fair value through net income. The amendments in ASU No. 2016-13 require a financial asset (or a group of financial assets) measured at amortized cost basis to be presented at the net amount expected to be collected. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial asset(s) to present the net carrying value at the amount expected to be collected on the financial asset. ASU No. 2016-13 also amends the impairment model for available-for-sale debt securities. An entity will recognize an allowance for credit losses on available-for-sale debt securities as a contra-account to the amortized cost basis rather than as a direct reduction of the amortized cost basis of the investment, as is currently required. ASU No. 2016-13 also requires new disclosures. For financial assets measured at amortized cost, an entity will be required to disclose information about how it developed its allowance for credit losses, including changes in the factors that influenced management’s estimate of expected credit losses and the reasons for those changes. For financing receivables and net investments in leases measured at amortized cost, an entity will be required to further disaggregate the information it currently discloses about the credit quality of these assets by year of the asset’s origination for as many as five annual periods. For available-for-sale debt securities, an entity will be required to provide a roll-forward of the allowance for credit losses and an aging analysis for securities that are past due. ASU No. 2016-13 is effective for annual periods beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company is still evaluating the impact of adopting ASU No. 2016-13 on its financial statements. In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework -Changes to the Disclosure Requirements for Fair Value Measurement (“ASU No. 2018-13”). The primary focus of ASU 2018-13 is to improve the effectiveness of the disclosure requirements for fair value measurements. ASU No. 2018-13 removes the requirement to disclose the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, the policy for the timing of transfers between levels and the valuation processes for Level 3 fair value measurements. It also adds a requirement to disclose changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period and to disclose the range and weighted average of significant unobservable inputs used to develop recurring and nonrecurring Level 3 fair value measurements. For certain unobservable inputs, entities may disclose other quantitative information in lieu of the weighted average if the other quantitative information would be a more reasonable and rational method to reflect the distribution of unobservable inputs used to develop the Level 3 fair value measurement. In addition, public entities are required to provide information about the measurement uncertainty of recurring Level 3 fair value measurements from the use of significant unobservable inputs if those inputs reasonably could have been different at the reporting date. ASU No. 2018-13 is effective for annual periods beginning after December 15, 2019, including interim periods within those fiscal years. Entities are permitted to early adopt either the entire standard or only the provisions that eliminate or modify the requirements. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. The Company is still evaluating the impact of adopting ASU No. 2018-13 on its financial statements, but does not expect the adoption of ASU No. 2018-13 to have a material impact on its financial statements.
Fair Value Measurements	Cash and cash equivalents, restricted cash, rent and other receivables and accounts payable and accrued liabilities: These balances approximate their fair values due to the short maturities of these items. Real estate equity securities : The Company’s Whitestone REIT and Franklin Street Properties Corp. real estate equity securities are presented at fair value on the accompanying consolidated balance sheet. The fair values of Whitestone REIT and Franklin Street Properties Corp. real estate equity securities were based on quoted prices in an active market on a major stock exchange. The Company classifies these inputs as Level 1 inputs. As of December 31, 2017, the Company owned 43,999,500 shares of common units of Keppel-KBS US REIT. The fair value measurement of these shares was based on a quoted price in an active market, adjusted for the lack of marketability during the Unit Lockout Periods. On May 8, 2018, 21,999,750 shares of common units of Keppel-KBS US REIT were transfered from Level 2 to Level 1 inputs as a result of the Unit Lockout Period expiring. As of September 30, 2018 , the Company owned 43,999,500 shares of common units of Keppel-KBS US REIT. The fair value measurement on 21,999,750 shares are based on a quoted price in an active market on a major stock exchange. The Company classifies these inputs as Level 1 inputs. The fair value measurement on the remaining 21,999,750 shares are based on a quoted price in an active market on a major stock exchange, adjusted for the lack of marketability during the remaining Unit Lockout Period. The Company utilized inputs, all of which were deemed to be significant, including the quoted stock price, risk-free rate and expected volatility, in determining the value of the shares and the Company notes that the most significant input in its valuation model is the quoted price in an active market. However, as the valuation of the stock is adjusted for the lack of marketability using market-corroborated inputs, the Company categorizes the measurement of such securities as Level 2 inputs. Real estate debt securities : The Company’s real estate debt securities are presented in the accompanying consolidated balance sheets at their amortized cost net of recorded loss reserves (if any) and not at fair value. The fair value of real estate debt securities was estimated using an internal valuation model that considers the expected cash flows for the loans, underlying collateral values (for collateral dependent loans) and estimated yield requirements of institutional investors for real estate debt securities with similar characteristics, including remaining loan term, loan-to-value, type of collateral and other credit enhancements. The Company classifies these inputs as Level 3 inputs. Notes and bonds payable: The fair values of the Company’s notes and bonds payable are estimated using a discounted cash flow analysis based on management’s estimates of current market interest rates for instruments with similar characteristics, including remaining loan term, loan-to-value ratio, type of collateral and other credit enhancements. Additionally, when determining the fair value of liabilities in circumstances in which a quoted price in an active market for an identical liability is not available, the Company measures fair value using (i) a valuation technique that uses the quoted price of the identical liability when traded as an asset or quoted prices for similar liabilities or similar liabilities when traded as assets or (ii) another valuation technique that is consistent with the principles of fair value measurement, such as the income approach or the market approach. The Company classifies these inputs as Level 3 inputs. The Company’s bonds issued in Israel are publicly traded on the Tel-Aviv Stock Exchange. The Company used the quoted price as of September 30, 2018 for the fair value of its bonds issued in Israel. The Company classifies this input as a Level 1 input. Derivative instruments : The Company’s derivative instruments are presented at fair value on the accompanying consolidated balance sheets. The valuation of these instruments is determined using a proprietary model that utilizes observable inputs. As such, the Company classifies these inputs as Level 2 inputs. The fair value of interest rate caps (floors) are determined using the market standard methodology of discounting the future expected cash payments (receipts) which would occur if variable interest rates rise above (below) the strike rate of the caps (floors). The variable interest rates used in the calculation of projected payments (receipts) on the cap (floor) are based on an expectation of future interest rates derived from observed market interest rate curves and volatilities. The fair value of foreign currency option and collar is based on a Black-Scholes model tailored for currency derivatives.

REAL ESTATE HELD FOR INVESTME_2

REAL ESTATE HELD FOR INVESTMENT (Tables)	9 Months Ended
	Sep. 30, 2018
Real Estate [Abstract]
Schedule of Real Estate Investments	The Company’s highest tenant industry concentrations (greater than 10% of annualized base rent) were as follows: Industry Number of Tenants Annualized Base Rent (1) (in thousands) Percentage of Annualized Base Rent Health Care and Social Services 15 $ 6,659 10.1 % _____________________ (1) Annualized base rent represents annualized contractual base rental income as of September 30, 2018 , adjusted to straight-line any contractual tenant concessions (including free rent), rent increases and rent decreases from the lease’s inception through the balance of the lease term. The following table summarizes the Company’s real estate held for investment as of September 30, 2018 and December 31, 2017 , respectively (in thousands): September 30, 2018 December 31, 2017 Land $ 192,765 $ 155,046 Buildings and improvements 628,748 361,118 Tenant origination and absorption costs 39,315 23,212 Total real estate, cost 860,828 539,376 Accumulated depreciation and amortization (56,749 ) (37,154 ) Total real estate, net $ 804,079 $ 502,222 The following table provides summary information regarding the Company’s real estate held for investment as of September 30, 2018 (in thousands): Property Date Acquired or Foreclosed on City State Property Type Land Building Tenant Origination and Absorption Total Real Estate, at Cost Accumulated Depreciation and Amortization Total Real Estate, Net Ownership % Richardson Portfolio: Palisades Central I 11/23/2011 Richardson TX Office $ 1,037 $ 10,714 $ — $ 11,751 $ (2,646 ) $ 9,105 90.0 % Palisades Central II 11/23/2011 Richardson TX Office 810 17,954 — 18,764 (4,115 ) 14,649 90.0 % Greenway I 11/23/2011 Richardson TX Office 561 2,084 — 2,645 (711 ) 1,934 90.0 % Greenway III 11/23/2011 Richardson TX Office 702 4,068 559 5,329 (1,953 ) 3,376 90.0 % Undeveloped Land 11/23/2011 Richardson TX Undeveloped Land 3,134 — — 3,134 — 3,134 90.0 % Total Richardson Portfolio 6,244 34,820 559 41,623 (9,425 ) 32,198 Park Highlands (1) 12/30/2011 North Las Vegas NV Undeveloped Land 29,845 — — 29,845 — 29,845 (1) Burbank Collection 12/12/2012 Burbank CA Retail 4,175 12,544 725 17,444 (2,960 ) 14,484 90.0 % Park Centre 03/28/2013 Austin TX Office 3,251 27,841 — 31,092 (4,361 ) 26,731 100.0 % 1180 Raymond 08/20/2013 Newark NJ Apartment 8,292 38,372 — 46,664 (6,305 ) 40,359 100.0 % Park Highlands II 12/10/2013 North Las Vegas NV Undeveloped Land 25,532 — — 25,532 — 25,532 100.0 % 424 Bedford 01/31/2014 Brooklyn NY Apartment 8,860 25,909 — 34,769 (3,405 ) 31,364 90.0 % Richardson Land II 09/04/2014 Richardson TX Undeveloped Land 3,418 — — 3,418 — 3,418 90.0 % Westpark Portfolio 05/10/2016 Redmond WA Office/Flex/Industrial 36,085 93,362 6,352 135,799 (11,681 ) 124,118 100.0 % Crown Pointe 02/14/2017 Dunwoody GA Office 22,590 63,662 5,528 91,780 (6,855 ) 84,925 100.0 % 125 John Carpenter 09/15/2017 Irving TX Office 2,755 76,368 8,840 87,963 (4,636 ) 83,327 100.0 % Marquette Plaza 03/01/2018 Minneapolis MN Office 10,387 72,094 4,405 86,886 (2,265 ) 84,621 100.0 % City Tower 03/06/2018 Orange CA Office 13,930 129,713 8,120 151,763 (3,964 ) 147,799 100.0 % Eight & Nine Corporate Centre 06/08/2018 Franklin TN Office 17,401 54,063 4,786 76,250 (892 ) 75,358 100.0 % $ 192,765 $ 628,748 $ 39,315 $ 860,828 $ (56,749 ) $ 804,079 _____________________ (1) On September 7, 2016, a subsidiary of the Company that owns a portion of Park Highlands, sold 820 units of 10% Class A non-voting preferred membership units for $0.8 million to accredited investors. The amount of the Class A non-voting preferred membership units raised, net of offering costs, is included in other liabilities on the accompanying consolidated balance sheets.
Schedule of Future Minimum Rental Income for Company's Properties	As of September 30, 2018 , the future minimum rental income from the Company’s properties, excluding apartment leases, under non-cancelable operating leases was as follows (in thousands): October 1, 2018 through December 31, 2018 $ 15,168 2019 61,898 2020 56,312 2021 49,918 2022 42,432 Thereafter 138,775 $ 364,503

TENANT ORIGINATION AND ABSORP_2

TENANT ORIGINATION AND ABSORPTION COSTS, ABOVE-MARKET LEASE ASSETS AND BELOW-MARKET LEASE LIABILITIES (Tables)	9 Months Ended
	Sep. 30, 2018
Tenant Origination and Absorption Costs, Above-Market Lease Assets and Below-Market Lease Liabilities [Abstract]
Tenant Origination and Absorption Costs, Above-Market Lease Assets and Below-Market Lease Liabilities	As of September 30, 2018 and December 31, 2017 , the Company’s tenant origination and absorption costs, above-market lease assets and below-market lease liabilities (excluding fully amortized assets and liabilities and accumulated amortization) were as follows (in thousands): Tenant Origination and Absorption Costs Above-Market Lease Assets Below-Market Lease Liabilities September 30, 2018 December 31, 2017 September 30, 2018 December 31, 2017 September 30, 2018 December 31, 2017 Cost $ 39,315 $ 23,212 $ 3,731 $ 17 $ (7,222 ) $ (3,636 ) Accumulated Amortization (10,281 ) (5,733 ) (246 ) (7 ) 1,668 793 Net Amount $ 29,034 $ 17,479 $ 3,485 $ 10 $ (5,554 ) $ (2,843 )
Amortization of Tenant Origination and Absorption Costs, Above-Market Leases and Below-Market Lease Liabilities	Increases (decreases) in net income as a result of amortization of the Company’s tenant origination and absorption costs, above-market lease assets and below-market lease liabilities for the three and nine months ended September 30, 2018 and 2017 were as follows (in thousands): Tenant Origination and Above-Market Below-Market For the Three Months Ended September 30, For the Three Months Ended September 30, For the Three Months Ended September 30, 2018 2017 2018 2017 2018 2017 Amortization $ (2,312 ) $ (2,190 ) $ (104 ) $ (62 ) $ 457 $ 278 Tenant Origination and Above-Market Below-Market For the Nine Months Ended For the Nine Months Ended For the Nine Months Ended 2018 2017 2018 2017 2018 2017 Amortization $ (5,937 ) $ (8,268 ) $ (259 ) $ (229 ) $ 1,112 $ 2,482

REAL ESTATE EQUITY SECURITIES (

REAL ESTATE EQUITY SECURITIES (Tables)	9 Months Ended
	Sep. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Schedule of Real Estate Equity Securities	The following table sets forth the number of shares owned by the Company and the related carrying value of the shares as of September 30, 2018 and December 31, 2017 (dollars in thousands): September 30, 2018 December 31, 2017 Real Estate Equity Security Number of Shares Owned Total Carrying Value Number of Shares Owned Total Carrying Value Whitestone REIT 3,722,019 $ 51,662 3,603,189 $ 51,922 Keppel-KBS US REIT 43,999,500 34,474 43,999,500 38,141 Franklin Street Properties Corp. 1,576,809 12,599 — — 49,298,328 $ 98,735 47,602,689 $ 90,063
Schedule of Activity of Real Estate Securities	The following summarizes the activity related to real estate equity securities for the nine months ended September 30, 2018 (in thousands): Amortized Cost Basis Unrealized Gain (Loss) (1) Total Real estate equity securities - December 31, 2017 $ 64,917 $ 25,146 $ 90,063 Acquisition of real estate equity securities 15,676 — 15,676 Acquisition fee to affiliate and purchase commission 175 — 175 Disposition of real estate equity securities (554 ) (79 ) (633 ) Loss on real estate equity securities — (6,546 ) (6,546 ) Real estate equity securities - September 30, 2018 $ 80,214 $ 18,521 $ 98,735 _____________________ (1) As of December 31, 2017 , unrealized gain (loss) due to the change in market value of real estate equity securities was recorded to accumulated other comprehensive income. Effective January 1, 2018, upon the adoption of ASU No. 2016-01, unrealized gain (losses) on real estate equity securities are recorded in earnings on the accompanying consolidated statement of operations.
Gain (Loss) on Investments	The following summarizes the portion of gain and loss for the period related to real estate equity securities held during the three and nine months ended September 30, 2018 (in thousands): For the Three Months Ended September 30, 2018 For the Nine Months Ended September 30, 2018 Net gain (loss) recognized during the period on real estate equity securities $ 741 $ (6,546 ) Less: Net gain (loss) recognized during the period on real estate equity securities sold during the period 57 (32 ) Unrealized gain (loss) recognized during the reporting period on real estate equity securities still held at September 30, 2018 $ 684 $ (6,514 )

REAL ESTATE DEBT SECURITIES (Ta

REAL ESTATE DEBT SECURITIES (Tables)	9 Months Ended
	Sep. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Schedule of Activity of Real Estate Debt Securities	As of September 30, 2018 , the Company owned an investment in real estate debt securities. The Company’s investment in real estate debt securities is classified as held to maturity, as the Company has the intent and ability to hold its investment until maturity, and it is not more likely than not that the Company would be required to sell its investment before recovery of the Company’s amortized cost basis. The information for those real estate debt securities as of September 30, 2018 and December 31, 2017 is set forth below (in thousands): Debt Securities Name Dates Acquired Debt Securities Type Outstanding Principal Balance as of September 30, 2018 (1) Book Value as of September 30, 2018 (2) Book Value as of December 31, 2017 (2) Contractual Interest Rate (3) Annualized Effective Interest Rate (3) Maturity Date Battery Point Series B Preferred Units (4) 10/28/2016 / 03/30/2017 / 05/12/2017 Series B Preferred Units $ 17,500 $ 17,855 $ 17,751 12.0 % 11.1 % 10/28/2019 _____________________ (1) Outstanding principal balance as of September 30, 2018 represents principal balance outstanding under the real estate debt securities. (2) Book value of the real estate debt securities represents outstanding principal balance adjusted for unamortized acquisition discounts, origination fees and direct origination and acquisition costs and additional interest accretion. (3) Contractual interest rate is the stated interest rate on the face of the real estate securities. Annualized effective interest rate is calculated as the actual interest income recognized in 2018 , using the interest method, annualized (if applicable) and divided by the average amortized cost basis of the investment. The annualized effective interest rate and contractual interest rate presented are as of September 30, 2018 . (4) On October 31, 2018 , the Company received a partial principal prepayment of the real estate debt securities in the amount of $4.5 million . The following summarizes the activity related to real estate debt securities for the nine months ended September 30, 2018 (in thousands): Real estate debt securities - December 31, 2017 $ 17,751 Deferred interest receivable and interest accretion 68 Accretion of commitment fee, net of closing costs 36 Real estate debt securities - September 30, 2018 $ 17,855
Schedule of Interest Income from Real Estate Debt Securities	For the three and nine months ended September 30, 2018 and 2017 , interest income from real estate debt securities consisted of the following (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Contractual interest income $ 537 $ 403 $ 1,421 $ 815 Interest (amortization) accretion (37 ) 97 68 218 Accretion of commitment fee, net of closing costs and acquisition fee 13 11 36 238 Interest income from real estate debt securities $ 513 $ 511 $ 1,525 $ 1,271

REAL ESTATE SALES (Tables)

REAL ESTATE SALES (Tables)	9 Months Ended
	Sep. 30, 2018
Discontinued Operations and Disposal Groups [Abstract]
Schedule of Assets and Liabilities of Real Estate Held-for-Sale	The following summary presents the major components of assets and liabilities related to real estate held for sale as of September 30, 2018 and December 31, 2017 (in thousands): September 30, 2018 December 31, 2017 Assets related to real estate held for sale Real estate, cost $ — $ 35,308 Accumulated depreciation and amortization — (4,663 ) Real estate, net — 30,645 Other assets — 1,965 Total assets related to real estate held for sale $ — $ 32,610 Liabilities related to real estate held for sale Notes payable, net — 27,515 Total liabilities related to real estate held for sale $ — $ 27,515
Schedule of Revenue and Expenses of Real Estate Held-for-Sale	The following table summarizes certain revenue and expenses related to these properties for the three and nine months ended September 30, 2018 and 2017 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Revenues Rental income $ 185 $ 17,129 $ 2,255 $ 53,262 Tenant reimbursements and other operating income 16 5,028 267 15,511 Total revenues $ 201 $ 22,157 $ 2,522 $ 68,773 Expenses Operating, maintenance, and management $ 20 $ 6,702 $ 453 $ 19,453 Real estate taxes and insurance (137 ) 3,170 150 9,649 Asset management fees to affiliate 79 1,371 351 4,197 Depreciation and amortization — 8,064 483 24,296 Interest expense 83 3,843 623 10,843 Total expenses $ 45 $ 23,150 $ 2,060 $ 68,438

NOTES AND BOND PAYABLE (Tables)

NOTES AND BOND PAYABLE (Tables)	9 Months Ended
	Sep. 30, 2018
Notes and Bonds Payable [Abstract]
Schedule of Long-term Debt Instruments	As of September 30, 2018 and December 31, 2017 , the Company’s notes and bonds payable, including notes payable related to real estate held for sale, consisted of the following (dollars in thousands): Book Value as of September 30, 2018 Book Value as of December 31, 2017 Contractual Interest Rate as of September 30, 2018 (1) Effective Interest Rate at September 30, 2018 (1) Payment Type Maturity Date (2) Richardson Portfolio Mortgage Loan $ 32,435 $ 36,886 One-Month LIBOR + 2.10% 4.20% Principal & Interest 11/01/2018 (3) Portfolio Mortgage Loan (4) 8,772 9,877 One-Month LIBOR + 2.25% 4.36% Principal & Interest 07/01/2019 Burbank Collection Mortgage Loan 10,777 10,958 One-Month LIBOR + 2.35% 4.48% Principal & Interest 09/30/2019 1180 Raymond Bond Payable 6,325 6,460 6.50% 6.50% Principal & Interest 09/01/2036 Central Building Mortgage Loan (5) — 27,600 (5) (5) (5) (5) 424 Bedford Mortgage Loan 23,856 24,282 3.91% 3.91% Principal & Interest 10/01/2022 1180 Raymond Mortgage Loan 30,730 31,000 One-Month LIBOR + 2.25% 4.36% Principal & Interest 12/01/2018 KBS SOR (BVI) Holdings, Ltd. Series A Debentures (6) 266,854 278,801 4.25% 4.25% (6) 03/01/2023 Westpark Portfolio Mortgage Loan 85,020 85,200 One-Month LIBOR + 2.50% 4.60% Interest Only (7) 07/01/2020 Crown Pointe Mortgage Loan 51,171 50,500 One-Month LIBOR + 2.60% 4.70% Interest Only 02/13/2020 125 John Carpenter Mortgage Loan 50,130 50,130 (8) 3.86% Interest Only 10/01/2022 City Tower Mortgage Loan 89,000 — One-Month LIBOR + 1.55% 3.65% Interest Only 03/05/2021 Marquette Plaza Mortgage Loan 50,800 — One-Month LIBOR + 1.55% 3.65% Interest Only 06/06/2021 Eight & Nine Corporate Centre Mortgage Loan 43,880 — One-Month LIBOR + 1.60% 3.70% Interest Only 06/08/2021 Total Notes and Bonds Payable principal outstanding 749,750 611,694 Net Premium/(Discount) on Notes and Bonds Payable (9) 182 137 Deferred financing costs, net (8,803 ) (8,788 ) Total Notes and Bonds Payable, net $ 741,129 $ 603,043 _____________________ (1) Contractual interest rate represents the interest rate in effect under the loan as of September 30, 2018 . Effective interest rate is calculated as the actual interest rate in effect as of September 30, 2018 (consisting of the contractual interest rate and contractual floor rates), using interest rate indices at September 30, 2018 , where applicable. (2) Represents the initial maturity date or the maturity date as extended as of September 30, 2018 ; subject to certain conditions, the maturity dates of certain loans may be extended beyond the date shown. (3) Subsequent to September 30, 2018 , the Richardson Portfolio Mortgage Loan was refinanced. The maturity date of the loan was extended to November 1, 2021, with two one -year extension options, subject to certain conditions contained in the loan documents and the payment of an extension fee. The refinanced loan bears interest at a floating rate of 2.5% over one-month LIBOR. (4) The Portfolio Mortgage Loan is secured by Park Centre. (5) On July 17, 2018, in connection with the disposition of the Central Building, the Company repaid the $27.6 million outstanding principal balance due under the Central Building Mortgage Loan. (6) See “ – Israeli Bond Financing” below. (7) Represents the payment type required under the loan as of September 30, 2018 . Certain future monthly payments due under this loan also include amortizing principal payments. For more information of the Company’s contractual obligations under its notes and bonds payable, see five-year maturity table below. (8) The 125 John Carpenter Mortgage Loan bears interest at a floating rate of the greater of (a) 2.0% or (b) 175 basis points over one-month LIBOR. (9) Represents the unamortized premium/discount on notes and bonds payable due to the above- and below-market interest rates when the debt was assumed. The discount/premium is amortized over the remaining life of the notes and bonds payable.
Schedule of Maturities of Long-term Debt	The following is a schedule of maturities, including principal amortization payments, for all notes and bonds payable outstanding as of September 30, 2018 (in thousands): October 1, 2018 through December 31, 2018 $ 64,024 2019 74,414 2020 189,056 2021 237,929 2022 125,546 Thereafter 58,781 $ 749,750

DERIVATIVE INSTRUMENTS (Tables)

DERIVATIVE INSTRUMENTS (Tables)	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Interest Rate Derivatives	The following table summarizes the notional amount and other information related to the Company’s foreign currency collar and foreign currency option as of September 30, 2018 and December 31, 2017 . The notional amount is an indication of the extent of the Company’s involvement in each instrument at that time, but does not represent exposure to credit, interest rate or market risks (currency in thousands): September 30, 2018 December 31, 2017 Strike Price Trade Date Maturity Date Derivative Instruments Number of Instruments Notional Amount Number of Instruments Notional Amount Derivative instruments not designated as hedging instruments Foreign currency collar 1 776,182 ILS — — 3.54 - 3.66 ILS - USD 08/20/2018 02/28/2019 Foreign currency option — $ — 1 $285,361 3.40 ILS-USD 08/03/2017 08/03/2018 The following table summarizes the notional amounts and other information related to the Company’s derivative instruments as of September 30, 2018 . The notional amount is an indication of the extent of the Company’s involvement in the instrument at that time, but does not represent exposure to credit, interest rate or market risks (dollars in thousands): Derivative Instrument Effective Date Maturity Date Notional Value Reference Rate Interest rate cap 02/21/2017 02/13/2020 $ 46,875 One-month LIBOR at 3.00% Interest rate cap 04/02/2018 03/05/2021 $ 77,513 One-month LIBOR at 3.50%
Schedule of Derivative Instruments in Statement of Financial Position	The following table sets forth the fair value of the Company’s derivative instruments as well as their classification on the consolidated balance sheets as of September 30, 2018 and December 31, 2017 (dollars in thousands): September 30, 2018 December 31, 2017 Derivative Instruments Balance Sheet Location Number of Instruments Fair Value Number of Instruments Fair Value Derivative instruments not designated as hedging instruments Interest rate caps Prepaid expenses and other assets 2 $ 156 1 $ 14 Foreign currency option Prepaid expenses and other assets — — 1 4,243 Foreign currency collar Prepaid expenses and other assets 1 171 — —

FAIR VALUE DISCLOSURES (Tables)

FAIR VALUE DISCLOSURES (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Schedule of Face Value, Carrying Amounts and Fair Value	The following were the face values, carrying amounts and fair values of the Company’s financial instruments as of September 30, 2018 and December 31, 2017 , which carrying amounts do not approximate the fair values (in thousands): September 30, 2018 December 31, 2017 Face Value Carrying Amount Fair Value Face Value Carrying Amount Fair Value Financial asset: Real estate debt securities $ 17,500 $ 17,855 $ 17,459 $ 17,500 $ 17,751 $ 17,386 Financial liabilities: Notes and bond payable $ 482,896 $ 479,296 $ 487,215 $ 332,893 $ 330,727 $ 335,212 KBS SOR (BVI) Holdings, Ltd. Series A Debentures $ 266,854 $ 261,833 $ 271,353 $ 278,801 $ 272,316 $ 296,069
Fair Value, Assets Measured on Recurring Basis	As of September 30, 2018 , the Company measured the following assets at fair value (in thousands): Fair Value Measurements Using Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Recurring Basis: Real estate equity securities $ 98,735 $ 81,641 $ 17,094 $ — Asset derivative - interest rate caps $ 156 $ — $ 156 $ — Asset derivative - foreign currency collar $ 171 $ — $ 171 $ —

RELATED PARTY TRANSACTIONS (Tab

RELATED PARTY TRANSACTIONS (Tables)	9 Months Ended
	Sep. 30, 2018
Related Party Transactions [Abstract]
Schedule of Related Party Costs	Pursuant to the terms of these agreements, summarized below are the related-party costs incurred by the Company for the three and nine months ended September 30, 2018 and 2017 , respectively, and any related amounts payable as of September 30, 2018 and December 31, 2017 (in thousands): Incurred Payable as of Three Months Ended September 30, Nine Months Ended September 30, September 30, 2018 December 31, 2017 2018 2017 2018 2017 Expensed Asset management fees $ 2,299 $ 2,800 $ 6,342 $ 8,404 $ — $ — Reimbursable operating expenses (1) 90 51 288 184 65 26 Disposition fees (2) 860 — 860 785 — — Capitalized Acquisition fees on real estate — 71 3,094 907 — — Acquisition fees on real estate equity securities — 43 157 429 — — $ 3,249 $ 2,965 $ 10,741 $ 10,709 $ 65 $ 26 _____________________ (1) The Advisor may seek reimbursement for certain employee costs under the Advisory Agreement. The Company has reimbursed the Advisor for the Company’s allocable portion of the salaries, benefits and overhead of internal audit department personnel providing services to the Company. These amounts totaled $74,000 and $235,000 for the three and nine months ended September 30, 2018 , respectively, and $49,000 and $168,000 for the three and nine months ended September 30, 2017 , respectively, and were the only employee costs reimbursed under the Advisory Agreement during these periods. The Company will not reimburse for employee costs in connection with services for which the Advisor earns acquisition, origination or disposition fees (other than reimbursement of travel and communication expenses) or for the salaries or benefits the Advisor or its affiliates may pay to the Company’s executive officers. In addition to the amounts above, the Company reimburses the Advisor for certain of the Company’s direct costs incurred from third parties that were initially paid by the Advisor on behalf of the Company. (2) Disposition fees with respect to real estate sold are included in the gain on sale of real estate in the accompanying consolidated statements of operations.

INVESTMENT IN UNCONSOLIDATED _2

INVESTMENT IN UNCONSOLIDATED JOINT VENTURES (Tables)	9 Months Ended
	Sep. 30, 2018
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Investments in Unconsolidated Joint Ventures	Summarized financial information for the 110 William Joint Venture follows (in thousands): September 30, 2018 December 31, 2017 Assets: Real estate assets, net of accumulated depreciation and amortization $ 237,302 $ 248,269 Other assets 39,484 32,331 Total assets $ 276,786 $ 280,600 Liabilities and equity: Notes payable, net $ 266,326 $ 260,108 Other liabilities 8,843 11,016 Partners’ capital 1,617 9,476 Total liabilities and equity $ 276,786 $ 280,600 Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Revenues $ 10,137 $ 9,614 $ 29,897 $ 27,328 Expenses: Operating, maintenance, and management 2,550 2,577 7,313 7,343 Real estate taxes and insurance 1,715 1,637 5,005 4,725 Depreciation and amortization 4,075 4,664 12,420 12,277 Interest expense 4,557 3,951 13,092 9,150 Total expenses 12,897 12,829 37,830 33,495 Other income 37 14 75 42 Net loss $ (2,723 ) $ (3,201 ) $ (7,858 ) $ (6,125 ) Company’s equity in loss of unconsolidated joint venture $ (1,644 ) $ (1,930 ) $ (4,746 ) $ (3,706 ) As of September 30, 2018 and December 31, 2017 , the Company’s investments in unconsolidated joint ventures were composed of the following (dollars in thousands): Investment Balance at Joint Venture Number of Properties Location Ownership % September 30, 2018 December 31, 2017 NIP Joint Venture 2 Various Less than 5.0% $ 1,476 $ 3,674 110 William Joint Venture 1 New York, New York 60.0% 2,414 7,160 353 Sacramento Joint Venture 1 San Francisco, California 55.0% 43,414 44,743 $ 47,304 $ 55,577 Summarized financial information for the 353 Sacramento Joint Venture follows (in thousands): September 30, 2018 December 31, 2017 Assets: Real estate assets, net of accumulated depreciation and amortization $ 179,420 $ 171,066 Other assets 9,219 6,472 Total assets $ 188,639 $ 177,538 Liabilities and equity: Notes payable, net $ 96,562 $ 89,423 Other liabilities 13,625 7,313 Partners’ capital 78,452 80,802 Total liabilities and equity $ 188,639 $ 177,538 For the Three Months Ended September 30, 2018 For the Nine Months Ended September 30, 2018 For the Period from July 6, 2017 to September 30, 2017 Revenues $ 2,475 $ 7,771 $ 3,507 Expenses: Operating, maintenance, and management 906 2,675 936 Real estate taxes and insurance 611 1,828 603 Depreciation and amortization 1,408 4,245 1,724 Interest expense 1,426 4,013 1,138 Total expenses 4,351 12,761 4,401 Net loss $ (1,876 ) $ (4,990 ) $ (894 ) Company’s equity in loss of unconsolidated joint venture $ (1,000 ) $ (2,648 ) $ (222 )

SUPPLEMENTAL CASH FLOW AND SI_2

SUPPLEMENTAL CASH FLOW AND SIGNIFICANT NONCASH TRANSACTION DISCLOSURES (Tables)	9 Months Ended
	Sep. 30, 2018
Supplemental Cash Flow and Significant Noncash Transaction Disclosures [Abstract]
Schedule of Cash Flow, Supplemental Disclosures	Supplemental cash flow and significant noncash transaction disclosures were as follows (in thousands): Nine Months Ended September 30, 2018 2017 Supplemental Disclosure of Cash Flow Information: Interest paid, net of capitalized interest of $1,916 and $1,732 for the nine months ended September 30, 2018 and 2017 , respectively $ 22,485 $ 27,732 Supplemental Disclosure of Significant Noncash Transactions: Assets and liabilities deconsolidated in connection with the 353 Sacramento partial sale: Real estate, net — 170,586 Rents and other receivables, net — 1,244 Prepaid expenses and other assets — 555 Notes payable, net — 87,132 Accounts payable and accrued liabilities — 1,574 Below-market leases, net — 2,960 Other liabilities — 924 Application of escrow deposits to acquisition of real estate — 2,000 Increase in accrued improvements to real estate 1,179 1,319 Distributions paid to common stockholders through common stock issuances pursuant to the dividend reinvestment plan 1,418 8,666 Distributions paid to common stockholders through common stock issuances pursuant to the December 2017 special dividend 150,299 —

ORGANIZATION (Details)

ORGANIZATION (Details) $ in Thousands	Mar. 08, 2016USD ($)	Mar. 08, 2016ILS (₪)	Mar. 08, 2016ILS (₪)	Mar. 07, 2016ILS (₪)	Mar. 02, 2016ILS (₪)	Mar. 01, 2016ILS (₪)	Dec. 31, 2017USD ($)shares	Sep. 30, 2018USD ($)aportfoliopropertyinvestmentshares	Dec. 31, 2017USD ($)shares	Nov. 14, 2012USD ($)shares	Sep. 30, 2018USD ($)aportfoliopropertyinvestmentshares	Dec. 18, 2015shares	Oct. 23, 2012USD ($)shares	Dec. 29, 2011USD ($)shares	Jan. 08, 2009shares
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)							52,053,817	54,231,264	52,053,817		54,231,264		55,249	220,994
Partnership interest in Operating Partnership								0.10%
Partnership interest in the Operating Partnership and is its sole limited partner								99.90%
Issuance of common stock | $								$ 1,418	$ 8,666	$ 561,700
Shares of common stock sold under dividend reinvestment plan, value | $											$ 75,500
Redemptions of common stock | $								120,544	74,780		272,300
Common stock, value, issued | $							$ 521	$ 542	$ 521		$ 542		$ 500	$ 2,000
Number of investments in unconsolidated joint venture | investment								3			3
Number of investments in debt securities | investment								1			1
Number of investments in equity securities | investment								3			3
Office Properties
Organizational Structure [Line Items]
Number of real estate properties consolidated | property								6			6
Number of real estate properties | property								6			6
Office Portfolio
Organizational Structure [Line Items]
Number of real estate properties | portfolio								1			1
Office Buildings, Portfolio
Organizational Structure [Line Items]
Number of real estate properties | property								4			4
Undeveloped Land, Portfolio
Organizational Structure [Line Items]
Real estate area of undeveloped land | a								14			14
Office/Flex/Industrial Portfolio
Organizational Structure [Line Items]
Number of real estate properties | property								1			1
Office/Flex/Industrial Buildings
Organizational Structure [Line Items]
Number of real estate properties | property								21			21
Retail Property, Portfolio
Organizational Structure [Line Items]
Number of real estate properties | property								1			1
Undeveloped Land
Organizational Structure [Line Items]
Real estate area of undeveloped land | a								1,000			1,000
Number of investments in real estate | investment								3			3
Series A Debentures | Bonds Payable
Organizational Structure [Line Items]
Maximum borrowing capacity (in shares) | ₪					₪ 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
Principal installment payments required as percent of total debt					20.00%
Special Dividends
Organizational Structure [Line Items]
Common stock, shares issued (in shares)								13,069,487			13,069,487
Maximum | Series A Debentures | Bonds Payable
Organizational Structure [Line Items]
Contractual interest rate, percentage					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)								123,288	585,192	56,584,976
Issuance of common stock | $								$ 1	$ 6
Shares of common stock sold under dividend reinvestment plan, (in shares)											6,743,649
Redemptions of common stock (in shares)								11,015,328	5,307,142		22,463,092
Redemptions of common stock | $							$ 4,400	$ 110	$ 53
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
KBS Strategic Opportunity BVI
Organizational Structure [Line Items]
Common stock, shares authorized (in shares)												50,000
KBS Strategic Opportunity BVI | Operating Partnership
Organizational Structure [Line Items]
Common stock, shares issued (in shares)												10,000

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Redeemable Common Stock) (Details) - USD ($)	Jun. 01, 2018	Apr. 23, 2018	Dec. 30, 2016	Dec. 31, 2017	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2018	Aug. 09, 2018
Summary of Significant Accounting Policies [Line Items]
Minimum share holding period to be available for redemption					1 year
Maximum number of shares redeemable per quarter, value					$ 3,000,000
Redemption value					$ 1,000,000		$ 1,000,000
Period of increase or decrease of funding available for redemption					10 days
Additional increase in authorized amount								$ 6,000,000
Remaining authorized repurchase amount					$ 3,000,000		3,000,000
Maximum percentage of weighted-average shares outstanding available for redemption during any calendar year					5.00%
Redemption price percentage of most recent estimated value per share			95.00%
Share redemption program, termination period			10 days
Redemptions of common stock					$ 120,544,000	$ 74,780,000	272,300,000
Other liabilities				$ 16,966,000	16,538,000	16,966,000	16,538,000
Common Stock
Summary of Significant Accounting Policies [Line Items]
Number of shares non-redeemable do to limitation, value					16,100,000
Redemptions of common stock				4,400,000	110,000	53,000
SOR Offer
Summary of Significant Accounting Policies [Line Items]
Stock repurchase program, number of shares authorized to be repurchased (in shares)		8,234,217
Treasury stock acquired, cost per share (in dollars per share)	$ 10.93	$ 10.93
Stock repurchase program, authorized amount		$ 90,000,000
Treasury stock, shares, acquired (in shares)	9,527,724	1,294,910
Treasury stock, value, acquired	$ 104,100,000	$ 14,100,000
Unfulfilled Redemption Request
Summary of Significant Accounting Policies [Line Items]
Other liabilities				$ 8,600,000	$ 4,400,000	$ 8,600,000	$ 4,400,000

SUMMARY OF SIGNIFICANT ACCOUN_4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Revenue Recognition, Real Estate Sale and Equity Securities) (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2018USD ($)	Jul. 02, 2018a	Feb. 28, 2018a	Jan. 01, 2018USD ($)	Dec. 31, 2017USD ($)a
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustments to retained earnings						$ 2,472
Contract liability	$ 1,700	$ 1,700				$ 3,100
Park Highlands | Undeveloped Land | Disposed of by Sale
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Area of land sold | a			83	26		102
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustments to retained earnings						$ 27,618
Accounting Standards Update 2014-09 | Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustments to retained earnings					$ 2,500
Accounting Standards Update 2014-09 | Difference between Revenue Guidance in Effect before and after Topic 606
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Tenant reimbursements	$ 500	$ 1,400
Accounting Standards Update 2016-01 | Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustments to retained earnings						$ 25,100

SUMMARY OF SIGNIFICANT ACCOUN_5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Investments and Reclassifications) (Details) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018USD ($)property	Dec. 31, 2017USD ($)property
Investment [Line Items]
Investments in unconsolidated joint ventures	$ 47,304	$ 55,577
Disposed of by Sale | Office Properties
Investment [Line Items]
Number of real estate properties disposed | property	1	12
NIP Joint Venture
Investment [Line Items]
Investments in unconsolidated joint ventures	$ 1,476	$ 3,674

SUMMARY OF SIGNIFICANT ACCOUN_6

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Segments and Per Share Data) (Narrative) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2018$ / shares	Sep. 30, 2017$ / shares	Sep. 30, 2018segment$ / shares	Sep. 30, 2017$ / shares
Accounting Policies [Abstract]
Number of reportable segments | segment			1
Distributions declared per common share (in dollars per share) | $ / shares	$ 0.015975	$ 0.09452055	$ 0.047925	$ 0.28047945

REAL ESTATE HELD FOR INVESTME_3

REAL ESTATE HELD FOR INVESTMENT (Narrative) (Details) ft² in Millions	Sep. 30, 2018aft²unitpropertyinvestment
Real Estate Properties [Line Items]
Rentable square feet | ft²	3.8
Percentage of portfolio occupied	76.00%
Office Properties
Real Estate Properties [Line Items]
Number of real estate properties	6
Undeveloped Land, Portfolio
Real Estate Properties [Line Items]
Real estate area of undeveloped land | a	14
Office/Flex/Industrial Portfolio
Real Estate Properties [Line Items]
Number of real estate properties	1
Office/Flex/Industrial Buildings
Real Estate Properties [Line Items]
Number of real estate properties	21
Retail Property, Portfolio
Real Estate Properties [Line Items]
Number of real estate properties	1
Apartment Property
Real Estate Properties [Line Items]
Number of real estate properties	2
Apartment Building
Real Estate Properties [Line Items]
Rentable square feet | ft²	0.3
Percentage of portfolio occupied	94.00%
Number of units in real estate property | unit	383
Undeveloped Land
Real Estate Properties [Line Items]
Real estate area of undeveloped land | a	1,000
Number of investments in real estate | investment	3

REAL ESTATE HELD FOR INVESTME_4

REAL ESTATE HELD FOR INVESTMENT (Schedule of Real Estate Investments) (Details) $ in Thousands	Sep. 07, 2016USD ($)unit	Sep. 30, 2018USD ($)	Dec. 31, 2017USD ($)
Real Estate Properties [Line Items]
Total real estate, cost		$ 860,828	$ 539,376
Accumulated depreciation and amortization		(56,749)	(37,154)
Total real estate, net		804,079	502,222
Subsidiary of Common Parent
Real Estate Properties [Line Items]
Interest rate on Class A non-voting preferred membership units	10.00%
Proceeds from sale of units	$ 800
Subsidiary of Common Parent | Disposed of by Sale
Real Estate Properties [Line Items]
Number of real estate units | unit	820
Richardson Portfolio
Real Estate Properties [Line Items]
Total real estate, cost		41,623
Accumulated depreciation and amortization		(9,425)
Total real estate, net		$ 32,198
Palisades Central I
Real Estate Properties [Line Items]
Date Acquired or Foreclosed on		Nov. 23, 2011
Total real estate, cost		$ 11,751
Accumulated depreciation and amortization		(2,646)
Total real estate, net		$ 9,105
Ownership %		90.00%
Palisades Central II
Real Estate Properties [Line Items]
Date Acquired or Foreclosed on		Nov. 23, 2011
Total real estate, cost		$ 18,764
Accumulated depreciation and amortization		(4,115)
Total real estate, net		$ 14,649
Ownership %		90.00%
Greenway I
Real Estate Properties [Line Items]
Date Acquired or Foreclosed on		Nov. 23, 2011
Total real estate, cost		$ 2,645
Accumulated depreciation and amortization		(711)
Total real estate, net		$ 1,934
Ownership %		90.00%
Greenway III
Real Estate Properties [Line Items]
Date Acquired or Foreclosed on		Nov. 23, 2011
Total real estate, cost		$ 5,329
Accumulated depreciation and amortization		(1,953)
Total real estate, net		$ 3,376
Ownership %		90.00%
Undeveloped Land
Real Estate Properties [Line Items]
Date Acquired or Foreclosed on		Nov. 23, 2011
Total real estate, cost		$ 3,134
Accumulated depreciation and amortization		0
Total real estate, net		$ 3,134
Ownership %		90.00%
Park Highlands
Real Estate Properties [Line Items]
Date Acquired or Foreclosed on		Dec. 30, 2011
Total real estate, cost		$ 29,845
Accumulated depreciation and amortization		0
Total real estate, net		$ 29,845
Burbank Collection
Real Estate Properties [Line Items]
Date Acquired or Foreclosed on		Dec. 12, 2012
Total real estate, cost		$ 17,444
Accumulated depreciation and amortization		(2,960)
Total real estate, net		$ 14,484
Ownership %		90.00%
Park Centre
Real Estate Properties [Line Items]
Date Acquired or Foreclosed on		Mar. 28, 2013
Total real estate, cost		$ 31,092
Accumulated depreciation and amortization		(4,361)
Total real estate, net		$ 26,731
Ownership %		100.00%
1180 Raymond
Real Estate Properties [Line Items]
Date Acquired or Foreclosed on		Aug. 20, 2013
Total real estate, cost		$ 46,664
Accumulated depreciation and amortization		(6,305)
Total real estate, net		$ 40,359
Ownership %		100.00%
Park Highlands II
Real Estate Properties [Line Items]
Date Acquired or Foreclosed on		Dec. 10, 2013
Total real estate, cost		$ 25,532
Accumulated depreciation and amortization		0
Total real estate, net		$ 25,532
Ownership %		100.00%
424 Bedford
Real Estate Properties [Line Items]
Date Acquired or Foreclosed on		Jan. 31, 2014
Total real estate, cost		$ 34,769
Accumulated depreciation and amortization		(3,405)
Total real estate, net		$ 31,364
Ownership %		90.00%
Richardson Land II
Real Estate Properties [Line Items]
Date Acquired or Foreclosed on		Sep. 4, 2014
Total real estate, cost		$ 3,418
Accumulated depreciation and amortization		0
Total real estate, net		$ 3,418
Ownership %		90.00%
Westpark Portfolio
Real Estate Properties [Line Items]
Date Acquired or Foreclosed on		May 10, 2016
Total real estate, cost		$ 135,799
Accumulated depreciation and amortization		(11,681)
Total real estate, net		$ 124,118
Ownership %		100.00%
Crown Pointe
Real Estate Properties [Line Items]
Date Acquired or Foreclosed on		Feb. 14, 2017
Total real estate, cost		$ 91,780
Accumulated depreciation and amortization		(6,855)
Total real estate, net		$ 84,925
Ownership %		100.00%
125 John Carpenter
Real Estate Properties [Line Items]
Date Acquired or Foreclosed on		Sep. 15, 2017
Total real estate, cost		$ 87,963
Accumulated depreciation and amortization		(4,636)
Total real estate, net		$ 83,327
Ownership %		100.00%
Marquette Plaza
Real Estate Properties [Line Items]
Date Acquired or Foreclosed on		Mar. 1, 2018
Total real estate, cost		$ 86,886
Accumulated depreciation and amortization		(2,265)
Total real estate, net		$ 84,621
Ownership %		100.00%
City Tower
Real Estate Properties [Line Items]
Date Acquired or Foreclosed on		Mar. 6, 2018
Total real estate, cost		$ 151,763
Accumulated depreciation and amortization		(3,964)
Total real estate, net		$ 147,799
Ownership %		100.00%
Eight & Nine Corporate Centre
Real Estate Properties [Line Items]
Date Acquired or Foreclosed on		Jun. 8, 2018
Total real estate, cost		$ 76,250
Accumulated depreciation and amortization		(892)
Total real estate, net		$ 75,358
Ownership %		100.00%
Land
Real Estate Properties [Line Items]
Total real estate, cost		$ 192,765	155,046
Land | Richardson Portfolio
Real Estate Properties [Line Items]
Total real estate, cost		6,244
Land | Palisades Central I
Real Estate Properties [Line Items]
Total real estate, cost		1,037
Land | Palisades Central II
Real Estate Properties [Line Items]
Total real estate, cost		810
Land | Greenway I
Real Estate Properties [Line Items]
Total real estate, cost		561
Land | Greenway III
Real Estate Properties [Line Items]
Total real estate, cost		702
Land | Undeveloped Land
Real Estate Properties [Line Items]
Total real estate, cost		3,134
Land | Park Highlands
Real Estate Properties [Line Items]
Total real estate, cost		29,845
Land | Burbank Collection
Real Estate Properties [Line Items]
Total real estate, cost		4,175
Land | Park Centre
Real Estate Properties [Line Items]
Total real estate, cost		3,251
Land | 1180 Raymond
Real Estate Properties [Line Items]
Total real estate, cost		8,292
Land | Park Highlands II
Real Estate Properties [Line Items]
Total real estate, cost		25,532
Land | 424 Bedford
Real Estate Properties [Line Items]
Total real estate, cost		8,860
Land | Richardson Land II
Real Estate Properties [Line Items]
Total real estate, cost		3,418
Land | Westpark Portfolio
Real Estate Properties [Line Items]
Total real estate, cost		36,085
Land | Crown Pointe
Real Estate Properties [Line Items]
Total real estate, cost		22,590
Land | 125 John Carpenter
Real Estate Properties [Line Items]
Total real estate, cost		2,755
Land | Marquette Plaza
Real Estate Properties [Line Items]
Total real estate, cost		10,387
Land | City Tower
Real Estate Properties [Line Items]
Total real estate, cost		13,930
Land | Eight & Nine Corporate Centre
Real Estate Properties [Line Items]
Total real estate, cost		17,401
Buildings and improvements
Real Estate Properties [Line Items]
Total real estate, cost		628,748	361,118
Buildings and improvements | Richardson Portfolio
Real Estate Properties [Line Items]
Total real estate, cost		34,820
Buildings and improvements | Palisades Central I
Real Estate Properties [Line Items]
Total real estate, cost		10,714
Buildings and improvements | Palisades Central II
Real Estate Properties [Line Items]
Total real estate, cost		17,954
Buildings and improvements | Greenway I
Real Estate Properties [Line Items]
Total real estate, cost		2,084
Buildings and improvements | Greenway III
Real Estate Properties [Line Items]
Total real estate, cost		4,068
Buildings and improvements | Undeveloped Land
Real Estate Properties [Line Items]
Total real estate, cost		0
Buildings and improvements | Park Highlands
Real Estate Properties [Line Items]
Total real estate, cost		0
Buildings and improvements | Burbank Collection
Real Estate Properties [Line Items]
Total real estate, cost		12,544
Buildings and improvements | Park Centre
Real Estate Properties [Line Items]
Total real estate, cost		27,841
Buildings and improvements | 1180 Raymond
Real Estate Properties [Line Items]
Total real estate, cost		38,372
Buildings and improvements | Park Highlands II
Real Estate Properties [Line Items]
Total real estate, cost		0
Buildings and improvements | 424 Bedford
Real Estate Properties [Line Items]
Total real estate, cost		25,909
Buildings and improvements | Richardson Land II
Real Estate Properties [Line Items]
Total real estate, cost		0
Buildings and improvements | Westpark Portfolio
Real Estate Properties [Line Items]
Total real estate, cost		93,362
Buildings and improvements | Crown Pointe
Real Estate Properties [Line Items]
Total real estate, cost		63,662
Buildings and improvements | 125 John Carpenter
Real Estate Properties [Line Items]
Total real estate, cost		76,368
Buildings and improvements | Marquette Plaza
Real Estate Properties [Line Items]
Total real estate, cost		72,094
Buildings and improvements | City Tower
Real Estate Properties [Line Items]
Total real estate, cost		129,713
Buildings and improvements | Eight & Nine Corporate Centre
Real Estate Properties [Line Items]
Total real estate, cost		54,063
Tenant origination and absorption costs
Real Estate Properties [Line Items]
Total real estate, cost		39,315	$ 23,212
Tenant origination and absorption costs | Richardson Portfolio
Real Estate Properties [Line Items]
Total real estate, cost		559
Tenant origination and absorption costs | Palisades Central I
Real Estate Properties [Line Items]
Total real estate, cost		0
Tenant origination and absorption costs | Palisades Central II
Real Estate Properties [Line Items]
Total real estate, cost		0
Tenant origination and absorption costs | Greenway I
Real Estate Properties [Line Items]
Total real estate, cost		0
Tenant origination and absorption costs | Greenway III
Real Estate Properties [Line Items]
Total real estate, cost		559
Tenant origination and absorption costs | Undeveloped Land
Real Estate Properties [Line Items]
Total real estate, cost		0
Tenant origination and absorption costs | Park Highlands
Real Estate Properties [Line Items]
Total real estate, cost		0
Tenant origination and absorption costs | Burbank Collection
Real Estate Properties [Line Items]
Total real estate, cost		725
Tenant origination and absorption costs | Park Centre
Real Estate Properties [Line Items]
Total real estate, cost		0
Tenant origination and absorption costs | 1180 Raymond
Real Estate Properties [Line Items]
Total real estate, cost		0
Tenant origination and absorption costs | Park Highlands II
Real Estate Properties [Line Items]
Total real estate, cost		0
Tenant origination and absorption costs | 424 Bedford
Real Estate Properties [Line Items]
Total real estate, cost		0
Tenant origination and absorption costs | Richardson Land II
Real Estate Properties [Line Items]
Total real estate, cost		0
Tenant origination and absorption costs | Westpark Portfolio
Real Estate Properties [Line Items]
Total real estate, cost		6,352
Tenant origination and absorption costs | Crown Pointe
Real Estate Properties [Line Items]
Total real estate, cost		5,528
Tenant origination and absorption costs | 125 John Carpenter
Real Estate Properties [Line Items]
Total real estate, cost		8,840
Tenant origination and absorption costs | Marquette Plaza
Real Estate Properties [Line Items]
Total real estate, cost		4,405
Tenant origination and absorption costs | City Tower
Real Estate Properties [Line Items]
Total real estate, cost		8,120
Tenant origination and absorption costs | Eight & Nine Corporate Centre
Real Estate Properties [Line Items]
Total real estate, cost		$ 4,786

REAL ESTATE HELD FOR INVESTME_5

REAL ESTATE HELD FOR INVESTMENT (Operating Leases) (Narrative) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2018USD ($)tenant	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Operating Leased Assets [Line Items]
Recognition of deferred revenue, net of discontinued operations	$ 3.5	$ 1.7
Deferred rent receivables	10.9		$ 6.6
Incentive to Lessee	$ 1.5		0.8
Number of tenants | tenant	350
Other Liabilities
Operating Leased Assets [Line Items]
Security deposit liability	$ 5.1		$ 4.3
Maximum
Operating Leased Assets [Line Items]
Operating lease, term	13 years 8 months 12 days
Weighted Average
Operating Leased Assets [Line Items]
Operating lease, term	4 years 7 months 6 days
Apartment Building
Operating Leased Assets [Line Items]
Operating lease, term	1 year

REAL ESTATE HELD FOR INVESTME_6

REAL ESTATE HELD FOR INVESTMENT (Future Minimum Rental Income) (Details) $ in Thousands	Sep. 30, 2018USD ($)
Real Estate [Abstract]
October 1, 2018 through December 31, 2018	$ 15,168
2,019	61,898
2,020	56,312
2,021	49,918
2,022	42,432
Thereafter	138,775
Future minimum rental income	$ 364,503

REAL ESTATE HELD FOR INVESTME_7

REAL ESTATE HELD FOR INVESTMENT (Highest Tenant Industry Concentrations- Greater than 10% of Annual Base Rent) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)tenant
Concentration Risk [Line Items]
Number of tenants	350
Health Care and Social Services
Concentration Risk [Line Items]
Number of tenants	15
Annualized Base Rent | $	$ 6,659
Percentage of Annualized Base Rent	10.10%

REAL ESTATE HELD FOR INVESTME_8

REAL ESTATE HELD FOR INVESTMENT (Geographic Concentration Risk) (Details) - Assets, Total	9 Months Ended
	Sep. 30, 2018
California
Concentration Risk [Line Items]
Concentration risk, percentage	14.60%
Texas
Concentration Risk [Line Items]
Concentration risk, percentage	13.10%
Washington
Concentration Risk [Line Items]
Concentration risk, percentage	11.20%

REAL ESTATE HELD FOR INVESTME_9

REAL ESTATE HELD FOR INVESTMENT (Recent Real Estate Acquisition) (Details) $ in Thousands	Jun. 08, 2018USD ($)aft²	Mar. 06, 2018USD ($)aft²property	Mar. 01, 2018USD ($)aft²property	Sep. 30, 2018USD ($)ft²	Dec. 31, 2017USD ($)
Business Acquisition [Line Items]
Rentable square feet | ft²				3,800,000
Total real estate, cost				$ 860,828	$ 539,376
Above market lease assets				3,485	10
Below-market leases				5,554	2,843
Land
Business Acquisition [Line Items]
Total real estate, cost				192,765	155,046
Buildings and improvements
Business Acquisition [Line Items]
Total real estate, cost				628,748	361,118
Tenant origination and absorption costs
Business Acquisition [Line Items]
Total real estate, cost				39,315	$ 23,212
Marquette Plaza
Business Acquisition [Line Items]
Total real estate, cost				86,886
Marquette Plaza | Land
Business Acquisition [Line Items]
Total real estate, cost				10,387
Marquette Plaza | Buildings and improvements
Business Acquisition [Line Items]
Total real estate, cost				72,094
Marquette Plaza | Tenant origination and absorption costs
Business Acquisition [Line Items]
Total real estate, cost				$ 4,405
Marquette Plaza | Office Properties
Business Acquisition [Line Items]
Number of real estate properties acquired | property		1
Rentable square feet | ft²			522,656
Area of land | a			2.5
Purchase price			$ 88,300
Capitalized acquisition costs			1,100
Above market lease assets			3,700
Below-market leases			$ 600
Marquette Plaza | Office Properties | Tenant origination and absorption costs
Business Acquisition [Line Items]
Remaining amortization period			6 years 7 months 6 days
Marquette Plaza | Office Properties | Above-Market Lease Assets
Business Acquisition [Line Items]
Remaining amortization period			11 years 8 months 12 days
Marquette Plaza | Office Properties | Below-market lease liabilities
Business Acquisition [Line Items]
Remaining amortization period			2 years 4 months 24 days
Marquette Plaza | Office Properties | Land
Business Acquisition [Line Items]
Total real estate, cost			$ 10,400
Marquette Plaza | Office Properties | Buildings and improvements
Business Acquisition [Line Items]
Total real estate, cost			71,400
Marquette Plaza | Office Properties | Tenant origination and absorption costs
Business Acquisition [Line Items]
Total real estate, cost			$ 4,500
City Tower | Office Properties
Business Acquisition [Line Items]
Number of real estate properties acquired | property			1
Rentable square feet | ft²		431,007
Area of land | a		4.9
Purchase price		$ 147,100
Capitalized acquisition costs		1,600
Below-market leases		$ 1,200
City Tower | Office Properties | Tenant origination and absorption costs
Business Acquisition [Line Items]
Remaining amortization period		5 years 2 months 12 days
City Tower | Office Properties | Below-market lease liabilities
Business Acquisition [Line Items]
Remaining amortization period		6 years 7 months 6 days
City Tower | Office Properties | Land
Business Acquisition [Line Items]
Total real estate, cost		$ 13,900
City Tower | Office Properties | Buildings and improvements
Business Acquisition [Line Items]
Total real estate, cost		127,900
City Tower | Office Properties | Tenant origination and absorption costs
Business Acquisition [Line Items]
Total real estate, cost		$ 8,100
Eight & Nine Corporate Centre | Office Properties
Business Acquisition [Line Items]
Rentable square feet | ft²	311,864
Area of land | a	27.6
Purchase price	$ 73,000
Capitalized acquisition costs	1,200
Below-market leases	$ 2,000
Eight & Nine Corporate Centre | Office Properties | Tenant origination and absorption costs
Business Acquisition [Line Items]
Remaining amortization period	6 years 4 months 24 days
Eight & Nine Corporate Centre | Office Properties | Below-market lease liabilities
Business Acquisition [Line Items]
Remaining amortization period	7 years 4 months 24 days
Eight & Nine Corporate Centre | Office Properties | Land
Business Acquisition [Line Items]
Total real estate, cost	$ 17,400
Eight & Nine Corporate Centre | Office Properties | Buildings and improvements
Business Acquisition [Line Items]
Total real estate, cost	54,000
Eight & Nine Corporate Centre | Office Properties | Tenant origination and absorption costs
Business Acquisition [Line Items]
Total real estate, cost	$ 4,800

REAL ESTATE HELD FOR INVESTM_10

REAL ESTATE HELD FOR INVESTMENT (Recent Real Estate Land Sales) (Details) $ in Thousands	Jul. 02, 2018USD ($)a	Feb. 28, 2018USD ($)a	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Dec. 31, 2017a
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of real estate			$ 44,692	$ 2,239	$ 45,340	$ 36,267
Park Highlands | Disposed of by Sale | Undeveloped Land
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of land sold | a	83	26					102
Proceeds from sale of land	$ 18,700	$ 2,500
Gain on sale of real estate	12,600	700
Gross profit, deferred	$ 1,100	$ 300

REAL ESTATE HELD FOR INVESTM_11

REAL ESTATE HELD FOR INVESTMENT (Potential Real Estate Disposition) (Details) $ in Millions	Sep. 30, 2018ft²shares	Sep. 23, 2018USD ($)	May 10, 2016aft²property
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Rentable square feet	3,800,000
SREIT
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership percentage	6.97%
SREIT
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of shares owned (in shares) | shares	43,999,500
Westpark Portfolio | Plan | Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sale price | $		$ 169.4
Westpark Portfolio | Office/Flex/Industrial Buildings
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties acquired | property			21
Rentable square feet			778,472
Area of land | a			41

TENANT ORIGINATION AND ABSORP_3

TENANT ORIGINATION AND ABSORPTION COSTS, ABOVE-MARKET LEASE ASSETS AND BELOW-MARKET LEASE LIABILITIES (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Tenant Origination and Absorption Costs, Above-Market Lease Assets and Below-Market Lease Liabilities [Abstract]
Tenant Origination And Absorption Costs, Cost	$ 39,315		$ 39,315		$ 23,212
Tenant Origination and Absorption Costs, Accumulated Amortization	(10,281)		(10,281)		(5,733)
Tenant Origination and Absorption Costs, Net Amount	29,034		29,034		17,479
Tenant Origination and Absorption Costs, Amortization	(2,312)	$ (2,190)	(5,937)	$ (8,268)
Above-Market Lease Assets, Cost	3,731		3,731		17
Above-Market Lease Assets, Accumulated Amortization	(246)		(246)		(7)
Above-Market Lease Assets, Net Amount	3,485		3,485		10
Above-Market Lease Assets, Amortization	(104)	(62)	(259)	(229)
Below-Market Lease Liabilities, Cost	(7,222)		(7,222)		(3,636)
Below-Market Lease Liabilities, Accumulated Amortization	1,668		1,668		793
Below-Market Lease Liabilities, Net Amount	(5,554)		(5,554)		$ (2,843)
Below-Market Lease Liabilities, Amortization	$ 457	$ 278	$ 1,112	$ 2,482

TENANT ORIGINATION AND ABSORP_4

TENANT ORIGINATION AND ABSORPTION COSTS, ABOVE-MARKET LEASE ASSETS AND BELOW-MARKET LEASE LIABILITIES (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Tenant Origination and Absorption Costs, Above-Market Lease Assets and Below-Market Lease Liabilities [Line Items]
Tax abatement asset	$ 4,600		$ 4,600		$ 5,300
Depreciation and amortization	9,826	$ 13,228	26,133	$ 43,136
Property Tax Abatement Intangible Asset
Tenant Origination and Absorption Costs, Above-Market Lease Assets and Below-Market Lease Liabilities [Line Items]
Depreciation and amortization	$ 200	$ 200	$ 700	$ 700

REAL ESTATE EQUITY SECURITIES_2

REAL ESTATE EQUITY SECURITIES (Narrative) (Details) $ in Thousands	Nov. 08, 2017propertyshares	Sep. 30, 2018USD ($)investment	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)investmentshares	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)shares	Nov. 14, 2012USD ($)shares
Schedule of Available-for-sale Securities [Line Items]
Number of investments in equity securities | investment		3		3
Issuance of common stock | $				$ 1,418		$ 8,666	$ 561,700
Available-for-sale securities, lack of marketability | $		$ 300		300		$ 1,700
Dividend income from real estate equity securities | $		2,885	$ 1,015	$ 5,146	$ 1,505
Singapore Portfolio
Schedule of Available-for-sale Securities [Line Items]
Number of real estate properties disposed | property	11
Common Stock
Schedule of Available-for-sale Securities [Line Items]
Issuance of common stock (in shares) | shares				(123,288)		(585,192)	(56,584,976)
Issuance of common stock | $				$ 1		$ 6
Franklin Street Properties Corp.
Schedule of Available-for-sale Securities [Line Items]
Cost basis | $		14,000		14,000
Whitestone REIT
Schedule of Available-for-sale Securities [Line Items]
Cost basis | $		$ 1,900		$ 1,900
Whitestone REIT | Common Stock
Schedule of Available-for-sale Securities [Line Items]
Issuance of common stock (in shares) | shares				(46,170)
Issuance of common stock | $				$ 600
Available-for-sale Securities | Franklin Street Properties Corp.
Schedule of Available-for-sale Securities [Line Items]
Shares purchased (in shares) | shares				1,576,809
Available-for-sale Securities | Whitestone REIT
Schedule of Available-for-sale Securities [Line Items]
Shares purchased (in shares) | shares				165,000
Available-for-sale Securities | Keppel-KBS US REIT
Schedule of Available-for-sale Securities [Line Items]
Shares purchased (in shares) | shares	43,999,500			43,999,500		43,999,500
Available-for-sale Securities | Keppel-KBS US REIT | Not to Sell, Transfer or Assign until May 8, 2018
Schedule of Available-for-sale Securities [Line Items]
Sale of stock, number of shares issued in transaction upon specific arrangements (in shares) | shares	21,999,750
Available-for-sale Securities | Keppel-KBS US REIT | Not to Sell, Transfer or Assign until November 8, 2018
Schedule of Available-for-sale Securities [Line Items]
Sale of stock, number of shares issued in transaction upon specific arrangements (in shares) | shares	21,999,750

REAL ESTATE EQUITY SECURITIES_3

REAL ESTATE EQUITY SECURITIES (Shares Owned) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Total Carrying Value	$ 98,735	$ 90,063
Available-for-sale Securities
Schedule of Available-for-sale Securities [Line Items]
Number of Shares Owned (in shares)	49,298,328	47,602,689
Whitestone REIT
Schedule of Available-for-sale Securities [Line Items]
Total Carrying Value	$ 51,662	$ 51,922
Whitestone REIT | Available-for-sale Securities
Schedule of Available-for-sale Securities [Line Items]
Number of Shares Owned (in shares)	3,722,019	3,603,189
Keppel-KBS US REIT
Schedule of Available-for-sale Securities [Line Items]
Total Carrying Value	$ 34,474	$ 38,141
Keppel-KBS US REIT | Available-for-sale Securities
Schedule of Available-for-sale Securities [Line Items]
Number of Shares Owned (in shares)	43,999,500	43,999,500
Franklin Street Properties Corp.
Schedule of Available-for-sale Securities [Line Items]
Total Carrying Value	$ 12,599	$ 0
Franklin Street Properties Corp. | Available-for-sale Securities
Schedule of Available-for-sale Securities [Line Items]
Number of Shares Owned (in shares)	1,576,809	0

REAL ESTATE EQUITY SECURITIES_4

REAL ESTATE EQUITY SECURITIES (Schedule of Activity of Real Estate Securities) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017
Available-for-sale Securities [Roll Forward]
Real estate securities, Amortized Cost Basis		$ 64,917
Real estate securities, Unrealized Gain (Loss)		25,146
Real estate securities, Total		90,063
Acquisition of real estate equity securities		15,676
Acquisition fee to affiliate and purchase commission		175
Disposition of real estate equity securities, Amortized Cost Basis		(554)
Disposition of real estate equity securities, Unrealized Gain (Loss)		(79)
Disposition of real estate equity securities, Total		(633)	$ 0
Loss on real estate equity securities	$ 741	(6,546)
Real estate securities, Amortized Cost Basis	80,214	80,214
Real estate securities, Unrealized Gain (Loss)	18,521	18,521
Real estate securities, Total	$ 98,735	$ 98,735

REAL ESTATE EQUITY SECURITIES_5

REAL ESTATE EQUITY SECURITIES (Portion of Gain and Loss) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Net gain (loss) recognized during the period on real estate equity securities	$ 741	$ (6,546)
Less: Net gain (loss) recognized during the period on real estate equity securities sold during the period	57	(32)
Unrealized gain (loss) recognized during the reporting period on real estate equity securities still held at September 30, 2018	$ 684	$ (6,514)

REAL ESTATE DEBT SECURITIES (Sc

REAL ESTATE DEBT SECURITIES (Schedule of Investments in Debt Securities) (Details) $ in Thousands	Oct. 31, 2018USD ($)	Sep. 30, 2018USD ($)investment	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)investment	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Investments, Debt and Equity Securities [Abstract]
Number of debt investments | investment		1		1
Investment [Line Items]
Outstanding Principal Balance		$ 17,500		$ 17,500		$ 17,500
Debt Securities
Investment [Line Items]
Income from real estate debt securities		513	$ 511	1,525	$ 1,271
Subsequent Event | Debt Securities
Investment [Line Items]
Income from real estate debt securities	$ 4,500
Point Trust LLC | Series B Preferred Units
Investment [Line Items]
Outstanding Principal Balance		17,500		17,500
Book Value		$ 17,855		$ 17,855		$ 17,751
Contractual Interest Rate		12.00%		12.00%
Annualized Effective Interest Rate		11.10%		11.10%

REAL ESTATE DEBT SECURITIES (_2

REAL ESTATE DEBT SECURITIES (Schedule of Activity of Real Estate Securities) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Held-to-maturity Securities [Roll Forward]
Real estate debt securities - December 31, 2017	$ 17,500
Real estate debt securities - September 30, 2018	17,500
Debt Securities
Held-to-maturity Securities [Roll Forward]
Real estate debt securities - December 31, 2017	17,751
Deferred interest receivable and interest accretion	68
Accretion of commitment fee, net of closing costs	36
Real estate debt securities - September 30, 2018	$ 17,855

REAL ESTATE DEBT SECURITIES (In

REAL ESTATE DEBT SECURITIES (Interest Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Investment [Line Items]
Contractual interest income	$ 253	$ 340	$ 1,602	$ 536
Debt Securities
Investment [Line Items]
Contractual interest income	537	403	1,421	815
Interest (amortization) accretion	(37)	97	68	218
Accretion of commitment fee, net of closing costs and acquisition fee	13	11	36	238
Interest income from real estate debt securities	$ 513	$ 511	$ 1,525	$ 1,271

REAL ESTATE SALES (Details)

REAL ESTATE SALES (Details) $ in Thousands	Jul. 17, 2018USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)property	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)property	Jul. 10, 2013aft²property
Real Estate Properties [Line Items]
Total real estate, cost		$ 860,828		$ 860,828		$ 539,376
Accumulated depreciation and amortization		56,749		56,749		$ 37,154
Office Properties | Central Building
Real Estate Properties [Line Items]
Number of real estate properties acquired | property							1
Net rentable area | ft²							191,784
Area of land | a							0.6
Disposed of by Sale
Revenues
Rental income		185	$ 17,129	2,255	$ 53,262
Tenant reimbursements and other operating income		16	5,028	267	15,511
Total revenues		201	22,157	2,522	68,773
Expenses
Operating, maintenance, and management		20	6,702	453	19,453
Real estate taxes and insurance		(137)	3,170	150	9,649
Asset management fees to affiliate		79	1,371	351	4,197
Depreciation and amortization		0	8,064	483	24,296
Interest expense		83	3,843	623	10,843
Total expenses		45	$ 23,150	$ 2,060	$ 68,438
Disposed of by Sale | Central Building
Real Estate Properties [Line Items]
Sale price	$ 67,500
Total real estate, cost	32,600
Accumulated depreciation and amortization	5,600
Gain on disposal	$ 32,100
Disposed of by Sale | Office Properties
Real Estate Properties [Line Items]
Number of real estate properties disposed | property				1		12
Held-for-sale
Assets and Liabilities
Real estate, cost		0		$ 0		$ 35,308
Accumulated depreciation and amortization		0		0		(4,663)
Real estate, net		0		0		30,645
Other assets		0		0		1,965
Total assets related to real estate held for sale		0		0		32,610
Notes payable, net		0		0		27,515
Total liabilities related to real estate held for sale		$ 0		$ 0		$ 27,515

NOTES AND BOND PAYABLE (Schedul

NOTES AND BOND PAYABLE (Schedule of Long-term Debt Instruments) (Details) $ in Thousands	Jul. 17, 2018USD ($)	Mar. 06, 2018	Nov. 08, 2018extension	Sep. 30, 2018USD ($)	Dec. 31, 2017USD ($)
Debt Instrument [Line Items]
Total Notes and Bonds Payable principal outstanding				$ 749,750	$ 611,694
Net Premium/(Discount) on Notes and Bonds Payable				182	137
Deferred financing costs, net				(8,803)	(8,788)
Notes and bonds payable, net				741,129	603,043
Mortgages | Richardson Portfolio Mortgage Loan
Debt Instrument [Line Items]
Notes payable, net				$ 32,435	36,886
Interest rate, effective percentage				4.20%
Mortgages | Richardson Portfolio Mortgage Loan | Subsequent Event
Debt Instrument [Line Items]
Number of extensions | extension			2
Extension period			1 year
Mortgages | Richardson Portfolio Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate				2.10%
Mortgages | Richardson Portfolio Mortgage Loan | One-month LIBOR | Subsequent Event
Debt Instrument [Line Items]
Basis spread on variable rate			2.50%
Mortgages | Portfolio Mortgage Loan
Debt Instrument [Line Items]
Notes payable, net				$ 8,772	9,877
Interest rate, effective percentage				4.36%
Mortgages | Portfolio Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate				2.25%
Mortgages | Burbank Collection Mortgage Loan
Debt Instrument [Line Items]
Notes payable, net				$ 10,777	10,958
Interest rate, effective percentage				4.48%
Mortgages | Burbank Collection Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate				2.35%
Mortgages | 1180 Raymond Bond Payable
Debt Instrument [Line Items]
Bonds payable				$ 6,325	6,460
Contractual interest rate, percentage				6.50%
Interest rate, effective percentage				6.50%
Mortgages | Central Building Mortgage Loan
Debt Instrument [Line Items]
Notes payable, net				$ 0	27,600
Extinguishment of debt	$ 27,600
Mortgages | Central Building Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate				1.75%
Mortgages | 424 Bedford Mortgage Loan
Debt Instrument [Line Items]
Notes payable, net				$ 23,856	24,282
Contractual interest rate, percentage				3.91%
Interest rate, effective percentage				3.91%
Mortgages | 1180 Raymond Mortgage Loan
Debt Instrument [Line Items]
Notes payable, net				$ 30,730	31,000
Interest rate, effective percentage				4.36%
Mortgages | 1180 Raymond Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate				2.25%
Mortgages | KBS SOR (BVI) Holdings, Ltd. Series A Debentures
Debt Instrument [Line Items]
Notes payable, net				$ 266,854	278,801
Contractual interest rate, percentage				4.25%
Interest rate, effective percentage				4.25%
Mortgages | Westpark Portfolio Mortgage Loan
Debt Instrument [Line Items]
Notes payable, net				$ 85,020	85,200
Interest rate, effective percentage				4.60%
Mortgages | Westpark Portfolio Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate				2.50%
Mortgages | Crown Pointe Mortgage Loan
Debt Instrument [Line Items]
Notes payable, net				$ 51,171	50,500
Interest rate, effective percentage				4.70%
Mortgages | Crown Pointe Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate				2.60%
Mortgages | 125 John Carpenter Mortgage Loan
Debt Instrument [Line Items]
Notes payable, net				$ 50,130	50,130
Interest rate, effective percentage				3.86%
Interest rate during period				2.00%
Mortgages | 125 John Carpenter Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate				1.75%
Mortgages | City Tower Mortgage Loan
Debt Instrument [Line Items]
Notes payable, net				$ 89,000	0
Interest rate, effective percentage				3.65%
Mortgages | City Tower Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate		1.55%		1.55%
Mortgages | Marquette Plaza Mortgage Loan
Debt Instrument [Line Items]
Notes payable, net				$ 50,800	0
Interest rate, effective percentage				3.65%
Mortgages | Marquette Plaza Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate				1.55%
Mortgages | Eight & Nine Corporate Centre Mortgage Loan
Debt Instrument [Line Items]
Notes payable, net				$ 43,880	$ 0
Interest rate, effective percentage				3.70%
Mortgages | Eight & Nine Corporate Centre Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate				1.60%

NOTES AND BOND PAYABLE (Narrati

NOTES AND BOND PAYABLE (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Debt Instrument [Line Items]
Interest expense	$ 8,404	$ 9,618	$ 22,814	$ 29,327
Amortization of deferred financing costs	1,000	1,000	2,675	3,578
Interest capitalized			1,916	1,732
Interest payable	2,600		2,600		$ 5,100
Undeveloped Land
Debt Instrument [Line Items]
Interest capitalized	$ 600	$ 600	$ 1,900	$ 1,700

NOTES AND BOND PAYABLE (Sched_2

NOTES AND BOND PAYABLE (Schedule of Maturities of Long-term Debt) (Details) $ in Thousands	Sep. 30, 2018USD ($)
Notes and Bonds Payable [Abstract]
October 1, 2018 through December 31, 2018	$ 64,024
2,019	74,414
2,020	189,056
2,021	237,929
2,022	125,546
Thereafter	58,781
Notes and bond payable outstanding	$ 749,750

NOTES AND BOND PAYABLE (Recent

NOTES AND BOND PAYABLE (Recent Bond Financing) (Details)	Mar. 08, 2016USD ($)	Mar. 08, 2016ILS (₪)	Mar. 08, 2016ILS (₪)	Mar. 07, 2016ILS (₪)	Mar. 02, 2016ILS (₪)	Mar. 01, 2016ILS (₪)	Sep. 30, 2018USD ($)instrument	Dec. 31, 2017ILS (₪)instrument
Foreign currency collars | Derivative instruments not designated as hedging instruments
Debt Instrument [Line Items]
Number of Instruments | instrument							1	0
Notional amount							$ 776,182,000	₪ 0
Bonds Payable | Series A Debentures
Debt Instrument [Line Items]
Maximum borrowing capacity (in shares) | ₪					₪ 1,000,000,000
Interest rate during period	4.25%	4.25%
Proceeds from issuance of debt	$ 249,200,000	₪ 970,200,000	₪ 970,200,000	₪ 127,700,000		₪ 842,500,000
Principal installment payments required as percent of total debt					20.00%
Bonds Payable | Series A Debentures | Maximum
Debt Instrument [Line Items]
Interest rate during period					4.25%

DERIVATIVE INSTRUMENTS (Details

DERIVATIVE INSTRUMENTS (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)instrument	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)instrument	Sep. 30, 2017USD ($)	Aug. 20, 2018	Dec. 31, 2017USD ($)instrument	Dec. 31, 2017ILS (₪)instrument	Aug. 03, 2017
Foreign currency collars
Derivative [Line Items]
Gain (loss) recognized on derivatives		$ 8,100,000		$ 10,900,000
Foreign currency transaction gain (loss)	$ (200,000)	(3,700,000)	$ 13,200,000	(22,400,000)
Foreign currency option
Derivative [Line Items]
Purchase of derivative			0	3,434,000
Gain (loss) recognized on derivatives	(200,000)		(4,100,000)
Interest Rate Cap
Derivative [Line Items]
Purchase of derivative			163,000	107,000
Unrealized loss on derivatives	$ 10,000	$ (14,000)	$ (21,000)	$ (102,000)
Derivative instruments not designated as hedging instruments | Foreign currency collars
Derivative [Line Items]
Number of Instruments | instrument	1		1			0	0
Notional Amount	$ 776,182,000		$ 776,182,000				₪ 0
Derivative instruments not designated as hedging instruments | Foreign currency collars | Prepaid expenses and other assets
Derivative [Line Items]
Number of Instruments | instrument	1		1			0	0
Derivative Asset	$ 171,000		$ 171,000			$ 0
Derivative instruments not designated as hedging instruments | Foreign currency collars | Minimum
Derivative [Line Items]
Strike Price					3.54
Derivative instruments not designated as hedging instruments | Foreign currency collars | Maximum
Derivative [Line Items]
Strike Price					3.66
Derivative instruments not designated as hedging instruments | Foreign currency option
Derivative [Line Items]
Number of Instruments | instrument	0		0			1	1
Notional Amount	$ 0		$ 0			$ 285,361,000
Strike Price								3.40
Derivative instruments not designated as hedging instruments | Foreign currency option | Prepaid expenses and other assets
Derivative [Line Items]
Number of Instruments | instrument	0		0			1	1
Derivative Asset	$ 0		$ 0			$ 4,243,000
Derivative instruments not designated as hedging instruments | Interest Rate Cap
Derivative [Line Items]
Number of Instruments | instrument	2		2
Notional Amount	$ 46,875,000		$ 46,875,000
Maturity Date			Feb. 13, 2020
Derivative instruments not designated as hedging instruments | Interest Rate Cap | Prepaid expenses and other assets
Derivative [Line Items]
Number of Instruments | instrument	2		2			1	1
Derivative Asset	$ 156,000		$ 156,000			$ 14,000
Derivative instruments not designated as hedging instruments | Interest Rate Cap | One-month LIBOR
Derivative [Line Items]
Reference Rate	3.00%		3.00%
Derivative instruments not designated as hedging instruments | Interest Rate Cap, Effective Date 4/2/18
Derivative [Line Items]
Notional Amount	$ 77,513,000		$ 77,513,000
Maturity Date			Mar. 5, 2021
Derivative instruments not designated as hedging instruments | Interest Rate Cap, Effective Date 4/2/18 | One-month LIBOR
Derivative [Line Items]
Reference Rate	3.50%		3.50%

FAIR VALUE DISCLOSURES (Narrati

FAIR VALUE DISCLOSURES (Narrative) (Details) - Available-for-sale Securities - Keppel-KBS US REIT - shares	Mar. 31, 2018	Nov. 08, 2017	Sep. 30, 2018	Dec. 31, 2017	May 08, 2018
Schedule of Available-for-sale Securities [Line Items]
Shares owned (in shares)		43,999,500	43,999,500	43,999,500
Shares transfered from Level 2 to Level 1 (in shares)					21,999,750
Lack of Marketability
Schedule of Available-for-sale Securities [Line Items]
Shares owned (in shares)	21,999,750
Level 1
Schedule of Available-for-sale Securities [Line Items]
Shares owned (in shares)	21,999,750

FAIR VALUE DISCLOSURES (Schedul

FAIR VALUE DISCLOSURES (Schedule of Face Value, Carrying Amounts and Fair Value) (Details) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Real estate debt securities, Face Value	$ 17,500,000	$ 17,500,000
Notes and bond payable, Face Value	482,896,000	332,893,000
Series A Debentures
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes and bond payable, Face Value	266,854,000	278,801,000
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Real estate debt securities, Value	17,855,000	17,751,000
Notes and bond payable, Value	479,296,000	330,727,000
Carrying Amount | Series A Debentures
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes and bond payable, Value	261,833,000	272,316,000
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Real estate debt securities, Value	17,459,000	17,386,000
Notes and bond payable, Value	487,215,000	335,212,000
Fair Value | Series A Debentures
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes and bond payable, Value	$ 271,353,000	$ 296,069,000

FAIR VALUE DISCLOSURES (Sched_2

FAIR VALUE DISCLOSURES (Schedule of Assets and Liabilities at Fair Value) (Details) - Recurring Basis $ in Thousands	Sep. 30, 2018USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Real estate equity securities	$ 98,735
Asset derivative - foreign currency collar	171
Interest Rate Cap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset derivative - interest rate caps	156
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Real estate equity securities	81,641
Asset derivative - foreign currency collar	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Interest Rate Cap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset derivative - interest rate caps	0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Real estate equity securities	17,094
Asset derivative - foreign currency collar	171
Significant Other Observable Inputs (Level 2) | Interest Rate Cap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset derivative - interest rate caps	156
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Real estate equity securities	0
Asset derivative - foreign currency collar	0
Significant Unobservable Inputs (Level 3) | Interest Rate Cap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset derivative - interest rate caps	$ 0

RELATED PARTY TRANSACTIONS (Det

RELATED PARTY TRANSACTIONS (Details) $ in Thousands	Nov. 08, 2017property	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Related Party Transaction [Line Items]
Payable as of		$ 65		$ 65		$ 26
Payment for administrative fees		74	$ 49	235	$ 168
Singapore Portfolio
Related Party Transaction [Line Items]
Number of real estate properties disposed | property	11
Advisor and Dealer Manager
Related Party Transaction [Line Items]
Capitalized		3,249	2,965	10,741	10,709
Payable as of		65		65		26
Advisor and Dealer Manager | Asset management fees
Related Party Transaction [Line Items]
Expensed		2,299	2,800	6,342	8,404
Payable as of		0		0		0
Advisor and Dealer Manager | Reimbursable operating expenses
Related Party Transaction [Line Items]
Expensed		90	51	288	184
Payable as of		65		65		26
Advisor and Dealer Manager | Disposition fees
Related Party Transaction [Line Items]
Expensed		860	0	860	785
Payable as of		0		0		0
Advisor and Dealer Manager | Acquisition fees on real estate
Related Party Transaction [Line Items]
Capitalized		0	71	3,094	907
Payable as of		0		0		0
Advisor and Dealer Manager | Acquisition fees on real estate equity securities
Related Party Transaction [Line Items]
Capitalized		0	43	157	429
Payable as of		0		0		$ 0
KBS Capital Advisors LLC | Evaluate certain strategic transactions
Related Party Transaction [Line Items]
Capitalized			$ 400
KBS Capital Advisors LLC | Property insurance rebate
Related Party Transaction [Line Items]
Capitalized		$ 100		$ 100	$ 100

INVESTMENT IN UNCONSOLIDATED _3

INVESTMENT IN UNCONSOLIDATED JOINT VENTURES (Investments in Unconsolidated Joint Ventures) (Details) $ in Thousands	Sep. 30, 2018USD ($)property	Dec. 31, 2017USD ($)
Schedule of Equity Method Investments [Line Items]
Investment Balance	$ 47,304	$ 55,577
NIP Joint Venture
Schedule of Equity Method Investments [Line Items]
Number of Properties | property	2
Investment Balance	$ 1,476	3,674
NIP Joint Venture | Maximum
Schedule of Equity Method Investments [Line Items]
Ownership %	5.00%
110 William Joint Venture
Schedule of Equity Method Investments [Line Items]
Number of Properties | property	1
Ownership %	60.00%
Investment Balance	$ 2,414	7,160
353 Sacramento Joint Venture
Schedule of Equity Method Investments [Line Items]
Number of Properties | property	1
Ownership %	55.00%
Investment Balance	$ 43,414	$ 44,743

INVESTMENT IN UNCONSOLIDATED _4

INVESTMENT IN UNCONSOLIDATED JOINT VENTURES (Narrative) (Details) $ in Thousands	May 18, 2012USD ($)	Sep. 30, 2018USD ($)ft²	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)ft²	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)	Jul. 06, 2017	May 02, 2014ft²
Schedule of Equity Method Investments [Line Items]
Contributions to joint venture				$ 1,320	$ 0
Investments in unconsolidated joint ventures		$ 47,304		47,304		$ 55,577
Income from unconsolidated joint venture		$ 244	$ 0	$ 428	1,869
Rentable square feet | ft²		3,800,000		3,800,000
Joint Venture
Schedule of Equity Method Investments [Line Items]
Ownership interest							55.00%
Office Properties | 353 Sacramento | Disposed of by Sale
Schedule of Equity Method Investments [Line Items]
Ownership interest							45.00%
110 William JV Partner
Schedule of Equity Method Investments [Line Items]
Return of capital				$ 58,200
Capital distribution				38,800
Migdal Members
Schedule of Equity Method Investments [Line Items]
Ownership interest							45.00%
NIP Joint Venture
Schedule of Equity Method Investments [Line Items]
Contributions to joint venture	$ 8,000
Investments in unconsolidated joint ventures		$ 1,476		1,476		3,674
Distributions		1,200		2,600	2,900
Income from unconsolidated joint venture		200		400	1,900
Return of capital		$ 1,000		$ 2,200	$ 1,000
NIP Joint Venture | Maximum
Schedule of Equity Method Investments [Line Items]
Ownership interest		5.00%		5.00%
110 William Joint Venture
Schedule of Equity Method Investments [Line Items]
Ownership interest		60.00%		60.00%
Investments in unconsolidated joint ventures		$ 2,414		$ 2,414		7,160
Rentable square feet | ft²								928,157
Area of land | ft²								0.8
Acquisition related costs				1,500
110 William Joint Venture | 110 William JV Partner
Schedule of Equity Method Investments [Line Items]
Ownership interest								60.00%
Noncontrolling interest								40.00%
353 Sacramento Joint Venture
Schedule of Equity Method Investments [Line Items]
Contributions to joint venture				$ 1,300
Ownership interest		55.00%		55.00%
Investments in unconsolidated joint ventures		$ 43,414		$ 43,414		$ 44,743

INVESTMENT IN UNCONSOLIDATED _5

INVESTMENT IN UNCONSOLIDATED JOINT VENTURES (Summarized Financial Information - 110 William Joint Venture) (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Real estate assets, net of accumulated depreciation and amortization	$ 804,079	$ 804,079		$ 804,079		$ 502,222
Total assets	1,109,499	1,109,499		1,109,499		1,101,574
Other liabilities	16,538	16,538		16,538		16,966
Total liabilities and equity	1,109,499	1,109,499		1,109,499		1,101,574
Income Statement [Abstract]
Revenues	27,156		$ 36,414	72,082	$ 114,648
Operating, maintenance, and management	8,336		11,431	21,395	33,638
Real estate taxes and insurance	3,208		4,780	8,982	14,932
Depreciation and amortization	9,826		13,228	26,133	43,136
Interest expense	8,404		9,618	22,814	29,327
Total expenses	33,569		47,381	82,597	145,006
Net income (loss) attributable to common stockholders	36,497		(10,534)	22,852	4,220
Company’s equity in loss of unconsolidated joint venture	(2,644)		(2,152)	(7,394)	(3,928)
110 William Joint Venture
Balance Sheet Related Disclosures [Abstract]
Real estate assets, net of accumulated depreciation and amortization	237,302	237,302		237,302		248,269
Other assets	39,484	39,484		39,484		32,331
Total assets	276,786	276,786		276,786		280,600
Notes payable, net	266,326	266,326		266,326		260,108
Other liabilities	8,843	8,843		8,843		11,016
Partners’ capital	1,617	1,617		1,617		9,476
Total liabilities and equity	276,786	276,786		276,786		280,600
Income Statement [Abstract]
Revenues	10,137		9,614	29,897	27,328
Operating, maintenance, and management	2,550		2,577	7,313	7,343
Real estate taxes and insurance	1,715		1,637	5,005	4,725
Depreciation and amortization	4,075		4,664	12,420	12,277
Interest expense	4,557		3,951	13,092	9,150
Total expenses	12,897		12,829	37,830	33,495
Other income	37		14	75	42
Net income (loss) attributable to common stockholders	(2,723)		(3,201)	(7,858)	(6,125)
Company’s equity in loss of unconsolidated joint venture	(1,644)		$ (1,930)	(4,746)	$ (3,706)
353 Sacramento Joint Venture
Balance Sheet Related Disclosures [Abstract]
Real estate assets, net of accumulated depreciation and amortization	179,420	179,420		179,420		171,066
Other assets	9,219	9,219		9,219		6,472
Total assets	188,639	188,639		188,639		177,538
Notes payable, net	96,562	96,562		96,562		89,423
Other liabilities	13,625	13,625		13,625		7,313
Partners’ capital	78,452	78,452		78,452		80,802
Total liabilities and equity	188,639	188,639		188,639		$ 177,538
Income Statement [Abstract]
Revenues	2,475	3,507		7,771
Operating, maintenance, and management	906	936		2,675
Real estate taxes and insurance	611	603		1,828
Depreciation and amortization	1,408	1,724		4,245
Interest expense	1,426	1,138		4,013
Total expenses	4,351	4,401		12,761
Net income (loss) attributable to common stockholders	(1,876)	(894)		(4,990)
Company’s equity in loss of unconsolidated joint venture	$ (1,000)	$ (222)		$ (2,648)

SUPPLEMENTAL CASH FLOW AND SI_3

SUPPLEMENTAL CASH FLOW AND SIGNIFICANT NONCASH TRANSACTION DISCLOSURES (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Supplemental Disclosure of Cash Flow Information:
Interest paid, net of capitalized interest of $1,916 and $1,732 for the nine months ended September 30, 2018 and 2017, respectively	$ 22,485	$ 27,732
Interest capitalized	1,916	1,732
Assets and liabilities deconsolidated in connection with the 353 Sacramento partial sale:
Real estate, net	804,079		$ 502,222
Rents and other receivables, net	14,103		8,755
Prepaid expenses and other assets	18,056		17,404
Accounts payable and accrued liabilities	17,788		16,686
Below-market leases, net	5,554		2,843
Other liabilities	16,538		$ 16,966
Application of escrow deposits to acquisition of real estate	0	2,000
Increase in accrued improvements to real estate	1,179	1,319
Distributions paid to common stockholders through common stock issuances pursuant to the dividend reinvestment plan	1,418	8,666
Distributions paid to common stockholders through common stock issuances pursuant to the December 2017 special dividend	150,299	0
353 Sacramento
Assets and liabilities deconsolidated in connection with the 353 Sacramento partial sale:
Real estate, net	0	170,586
Rents and other receivables, net	0	1,244
Prepaid expenses and other assets	0	555
Notes payable, net	0	87,132
Accounts payable and accrued liabilities	0	1,574
Below-market leases, net	0	2,960
Other liabilities	$ 0	$ 924

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Details) - KBS Capital Advisors LLC $ in Millions	Sep. 30, 2018USD ($)
Related Party Transaction [Line Items]
Noncompounded return on invested capital as percent per year, percent	7.00%
Percent of net cash flows to be received by related party, percent	15.00%
Distributions paid from operating cash flows, annual return, percent	7.00%
Incentive Compensation
Related Party Transaction [Line Items]
Liabilities at fair value	$ 43

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details) $ in Thousands	Oct. 16, 2018USD ($)a	Sep. 30, 2018USD ($)	Jul. 17, 2018USD ($)	Dec. 31, 2017USD ($)
Subsequent Event [Line Items]
Real estate held for sale, net		$ 0		$ 30,645
Central Building | Disposed of by Sale
Subsequent Event [Line Items]
Sale price			$ 67,500
Subsequent Event | Park Highlands Undeveloped Land | Disposed of by Sale
Subsequent Event [Line Items]
Area of land sold | a	15
Sale price	$ 3,500