KBS Real Estate Investment Trust III (KBSR) 10-Q 8 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Nov. 02, 2018
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Entity Registrant Name	KBS Real Estate Investment Trust III, Inc.
Entity Central Index Key	1,482,430
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		177,207,876

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Real estate:
Land	$ 393,434	$ 390,685
Buildings and improvements	2,788,881	2,680,838
Construction in progress	29,721	67,826
Tenant origination and absorption costs	212,737	230,576
Total real estate held for investment, cost	3,424,773	3,369,925
Less accumulated depreciation and amortization	(508,654)	(435,808)
Total real estate held for investment, net	2,916,119	2,934,117
Real estate held for sale, net	0	28,017
Total real estate, net	2,916,119	2,962,134
Cash and cash equivalents	78,186	65,486
Investment in unconsolidated joint venture	34,662	33,997
Rents and other receivables, net	96,496	79,317
Above-market leases, net	4,563	5,861
Assets related to real estate held for sale, net	0	1,786
Prepaid expenses and other assets	107,213	72,226
Total assets	3,237,239	3,220,807
Notes payable, net
Notes payable related to real estate held for investment, net	2,068,199	1,920,138
Note payable related to real estate held for sale, net	0	21,648
Total notes payable, net	2,068,199	1,941,786
Accounts payable and accrued liabilities	79,328	71,012
Due to affiliate	6,271	3,239
Distributions payable	9,424	9,982
Below-market leases, net	18,930	24,610
Liabilities related to real estate held for sale, net	0	50
Redeemable common stock payable	10,353	18,870
Other liabilities	24,218	30,935
Total liabilities	2,216,723	2,100,484
Commitments and contingencies (Note 10)
Redeemable common stock	40,618	40,915
KBS Real Estate Investment Trust III, Inc. stockholders’ equity
Preferred stock, $.01 par value per share; 10,000,000 shares authorized, no shares issued and outstanding	0	0
Common stock, $.01 par value per share; 1,000,000,000 shares authorized, 176,422,788 and 180,864,707 shares issued and outstanding as of September 30, 2018 and December 31, 2017, respectively	1,764	1,809
Additional paid-in capital	1,548,370	1,591,640
Cumulative distributions and net losses	(570,536)	(514,451)
Accumulated other comprehensive income	0	110
Total KBS Real Estate Investment Trust III, Inc. stockholders’ equity	979,598	1,079,108
Noncontrolling interest	300	300
Total equity	979,898	1,079,408
Total liabilities and equity	$ 3,237,239	$ 3,220,807

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)	176,422,788	180,864,707
Common stock, shares outstanding (in shares)	176,422,788	180,864,707

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	$ 80,086	$ 77,798	$ 238,422	$ 236,200
Tenant reimbursements	20,185	19,063	61,297	57,652
Other operating income	5,874	5,697	18,181	17,124
Total revenues	106,145	102,558	317,900	310,976
Expenses:
Operating, maintenance and management	26,397	25,293	73,852	70,765
Real estate taxes and insurance	16,898	16,460	52,158	48,721
Asset management fees to affiliate	6,830	6,587	20,188	19,223
General and administrative expenses	3,166	983	6,701	3,324
Depreciation and amortization	40,824	41,151	118,831	124,370
Interest expense	16,584	15,460	29,911	45,257
Total expenses	110,699	105,934	301,641	311,660
Other income (loss):
Other income	3	0	1,879	650
Other interest income	108	23	204	73
Equity in income (loss) of unconsolidated joint venture	373	0	25	(1)
Gain on sale of real estate, net	0	0	11,942	0
Total other income, net	484	23	14,050	722
Net (loss) income	(4,070)	(3,353)	30,309	38
Net loss attributable to noncontrolling interest	0	202	0	229
Net (loss) income attributable to common stockholders	$ (4,070)	$ (3,151)	$ 30,309	$ 267
Net (loss) income per common share, basic and diluted (in dollars per share)	$ (0.02)	$ (0.02)	$ 0.17	$ 0
Weighted-average number of common shares outstanding, basic and diluted (in shares)	176,040,649	180,975,877	177,729,817	181,320,425

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 (loss) income	$ (4,070)	$ (3,151)	$ 30,309	$ 267
Other comprehensive (loss) income:
Unrealized income on derivative instruments designated as cash flow hedges	5	13	88	602
Reclassification adjustment realized in net income (effective portion)	(90)	253	(198)	1,717
Total other comprehensive (loss) income	(85)	266	(110)	2,319
Total comprehensive (loss) income	(4,155)	(2,885)	30,199	2,586
Total comprehensive loss attributable to noncontrolling interest	0	202	0	229
Total comprehensive (loss) income attributable to common stockholders	$ (4,155)	$ (2,683)	$ 30,199	$ 2,815

CONSOLIDATED STATEMENTS OF EQUI

CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	Total Stockholders’ Equity	Common Stock	Additional Paid-in Capital	Cumulative Distributions and Net Income (Losses)	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest
Balance (in shares) at Dec. 31, 2016			180,890,572
Balance at Dec. 31, 2016	$ 1,193,376	$ 1,193,076	$ 1,809	$ 1,591,652	$ (398,087)	$ (2,298)	$ 300
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,374	1,374			1,374
Other comprehensive income (loss)	2,408	2,408				2,408
Issuance of common stock (in shares)			5,919,223
Issuance of common stock	59,785	59,785	$ 59	59,726
Transfers from redeemable common stock	2,086	2,086		2,086
Redemptions of common stock (in shares)			(5,945,088)
Redemptions of common stock	(61,871)	(61,871)	$ (59)	(61,812)
Distributions declared	(117,738)	(117,738)			(117,738)
Other offering costs	$ (12)	(12)		(12)
Balance (in shares) at Dec. 31, 2017	180,864,707		180,864,707
Balance at Dec. 31, 2017	$ 1,079,408	1,079,108	$ 1,809	1,591,640	(514,451)	110	300
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	30,309	30,309			30,309		0
Other comprehensive income (loss)	(110)	(110)				(110)
Issuance of common stock (in shares)			3,806,525
Issuance of common stock	42,443	42,443	$ 38	42,405
Transfers from redeemable common stock	8,813	8,813		8,813
Redemptions of common stock (in shares)			(8,248,444)
Redemptions of common stock	(94,569)	(94,569)	$ (83)	(94,486)
Distributions declared	(86,394)	(86,394)			(86,394)
Other offering costs	$ (2)	(2)		(2)
Balance (in shares) at Sep. 30, 2018	176,422,788		176,422,788
Balance at Sep. 30, 2018	$ 979,898	$ 979,598	$ 1,764	$ 1,548,370	$ (570,536)	$ 0	$ 300

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash Flows from Operating Activities:
Net income	$ 30,309	$ 38
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	118,831	124,370
Equity in (income) loss of unconsolidated joint venture	(25)	1
Deferred rents	(6,932)	(8,527)
Loss due to property damage	0	371
Bad debt expense	768	1,065
Amortization of above- and below-market leases, net	(4,360)	(5,189)
Amortization of deferred financing costs	4,693	3,537
Unrealized gains on derivative instruments	(30,102)	(2,579)
Gain on sale of real estate	(11,942)	0
Changes in operating assets and liabilities:
Rents and other receivables	(10,983)	(4,168)
Prepaid expenses and other assets	(19,295)	(18,881)
Accounts payable and accrued liabilities	10,534	5,709
Other liabilities	(5,023)	(5,145)
Due to affiliates	2,535	(37)
Net cash provided by operating activities	79,008	90,565
Cash Flows from Investing Activities:
Improvements to real estate	(70,754)	(54,070)
Proceeds from sale of real estate, net	41,649	0
Payments for construction in progress	(24,979)	(32,967)
Investment in unconsolidated joint venture	(426)	(33,421)
Escrow deposits for tenant improvements	1,111	(3,762)
Insurance proceeds received for property damage	4,629	0
Net cash used in investing activities	(48,770)	(124,220)
Cash Flows from Financing Activities:
Proceeds from notes payable	162,035	107,385
Principal payments on notes payable	(40,327)	(1,893)
Payments of deferred financing costs	(166)	(1,264)
Payments to redeem common stock	(94,569)	(54,669)
Payments of other offering costs	(2)	(1)
Distributions paid to common stockholders	(44,509)	(43,396)
Net cash (used in) provided by financing activities	(17,538)	6,162
Net increase (decrease) in cash and cash equivalents	12,700	(27,493)
Cash and cash equivalents, beginning of period	65,486	72,068
Cash and cash equivalents, end of period	78,186	44,575
Supplemental Disclosure of Cash Flow Information:
Interest paid, net of capitalized interest of $2,452 and $1,543 for the nine months ended September 30, 2018 and 2017, respectively	54,623	43,101
Supplemental Disclosure of Noncash Investing and Financing Activities:
Distributions paid to common stockholders through common stock issuances pursuant to the dividend reinvestment plan	42,443	45,098
Increase in accrued improvements to real estate	0	8,149
Increase in construction in progress payable	2,533	856
Increase in acquisition fee related to construction in progress due to affiliate	303	234
Increase in acquisition fee on unconsolidated joint venture due to affiliate	$ 194	$ 173

CONSOLIDATED STATEMENTS OF CA_2

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Statement of Cash Flows [Abstract]
Interest capitalized	$ 2,452	$ 1,543

ORGANIZATION

ORGANIZATION	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
ORGANIZATION	ORGANIZATION KBS Real Estate Investment Trust III, Inc. (the “Company”) was formed on December 22, 2009 as a Maryland corporation that elected to be taxed as a real estate investment trust (“REIT”) beginning with the taxable year ended December 31, 2011 and it intends to continue to operate in such manner. Substantially all of the Company’s business is conducted through KBS Limited Partnership III (the “Operating Partnership”), a Delaware limited partnership. The Company is the sole general partner of and owns a 0.1% partnership interest in the Operating Partnership. KBS REIT Holdings III LLC (“REIT Holdings III”), the limited partner of the Operating Partnership, 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 III. 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 entered into with the Advisor (the “Advisory Agreement”). On January 26, 2010, the Company issued 20,000 shares of its common stock to the Advisor at a purchase price of $10.00 per share. As of September 30, 2018 , the Advisor owned 20,000 shares of the Company’s common stock. The Company owns a diverse portfolio of real estate investments. As of September 30, 2018 , the Company owned 27 office properties and one mixed-use office/retail property and had made an investment in an unconsolidated joint venture to develop and operate an office/retail property. Additionally, as of September 30, 2018 , the Company had entered into a consolidated joint venture to develop and subsequently operate a multifamily apartment project, which is currently under construction. The Company commenced its initial public offering (the “Offering”) on October 26, 2010. Upon commencing the Offering, the Company retained KBS Capital Markets Group LLC (the “Dealer Manager”), an affiliate of the Company, to serve as the dealer manager of the Offering pursuant to a dealer manager agreement, as amended and restated (the “Dealer Manager Agreement”). The Company ceased offering shares of common stock in the primary Offering on May 29, 2015 and terminated the primary Offering on July 28, 2015. The Company sold 169,006,162 shares of common stock in the primary Offering for gross proceeds of $1.7 billion . As of September 30, 2018 , the Company had also sold 26,698,976 shares of common stock under its dividend reinvestment plan for gross offering proceeds of $267.2 million . Also as of September 30, 2018 , the Company had redeemed 19,560,813 shares sold in the Offering for $209.0 million . Additionally, on October 3, 2014, the Company issued 258,462 shares of common stock for $2.4 million in private transactions exempt from the registration requirements pursuant to Section 4(a)(2) of the Securities Act of 1933. The Company continues to offer shares of common stock under its dividend reinvestment plan. In some states, the Company will need to renew the registration statement annually or file a new registration statement to continue its dividend reinvestment plan offering. The Company may terminate its dividend reinvestment plan offering at any time.

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 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 Securities and Exchange Commission (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 III, the Operating Partnership, their direct and indirect wholly owned subsidiaries, and a joint venture 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 and condensed notes thereto in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and condensed notes. Actual results could materially differ from those estimates. 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 $2.2 million and $5.7 million , respectively, and were included in tenant reimbursements on the accompanying statements of operations. Sales 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. 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 , respectively. Distributions declared per common share were $0.164 and $ 0.486 for the three and nine months ended September 30, 2018 , respectively. Distributions declared per common share were $0.164 and $ 0.486 for the three and nine months ended September 30, 2017 , respectively. Distributions declared per common share assumes each share was issued and outstanding each day during the three and nine months ended September 30, 2018 and 2017 , respectively. For each day that was a record date for distributions during the three and nine months ended September 30, 2018 and 2017 , distributions were calculated at a rate of $0.00178082 per share per day. Each day during the periods from January 1, 2017 through September 30, 2017 and January 1, 2018 through September 30, 2018 was a record date for distributions. Segments The Company has invested in core real estate properties and real estate-related investments with the goal of acquiring a portfolio of income-producing investments. The Company’s real estate properties exhibit similar long-term financial performance and have similar economic characteristics to each other. As of September 30, 2018 , the Company aggregated its investments in real estate properties into one reportable business segment. Square Footage, Occupancy and Other Measures Square footage, occupancy, number of tenants and other measures, including annualized base rent and annualized base rent per square foot, or amounts derived from such measures, used to describe real estate investments included in these condensed notes to consolidated financial statements 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 Update 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 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 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, but does not expect the adoption of ASU No. 2016-13 to have a material impact 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.

REAL ESTATE

REAL ESTATE	9 Months Ended
	Sep. 30, 2018
Real Estate [Abstract]
REAL ESTATE	REAL ESTATE Real Estate Held for Investment As of September 30, 2018 , the Company’s real estate portfolio held for investment was composed of 27 office properties and one mixed-use office/retail property encompassing in the aggregate approximately 10.9 million rentable square feet. In addition, the Company had entered into a consolidated joint venture to develop and subsequently operate a multifamily apartment project, which is currently under construction. As of September 30, 2018 , the Company’s real estate portfolio was collectively 93% occupied. The following table summarizes the Company’s investments in real estate as of September 30, 2018 (in thousands): Property Date Acquired City State Property Type Total Real Estate, at Cost Accumulated Depreciation and Amortization Total Real Estate, Net Domain Gateway 09/29/2011 Austin TX Office $ 49,177 $ (15,150 ) $ 34,027 Town Center 03/27/2012 Plano TX Office 116,280 (27,923 ) 88,357 McEwen Building 04/30/2012 Franklin TN Office 37,130 (8,181 ) 28,949 Gateway Tech Center 05/09/2012 Salt Lake City UT Office 25,422 (6,300 ) 19,122 Tower on Lake Carolyn 12/21/2012 Irving TX Office 52,829 (11,403 ) 41,426 RBC Plaza 01/31/2013 Minneapolis MN Office 153,425 (36,417 ) 117,008 One Washingtonian Center 06/19/2013 Gaithersburg MD Office 91,953 (18,130 ) 73,823 Preston Commons 06/19/2013 Dallas TX Office 117,737 (22,638 ) 95,099 Sterling Plaza 06/19/2013 Dallas TX Office 79,076 (12,750 ) 66,326 201 Spear Street 12/03/2013 San Francisco CA Office 142,663 (14,838 ) 127,825 500 West Madison 12/16/2013 Chicago IL Office 435,174 (67,343 ) 367,831 222 Main 02/27/2014 Salt Lake City UT Office 165,437 (29,473 ) 135,964 Anchor Centre 05/22/2014 Phoenix AZ Office 96,085 (15,380 ) 80,705 171 17th Street 08/25/2014 Atlanta GA Office 133,339 (26,009 ) 107,330 Reston Square 12/03/2014 Reston VA Office 46,579 (8,111 ) 38,468 Ten Almaden 12/05/2014 San Jose CA Office 124,435 (16,618 ) 107,817 Towers at Emeryville 12/23/2014 Emeryville CA Office 273,887 (30,730 ) 243,157 101 South Hanley 12/24/2014 St. Louis MO Office 72,320 (11,040 ) 61,280 3003 Washington Boulevard 12/30/2014 Arlington VA Office 151,150 (19,003 ) 132,147 Village Center Station 05/20/2015 Greenwood Village CO Office 75,035 (9,863 ) 65,172 Park Place Village 06/18/2015 Leawood KS Office/Retail 127,930 (16,836 ) 111,094 201 17th Street 06/23/2015 Atlanta GA Office 102,679 (13,756 ) 88,923 Promenade I & II at Eilan 07/14/2015 San Antonio TX Office 62,646 (8,918 ) 53,728 CrossPoint at Valley Forge 08/18/2015 Wayne PA Office 90,352 (11,051 ) 79,301 515 Congress 08/31/2015 Austin TX Office 120,654 (13,309 ) 107,345 The Almaden 09/23/2015 San Jose CA Office 169,116 (15,813 ) 153,303 3001 Washington Boulevard 11/06/2015 Arlington VA Office 60,560 (4,511 ) 56,049 Carillon 01/15/2016 Charlotte NC Office 153,514 (16,534 ) 136,980 Hardware Village (1) 08/26/2016 Salt Lake City UT Development/Apartment 98,189 (626 ) 97,563 $ 3,424,773 $ (508,654 ) $ 2,916,119 ___________________ (1) On August 26, 2016, the Company, through an indirect wholly-owned subsidiary, entered into a joint venture (the “Hardware Village Joint Venture”) to develop and subsequently operate a multifamily apartment complex, located on the developable land at Gateway Tech Center. The Company owns a 99.24% equity interest in the joint venture. In July 2018, one of the two buildings consisting of 265 units was placed into service. As of September 30, 2018 , the following property represented more than 10% of the Company’s total assets: Property Location Rentable Total Real Estate, Net Percentage Annualized Base Rent (1) Average Annualized Base Rent per sq. ft. Occupancy 500 West Madison Chicago, IL 1,457,724 $ 367,831 11.4 % $ 33,080 $ 28.59 79.4 % _____________________ (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. Operating Leases 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 had remaining terms, excluding options to extend, of up to 13.6 years with a weighted-average remaining term of 4.4 years . Some of the leases have provisions to extend the term of the leases, options for early termination for all or a part of the leased premises 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 the tenant 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 lease and the creditworthiness of the tenant, but generally is not a significant amount. 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 related to tenant leases are included in other liabilities in the accompanying consolidated balance sheets and totaled $10.8 million and $11.5 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 $6.9 million and $8.5 million , respectively. As of September 30, 2018 and December 31, 2017 , the cumulative deferred rent balance was $88.7 million and $74.4 million , respectively, and is included in rents and other receivables on the accompanying balance sheets. The cumulative deferred rent balance included $15.7 million and $9.3 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 under its non-cancelable operating leases was as follows (in thousands): October 1, 2018 through December 31, 2018 $ 75,926 2019 295,053 2020 271,651 2021 246,040 2022 213,601 Thereafter 664,928 $ 1,767,199 As of September 30, 2018 , the Company’s real estate properties were leased to approximately 850 tenants over a diverse range of industries and geographic areas. The Company’s highest tenant industry concentration (greater than 10% of annualized base rent) was as follows: Industry Number of Tenants Annualized Base Rent (1) (in thousands) Percentage of Annualized Base Rent Finance 151 $ 62,011 19.8 % _____________________ (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. As of September 30, 2018 , no other tenant industries accounted for more than 10% of annualized base rent and no tenant 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 net investments in real estate in California, Texas and Illinois represented 20% , 15% and 11% of the Company’s total assets, respectively. As a result, the geographic concentration of the Company’s portfolio makes it particularly susceptible to adverse economic developments in the California, Texas and Illinois 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 pay distributions to stockholders. Property Damage In December 2017, 222 Main located in Salt Lake City, Utah suffered physical damages due to a broken sprinkler pipe. The Company’s insurance policy provides coverage for property damage and business interruption subject to a deductible of up to $5,000 per incident. Based on management’s estimates, the Company recognized an estimated aggregate loss due to damages of $7.9 million during the year ended December 31, 2017, which was reduced by $7.9 million of estimated insurance recoveries related to such damages, which the Company determined were probable of collection. The aggregate net loss of $5,000 due to damages during the year ended December 31, 2017 was classified as operating, maintenance and management expenses in the Company’s consolidated statement of operations for the year ended December 31, 2017 included in the Company’s Annual Report on Form 10-K filed with the SEC and relates to the Company’s insurance deductible. During the nine months ended September 30, 2018 , the Company received $4.6 million in insurance recoveries relating to the property damage. In addition, the Company reduced the estimated aggregate loss due to damages and the estimated insurance recoveries related to such damages by $2.4 million . During the nine months ended September 30, 2018 , the Company recorded $0.6 million of business interruption insurance recovery, which is included in rental income on the accompanying consolidated statements of operations. During the nine months ended September 30, 2018 , the Company received $1.3 million of business interruption insurance recovery, consisting of $0.7 million of revenue related to the year ended December 31, 2017 and $0.6 million of revenue related to the period from January through May 2018. As of September 30, 2018 , the Company recorded $0.9 million of insurance recoveries receivable, which is included in prepaid expenses and other assets on the accompanying consolidated balance sheet. Real Estate Sales In accordance with ASU No. 2014-08, Presentation of Financial Statements (Topic 205) and Property, Plant, and Equipment (Topic 360): Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity (“ASU No. 2014-08”), results of operations from properties that are classified as held for sale in the ordinary course of business would generally be included in continuing operations on the Company’s consolidated statements of operations. During the nine months ended September 30, 2018 , the Company disposed of one office property. During the year ended December 31, 2017 , the Company did not dispose of any real estate properties. On November 6, 2014, the Company, through an indirect wholly owned subsidiary, acquired an office property containing 220,020 rentable square feet located on approximately 13.9 acres of land in Rocklin, California (“Rocklin Corporate Center”). On May 25, 2018, the Company sold Rocklin Corporate Center to a purchaser unaffiliated with the Company or the Advisor for $42.9 million before closing costs and credits. The carrying value of Rocklin Corporate Center as of the disposition date was $29.7 million , which was net of $6.0 million of accumulated depreciation and amortization. The Company recognized a gain on sale of $11.9 million related to the disposition of Rocklin Corporate Center. The results of operations for the property sold during the nine months ended September 30, 2018 and gain on sale as of September 30, 2018 are included in continuing operations on the Company’s consolidated statements of operations. The following table summarizes certain revenues and expenses related to this property for the three and nine months ended September 30, 2018 and 2017 (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 Revenues Rental income $ — $ 1,135 $ 1,802 $ 3,375 Tenant reimbursements and other operating income — 41 110 112 Total revenues $ — $ 1,176 $ 1,912 $ 3,487 Expenses Operating, maintenance, and management $ — $ 464 $ 463 $ 1,086 Real estate taxes and insurance — 131 213 348 Asset management fees to affiliate — 67 105 198 Depreciation and amortization — 543 — 1,605 Interest expense — 176 320 483 Total expenses $ — $ 1,381 $ 1,101 $ 3,720 The following summary presents the major components of assets and liabilities related to real estate held for sale as of December 31, 2017 (in thousands). No real estate properties were held for sale as of September 30, 2018 . September 30, 2018 December 31, 2017 Assets related to real estate held for sale Total real estate, at cost $ — $ 33,575 Accumulated depreciation and amortization — (5,558 ) Real estate held for sale, net — 28,017 Other assets — 1,786 Total assets related to real estate held for sale $ — $ 29,803 Liabilities related to real estate held for sale Notes payable, net — 21,648 Other liabilities — 50 Total liabilities related to real estate held for sale $ — $ 21,698

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 $ 212,737 $ 230,576 $ 11,916 $ 12,301 $ (41,270 ) $ (47,459 ) Accumulated Amortization (114,422 ) (108,078 ) (7,353 ) (6,440 ) 22,340 22,849 Net Amount $ 98,315 $ 122,498 $ 4,563 $ 5,861 $ (18,930 ) $ (24,610 ) 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 Absorption Costs Above-Market Lease Assets Below-Market Lease Liabilities 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 $ (8,184 ) $ (10,202 ) $ (430 ) $ (527 ) $ 2,203 $ 2,184 Tenant Origination and Absorption Costs Above-Market Lease Assets Below-Market Lease Liabilities For the Nine Months Ended September 30, For the Nine Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 2018 2017 Amortization $ (24,182 ) $ (32,321 ) $ (1,325 ) $ (1,774 ) $ 5,685 $ 6,963

INVESTMENT IN UNCONSOLIDATED JO

INVESTMENT IN UNCONSOLIDATED JOINT VENTURE	9 Months Ended
	Sep. 30, 2018
Equity Method Investments and Joint Ventures [Abstract]
INVESTMENT IN UNCONSOLIDATED JOINT VENTURE	INVESTMENT IN UNCONSOLIDATED JOINT VENTURE On March 3, 2017, the Company, through an indirect wholly owned subsidiary, acquired a 75% equity interest in an existing company and created a joint venture (the “Village Center Station II Joint Venture”) with an unaffiliated developer, Shea Village Center Station II, LLC (the “Developer”) to develop and subsequently operate a 12-story office building and an adjacent two-story office/retail building in the Denver submarket of Greenwood Village, Colorado (together, “Village Center Station II”). The total cost of the development was approximately $111.2 million and the Company’s initial capital contribution to the Village Center Station II Joint Venture was $32.3 million . The Village Center Station II Joint Venture funded the construction of Village Center Station II with capital contributions from its members and proceeds from a construction loan for borrowings of up to $78.5 million . As of September 30, 2018 , $66.4 million had been drawn under the construction loan. The Company has concluded that the Village Center Station II Joint Venture qualifies as a Variable Interest Entity (“VIE”) and determined that it is not the primary beneficiary of this VIE and to account for its investment in the project under the equity method of accounting. The construction of Village Center Station II was substantially completed in May 2018. The Developer has an option, provided the put conditions have been satisfied, the most significant of which is completion of the project, to require the Company to purchase its 25% equity interest. If the Developer does not make such request, the Company has the right to purchase the Developer’s 25% equity interest. In October 2018, the Company purchased the Developer’s 25% equity interest for $28.2 million . As of September 30, 2018 , the book value of the Company’s investment in the Village Center Station II Joint Venture was $34.7 million which includes $2.3 million of acquisition costs and capitalized interest incurred directly by the Company. As of September 30, 2018 , the Company’s maximum loss exposure related to its investment in the Village Center Station II Joint Venture is equal to the carrying value of its $34.7 million investment. Summarized financial information for the Village Center Station II Joint Venture is as follows (in thousands): September 30, 2018 Assets: Real estate, net $ 104,774 Cash and cash equivalents 3,630 Other assets 4,631 Total assets $ 113,035 Liabilities and equity: Accounts payable $ 2,338 Notes payable, net 66,358 Other liabilities 1,191 Members’ capital 43,148 Total liabilities and equity $ 113,035 Nine Months Ended September 30, 2018 Revenues $ 3,083 Expenses: Operating, maintenance, and management 20 Depreciation and amortization 1,925 Interest expense 1,100 Total expenses 3,045 Other expenses $ 5 Net income $ 33 Company ’s equity in income of unconsolidated joint venture $ 25

NOTES PAYABLE

NOTES PAYABLE	9 Months Ended
	Sep. 30, 2018
Notes Payable [Abstract]
NOTES PAYABLE	NOTES PAYABLE As of September 30, 2018 and December 31, 2017 , the Company’s notes payable 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 (1) Effective Interest Rate as of September 30, 2018 (1) Payment Type Maturity Date (2) Portfolio Loan (3) $ 188,460 $ 188,460 One-month LIBOR + 1.90% 4.00% Interest Only 06/01/2019 222 Main Mortgage Loan 98,016 99,471 3.97% 3.97% Principal & Interest 03/01/2021 Anchor Centre Mortgage Loan 49,799 50,000 One-month LIBOR + 1.50% 3.60% Principal & Interest 06/01/2019 171 17th Street Mortgage Loan 84,668 85,292 One-month LIBOR + 1.45% 3.55% Principal & Interest 09/01/2019 Reston Square Mortgage Loan 29,567 29,800 One-month LIBOR + 1.50% 3.80% Principal & Interest 02/01/2019 101 South Hanley Mortgage Loan 42,401 40,557 One-month LIBOR + 1.55% 3.87% Principal & Interest 01/01/2020 3003 Washington Boulevard Mortgage Loan 90,378 90,378 One-month LIBOR + 1.55% 3.55% Interest Only 02/01/2020 Rocklin Corporate Center Mortgage Loan (4) — 21,689 (4) (4) (4) (4) 201 17th Street Mortgage Loan 64,428 64,428 One-month LIBOR + 1.40% 3.54% Interest Only 08/01/2019 CrossPoint at Valley Forge Mortgage Loan 51,000 51,000 One-month LIBOR + 1.50% 3.33% Interest Only (5) 09/01/2022 The Almaden Mortgage Loan 93,000 93,000 4.20% 4.20% Interest Only 01/01/2022 Promenade I & II at Eilan Mortgage Loan 37,300 37,300 One-month LIBOR + 1.75% 3.57% Interest Only 10/01/2022 515 Congress Mortgage Loan (6) 69,842 68,381 One-month LIBOR + 1.70% 3.63% Interest Only 11/01/2020 201 Spear Street Mortgage Loan 100,000 100,000 One-month LIBOR + 1.66% 3.77% Interest Only 01/01/2019 Carillon Mortgage Loan 92,197 90,248 One-month LIBOR + 1.65% 3.39% Interest Only 02/01/2020 3001 Washington Boulevard Mortgage Loan 30,229 28,404 One-month LIBOR + 1.60% 3.14% Interest Only 02/01/2019 Hardware Village Loan Facility (7) 43,842 21,011 One-month LIBOR + 3.25% 5.36% Interest Only 02/23/2020 Portfolio Loan Facility (8) 913,500 797,500 One-month LIBOR + 1.80% 3.82% Interest Only 11/03/2020 Total notes payable principal outstanding 2,078,627 1,956,919 Deferred financing costs, net (10,428 ) (15,133 ) Total notes payable, net $ 2,068,199 $ 1,941,786 _____________________ (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 the effect of interest rate swaps and caps, if applicable), using interest rate indices as of September 30, 2018 , where applicable. For further information regarding the Company's derivative instruments, see Note 7, “Derivative Instruments.” (2) Represents the maturity date as of September 30, 2018 ; subject to certain conditions, the maturity dates of certain loans may be extended beyond the dates shown. (3) As of September 30, 2018 , the Portfolio Loan was secured by Domain Gateway, the McEwen Building, Gateway Tech Center, the Tower on Lake Carolyn, Park Place Village and Village Center Station. The face amount of the Portfolio Loan is $ 255.0 million , of which $ 127.5 million is term debt and $ 127.5 million is revolving debt. As of September 30, 2018 , the outstanding balance under the loan consisted of $127.5 million of term debt and $61.0 million of revolving debt. As of September 30, 2018 , an additional $65.5 million of revolving debt remained available for immediate future disbursements, subject to certain conditions set forth in the loan agreement. The remaining $1.0 million of revolving debt is available for future disbursements upon the Company meeting certain financial coverage ratios and subject to certain conditions set forth in the loan agreement. During the remaining term of the Portfolio Loan, the Company has an option, which may be exercised up to two times, to increase the loan amount to a maximum of $350.0 million , of which 50% would be term debt and 50% would be revolving debt, with the addition of one or more properties to secure the Portfolio Loan, subject to certain conditions contained in the loan documents. Subsequent to September 30, 2018 , the Company entered into a portfolio revolving loan facility in the amount of up to $215.0 million , of which $ 104.0 million was used to pay down the Portfolio Loan and Domain Gateway, the McEwen Building and Gateway Tech Center were released as security under the Portfolio Loan. See Note 11, “Subsequent Events - Financing Subsequent to September 30, 2018 - Portfolio Revolving Loan Facility and Portfolio Loan.” (4) On May 25, 2018 , in connection with the disposition of Rocklin Corporate Center, the Company paid off the Rocklin Corporate Center Mortgage Loan. (5) Represents the payment type required under the loan as of September 30, 2018 . Certain future monthly payments due under the loan also include amortizing principal payments. For more information on the Company’s contractual obligations under its notes payable, see the five-year maturity table below. (6) Subsequent to September 30, 2018 , the Company entered into a portfolio revolving loan facility in the amount of up to $215.0 million , of which $69.8 million was used to pay off the 515 Congress Mortgage Loan. See Note 11, “Subsequent Events - Financing Subsequent to September 30, 2018 - Portfolio Revolving Loan Facility.” (7) As of September 30, 2018 , $43.8 million had been disbursed and $30.2 million remained available for future disbursements, subject to certain conditions contained in the loan documents. (8) As of September 30, 2018 , the Portfolio Loan Facility was secured by RBC Plaza, Preston Commons, Sterling Plaza, One Washingtonian Center, Towers at Emeryville, Ten Almaden, Town Center and 500 West Madison. The face amount of the Portfolio Loan Facility is $1.01 billion , of which $757.5 million is term debt and $252.5 million is revolving debt. As of September 30, 2018 , the outstanding balance under the loan consisted of $757.5 million of term debt and $156.0 million of revolving debt. As of September 30, 2018 , an additional $96.5 million of revolving debt remained available for immediate future disbursements, subject to certain conditions set forth in the loan agreement. During the remaining term of the Portfolio Loan Facility, the Company has an option to increase the loan amount by up to an additional $400.0 million in increments of $25.0 million , to a maximum of $1.41 billion , of which 75% would be term debt and 25% would be revolving debt, subject to certain conditions contained in the loan documents. During the three and nine months ended September 30, 2018 , the Company incurred $16.6 million and $29.9 million of interest expense, respectively. During the three and nine months ended September 30, 2017 , the Company incurred $15.5 million and $45.3 million of interest expense, respectively. Included in interest expense was: (i) the amortization of deferred financing costs of $1.6 million and $4.9 million for the three and nine months ended September 30, 2018 , respectively, and $1.3 million and $3.8 million for the three and nine months ended September 30, 2017 , respectively, and (ii) interest expense (including gains and losses) incurred as a result of the Company’s derivative instruments, which reduced interest expense by $5.1 million and $29.2 million for the three and nine months ended September 30, 2018 , respectively, and increased interest expense by $0.4 million and $3.1 million for the three and nine months ended September 30, 2017 , respectively. Additionally, the Company capitalized $0.3 million and $2.5 million of interest related to construction in progress during the three and nine months ended September 30, 2018 , respectively, and $0.7 million and $1.5 million of interest related to construction in progress during the three and nine months ended September 30, 2017 , respectively. As of September 30, 2018 and December 31, 2017 , $6.6 million and $6.1 million of interest expense were payable, respectively. The following is a schedule of maturities, including principal amortization payments, for all notes payable outstanding as of September 30, 2018 (in thousands): October 1, 2018 through December 31, 2018 $ 1,074 2019 549,285 2020 1,253,722 2021 93,956 2022 180,590 $ 2,078,627 The Company’s notes payable contain financial debt covenants. As of September 30, 2018 , the Company was in compliance with these 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. 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 interest rate swaps as a fixed rate payer to mitigate its exposure to rising interest rates on its variable rate notes payable. The value of interest rate swaps is 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 the fixed rate payer position and decrease the value of the variable rate payer position. As the remaining life of the interest rate swap decreases, the value of both positions will generally move towards zero. 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. The following table summarizes the notional amount and other information related to the Company’s interest rate swaps and cap 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 (dollars in thousands): September 30, 2018 December 31, 2017 Weighted-Average Fix Pay Rate Weighted-Average Remaining Term in Years Derivative Instruments Number of Instruments Notional Amount Number of Instruments Notional Amount Reference Rate as of September 30, 2018 Derivative instruments designated as hedging instruments Interest rate swaps — $ — 2 $ 118,400 (1) (1) (1) Derivative instruments not designated as hedging instruments Interest rate swaps 14 $ 1,209,147 16 $ 1,209,643 One-month LIBOR/ 2.03% 3.2 Interest rate cap 1 $ 100,000 — $ — One-month LIBOR/ 3.00% 0.3 _____________________ (1) Both interest rate swaps designated as hedging instruments matured during the nine months ended September 30, 2018 . 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 Fair Value Derivative instruments designated as hedging instruments Interest rate swaps Prepaid expenses and other assets, at fair value — $ — 1 $ 128 Interest rate swaps Other liabilities, at fair value — $ — 1 $ (18 ) Derivative instruments not designated as hedging instruments Interest rate swaps Prepaid expenses and other assets, at fair value 14 $ 34,819 10 $ 6,386 Interest rate cap Prepaid expenses and other assets, at fair value 1 $ — — $ — Interest rate swaps Other liabilities, at fair value — $ — 6 $ (1,677 ) The change in fair value of the effective portion of a derivative instrument that is designated as a cash flow hedge is recorded as other comprehensive income (loss) on the accompanying consolidated statements of comprehensive income (loss) and as other comprehensive income on the accompanying consolidated statements of equity. Amounts in other comprehensive income (loss) will be reclassified into earnings in the periods in which earnings are affected by the hedged cash flows. The change in fair value of the ineffective portion is recognized directly in earnings. With respect to swap agreements that are terminated for which it remains probable that the original hedged forecasted transactions (i.e., LIBOR-based debt service payments) will occur, the loss related to the termination of these swap agreements is included in accumulated other comprehensive income (loss) and is reclassified into earnings over the period of the original forecasted hedged transaction. The change in fair value of a derivative instrument that is not designated as a cash flow hedge is recorded as interest expense in the accompanying consolidated statements of operations. The following table summarizes the effects of derivative instruments on the Company’s consolidated statements of operations (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 Income statement related Derivatives designated as hedging instruments Amount of (income) expense recognized on interest rate swaps (effective portion) $ (90 ) $ 253 $ (198 ) $ 1,717 (90 ) 253 (198 ) 1,717 Derivatives not designated as hedging instruments Realized (gain) loss recognized on interest rate swaps (186 ) 1,108 1,123 3,966 Unrealized gain on interest rate swaps (4,784 ) (1,004 ) (30,110 ) (2,579 ) Fair value loss on interest rate cap 8 — 8 — (4,962 ) 104 (28,979 ) 1,387 (Decrease) increase in interest expense as a result of derivatives $ (5,052 ) $ 357 $ (29,177 ) $ 3,104 Other comprehensive income related Unrealized (losses) income on derivative instruments $ 5 $ 13 $ 88 $ 602 During the three and nine months ended September 30, 2018 and 2017 , there was no ineffective portion related to the change in fair value of the derivative instruments designated as cash flow hedges.

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 a combination of market quotes, pricing models and other 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 assets and liabilities for which it is practicable to estimate the fair value: Cash and cash equivalents, rent and other receivables, and accounts payable and accrued liabilities: These balances approximate their fair values due to the short maturities of these items. 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 proprietary model uses the contractual terms of the derivatives, including the period to maturity, as well as observable market-based inputs, including interest rate curves and volatility. The fair values of interest rate swaps are estimated using the market standard methodology of netting the discounted fixed cash payments and the discounted expected variable cash receipts. The variable cash receipts are based on an expectation of interest rates (forward curves) derived from observable market interest rate curves. In addition, credit valuation adjustments, which consider the impact of any credit risks to the contracts, are incorporated in the fair values to account for potential nonperformance risk. 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 (floors) are based on an expectation of future interest rates derived from observed market interest rate curves and volatilities. Notes payable: The fair values of the Company’s notes 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 a liability 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 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 following were the face values, carrying amounts and fair values of the Company’s notes payable as of September 30, 2018 and December 31, 2017 , which carrying amounts generally 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 liabilities: Notes payable $ 2,078,627 $ 2,068,199 $ 2,084,290 $ 1,956,919 $ 1,941,786 $ 1,950,965 Disclosure of the fair values of financial instruments is based on pertinent information available to the Company as of the period end and requires a significant amount of judgment. Low levels of transaction volume for certain financial instruments have 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 Significant Other Observable Inputs Significant Unobservable Inputs Recurring Basis: Asset derivatives - interest rate swaps $ 34,819 $ — $ 34,819 $ — Asset derivatives - interest rate cap $ — $ — $ — $ —

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS	9 Months Ended
	Sep. 30, 2018
Related Party Transactions [Abstract]
RELATED PARTY TRANSACTIONS	RELATED PARTY TRANSACTIONS The Company has entered into the Advisory Agreement with the Advisor and the Dealer Manager Agreement with the Dealer Manager. These agreements entitled the Advisor and/or the Dealer Manager to specified fees upon the provision of certain services with regard to the Offering and reimbursement of organization and offering costs incurred by the Advisor and the Dealer Manager on behalf of the Company and entitle the Advisor to specified fees upon the provision of certain services with regard to the investment of funds in real estate investments, the management of those investments, among other services, and the disposition of investments, as well as entitle the Advisor and/or the Dealer Manager to reimbursement of offering costs related to the dividend reinvestment plan incurred by the Advisor and the Dealer Manager on behalf of the Company and certain costs incurred by the Advisor in providing services to the Company. In addition, the Advisor is entitled to certain other fees, including an incentive fee upon achieving certain performance goals, as detailed in the Advisory Agreement. The Company has also entered into a fee reimbursement agreement with 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 DTCC 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 or 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 Strategic Opportunity REIT, Inc. (“KBS Strategic Opportunity REIT”), 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 Strategic Opportunity REIT, 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. In June 2018, the Company renewed its participation in the program. At renewal, KBS Strategic Opportunity REIT, KBS Strategic Opportunity REIT II and KBS Legacy Partners Apartment REIT elected to cease participation in the program and obtained separate insurance coverage. The program is effective through June 30, 2019. KBS REIT I elected to cease participation in the program at the June 2017 renewal and obtained separate insurance coverage. 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, December 31, 2018 2017 2018 2017 2018 2017 Expensed Asset management fees $ 6,830 $ 6,587 $ 20,188 $ 19,223 $ 2,232 $ 2,262 Reimbursement of operating expenses (1) (2) 1,862 59 2,964 255 2,686 121 Disposition fees (3) — — 429 — — — Capitalized Acquisition fee on development project 124 64 303 234 869 566 Acquisition fee on unconsolidated joint venture 32 120 194 497 484 290 Asset management fee on development project — — — 48 — — Asset management fee on unconsolidated joint venture — — — 14 — — $ 8,848 $ 6,830 $ 24,078 $ 20,271 $ 6,271 $ 3,239 _____________________ (1) Reimbursable operating expenses primarily consists of internal audit personnel costs, accounting software and cybersecurity related expenses incurred by the Advisor 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 $69,000 and $243,000 for the three and nine months ended September 30, 2018 , respectively, and $49,000 and $169,000 for the three and nine months ended September 30, 2017 , respectively, and were the only type of employee costs reimbursed under the Advisory Agreement for the three and nine months ended September 30, 2018 and 2017 , respectively. The Company will not reimburse for employee costs in connection with services for which the Advisor earns acquisition or origination fees 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) Reimbursement of operating expenses includes professional fees incurred related to the assessment of strategic alternatives for the three and nine months ended September 30, 2018 of $1.8 million and $2.7 million , respectively. (3) Disposition fees with respect to real estate sold are included in the gain on sale of real estate, net, in the accompanying consolidated statements of operations. In connection with the Offering, the Company’s sponsor, KBS Holdings LLC, agreed to provide additional indemnification to one of the participating broker-dealers. The Company agreed to add supplemental coverage to its directors’ and officers’ insurance coverage to insure the sponsor’s obligations under this indemnification agreement in exchange for reimbursement by the sponsor to the Company for all costs, expenses and premiums related to this supplemental coverage. During the nine months ended September 30, 2017 , the Advisor incurred $0.1 million for the costs of the supplemental coverage obtained by the Company. During each of the nine months ended September 30, 2018 and 2017 , the Advisor reimbursed the Company $0.2 million for property insurance rebates. Lease to Affiliate On May 29, 2015, the indirect wholly owned subsidiary of the Company that owns 3003 Washington Boulevard entered into a lease with an affiliate of the Advisor for 5,046 rentable square feet, or approximately 2.3% of the total rentable square feet, at 3003 Washington Boulevard. The lease commenced on October 1, 2015 and terminates on August 31, 2019. The annualized base rent, which represents annualized contractual base rental income as of September 30, 2018 , adjusted to straight-line any contractual tenant concessions (including free rent) and rent increases from the lease’s inception through the balance of the lease term, for this lease is approximately $0.2 million , and the average annual rental rate (net of rental abatements) over the lease term is $46.38 per square foot. During the three and nine months ended September 30, 2018 , the Company recognized $60,000 and $180,000 of revenue related to this lease, respectively. During the three and nine months ended September 30, 2017 , the Company recognized $61,000 and $180,000 of revenue related to this lease, respectively. Prior to their approval of the lease, the Company’s conflicts committee and board of directors determined the lease to be fair and reasonable to the Company. During the three months ended September 30, 2018 and 2017 , no other business transactions occurred between the Company and KBS REIT I, KBS REIT II, KBS Strategic Opportunity REIT, KBS Legacy Partners Apartment REIT, KBS Strategic Opportunity REIT II, KBS Growth & Income REIT, the Advisor, the Dealer Manager or other KBS-affiliated entities.

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 the respective services, the Company will be required to obtain such services from other sources. Legal Matters From time to time, the Company may be 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 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. Environmental As an owner of real estate, the Company is subject to various environmental laws of federal, state and local governments. Compliance with existing environmental laws is not expected to have a material adverse effect on the Company’s financial condition and results of operations as of September 30, 2018 .

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. Distributions Paid On October 1, 2018 , the Company paid distributions of $9.4 million , which related to distributions declared for daily record dates for each day in the period from September 1, 2018 through September 30, 2018 . On November 1, 2018 , the Company paid distributions of $9.8 million , which related to distributions declared for daily record dates for each day in the period from October 1, 2018 through October 31, 2018 . Distributions Authorized On October 8, 2018 , the Company’s board of directors authorized distributions based on daily record dates for the period from November 1, 2018 through November 30, 2018 , which the Company expects to pay in December 2018 . On November 5, 2018 , the Company’s board of directors authorized distributions based on daily record dates for the period from December 1, 2018 through December 31, 2018 , which the Company expects to pay in January 2019 . Investors may choose to receive cash distributions or purchase additional shares through the Company’s dividend reinvestment plan. Distributions for these periods will be calculated based on stockholders of record each day during these periods at a rate of $0.00178082 per share per day and equal a daily amount that, if paid each day for a 365-day period, would equal a 5.54% annualized rate based on the Company's December 6, 2017 estimated value per share of $11.73 . Financing Subsequent to September 30, 2018 Portfolio Revolving Loan Facility On October 17, 2018, the Company, through indirect wholly owned subsidiaries (each a “Borrower”), entered into a three -year loan facility with U.S. Bank, N.A., as administrative agent (the “Lender”), for a committed amount of up to $215.0 million (the “Portfolio Revolving Loan Facility”), of which $107.5 million is term debt and $107.5 million is revolving debt. At closing, $200.0 million was available for funding under the Portfolio Revolving Loan Facility with an additional $15.0 million available upon satisfaction of certain conditions set forth in the loan documents. At closing, $107.5 million of the term debt and $92.5 million of revolving debt was funded, of which approximately $69.8 million was used to pay off the 515 Congress Mortgage Loan and approximately $104.0 million was used to pay down one of the Company’s existing portfolio loan facilities. See “Portfolio Loan” below. The remaining amount was used to pay origination fees and accrued interest, with excess proceeds held by the Company for liquidity management. The Portfolio Revolving Loan Facility may be used for working capital, capital expenditures, real property acquisitions and other corporate purposes. The Portfolio Revolving Loan Facility matures on November 1, 2021, with two 12 -month extension options, subject to certain terms, conditions and fees as described in the loan documents. The Portfolio Revolving Loan Facility bears interest at a floating rate of 150 basis points over one-month LIBOR. Monthly payments are interest only with the entire balance and all outstanding interest and fees due at maturity. The Company will have the right to prepay all or a portion of the Portfolio Revolving Loan Facility, subject to certain expenses potentially incurred by the Lender as a result of the prepayment and subject to certain conditions contained in the loan documents. During the term of the Portfolio Revolving Loan Facility, the Company has an option to increase the committed amount of the Portfolio Revolving Loan Facility up to four times with each increase of the committed amount to be at least $15.0 million but no greater than, in the aggregate, an additional $170.0 million so that the committed amount will not exceed $385.0 million , of which 50% would be non-revolving debt and 50% would be revolving debt, with the addition of one or more properties to secure the loan, subject to certain terms and conditions contained in the loan documents. In addition, the Portfolio Revolving Loan Facility contains customary representations and warranties, financial and other covenants, events of default and remedies typical for this type of facility. The Portfolio Revolving Loan Facility is secured by 515 Congress, Domain Gateway, the McEwen Building, and Gateway Tech Center. KBS REIT Properties III, LLC (“REIT Properties III”), the Company’s wholly owned subsidiary, is providing a guaranty of (i) up to 25% of the committed amount under the Portfolio Revolving Loan Facility, as such amount may be adjusted from time to time pursuant to the terms of the loan documents, (ii) payment of, and agrees to protect, defend, indemnify and hold harmless each Lender for, from and against, any liability, obligation, deficiency, loss, damage, costs and expenses (including reasonable attorney’s fees), and any litigation which may at any time be imposed upon, incurred or suffered by any Lender because of (a) certain intentional acts committed by any Borrower, (b) fraud or intentional misrepresentations by Borrower or REIT Properties III in connection with the loan documents as described in the guaranty agreement, and (c) certain bankruptcy or insolvency proceedings involving Borrower, as such acts are described in the guaranty, and (iii) upon and subject to the events and conditions described in the guaranty, payment of certain indemnity obligations of Borrower related to environmental matters. Portfolio Loan On October 17, 2018, in connection with the Portfolio Revolving Loan Facility, the Company paid down the Portfolio Loan by approximately $104.0 million , of which $43.0 million was term debt and $61.0 million was revolving debt. Domain Gateway, the McEwen Building, and Gateway Tech Center were released as collateral under the Portfolio Loan. In accordance with the terms of the Portfolio Loan, the committed amount of the Portfolio Loan was reduced from $255.0 million to $169.0 million , of which $84.5 million is term debt and $84.5 million is revolving debt. As a result of the paydown, the Portfolio Loan outstanding principal balance was reduced to $84.5 million , all of which was term debt. The revolving debt of $84.5 million remained available for future disbursements, subject to certain conditions set forth in the loan agreement.

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 III, the Operating Partnership, their direct and indirect wholly owned subsidiaries, and a joint venture 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 and condensed notes thereto in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and condensed notes. Actual results could materially differ from those estimates.
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 $2.2 million and $5.7 million , respectively, and 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.
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 , respectively.
Segments	The Company has invested in core real estate properties and real estate-related investments with the goal of acquiring a portfolio of income-producing investments. The Company’s real estate properties exhibit similar long-term financial performance and have similar economic characteristics to each other. As of September 30, 2018 , the Company aggregated its investments in real estate properties into one reportable business segment.
Square Footage, Occupancy and Other Measures	Square footage, occupancy, number of tenants and other measures, including annualized base rent and annualized base rent per square foot, or amounts derived from such measures, used to describe real estate investments included in these condensed notes to consolidated financial statements 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 Update	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 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 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, but does not expect the adoption of ASU No. 2016-13 to have a material impact 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.

REAL ESTATE (Tables)

REAL ESTATE (Tables)	9 Months Ended
	Sep. 30, 2018
Real Estate [Abstract]
Schedule of Real Estate Investments	The following table summarizes the Company’s investments in real estate as of September 30, 2018 (in thousands): Property Date Acquired City State Property Type Total Real Estate, at Cost Accumulated Depreciation and Amortization Total Real Estate, Net Domain Gateway 09/29/2011 Austin TX Office $ 49,177 $ (15,150 ) $ 34,027 Town Center 03/27/2012 Plano TX Office 116,280 (27,923 ) 88,357 McEwen Building 04/30/2012 Franklin TN Office 37,130 (8,181 ) 28,949 Gateway Tech Center 05/09/2012 Salt Lake City UT Office 25,422 (6,300 ) 19,122 Tower on Lake Carolyn 12/21/2012 Irving TX Office 52,829 (11,403 ) 41,426 RBC Plaza 01/31/2013 Minneapolis MN Office 153,425 (36,417 ) 117,008 One Washingtonian Center 06/19/2013 Gaithersburg MD Office 91,953 (18,130 ) 73,823 Preston Commons 06/19/2013 Dallas TX Office 117,737 (22,638 ) 95,099 Sterling Plaza 06/19/2013 Dallas TX Office 79,076 (12,750 ) 66,326 201 Spear Street 12/03/2013 San Francisco CA Office 142,663 (14,838 ) 127,825 500 West Madison 12/16/2013 Chicago IL Office 435,174 (67,343 ) 367,831 222 Main 02/27/2014 Salt Lake City UT Office 165,437 (29,473 ) 135,964 Anchor Centre 05/22/2014 Phoenix AZ Office 96,085 (15,380 ) 80,705 171 17th Street 08/25/2014 Atlanta GA Office 133,339 (26,009 ) 107,330 Reston Square 12/03/2014 Reston VA Office 46,579 (8,111 ) 38,468 Ten Almaden 12/05/2014 San Jose CA Office 124,435 (16,618 ) 107,817 Towers at Emeryville 12/23/2014 Emeryville CA Office 273,887 (30,730 ) 243,157 101 South Hanley 12/24/2014 St. Louis MO Office 72,320 (11,040 ) 61,280 3003 Washington Boulevard 12/30/2014 Arlington VA Office 151,150 (19,003 ) 132,147 Village Center Station 05/20/2015 Greenwood Village CO Office 75,035 (9,863 ) 65,172 Park Place Village 06/18/2015 Leawood KS Office/Retail 127,930 (16,836 ) 111,094 201 17th Street 06/23/2015 Atlanta GA Office 102,679 (13,756 ) 88,923 Promenade I & II at Eilan 07/14/2015 San Antonio TX Office 62,646 (8,918 ) 53,728 CrossPoint at Valley Forge 08/18/2015 Wayne PA Office 90,352 (11,051 ) 79,301 515 Congress 08/31/2015 Austin TX Office 120,654 (13,309 ) 107,345 The Almaden 09/23/2015 San Jose CA Office 169,116 (15,813 ) 153,303 3001 Washington Boulevard 11/06/2015 Arlington VA Office 60,560 (4,511 ) 56,049 Carillon 01/15/2016 Charlotte NC Office 153,514 (16,534 ) 136,980 Hardware Village (1) 08/26/2016 Salt Lake City UT Development/Apartment 98,189 (626 ) 97,563 $ 3,424,773 $ (508,654 ) $ 2,916,119 ___________________ (1) On August 26, 2016, the Company, through an indirect wholly-owned subsidiary, entered into a joint venture (the “Hardware Village Joint Venture”) to develop and subsequently operate a multifamily apartment complex, located on the developable land at Gateway Tech Center. The Company owns a 99.24% equity interest in the joint venture. In July 2018, one of the two buildings consisting of 265 units was placed into service.
Schedules of Concentration of Risk, by Risk Factor	As of September 30, 2018 , the following property represented more than 10% of the Company’s total assets: Property Location Rentable Total Real Estate, Net Percentage Annualized Base Rent (1) Average Annualized Base Rent per sq. ft. Occupancy 500 West Madison Chicago, IL 1,457,724 $ 367,831 11.4 % $ 33,080 $ 28.59 79.4 % _____________________ (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. As of September 30, 2018 , the Company’s real estate properties were leased to approximately 850 tenants over a diverse range of industries and geographic areas. The Company’s highest tenant industry concentration (greater than 10% of annualized base rent) was as follows: Industry Number of Tenants Annualized Base Rent (1) (in thousands) Percentage of Annualized Base Rent Finance 151 $ 62,011 19.8 % _____________________ (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.
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 under its non-cancelable operating leases was as follows (in thousands): October 1, 2018 through December 31, 2018 $ 75,926 2019 295,053 2020 271,651 2021 246,040 2022 213,601 Thereafter 664,928 $ 1,767,199
Schedule of Revenue and Expenses of Real Estate Held-for-Sale	The results of operations for the property sold during the nine months ended September 30, 2018 and gain on sale as of September 30, 2018 are included in continuing operations on the Company’s consolidated statements of operations. The following table summarizes certain revenues and expenses related to this property for the three and nine months ended September 30, 2018 and 2017 (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 Revenues Rental income $ — $ 1,135 $ 1,802 $ 3,375 Tenant reimbursements and other operating income — 41 110 112 Total revenues $ — $ 1,176 $ 1,912 $ 3,487 Expenses Operating, maintenance, and management $ — $ 464 $ 463 $ 1,086 Real estate taxes and insurance — 131 213 348 Asset management fees to affiliate — 67 105 198 Depreciation and amortization — 543 — 1,605 Interest expense — 176 320 483 Total expenses $ — $ 1,381 $ 1,101 $ 3,720
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 December 31, 2017 (in thousands). No real estate properties were held for sale as of September 30, 2018 . September 30, 2018 December 31, 2017 Assets related to real estate held for sale Total real estate, at cost $ — $ 33,575 Accumulated depreciation and amortization — (5,558 ) Real estate held for sale, net — 28,017 Other assets — 1,786 Total assets related to real estate held for sale $ — $ 29,803 Liabilities related to real estate held for sale Notes payable, net — 21,648 Other liabilities — 50 Total liabilities related to real estate held for sale $ — $ 21,698

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 $ 212,737 $ 230,576 $ 11,916 $ 12,301 $ (41,270 ) $ (47,459 ) Accumulated Amortization (114,422 ) (108,078 ) (7,353 ) (6,440 ) 22,340 22,849 Net Amount $ 98,315 $ 122,498 $ 4,563 $ 5,861 $ (18,930 ) $ (24,610 )
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 Absorption Costs Above-Market Lease Assets Below-Market Lease Liabilities 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 $ (8,184 ) $ (10,202 ) $ (430 ) $ (527 ) $ 2,203 $ 2,184 Tenant Origination and Absorption Costs Above-Market Lease Assets Below-Market Lease Liabilities For the Nine Months Ended September 30, For the Nine Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 2018 2017 Amortization $ (24,182 ) $ (32,321 ) $ (1,325 ) $ (1,774 ) $ 5,685 $ 6,963

INVESTMENT IN UNCONSOLIDATED _2

INVESTMENT IN UNCONSOLIDATED JOINT VENTURE (Tables)	9 Months Ended
	Sep. 30, 2018
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Financial Information for Joint Ventures	Summarized financial information for the Village Center Station II Joint Venture is as follows (in thousands): September 30, 2018 Assets: Real estate, net $ 104,774 Cash and cash equivalents 3,630 Other assets 4,631 Total assets $ 113,035 Liabilities and equity: Accounts payable $ 2,338 Notes payable, net 66,358 Other liabilities 1,191 Members’ capital 43,148 Total liabilities and equity $ 113,035 Nine Months Ended September 30, 2018 Revenues $ 3,083 Expenses: Operating, maintenance, and management 20 Depreciation and amortization 1,925 Interest expense 1,100 Total expenses 3,045 Other expenses $ 5 Net income $ 33 Company ’s equity in income of unconsolidated joint venture $ 25

NOTES PAYABLE (Tables)

NOTES PAYABLE (Tables)	9 Months Ended
	Sep. 30, 2018
Notes Payable [Abstract]
Schedule of Long-term Debt Instruments	As of September 30, 2018 and December 31, 2017 , the Company’s notes payable 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 (1) Effective Interest Rate as of September 30, 2018 (1) Payment Type Maturity Date (2) Portfolio Loan (3) $ 188,460 $ 188,460 One-month LIBOR + 1.90% 4.00% Interest Only 06/01/2019 222 Main Mortgage Loan 98,016 99,471 3.97% 3.97% Principal & Interest 03/01/2021 Anchor Centre Mortgage Loan 49,799 50,000 One-month LIBOR + 1.50% 3.60% Principal & Interest 06/01/2019 171 17th Street Mortgage Loan 84,668 85,292 One-month LIBOR + 1.45% 3.55% Principal & Interest 09/01/2019 Reston Square Mortgage Loan 29,567 29,800 One-month LIBOR + 1.50% 3.80% Principal & Interest 02/01/2019 101 South Hanley Mortgage Loan 42,401 40,557 One-month LIBOR + 1.55% 3.87% Principal & Interest 01/01/2020 3003 Washington Boulevard Mortgage Loan 90,378 90,378 One-month LIBOR + 1.55% 3.55% Interest Only 02/01/2020 Rocklin Corporate Center Mortgage Loan (4) — 21,689 (4) (4) (4) (4) 201 17th Street Mortgage Loan 64,428 64,428 One-month LIBOR + 1.40% 3.54% Interest Only 08/01/2019 CrossPoint at Valley Forge Mortgage Loan 51,000 51,000 One-month LIBOR + 1.50% 3.33% Interest Only (5) 09/01/2022 The Almaden Mortgage Loan 93,000 93,000 4.20% 4.20% Interest Only 01/01/2022 Promenade I & II at Eilan Mortgage Loan 37,300 37,300 One-month LIBOR + 1.75% 3.57% Interest Only 10/01/2022 515 Congress Mortgage Loan (6) 69,842 68,381 One-month LIBOR + 1.70% 3.63% Interest Only 11/01/2020 201 Spear Street Mortgage Loan 100,000 100,000 One-month LIBOR + 1.66% 3.77% Interest Only 01/01/2019 Carillon Mortgage Loan 92,197 90,248 One-month LIBOR + 1.65% 3.39% Interest Only 02/01/2020 3001 Washington Boulevard Mortgage Loan 30,229 28,404 One-month LIBOR + 1.60% 3.14% Interest Only 02/01/2019 Hardware Village Loan Facility (7) 43,842 21,011 One-month LIBOR + 3.25% 5.36% Interest Only 02/23/2020 Portfolio Loan Facility (8) 913,500 797,500 One-month LIBOR + 1.80% 3.82% Interest Only 11/03/2020 Total notes payable principal outstanding 2,078,627 1,956,919 Deferred financing costs, net (10,428 ) (15,133 ) Total notes payable, net $ 2,068,199 $ 1,941,786 _____________________ (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 the effect of interest rate swaps and caps, if applicable), using interest rate indices as of September 30, 2018 , where applicable. For further information regarding the Company's derivative instruments, see Note 7, “Derivative Instruments.” (2) Represents the maturity date as of September 30, 2018 ; subject to certain conditions, the maturity dates of certain loans may be extended beyond the dates shown. (3) As of September 30, 2018 , the Portfolio Loan was secured by Domain Gateway, the McEwen Building, Gateway Tech Center, the Tower on Lake Carolyn, Park Place Village and Village Center Station. The face amount of the Portfolio Loan is $ 255.0 million , of which $ 127.5 million is term debt and $ 127.5 million is revolving debt. As of September 30, 2018 , the outstanding balance under the loan consisted of $127.5 million of term debt and $61.0 million of revolving debt. As of September 30, 2018 , an additional $65.5 million of revolving debt remained available for immediate future disbursements, subject to certain conditions set forth in the loan agreement. The remaining $1.0 million of revolving debt is available for future disbursements upon the Company meeting certain financial coverage ratios and subject to certain conditions set forth in the loan agreement. During the remaining term of the Portfolio Loan, the Company has an option, which may be exercised up to two times, to increase the loan amount to a maximum of $350.0 million , of which 50% would be term debt and 50% would be revolving debt, with the addition of one or more properties to secure the Portfolio Loan, subject to certain conditions contained in the loan documents. Subsequent to September 30, 2018 , the Company entered into a portfolio revolving loan facility in the amount of up to $215.0 million , of which $ 104.0 million was used to pay down the Portfolio Loan and Domain Gateway, the McEwen Building and Gateway Tech Center were released as security under the Portfolio Loan. See Note 11, “Subsequent Events - Financing Subsequent to September 30, 2018 - Portfolio Revolving Loan Facility and Portfolio Loan.” (4) On May 25, 2018 , in connection with the disposition of Rocklin Corporate Center, the Company paid off the Rocklin Corporate Center Mortgage Loan. (5) Represents the payment type required under the loan as of September 30, 2018 . Certain future monthly payments due under the loan also include amortizing principal payments. For more information on the Company’s contractual obligations under its notes payable, see the five-year maturity table below. (6) Subsequent to September 30, 2018 , the Company entered into a portfolio revolving loan facility in the amount of up to $215.0 million , of which $69.8 million was used to pay off the 515 Congress Mortgage Loan. See Note 11, “Subsequent Events - Financing Subsequent to September 30, 2018 - Portfolio Revolving Loan Facility.” (7) As of September 30, 2018 , $43.8 million had been disbursed and $30.2 million remained available for future disbursements, subject to certain conditions contained in the loan documents. (8) As of September 30, 2018 , the Portfolio Loan Facility was secured by RBC Plaza, Preston Commons, Sterling Plaza, One Washingtonian Center, Towers at Emeryville, Ten Almaden, Town Center and 500 West Madison. The face amount of the Portfolio Loan Facility is $1.01 billion , of which $757.5 million is term debt and $252.5 million is revolving debt. As of September 30, 2018 , the outstanding balance under the loan consisted of $757.5 million of term debt and $156.0 million of revolving debt. As of September 30, 2018 , an additional $96.5 million of revolving debt remained available for immediate future disbursements, subject to certain conditions set forth in the loan agreement. During the remaining term of the Portfolio Loan Facility, the Company has an option to increase the loan amount by up to an additional $400.0 million in increments of $25.0 million , to a maximum of $1.41 billion , of which 75% would be term debt and 25% would be revolving debt, subject to certain conditions contained in the loan documents.
Schedule of Maturities of Long-term Debt	The following is a schedule of maturities, including principal amortization payments, for all notes payable outstanding as of September 30, 2018 (in thousands): October 1, 2018 through December 31, 2018 $ 1,074 2019 549,285 2020 1,253,722 2021 93,956 2022 180,590 $ 2,078,627

DERIVATIVE INSTRUMENTS (Tables)

DERIVATIVE INSTRUMENTS (Tables)	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Notional and Fair Value of Interest Rate Swaps Designated as Cash Flow Hedges	The following table summarizes the notional amount and other information related to the Company’s interest rate swaps and cap 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 (dollars in thousands): September 30, 2018 December 31, 2017 Weighted-Average Fix Pay Rate Weighted-Average Remaining Term in Years Derivative Instruments Number of Instruments Notional Amount Number of Instruments Notional Amount Reference Rate as of September 30, 2018 Derivative instruments designated as hedging instruments Interest rate swaps — $ — 2 $ 118,400 (1) (1) (1) Derivative instruments not designated as hedging instruments Interest rate swaps 14 $ 1,209,147 16 $ 1,209,643 One-month LIBOR/ 2.03% 3.2 Interest rate cap 1 $ 100,000 — $ — One-month LIBOR/ 3.00% 0.3 _____________________ (1) Both interest rate swaps designated as hedging instruments matured during the nine months ended September 30, 2018 .
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	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 Fair Value Derivative instruments designated as hedging instruments Interest rate swaps Prepaid expenses and other assets, at fair value — $ — 1 $ 128 Interest rate swaps Other liabilities, at fair value — $ — 1 $ (18 ) Derivative instruments not designated as hedging instruments Interest rate swaps Prepaid expenses and other assets, at fair value 14 $ 34,819 10 $ 6,386 Interest rate cap Prepaid expenses and other assets, at fair value 1 $ — — $ — Interest rate swaps Other liabilities, at fair value — $ — 6 $ (1,677 )
Schedule of Derivative Instruments in Statement of Operations	The following table summarizes the effects of derivative instruments on the Company’s consolidated statements of operations (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 Income statement related Derivatives designated as hedging instruments Amount of (income) expense recognized on interest rate swaps (effective portion) $ (90 ) $ 253 $ (198 ) $ 1,717 (90 ) 253 (198 ) 1,717 Derivatives not designated as hedging instruments Realized (gain) loss recognized on interest rate swaps (186 ) 1,108 1,123 3,966 Unrealized gain on interest rate swaps (4,784 ) (1,004 ) (30,110 ) (2,579 ) Fair value loss on interest rate cap 8 — 8 — (4,962 ) 104 (28,979 ) 1,387 (Decrease) increase in interest expense as a result of derivatives $ (5,052 ) $ 357 $ (29,177 ) $ 3,104 Other comprehensive income related Unrealized (losses) income on derivative instruments $ 5 $ 13 $ 88 $ 602

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 notes payable as of September 30, 2018 and December 31, 2017 , which carrying amounts generally 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 liabilities: Notes payable $ 2,078,627 $ 2,068,199 $ 2,084,290 $ 1,956,919 $ 1,941,786 $ 1,950,965
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 Significant Other Observable Inputs Significant Unobservable Inputs Recurring Basis: Asset derivatives - interest rate swaps $ 34,819 $ — $ 34,819 $ — Asset derivatives - interest rate cap $ — $ — $ — $ —

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, December 31, 2018 2017 2018 2017 2018 2017 Expensed Asset management fees $ 6,830 $ 6,587 $ 20,188 $ 19,223 $ 2,232 $ 2,262 Reimbursement of operating expenses (1) (2) 1,862 59 2,964 255 2,686 121 Disposition fees (3) — — 429 — — — Capitalized Acquisition fee on development project 124 64 303 234 869 566 Acquisition fee on unconsolidated joint venture 32 120 194 497 484 290 Asset management fee on development project — — — 48 — — Asset management fee on unconsolidated joint venture — — — 14 — — $ 8,848 $ 6,830 $ 24,078 $ 20,271 $ 6,271 $ 3,239 _____________________ (1) Reimbursable operating expenses primarily consists of internal audit personnel costs, accounting software and cybersecurity related expenses incurred by the Advisor 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 $69,000 and $243,000 for the three and nine months ended September 30, 2018 , respectively, and $49,000 and $169,000 for the three and nine months ended September 30, 2017 , respectively, and were the only type of employee costs reimbursed under the Advisory Agreement for the three and nine months ended September 30, 2018 and 2017 , respectively. The Company will not reimburse for employee costs in connection with services for which the Advisor earns acquisition or origination fees 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) Reimbursement of operating expenses includes professional fees incurred related to the assessment of strategic alternatives for the three and nine months ended September 30, 2018 of $1.8 million and $2.7 million , respectively. (3) Disposition fees with respect to real estate sold are included in the gain on sale of real estate, net, in the accompanying consolidated statements of operations.

ORGANIZATION (Details)

ORGANIZATION (Details) $ / shares in Units, $ in Thousands	Oct. 03, 2014USD ($)shares	Sep. 30, 2018USD ($)propertyshares	Dec. 31, 2017USD ($)shares	May 29, 2016USD ($)shares	Sep. 30, 2018USD ($)propertyshares	Jan. 26, 2010$ / sharesshares
Organizational Structure [Line Items]
Partnership interest in Operating Partnership		0.10%
Partnership interest in the Operating Partnership and is its sole limited partner		99.90%
Common stock, shares issued (in shares)		176,422,788	180,864,707		176,422,788
Issuance of common stock | $		$ 42,443	$ 59,785
Redemptions of common stock | $		$ 94,569	$ 61,871
Private Placement
Organizational Structure [Line Items]
Issuance of common stock (in shares)	258,462
Issuance of common stock | $	$ 2,400
Office Properties
Organizational Structure [Line Items]
Number of real estate properties | property		27			27
Mixed-use Office/Retail Property
Organizational Structure [Line Items]
Number of real estate properties | property		1			1
Common Stock
Organizational Structure [Line Items]
Shares held by affiliate (in shares)		20,000			20,000
Issuance of common stock (in shares)		3,806,525	5,919,223	169,006,162
Issuance of common stock | $		$ 38	$ 59	$ 1,700,000
Shares of common stock sold under dividend reinvestment plan, shares					26,698,976
Shares of common stock sold under dividend reinvestment plan, value | $					$ 267,200
Redemptions of common stock (in shares)		8,248,444	5,945,088		19,560,813
Redemptions of common stock | $		$ 83	$ 59		$ 209,000
KBS Capital Advisors LLC
Organizational Structure [Line Items]
Common stock, shares issued (in shares)						20,000
Common stock, purchase price per share (in dollars per share) | $ / shares						$ 10

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)$ / shares	Sep. 30, 2017USD ($)$ / shares	Sep. 30, 2018USD ($)segment$ / shares	Sep. 30, 2017USD ($)$ / shares
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Tenant reimbursements | $	$ 20,185	$ 19,063	$ 61,297	$ 57,652
Distributions declared per share (in dollars per share) | $ / shares	$ 0.164	$ 0.164	$ 0.486	$ 0.486
Distribution rate per share per day, declared (in dollars per share) | $ / shares	$ 0.00178082	$ 0.00178082	$ 0.00178082	$ 0.00178082
Number of reportable segments | segment			1
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Tenant reimbursements | $	$ 2,200		$ 5,700

REAL ESTATE (Narrative) (Detail

REAL ESTATE (Narrative) (Details) ft² in Millions	Sep. 30, 2018ft²property
Real Estate Properties [Line Items]
Rentable square feet | ft²	10.9
Percentage of portfolio occupied	93.00%
Office Properties
Real Estate Properties [Line Items]
Number of real estate properties	27
Mixed-use Office/Retail Property
Real Estate Properties [Line Items]
Number of real estate properties	1
Held for Investment | Office Properties
Real Estate Properties [Line Items]
Number of real estate properties	27

REAL ESTATE (Schedule of Real E

REAL ESTATE (Schedule of Real Estate Investments) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)	Jul. 31, 2018unit	Dec. 31, 2017USD ($)	Aug. 26, 2016
Real Estate Properties [Line Items]
Total Real Estate at Cost	$ 3,424,773		$ 3,369,925
Accumulated Depreciation and Amortization	(508,654)		(435,808)
Total real estate held for investment, net	$ 2,916,119		$ 2,934,117
Joint Venture
Real Estate Properties [Line Items]
Equity interest in joint venture				99.24%
Domain Gateway | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Sep. 29, 2011
Total Real Estate at Cost	$ 49,177
Accumulated Depreciation and Amortization	(15,150)
Total real estate held for investment, net	$ 34,027
Town Center | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Mar. 27, 2012
Total Real Estate at Cost	$ 116,280
Accumulated Depreciation and Amortization	(27,923)
Total real estate held for investment, net	$ 88,357
McEwen Building | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Apr. 30, 2012
Total Real Estate at Cost	$ 37,130
Accumulated Depreciation and Amortization	(8,181)
Total real estate held for investment, net	$ 28,949
Gateway Tech Center | Office Properties
Real Estate Properties [Line Items]
Date Acquired	May 9, 2012
Total Real Estate at Cost	$ 25,422
Accumulated Depreciation and Amortization	(6,300)
Total real estate held for investment, net	$ 19,122
Tower on Lake Carolyn | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Dec. 21, 2012
Total Real Estate at Cost	$ 52,829
Accumulated Depreciation and Amortization	(11,403)
Total real estate held for investment, net	$ 41,426
RBC Plaza | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Jan. 31, 2013
Total Real Estate at Cost	$ 153,425
Accumulated Depreciation and Amortization	(36,417)
Total real estate held for investment, net	$ 117,008
One Washingtonian Center | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Jun. 19, 2013
Total Real Estate at Cost	$ 91,953
Accumulated Depreciation and Amortization	(18,130)
Total real estate held for investment, net	$ 73,823
Preston Commons | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Jun. 19, 2013
Total Real Estate at Cost	$ 117,737
Accumulated Depreciation and Amortization	(22,638)
Total real estate held for investment, net	$ 95,099
Sterling Plaza | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Jun. 19, 2013
Total Real Estate at Cost	$ 79,076
Accumulated Depreciation and Amortization	(12,750)
Total real estate held for investment, net	$ 66,326
201 Spear Street | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Dec. 3, 2013
Total Real Estate at Cost	$ 142,663
Accumulated Depreciation and Amortization	(14,838)
Total real estate held for investment, net	$ 127,825
500 West Madison | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Dec. 16, 2013
Total Real Estate at Cost	$ 435,174
Accumulated Depreciation and Amortization	(67,343)
Total real estate held for investment, net	$ 367,831
222 Main | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Feb. 27, 2014
Total Real Estate at Cost	$ 165,437
Accumulated Depreciation and Amortization	(29,473)
Total real estate held for investment, net	$ 135,964
Anchor Centre | Office Properties
Real Estate Properties [Line Items]
Date Acquired	May 22, 2014
Total Real Estate at Cost	$ 96,085
Accumulated Depreciation and Amortization	(15,380)
Total real estate held for investment, net	$ 80,705
171 17th Street | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Aug. 25, 2014
Total Real Estate at Cost	$ 133,339
Accumulated Depreciation and Amortization	(26,009)
Total real estate held for investment, net	$ 107,330
Reston Square | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Dec. 3, 2014
Total Real Estate at Cost	$ 46,579
Accumulated Depreciation and Amortization	(8,111)
Total real estate held for investment, net	$ 38,468
Ten Almaden | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Dec. 5, 2014
Total Real Estate at Cost	$ 124,435
Accumulated Depreciation and Amortization	(16,618)
Total real estate held for investment, net	$ 107,817
Towers at Emeryville | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Dec. 23, 2014
Total Real Estate at Cost	$ 273,887
Accumulated Depreciation and Amortization	(30,730)
Total real estate held for investment, net	$ 243,157
101 South Hanley | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Dec. 24, 2014
Total Real Estate at Cost	$ 72,320
Accumulated Depreciation and Amortization	(11,040)
Total real estate held for investment, net	$ 61,280
3003 Washington Boulevard | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Dec. 30, 2014
Total Real Estate at Cost	$ 151,150
Accumulated Depreciation and Amortization	(19,003)
Total real estate held for investment, net	$ 132,147
Village Center Station | Office Properties
Real Estate Properties [Line Items]
Date Acquired	May 20, 2015
Total Real Estate at Cost	$ 75,035
Accumulated Depreciation and Amortization	(9,863)
Total real estate held for investment, net	$ 65,172
Park Place Village | Office/Retail
Real Estate Properties [Line Items]
Date Acquired	Jun. 18, 2015
Total Real Estate at Cost	$ 127,930
Accumulated Depreciation and Amortization	(16,836)
Total real estate held for investment, net	$ 111,094
201 17th Street | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Jun. 23, 2015
Total Real Estate at Cost	$ 102,679
Accumulated Depreciation and Amortization	(13,756)
Total real estate held for investment, net	$ 88,923
Promenade I & II at Eilan | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Jul. 14, 2015
Total Real Estate at Cost	$ 62,646
Accumulated Depreciation and Amortization	(8,918)
Total real estate held for investment, net	$ 53,728
CrossPoint at Valley Forge | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Aug. 18, 2015
Total Real Estate at Cost	$ 90,352
Accumulated Depreciation and Amortization	(11,051)
Total real estate held for investment, net	$ 79,301
515 Congress | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Aug. 31, 2015
Total Real Estate at Cost	$ 120,654
Accumulated Depreciation and Amortization	(13,309)
Total real estate held for investment, net	$ 107,345
The Almaden | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Sep. 23, 2015
Total Real Estate at Cost	$ 169,116
Accumulated Depreciation and Amortization	(15,813)
Total real estate held for investment, net	$ 153,303
3001 Washington Boulevard | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Nov. 6, 2015
Total Real Estate at Cost	$ 60,560
Accumulated Depreciation and Amortization	(4,511)
Total real estate held for investment, net	$ 56,049
Carillon | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Jan. 15, 2016
Total Real Estate at Cost	$ 153,514
Accumulated Depreciation and Amortization	(16,534)
Total real estate held for investment, net	$ 136,980
Hardware Village | Development/Apartment
Real Estate Properties [Line Items]
Date Acquired	Aug. 26, 2016
Total Real Estate at Cost	$ 98,189
Accumulated Depreciation and Amortization	(626)
Total real estate held for investment, net	$ 97,563
Hardware Village, West | Joint Venture
Real Estate Properties [Line Items]
Number of units in real estate property | unit		265

REAL ESTATE (Properties Represe

REAL ESTATE (Properties Represented More than 10% of Company’s Total Assets) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)ft²$ / ft²	Dec. 31, 2017USD ($)
Real Estate Properties [Line Items]
Rentable Square Feet | ft²	10,900,000
Total Real Estate, Net	$ 2,916,119	$ 2,934,117
Occupancy	93.00%
500 West Madison | Assets, Total
Real Estate Properties [Line Items]
Rentable Square Feet | ft²	1,457,724
Total Real Estate, Net	$ 367,831
Percentage of Total Assets	11.40%
Annualized Base Rent	$ 33,080
Average Annualized Base Rent per sq. ft. | $ / ft²	28.59
Occupancy	79.40%

REAL ESTATE (Operating Leases)

REAL ESTATE (Operating Leases) (Narrative) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)tenant	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Operating Leased Assets [Line Items]
Deferred rent recognized	$ 6,932	$ 8,527
Deferred rent receivables	88,700		$ 74,400
Incentive to Lessee	$ 15,700		9,300
Number of tenants | tenant	850
Other liabilities, at fair value
Operating Leased Assets [Line Items]
Security deposit liability	$ 10,800		$ 11,500
Maximum
Operating Leased Assets [Line Items]
Operating lease, term	13 years 7 months 18 days
Weighted Average
Operating Leased Assets [Line Items]
Operating lease, term	4 years 4 months 16 days

REAL ESTATE (Future Minimum Ren

REAL ESTATE (Future Minimum Rental Income) (Details) $ in Thousands	Sep. 30, 2018USD ($)
Real Estate [Abstract]
October 1, 2018 through December 31, 2018	$ 75,926
2,019	295,053
2,020	271,651
2,021	246,040
2,022	213,601
Thereafter	664,928
Future minimum rental income	$ 1,767,199

REAL ESTATE (Highes Tenant Indu

REAL ESTATE (Highes Tenant Industry Concentrations- Grater than 10% of Annual Base Rent) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)tenant
Concentration Risk [Line Items]
Number of Tenants	850
Finance
Concentration Risk [Line Items]
Number of Tenants	151
Annualized Base Rent | $	$ 62,011
Percentage of Annualized Base Rent	19.80%

REAL ESTATE REAL ESTATE (Geogra

REAL ESTATE REAL ESTATE (Geographic Concentration Risk) (Narrative) (Details) - Assets, Total	9 Months Ended
	Sep. 30, 2018
California
Concentration Risk [Line Items]
Concentration risk, percentage	20.00%
Texas
Concentration Risk [Line Items]
Concentration risk, percentage	15.00%
Illinois
Concentration Risk [Line Items]
Concentration risk, percentage	11.00%

REAL ESTATE (Property Damage) (

REAL ESTATE (Property Damage) (Details) - USD ($)	9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Real Estate Properties [Line Items]
Insurance proceeds received for property damage	$ 4,629,000	$ 0
Physical Damage
Real Estate Properties [Line Items]
Maximum deductible per incident			$ 5,000
Loss due to property damages			7,900,000
Estimated insurance recoveries			7,900,000
Loss due to damages			$ 5,000
Insurance proceeds received for property damage	4,600,000
Reduction in estimated insurance damages	2,400,000
Business interruption insurance recorded	600,000
Business interruption insurance received	1,300,000
Insurance recoveries	900,000
Physical Damage | Fiscal Year 2017
Real Estate Properties [Line Items]
Business interruption insurance received	700,000
Physical Damage | January through May 2018
Real Estate Properties [Line Items]
Business interruption insurance received	$ 600,000

REAL ESTATE (Real Estate Sales

REAL ESTATE (Real Estate Sales - Narrative) (Details) $ in Thousands	May 25, 2018USD ($)	Sep. 30, 2018USD ($)property	Dec. 31, 2017USD ($)property	Nov. 06, 2014aft²property
Real Estate Properties [Line Items]
Total real estate held for investment, cost		$ 3,424,773	$ 3,369,925
Accumulated depreciation and amortization		$ 508,654	$ 435,808
Rocklin Corporate Center | Office Properties
Real Estate Properties [Line Items]
Number of real estate properties acquired | property				1
Net rentable area | ft²				220,020
Area of land | a				13.9
Disposed of by Sale
Real Estate Properties [Line Items]
Number of real estate properties disposed | property		1	0
Disposed of by Sale | Rocklin Corporate Center
Real Estate Properties [Line Items]
Disposal group, consideration	$ 42,900
Total real estate held for investment, cost	29,700
Accumulated depreciation and amortization	6,000
Gain on sale of real estate	$ 11,900

REAL ESTATE (Revenue and Expens

REAL ESTATE (Revenue and Expenses of Real Estate Sales) (Details) - Disposed of by Sale - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues
Rental income	$ 0	$ 1,135	$ 1,802	$ 3,375
Tenant reimbursements and other operating income	0	41	110	112
Total revenues	0	1,176	1,912	3,487
Expenses
Operating, maintenance, and management	0	464	463	1,086
Real estate taxes and insurance	0	131	213	348
Asset management fees to affiliate	0	67	105	198
Depreciation and amortization	0	543	0	1,605
Interest expense	0	176	320	483
Total expenses	$ 0	$ 1,381	$ 1,101	$ 3,720

REAL ESTATE (Schedule of Assets

REAL ESTATE (Schedule of Assets and Liabilities Related to Real Estate Held for Sale) (Details) - Held-for-sale $ in Thousands	Sep. 30, 2018USD ($)property	Dec. 31, 2017USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties | property	0
Assets related to real estate held for sale
Total real estate, at cost	$ 0	$ 33,575
Accumulated depreciation and amortization	0	(5,558)
Real estate held for sale, net	0	28,017
Other assets	0	1,786
Total assets related to real estate held for sale	0	29,803
Liabilities related to real estate held for sale
Notes payable, net	0	21,648
Other liabilities	0	50
Total liabilities related to real estate held for sale	$ 0	$ 21,698

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	$ 212,737		$ 212,737		$ 230,576
Tenant Origination and Absorption Costs, Accumulated Amortization	(114,422)		(114,422)		(108,078)
Tenant Origination and Absorption Costs, Net Amount	98,315		98,315		122,498
Tenant Origination and Absorption Costs, Amortization expense	(8,184)	$ (10,202)	(24,182)	$ (32,321)
Above-Market Lease Assets, Cost	11,916		11,916		12,301
Above-Market Lease Assets, Accumulated Amortization	(7,353)		(7,353)		(6,440)
Above-Market Lease Assets, Net Amount	4,563		4,563		5,861
Above-Market Lease Assets, Amortization expense	(430)	(527)	(1,325)	(1,774)
Below-Market Lease Liabilities, Cost	(41,270)		(41,270)		(47,459)
Below-Market Lease Liabilities, Accumulated Amortization	22,340		22,340		22,849
Below-Market Lease Liabilities, Net Amount	(18,930)		(18,930)		$ (24,610)
Below-Market Lease Liabilities, Amortization expense	$ 2,203	$ 2,184	$ 5,685	$ 6,963

INVESTMENT IN UNCONSOLIDATED _3

INVESTMENT IN UNCONSOLIDATED JOINT VENTURE (Narrative) (Details) - USD ($)	Mar. 03, 2017	Sep. 30, 2018	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Amount drawn		$ 2,078,627,000	$ 1,956,919,000
Equity method investments		34,662,000	$ 33,997,000
Village Center Station II Joint Venture | Village Center Station II Construction Loan | Secured Debt
Schedule of Equity Method Investments [Line Items]
Maximum borrowing capacity	$ 78,500,000
Amount drawn		66,400,000
Village Center Station II Joint Venture | Village Center Station II
Schedule of Equity Method Investments [Line Items]
Equity interest in joint venture	75.00%
Development costs	$ 111,200,000
Contributed capital	$ 32,300,000
Equity interest in joint venture to be purchased	25.00%
Equity interest in joint venture to be purchased, value	$ 28,200,000
Equity method investments		34,700,000
Equity method investments, acquisition cost		$ 2,300,000

INVESTMENT IN UNCONSOLIDATED _4

INVESTMENT IN UNCONSOLIDATED JOINT VENTURE (Summarized Financial Information) (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	Dec. 31, 2016
Assets
Real estate, net	$ 2,916,119		$ 2,916,119		$ 2,962,134
Cash and cash equivalents	78,186	$ 44,575	78,186	$ 44,575	65,486	$ 72,068
Total assets	3,237,239		3,237,239		3,220,807
Liabilities and equity
Accounts payable	79,328		79,328		71,012
Notes payable, net	2,068,199		2,068,199		1,941,786
Other liabilities	24,218		24,218		30,935
Total liabilities and equity	3,237,239		3,237,239		$ 3,220,807
Income Statement [Abstract]
Revenues	106,145	102,558	317,900	310,976
Expenses:
Operating, maintenance, and management	26,397	25,293	73,852	70,765
Depreciation and amortization	40,824	41,151	118,831	124,370
Interest expense	16,584	15,460	29,911	45,257
Total expenses	110,699	105,934	301,641	311,660
Net (loss) income attributable to common stockholders	(4,070)	(3,151)	30,309	267
Company’s equity in income of unconsolidated joint venture	373	$ 0	25	$ (1)
Village Center Station II Joint Venture
Assets
Real estate, net	104,774		104,774
Cash and cash equivalents	3,630		3,630
Other assets	4,631		4,631
Total assets	113,035		113,035
Liabilities and equity
Accounts payable	2,338		2,338
Notes payable, net	66,358		66,358
Other liabilities	1,191		1,191
Members’ capital	43,148		43,148
Total liabilities and equity	$ 113,035		113,035
Income Statement [Abstract]
Revenues			3,083
Expenses:
Operating, maintenance, and management			20
Depreciation and amortization			1,925
Interest expense			1,100
Total expenses			3,045
Other expenses			5
Net (loss) income attributable to common stockholders			33
Company’s equity in income of unconsolidated joint venture			$ 25

NOTES PAYABLE (Schedule of Long

NOTES PAYABLE (Schedule of Long-term Debt Instruments) (Details) - USD ($)	Oct. 17, 2018	Sep. 30, 2018	Oct. 16, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Total notes payable principal outstanding		$ 2,078,627,000		$ 1,956,919,000
Deferred financing costs, net		(10,428,000)		(15,133,000)
Total notes payable, net		2,068,199,000		1,941,786,000
Portfolio Loan | Subsequent Event
Debt Instrument [Line Items]
Total notes payable principal outstanding	$ 169,000,000		$ 255,000,000
Extinguishment of debt, amount	104,000,000
Portfolio Loan | Secured Debt
Debt Instrument [Line Items]
Total notes payable, net		127,500,000
Portfolio Loan | Revolving Credit Facility | Subsequent Event
Debt Instrument [Line Items]
Total notes payable principal outstanding	84,500,000
Unused borrowing capacity, amount	84,500,000
Extinguishment of debt, amount	61,000,000
515 Congress Mortgage Loan | Subsequent Event
Debt Instrument [Line Items]
Extinguishment of debt, amount	69,800,000
Portfolio Loan Facility | Secured Debt
Debt Instrument [Line Items]
Total notes payable, net		757,500,000
Portfolio Revolving Loan Facility | Subsequent Event
Debt Instrument [Line Items]
Maximum borrowing capacity	385,000,000
Unused borrowing capacity, amount	200,000,000
Additional increase	170,000,000
Increments of increase	15,000,000
Current borrowing capacity	215,000,000
Portfolio Revolving Loan Facility | Revolving Credit Facility | Subsequent Event
Debt Instrument [Line Items]
Loan, amount outstanding	$ 92,500,000
Maximum borrowing capacity, percentage	50.00%
Current borrowing capacity	$ 107,500,000
Portfolio Revolving Loan Facility | One-month LIBOR | Subsequent Event
Debt Instrument [Line Items]
Stated percentage	1.50%
Mortgages | Portfolio Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding		$ 188,460,000		188,460,000
Effective Interest Rate		4.00%
Maturity Date		Jun. 1, 2019
Mortgages | Portfolio Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate		1.90%
Mortgages | 222 Main Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding		$ 98,016,000		99,471,000
Stated percentage		3.97%
Effective Interest Rate		3.97%
Maturity Date		Mar. 1, 2021
Mortgages | Anchor Centre Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding		$ 49,799,000		50,000,000
Effective Interest Rate		3.60%
Maturity Date		Jun. 1, 2019
Mortgages | Anchor Centre Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate		1.50%
Mortgages | 171 17th Street Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding		$ 84,668,000		85,292,000
Effective Interest Rate		3.55%
Maturity Date		Sep. 1, 2019
Mortgages | 171 17th Street Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate		1.45%
Mortgages | Reston Square Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding		$ 29,567,000		29,800,000
Effective Interest Rate		3.80%
Maturity Date		Feb. 1, 2019
Mortgages | Reston Square Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate		1.50%
Mortgages | 101 South Hanley Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding		$ 42,401,000		40,557,000
Effective Interest Rate		3.87%
Maturity Date		Jan. 1, 2020
Mortgages | 101 South Hanley Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate		1.55%
Mortgages | 3003 Washington Boulevard Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding		$ 90,378,000		90,378,000
Effective Interest Rate		3.55%
Maturity Date		Feb. 1, 2020
Mortgages | 3003 Washington Boulevard Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate		1.55%
Mortgages | Rocklin Corporate Center Mortgage Loan (4)
Debt Instrument [Line Items]
Total notes payable principal outstanding		$ 0		21,689,000
Mortgages | 201 17th Street Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding		$ 64,428,000		64,428,000
Effective Interest Rate		3.54%
Maturity Date		Aug. 1, 2019
Mortgages | 201 17th Street Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate		1.40%
Mortgages | CrossPoint at Valley Forge Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding		$ 51,000,000		51,000,000
Effective Interest Rate		3.33%
Maturity Date		Sep. 1, 2022
Mortgages | CrossPoint at Valley Forge Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate		1.50%
Mortgages | The Almaden Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding		$ 93,000,000		93,000,000
Stated percentage		4.20%
Effective Interest Rate		4.20%
Maturity Date		Jan. 1, 2022
Mortgages | Promenade I & II at Eilan Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding		$ 37,300,000		37,300,000
Effective Interest Rate		3.57%
Maturity Date		Oct. 1, 2022
Mortgages | Promenade I & II at Eilan Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate		1.75%
Mortgages | 515 Congress Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding		$ 69,842,000		68,381,000
Effective Interest Rate		3.63%
Maturity Date		Nov. 1, 2020
Mortgages | 515 Congress Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate		1.70%
Mortgages | 201 Spear Street Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding		$ 100,000,000		100,000,000
Effective Interest Rate		3.77%
Maturity Date		Jan. 1, 2019
Mortgages | 201 Spear Street Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate		1.66%
Mortgages | Carillon Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding		$ 92,197,000		90,248,000
Effective Interest Rate		3.39%
Maturity Date		Feb. 1, 2020
Mortgages | Carillon Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate		1.65%
Mortgages | 3001 Washington Boulevard Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding		$ 30,229,000		28,404,000
Effective Interest Rate		3.14%
Maturity Date		Feb. 1, 2019
Mortgages | 3001 Washington Boulevard Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate		1.60%
Mortgages | Hardware Village Loan Facility
Debt Instrument [Line Items]
Total notes payable principal outstanding		$ 43,842,000		21,011,000
Effective Interest Rate		5.36%
Maturity Date		Feb. 23, 2020
Loan, amount outstanding		$ 43,800,000
Unused borrowing capacity, amount		$ 30,200,000
Mortgages | Hardware Village Loan Facility | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate		3.25%
Mortgages | Portfolio Loan Facility
Debt Instrument [Line Items]
Total notes payable principal outstanding		$ 913,500,000		$ 797,500,000
Effective Interest Rate		3.82%
Maturity Date		Nov. 3, 2020
Mortgages | Portfolio Loan Facility | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate		1.80%
Secured Debt | Portfolio Loan
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 255,000,000
Loan, amount outstanding		127,500,000
Potential maximum borrowing capacity		350,000,000
Secured Debt | Portfolio Loan | Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity		127,500,000
Loan, amount outstanding		61,000,000
Unused borrowing capacity, amount		$ 65,500,000
Maximum borrowing capacity, percentage		50.00%
Secured Debt | Portfolio Loan | Revolving Credit Facility | Upon Meeting Certain Financial Coverage Ratio and Subject to Certain Conditions
Debt Instrument [Line Items]
Unused borrowing capacity, amount		$ 1,000,000
Secured Debt | Portfolio Loan | Non-Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity, percentage		50.00%
Secured Debt | Portfolio Loan Facility
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 1,010,000,000
Loan, amount outstanding		757,500,000
Potential maximum borrowing capacity		1,410,000,000
Additional increase		400,000,000
Increments of increase		25,000,000
Secured Debt | Portfolio Loan Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity		252,500,000
Loan, amount outstanding		156,000,000
Unused borrowing capacity, amount		$ 96,500,000
Maximum borrowing capacity, percentage		25.00%
Secured Debt | Portfolio Loan Facility | Non-Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity, percentage		75.00%

NOTES PAYABLE (Narrative) (Deta

NOTES 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	$ 16,584	$ 15,460	$ 29,911	$ 45,257
Amortization of deferred financing costs			4,693	3,537
(Decrease) increase in interest expense incurred as a result of derivative instruments	(5,100)	400	(29,200)	3,100
Interest capitalized			2,452	1,543
Interest payable, current	6,600		6,600		$ 6,100
Construction in Progress
Debt Instrument [Line Items]
Interest capitalized	300	700	2,500	1,500
Interest Expense
Debt Instrument [Line Items]
Amortization of deferred financing costs	$ 1,600	$ 1,300	$ 4,900	$ 3,800

NOTES PAYABLE (Schedule of Matu

NOTES PAYABLE (Schedule of Maturities of Long-term Debt) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Notes Payable [Abstract]
October 1, 2018 through December 31, 2018	$ 1,074
2,019	549,285
2,020	1,253,722
2,021	93,956
2,022	180,590
Total notes payable	$ 2,078,627	$ 1,956,919

DERIVATIVE INSTRUMENTS (Notiona

DERIVATIVE INSTRUMENTS (Notional Amount) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)investment	Dec. 31, 2017USD ($)investment
Derivative instruments designated as hedging instruments | Interest rate swaps
Derivative [Line Items]
Number of Instruments | investment	0	2
Notional Amount | $	$ 0	$ 118,400
Derivative instruments not designated as hedging instruments | Interest rate swaps
Derivative [Line Items]
Number of Instruments | investment	14	16
Notional Amount | $	$ 1,209,147	$ 1,209,643
Weighted-Average Fix Pay Rate	2.03%
Weighted-Average Remaining Term in Years	3 years 2 months 12 days
Derivative instruments not designated as hedging instruments | Interest rate swaps | Minimum | One-month LIBOR
Derivative [Line Items]
Reference Rate	1.39%
Derivative instruments not designated as hedging instruments | Interest rate swaps | Maximum | One-month LIBOR
Derivative [Line Items]
Reference Rate	2.37%
Derivative instruments not designated as hedging instruments | Interest rate cap
Derivative [Line Items]
Number of Instruments | investment	1	0
Notional Amount | $	$ 100,000	$ 0
Weighted-Average Fix Pay Rate	3.00%
Weighted-Average Remaining Term in Years	3 months 18 days
Derivative instruments not designated as hedging instruments | Interest rate cap | One-month LIBOR
Derivative [Line Items]
Reference Rate	3.00%

DERIVATIVE INSTRUMENTS (Balance

DERIVATIVE INSTRUMENTS (Balance Sheet) (Details) $ in Thousands	Sep. 30, 2018USD ($)investmentInvestments	Dec. 31, 2017USD ($)investmentInvestments
Derivative instruments designated as hedging instruments | Interest rate swaps
Derivative [Line Items]
Number of Instruments	0	2
Derivative instruments designated as hedging instruments | Prepaid expenses and other assets, at fair value | Interest rate swaps
Derivative [Line Items]
Number of Instruments	0	1
Asset, Fair Value | $	$ 0	$ 128
Derivative instruments designated as hedging instruments | Other liabilities, at fair value | Interest rate swaps
Derivative [Line Items]
Number of Instruments	0	1
Liability, Fair Value | $	$ 0	$ (18)
Derivative instruments not designated as hedging instruments | Interest rate swaps
Derivative [Line Items]
Number of Instruments	14	16
Derivative instruments not designated as hedging instruments | Interest rate cap
Derivative [Line Items]
Number of Instruments	1	0
Derivative instruments not designated as hedging instruments | Prepaid expenses and other assets, at fair value | Interest rate swaps
Derivative [Line Items]
Number of Instruments | Investments	14	10
Asset, Fair Value | $	$ 34,819	$ 6,386
Derivative instruments not designated as hedging instruments | Prepaid expenses and other assets, at fair value | Interest rate cap
Derivative [Line Items]
Number of Instruments | Investments	1	0
Asset, Fair Value | $	$ 0	$ 0
Derivative instruments not designated as hedging instruments | Other liabilities, at fair value | Interest rate swaps
Derivative [Line Items]
Number of Instruments	0	6
Liability, Fair Value | $	$ 0	$ (1,677)

DERIVATIVE INSTRUMENTS (Stateme

DERIVATIVE INSTRUMENTS (Statement of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Derivative [Line Items]
Unrealized (losses) income on derivative instruments	$ 5	$ 13	$ 88	$ 602
Derivative instruments designated as hedging instruments
Derivative [Line Items]
Amount of (income) expense recognized on interest rate swaps (effective portion)	(90)	253	(198)	1,717
(Decrease) increase in interest expense as a result of derivatives	(90)	253	(198)	1,717
Derivative instruments not designated as hedging instruments
Derivative [Line Items]
(Decrease) increase in interest expense as a result of derivatives	(5,052)	357	(29,177)	3,104
Derivative instruments not designated as hedging instruments | Interest rate swaps
Derivative [Line Items]
Amount of (income) expense recognized on interest rate swaps (effective portion)	186	(1,108)	(1,123)	(3,966)
Unrealized gain (loss) on interest rate swaps	(4,784)	(1,004)	(30,110)	(2,579)
(Decrease) increase in interest expense as a result of derivatives	(4,962)	104	(28,979)	1,387
Derivative instruments not designated as hedging instruments | Interest rate cap
Derivative [Line Items]
Unrealized gain (loss) on interest rate swaps	$ 8	$ 0	$ 8	$ 0

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]
Debt face amount	$ 2,078,627,000	$ 1,956,919,000
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable, Value	2,068,199,000	1,941,786,000
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable, Value	$ 2,084,290,000	$ 1,950,965,000

FAIR VALUE DISCLOSURES (Assets

FAIR VALUE DISCLOSURES (Assets and Liabilities at Fair value) (Details) - Recurring Basis: $ in Thousands	Sep. 30, 2018USD ($)
Interest rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset derivatives	$ 34,819
Interest rate swaps | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset derivatives	0
Interest rate swaps | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset derivatives	34,819
Interest rate swaps | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset derivatives	0
Interest rate cap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset derivatives	0
Interest rate cap | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset derivatives	0
Interest rate cap | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset derivatives	0
Interest rate cap | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset derivatives	$ 0

RELATED PARTY TRANSACTIONS (Cos

RELATED PARTY TRANSACTIONS (Costs) (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
Related Party Transaction [Line Items]
Payable as of	$ 6,271		$ 6,271		$ 3,239
Administrative fees, amount paid	69	$ 49	243	$ 169
Professional fees incurred related to the assessment of strategic alternatives	1,800		2,700
Advisor and Dealer Manager
Related Party Transaction [Line Items]
Incurred	8,848	6,830	24,078	20,271
Payable as of	6,271		6,271		3,239
Advisor and Dealer Manager | Asset management fees
Related Party Transaction [Line Items]
Expenses	6,830	6,587	20,188	19,223
Payable as of	2,232		2,232		2,262
Advisor and Dealer Manager | Reimbursement of operating expenses
Related Party Transaction [Line Items]
Expenses	1,862	59	2,964	255
Payable as of	2,686		2,686		121
Advisor and Dealer Manager | Disposition fees
Related Party Transaction [Line Items]
Expenses	0	0	429	0
Payable as of	0		0		0
Advisor and Dealer Manager | Acquisition fee on development project
Related Party Transaction [Line Items]
Incurred	124	64	303	234
Payable as of	869		869		566
Advisor and Dealer Manager | Acquisition fee on unconsolidated joint venture
Related Party Transaction [Line Items]
Incurred	32	120	194	497
Payable as of	484		484		290
Advisor and Dealer Manager | Asset management fee on development project
Related Party Transaction [Line Items]
Incurred	0	0	0	48
Payable as of	0		0		0
Advisor and Dealer Manager | Asset management fee on unconsolidated joint venture
Related Party Transaction [Line Items]
Incurred	0	$ 0	0	$ 14
Payable as of	$ 0		$ 0		$ 0

RELATED PARTY TRANSACTIONS (Nar

RELATED PARTY TRANSACTIONS (Narrative) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	May 29, 2015USD ($)ft²$ / ft²
Affiliated Entity | Subsidiaries
Related Party Transaction [Line Items]
Net rentable area | ft²					5,046
Percent of total rentable square feet					2.30%
Annualized base rent					$ 200
Average annualized base rent per square foot | $ / ft²					46.38
Rental income	$ 60	$ 61	$ 180	$ 180
KBS Capital Advisors LLC
Related Party Transaction [Line Items]
Incurred			100
KBS Capital Advisors LLC | Property Insurance Rebate
Related Party Transaction [Line Items]
Incurred			$ 200	$ 200

SUBSEQUENT EVENTS (Distribution

SUBSEQUENT EVENTS (Distributions) (Details) - USD ($) $ / shares in Units, $ in Millions	Nov. 05, 2018	Nov. 01, 2018	Oct. 01, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 06, 2017
Subsequent Event [Line Items]
Distribution rate per share per day, declared (in dollars per share)				$ 0.00178082	$ 0.00178082	$ 0.00178082	$ 0.00178082
Dividend Authorized | Most Recent Primary Offering Purchase Price
Subsequent Event [Line Items]
Common stock, purchase price per share (in dollars per share)								$ 11.73
Subsequent Event | Dividend Paid
Subsequent Event [Line Items]
Dividends, common stock, cash		$ 9.8	$ 9.4
Subsequent Event | Dividend Authorized
Subsequent Event [Line Items]
Distribution rate per share per day, declared (in dollars per share)	$ 0.00178082
Distribution rate per share annualized, declared, based on current estimated value	5.54%

SUBSEQUENT EVENTS (Financing) (

SUBSEQUENT EVENTS (Financing) (Details)	Oct. 17, 2018USD ($)optionextension	Oct. 16, 2018USD ($)	Sep. 30, 2018USD ($)	Dec. 31, 2017USD ($)
Subsequent Event [Line Items]
Term debt			$ 2,078,627,000	$ 1,956,919,000
Long-term debt			$ 2,078,627,000	$ 1,956,919,000
Subsequent Event | Portfolio Revolving Loan Facility
Subsequent Event [Line Items]
Term	3 years
Current borrowing capacity	$ 215,000,000
Unused borrowing capacity, amount	$ 200,000,000
Number of extensions | extension	2
Extension period	12 months
Number of options to increase committed amount | option	4
Increments of increase	$ 15,000,000
Additional increase	170,000,000
Maximum borrowing capacity	$ 385,000,000
Guaranty provided as a percent of committed loan amount	25.00%
Subsequent Event | Portfolio Revolving Loan Facility | One-month LIBOR
Subsequent Event [Line Items]
Interest rate	1.50%
Subsequent Event | Portfolio Revolving Loan Facility | Subject to Certain Conditions
Subsequent Event [Line Items]
Unused borrowing capacity, amount	$ 15,000,000
Subsequent Event | Portfolio Revolving Loan Facility | Revolving Credit Facility
Subsequent Event [Line Items]
Current borrowing capacity	107,500,000
Loan, amount outstanding	$ 92,500,000
Maximum borrowing capacity, percentage	50.00%
Subsequent Event | Portfolio Revolving Loan Facility | Term debt
Subsequent Event [Line Items]
Term debt	$ 107,500,000
Loan, amount outstanding	$ 107,500,000
Maximum borrowing capacity, percentage	50.00%
Subsequent Event | 515 Congress Mortgage Loan
Subsequent Event [Line Items]
Extinguishment of debt, amount	$ 69,800,000
Subsequent Event | Portfolio Loan
Subsequent Event [Line Items]
Extinguishment of debt, amount	104,000,000
Long-term debt	169,000,000	$ 255,000,000
Subsequent Event | Portfolio Loan | Revolving Credit Facility
Subsequent Event [Line Items]
Unused borrowing capacity, amount	84,500,000
Extinguishment of debt, amount	61,000,000
Long-term debt	84,500,000
Subsequent Event | Portfolio Loan | Term debt
Subsequent Event [Line Items]
Extinguishment of debt, amount	43,000,000
Long-term debt	$ 84,500,000