KBS Real Estate Investment Trust III (KBSR) 10-Q 8 Aug 18 2018 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2018	Aug. 03, 2018
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q2
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		176,077,252

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Real estate:
Land	$ 390,685	$ 390,685
Buildings and improvements	2,709,462	2,680,838
Construction in progress	91,158	67,826
Tenant origination and absorption costs	219,080	230,576
Total real estate held for investment, cost	3,410,385	3,369,925
Less accumulated depreciation and amortization	(484,639)	(435,808)
Total real estate held for investment, net	2,925,746	2,934,117
Real estate held for sale, net	0	28,017
Total real estate, net	2,925,746	2,962,134
Cash and cash equivalents	63,831	65,486
Investment in unconsolidated joint venture	34,239	33,997
Rents and other receivables, net	87,252	79,317
Above-market leases, net	4,993	5,861
Assets related to real estate held for sale, net	0	1,786
Prepaid expenses and other assets	94,324	72,226
Total assets	3,210,385	3,220,807
Notes payable, net
Notes payable related to real estate held for investment, net	2,031,849	1,920,138
Note payable related to real estate held for sale, net	0	21,648
Total notes payable, net	2,031,849	1,941,786
Accounts payable and accrued liabilities	65,775	71,012
Due to affiliate	4,274	3,239
Distributions payable	9,499	9,982
Below-market leases, net	21,133	24,610
Liabilities related to real estate held for sale, net	0	50
Redeemable common stock payable	6,257	18,870
Other liabilities	26,655	30,935
Total liabilities	2,165,442	2,100,484
Commitments and contingencies (Note 10)
Redeemable common stock	32,045	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, 175,274,174 and 180,864,707 shares issued and outstanding as of June 30, 2018 and December 31, 2017, respectively	1,753	1,809
Additional paid-in capital	1,548,383	1,591,640
Cumulative distributions and net losses	(537,623)	(514,451)
Accumulated other comprehensive income	85	110
Total KBS Real Estate Investment Trust III, Inc. stockholders’ equity	1,012,598	1,079,108
Noncontrolling interest	300	300
Total equity	1,012,898	1,079,408
Total liabilities and equity	$ 3,210,385	$ 3,220,807

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Jun. 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)	175,274,174	180,864,707
Common stock, shares outstanding (in shares)	175,274,174	180,864,707

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS (unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues:
Rental income	$ 79,371	$ 77,582	$ 158,336	$ 158,403
Tenant reimbursements	21,613	19,484	41,113	38,589
Other operating income	6,592	5,953	12,306	11,426
Total revenues	107,576	103,019	211,755	208,418
Expenses:
Operating, maintenance and management	24,301	22,983	47,455	45,472
Real estate taxes and insurance	18,487	16,338	35,261	32,260
Asset management fees to affiliate	6,738	6,431	13,358	12,637
General and administrative expenses	2,012	1,117	3,535	2,341
Depreciation and amortization	39,025	41,524	78,006	83,219
Interest expense	12,517	16,896	13,327	29,797
Total expenses	103,080	105,289	190,942	205,726
Other income (loss):
Other income	1,575	650	1,876	650
Other interest income	84	25	96	50
Equity in loss of unconsolidated joint venture	(348)	0	(348)	(1)
Gain on sale of real estate, net	11,942	0	11,942	0
Total other income, net	13,253	675	13,566	699
Net income (loss)	17,749	(1,595)	34,379	3,391
Net loss attributable to noncontrolling interest	0	27	0	27
Net income (loss) attributable to common stockholders	$ 17,749	$ (1,568)	$ 34,379	$ 3,418
Net income per common share, basic and diluted (in dollars per share)	$ 0.10	$ (0.01)	$ 0.19	$ 0.02
Weighted-average number of common shares outstanding, basic and diluted (in shares)	177,649,492	181,548,488	178,588,342	181,497,075

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 17,749	$ (1,568)	$ 34,379	$ 3,418
Other comprehensive income (loss):
Unrealized (losses) income on derivative instruments designated as cash flow hedges	(1)	(136)	83	589
Reclassification adjustment realized in net income (effective portion)	(96)	570	(108)	1,464
Total other comprehensive (loss) income	(97)	434	(25)	2,053
Total comprehensive income (loss)	17,652	(1,134)	34,354	5,471
Total comprehensive loss attributable to noncontrolling interest	0	27	0	27
Total comprehensive income (loss) attributable to common stockholders	$ 17,652	$ (1,107)	$ 34,354	$ 5,498

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ 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	34,379	34,379			34,379		0
Other comprehensive income (loss)	(25)	(25)				(25)
Issuance of common stock (in shares)			2,556,146
Issuance of common stock	28,501	28,501	$ 25	28,476
Transfers from redeemable common stock	21,557	21,557		21,557
Redemptions of common stock (in shares)			(8,146,679)
Redemptions of common stock	(93,371)	(93,371)	$ (81)	(93,290)
Distributions declared	$ (57,551)	(57,551)			(57,551)
Balance (in shares) at Jun. 30, 2018	175,274,174		175,274,174
Balance at Jun. 30, 2018	$ 1,012,898	$ 1,012,598	$ 1,753	$ 1,548,383	$ (537,623)	$ 85	$ 300

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash Flows from Operating Activities:
Net income	$ 34,379	$ 3,391
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	78,006	83,219
Equity in loss of unconsolidated joint venture	348	1
Deferred rents	(4,947)	(5,504)
Loss due to property damage	0	238
Bad debt expense	110	210
Amortization of above- and below-market leases, net	(2,587)	(3,532)
Amortization of deferred financing costs	3,091	2,410
Unrealized gains on derivative instruments	(25,326)	(1,575)
Gain on sale of real estate	(11,942)	0
Changes in operating assets and liabilities:
Rents and other receivables	(3,067)	(2,313)
Prepaid expenses and other assets	(7,918)	(11,581)
Accounts payable and accrued liabilities	(5,113)	(5,601)
Other liabilities	(2,586)	(683)
Due to affiliates	695	(62)
Net cash provided by operating activities	53,143	58,618
Cash Flows from Investing Activities:
Improvements to real estate	(45,931)	(30,050)
Proceeds from sale of real estate, net	41,649	0
Payments for construction in progress	(19,092)	(21,239)
Investment in unconsolidated joint venture	(428)	(33,145)
Escrow deposits for tenant improvements	1,111	(7,744)
Insurance proceeds received for property damage	3,928	0
Net cash used in investing activities	(18,763)	(92,178)
Cash Flows from Financing Activities:
Proceeds from notes payable	126,168	93,396
Principal payments on notes payable	(39,266)	(1,210)
Payments of deferred financing costs	(108)	(1,254)
Payments to redeem common stock	(93,296)	(31,471)
Payments of other offering costs	0	(1)
Distributions paid to common stockholders	(29,533)	(28,707)
Net cash (used in) provided by financing activities	(36,035)	30,753
Net decrease in cash and cash equivalents	(1,655)	(2,807)
Cash and cash equivalents, beginning of period	65,486	72,068
Cash and cash equivalents, end of period	63,831	69,261
Supplemental Disclosure of Cash Flow Information:
Interest paid, net of capitalized interest of $2,150 and $820 for the six months ended June 30, 2018 and 2017, respectively	35,001	28,082
Supplemental Disclosure of Noncash Investing and Financing Activities:
Distributions paid to common stockholders through common stock issuances pursuant to the dividend reinvestment plan	28,501	30,097
Increase in construction in progress payable	4,055	9,715
Increase in acquisition fee related to construction in progress due to affiliate	179	170
Increase in acquisition fee on unconsolidated joint venture due to affiliate	$ 161	$ 53

CONSOLIDATED STATEMENTS OF CAS8

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) (unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Statement of Cash Flows [Abstract]
Interest capitalized	$ 2,150	$ 820

ORGANIZATION

ORGANIZATION	6 Months Ended
	Jun. 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 June 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 June 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 subsequently operate an office/retail property. Additionally, as of June 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 June 30, 2018 , the Company had also sold 25,448,597 shares of common stock under its dividend reinvestment plan for gross offering proceeds of $253.2 million . Also as of June 30, 2018 , the Company had redeemed 19,459,048 shares sold in the Offering for $207.8 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	6 Months Ended
	Jun. 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 six months ended June 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 six months ended June 30, 2018 , tenant reimbursements for substantial services accounted for under ASU No. 2014-09 were $1.9 million and $3.5 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 six months ended June 30, 2018 and 2017 , respectively. Distributions declared per common share were $0.162 and $ 0.322 for the three and six months ended June 30, 2018 , respectively. Distributions declared per common share were $0.162 and $ 0.322 for the three and six months ended June 30, 2017 , respectively. Distributions declared per common share assumes each share was issued and outstanding each day during the three and six months ended June 30, 2018 and 2017 , respectively. For each day that was a record date for distributions during the three and six months ended June 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 June 30, 2017 and January 1, 2018 through June 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 June 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. The Company is currently evaluating the impact of adopting the new lease accounting standard on its consolidated financial statements. 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. 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.

REAL ESTATE

REAL ESTATE	6 Months Ended
	Jun. 30, 2018
Real Estate [Abstract]
REAL ESTATE	REAL ESTATE Real Estate Held for Investment As of June 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 June 30, 2018 , the Company’s real estate portfolio was collectively 92% occupied. The following table summarizes the Company’s investments in real estate as of June 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 $ 47,755 $ (14,612 ) $ 33,143 Town Center 03/27/2012 Plano TX Office 116,063 (27,006 ) 89,057 McEwen Building 04/30/2012 Franklin TN Office 37,130 (7,843 ) 29,287 Gateway Tech Center 05/09/2012 Salt Lake City UT Office 24,480 (6,006 ) 18,474 Tower on Lake Carolyn 12/21/2012 Irving TX Office 53,419 (11,554 ) 41,865 RBC Plaza 01/31/2013 Minneapolis MN Office 153,392 (34,491 ) 118,901 One Washingtonian Center 06/19/2013 Gaithersburg MD Office 91,814 (17,198 ) 74,616 Preston Commons 06/19/2013 Dallas TX Office 117,914 (21,640 ) 96,274 Sterling Plaza 06/19/2013 Dallas TX Office 79,113 (12,340 ) 66,773 201 Spear Street 12/03/2013 San Francisco CA Office 143,555 (14,487 ) 129,068 500 West Madison 12/16/2013 Chicago IL Office 434,460 (63,935 ) 370,525 222 Main 02/27/2014 Salt Lake City UT Office 164,562 (27,797 ) 136,765 Anchor Centre 05/22/2014 Phoenix AZ Office 95,772 (14,941 ) 80,831 171 17th Street 08/25/2014 Atlanta GA Office 133,093 (24,324 ) 108,769 Reston Square 12/03/2014 Reston VA Office 46,817 (7,818 ) 38,999 Ten Almaden 12/05/2014 San Jose CA Office 122,908 (15,266 ) 107,642 Towers at Emeryville 12/23/2014 Emeryville CA Office 271,818 (30,710 ) 241,108 101 South Hanley 12/24/2014 St. Louis MO Office 72,010 (10,281 ) 61,729 3003 Washington Boulevard 12/30/2014 Arlington VA Office 151,150 (17,709 ) 133,441 Village Center Station 05/20/2015 Greenwood Village CO Office 77,406 (11,456 ) 65,950 Park Place Village 06/18/2015 Leawood KS Office/Retail 128,671 (16,041 ) 112,630 201 17th Street 06/23/2015 Atlanta GA Office 102,679 (12,625 ) 90,054 Promenade I & II at Eilan 07/14/2015 San Antonio TX Office 62,644 (8,208 ) 54,436 CrossPoint at Valley Forge 08/18/2015 Wayne PA Office 90,352 (10,155 ) 80,197 515 Congress 08/31/2015 Austin TX Office 119,934 (12,675 ) 107,259 The Almaden 09/23/2015 San Jose CA Office 168,337 (14,686 ) 153,651 3001 Washington Boulevard 11/06/2015 Arlington VA Office 58,882 (4,016 ) 54,866 Carillon 01/15/2016 Charlotte NC Office 153,097 (14,819 ) 138,278 Hardware Village (1) 08/26/2016 Salt Lake City UT Development/Apartment 91,158 — 91,158 $ 3,410,385 $ (484,639 ) $ 2,925,746 _____________________ (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. As of June 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 $ 370,525 11.5 % $ 33,746 $ 28.13 82.3 % _____________________ (1) Annualized base rent represents annualized contractual base rental income as of June 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 June 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, rights of first refusal to purchase the property at competitive market rates, 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 $11.1 million and $11.5 million as of June 30, 2018 and December 31, 2017 , respectively. During the six months ended June 30, 2018 and 2017 , the Company recognized deferred rent from tenants of $4.9 million and $5.5 million , respectively. As of June 30, 2018 and December 31, 2017 , the cumulative deferred rent balance was $80.5 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 $9.6 million and $9.3 million of unamortized lease incentives as of June 30, 2018 and December 31, 2017 , respectively. As of June 30, 2018 , the future minimum rental income from the Company’s properties under its non-cancelable operating leases was as follows (in thousands): July 1, 2018 through December 31, 2018 $ 148,952 2019 288,725 2020 258,983 2021 231,126 2022 197,819 Thereafter 564,996 $ 1,690,601 As of June 30, 2018 , the Company’s real estate properties were leased to approximately 900 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 153 $ 61,902 20.1 % _____________________ (1) Annualized base rent represents annualized contractual base rental income as of June 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 June 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 June 30, 2018 , the Company’s net investments in real estate in California, Texas and Illinois represented 20% , 15% and 12% 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 six months ended June 30, 2018 , the Company received $3.9 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 $1.9 million . During the six months ended June 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 six months ended June 30, 2018 , the Company received $1.1 million of business interruption insurance recovery, consisting of $0.7 million of revenue related to the year ended December 31, 2017 and $0.4 million of revenue related to the period from January through February 2018. As of June 30, 2018 , the Company recorded $2.3 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 six months ended June 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. The results of operations for the property sold during the six months ended June 30, 2018 and gain on sale as of June 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 six months ended June 30, 2018 and 2017 (in thousands): For the Three Months Ended June 30, For the Six Months Ended June 30, 2018 2017 2018 2017 Revenues Rental income $ 674 $ 1,125 $ 1,802 $ 2,240 Tenant reimbursements and other operating income 26 41 110 71 Total revenues $ 700 $ 1,166 $ 1,912 $ 2,311 Expenses Operating, maintenance, and management $ 142 $ 319 $ 462 $ 622 Real estate taxes and insurance 71 109 213 217 Asset management fees to affiliate 39 66 105 131 Depreciation and amortization — 537 — 1,062 Interest expense 127 163 320 307 Total expenses $ 379 $ 1,194 $ 1,100 $ 2,339 The following summary presents the major components of assets and liabilities related to real estate held for sale as of June 30, 2018 and December 31, 2017 (in thousands): June 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	6 Months Ended
	Jun. 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 June 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 June 30, 2018 December 31, 2017 June 30, 2018 December 31, 2017 June 30, 2018 December 31, 2017 Cost $ 219,080 $ 230,576 $ 11,956 $ 12,301 $ (43,602 ) $ (47,459 ) Accumulated Amortization (112,581 ) (108,078 ) (6,963 ) (6,440 ) 22,469 22,849 Net Amount $ 106,499 $ 122,498 $ 4,993 $ 5,861 $ (21,133 ) $ (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 six months ended June 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 June 30, For the Three Months Ended June 30, For the Three Months Ended June 30, 2018 2017 2018 2017 2018 2017 Amortization $ (7,856 ) $ (11,013 ) $ (439 ) $ (544 ) $ 1,655 $ 2,505 Tenant Origination and Absorption Costs Above-Market Lease Assets Below-Market Lease Liabilities For the Six Months Ended June 30, For the Six Months Ended June 30, For the Six Months Ended June 30, 2018 2017 2018 2017 2018 2017 Amortization $ (15,998 ) $ (22,119 ) $ (895 ) $ (1,247 ) $ 3,482 $ 4,779

INVESTMENT IN UNCONSOLIDATED JO

INVESTMENT IN UNCONSOLIDATED JOINT VENTURE	6 Months Ended
	Jun. 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 projected cost of the development is approximately $113.1 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 intends to fund 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 June 30, 2018 , $61.4 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. Under the joint venture agreement, the Company may be required to contribute up to 75% of additional requested contributions to the Village Center Station II Joint Venture. The Developer will fund all cost overruns (excluding certain overruns described in the Charter Communications lease) once the Village Center Station II Joint Venture has used all available funds in the development of Village Center Station II. 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. The expected purchase price of the Developer’s 25% equity interest is approximately $25.0 million . As of June 30, 2018 , the book value of the Company’s investment in the Village Center Station II Joint Venture was $34.2 million which includes $2.2 million of acquisition costs and capitalized interest incurred directly by the Company. As of June 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 $34.2 million investment. Summarized financial information for the Village Center Station II Joint Venture is as follows (in thousands): June 30, 2018 Assets: Real estate, net $ 105,080 Cash and cash equivalents 805 Other assets 3,821 Total assets $ 109,706 Liabilities and equity: Accounts payable $ 5,346 Notes payable, net 61,372 Other liabilities 336 Members’ capital 42,652 Total liabilities and equity $ 109,706 Six Months Ended June 30, 2018 Revenues $ 769 Expenses: Operating, maintenance, and management 2 Real estate taxes and insurance 42 Depreciation and amortization 770 Interest expense 407 Total expenses 1,221 Net loss $ (452 ) Company ’s equity in loss of unconsolidated joint venture $ (348 )

NOTES PAYABLE

NOTES PAYABLE	6 Months Ended
	Jun. 30, 2018
Notes Payable [Abstract]
NOTES PAYABLE	NOTES PAYABLE As of June 30, 2018 and December 31, 2017 , the Company’s notes payable consisted of the following (dollars in thousands): Book Value as of June 30, 2018 Book Value as of December 31, 2017 Contractual Interest Rate as of (1) Effective Interest Rate as of June 30, 2018 (1) Payment Type Maturity Date (2) Portfolio Loan (3) $ 188,460 $ 188,460 One-month LIBOR + 1.90% 3.88% Interest Only 06/01/2019 222 Main Mortgage Loan 98,506 99,471 3.97% 3.97% Principal & Interest 03/01/2021 Anchor Centre Mortgage Loan 49,950 50,000 One-month LIBOR + 1.50% 3.48% Principal & Interest 06/01/2019 171 17th Street Mortgage Loan (4) 84,876 85,292 One-month LIBOR + 1.45% 2.97% Principal & Interest 09/01/2018 Reston Square Mortgage Loan 29,654 29,800 One-month LIBOR + 1.50% 3.78% Principal & Interest 02/01/2019 101 South Hanley Mortgage Loan 42,526 40,557 One-month LIBOR + 1.55% 3.85% 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 — 21,689 (5) (5) (5) (5) 201 17th Street Mortgage Loan (6) 64,428 64,428 One-month LIBOR + 1.40% 3.51% Interest Only 08/01/2018 CrossPoint at Valley Forge Mortgage Loan 51,000 51,000 One-month LIBOR + 1.50% 3.33% Interest Only (7) 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 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% 3.65% Interest Only 01/01/2019 Carillon Mortgage Loan 91,675 90,248 One-month LIBOR + 1.65% 3.37% Interest Only 02/01/2020 3001 Washington Boulevard Mortgage Loan 28,404 28,404 One-month LIBOR + 1.60% 3.08% Interest Only 02/01/2019 Hardware Village Loan Facility (8) 35,322 21,011 One-month LIBOR + 3.25% 5.24% Interest Only 02/23/2020 Portfolio Loan Facility (9) 888,500 797,500 One-month LIBOR + 1.80% 3.83% Interest Only 11/03/2020 Total notes payable principal outstanding 2,043,821 1,956,919 Deferred financing costs, net (11,972 ) (15,133 ) Total notes payable, net $ 2,031,849 $ 1,941,786 _____________________ (1) Contractual interest rate represents the interest rate in effect under the loan as of June 30, 2018 . Effective interest rate is calculated as the actual interest rate in effect as of June 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 June 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 June 30, 2018 ; subject to certain conditions, the maturity dates of certain loans may be extended beyond the dates shown. (3) As of June 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 June 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 June 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. (4) Subsequent to June 30, 2018 , the 171 17th Street Mortgage Loan maturity date was extended to September 1, 2019. (5) On May 25, 2018 , in connection with the disposition of Rocklin Corporate Center, the Company paid off the Rocklin Corporate Center Mortgage Loan. (6) Subsequent to June 30, 2018 , the 201 17th Street Mortgage Loan maturity date was extended to August 1, 2019. (7) Represents the payment type required under the loan as of June 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. (8) As of June 30, 2018 , $35.3 million had been disbursed and $38.7 million remained available for future disbursements, subject to certain conditions contained in the loan documents. (9) As of June 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 June 30, 2018 , the outstanding balance under the loan consisted of $757.5 million of term debt and $131.0 million of revolving debt. As of June 30, 2018 , an additional $121.5 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 six months ended June 30, 2018 , the Company incurred $12.5 million and $13.3 million of interest expense, respectively. During the three and six months ended June 30, 2017 , the Company incurred $16.9 million and $29.8 million of interest expense, respectively. Included in interest expense was: (i) the amortization of deferred financing costs of $1.6 million and $3.3 million for the three and six months ended June 30, 2018 , respectively, and $1.3 million and $2.5 million for the three and six months ended June 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 $7.2 million and $24.1 million for the three and six months ended June 30, 2018 , respectively, and increased interest expense by $2.8 million and $2.7 million for the three and six months ended June 30, 2017 , respectively. Additionally, the Company capitalized $1.1 million and $2.1 million of interest related to construction in progress during the three and six months ended June 30, 2018 , respectively, and $0.7 million and $0.8 million of interest related to construction in progress during the three and six months ended June 30, 2017 , respectively. As of June 30, 2018 and December 31, 2017 , $6.5 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 June 30, 2018 (in thousands): July 1, 2018 through December 31, 2018 $ 151,030 2019 398,572 2020 1,219,673 2021 93,956 2022 180,590 $ 2,043,821 The Company’s notes payable contain financial debt covenants. As of June 30, 2018 , the Company was in compliance with these debt covenants.

DERIVATIVE INSTRUMENTS

DERIVATIVE INSTRUMENTS	6 Months Ended
	Jun. 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 following table summarizes the notional amount and other information related to the Company’s interest rate swaps as of June 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): June 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 June 30, 2018 Derivative instruments designated as hedging instruments Interest Rate Swaps 1 $ 68,400 2 $ 118,400 One-month LIBOR/ Fixed at 1.41% 1.41% 0.2 Derivative instruments not designated as hedging instruments Interest Rate Swaps 14 $ 1,209,329 16 $ 1,209,643 One-month LIBOR/ 2.03% 3.4 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 June 30, 2018 and December 31, 2017 (dollars in thousands): June 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 $ 85 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 $ 30,035 10 $ 6,386 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 June 30, For the Six Months Ended June 30, 2018 2017 2018 2017 Income statement related Derivatives designated as hedging instruments Amount of (income) expense recognized on interest rate swaps (effective portion) $ (96 ) $ 570 $ (108 ) $ 1,464 (96 ) 570 (108 ) 1,464 Derivatives not designated as hedging instruments Realized loss recognized on interest rate swaps 201 1,315 1,309 2,858 Unrealized (gain) loss on interest rate swaps (7,289 ) 963 (25,326 ) (1,575 ) (7,088 ) 2,278 (24,017 ) 1,283 (Decrease) increase in interest expense as a result of derivatives $ (7,184 ) $ 2,848 $ (24,125 ) $ 2,747 Other comprehensive income related Unrealized (losses) income on derivative instruments $ (1 ) $ (136 ) $ 83 $ 589 During the three and six months ended June 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. During the next 12 months, the Company expects to recognize additional interest income related to derivative instruments designated as cash flow hedges. The present value of the unrealized income expected to be recognized over the next 12 months related to derivative instruments designated as cash flow hedges totaled $0.1 million as of June 30, 2018 and was included in accumulated other comprehensive income (loss).

FAIR VALUE DISCLOSURES

FAIR VALUE DISCLOSURES	6 Months Ended
	Jun. 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. 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 June 30, 2018 and December 31, 2017 , which carrying amounts generally do not approximate the fair values (in thousands): June 30, 2018 December 31, 2017 Face Value Carrying Amount Fair Value Face Value Carrying Amount Fair Value Financial liabilities: Notes payable $ 2,043,821 $ 2,031,849 $ 2,050,669 $ 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 June 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 $ 30,120 $ — $ 30,120 $ —

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS	6 Months Ended
	Jun. 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 Legacy Partners Apartment REIT elected to cease participation in the program and obtain 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 six months ended June 30, 2018 and 2017 , respectively, and any related amounts payable as of June 30, 2018 and December 31, 2017 (in thousands): Incurred Payable as of Three Months Ended June 30, Six Months Ended June 30, June 30, December 31, 2018 2017 2018 2017 2018 2017 Expensed Asset management fees $ 6,738 $ 6,431 $ 13,358 $ 12,637 $ 2,214 $ 2,262 Reimbursement of operating expenses (1) 956 55 1,102 196 864 121 Disposition fees (2) 429 — 429 — — — Capitalized Acquisition fee on development project 110 60 179 170 745 566 Acquisition fee on unconsolidated joint venture 69 53 162 377 451 290 Asset management fee on development project — — — 48 — — Asset management fee on unconsolidated joint venture — — — 14 — — $ 8,302 $ 6,599 $ 15,230 $ 13,442 $ 4,274 $ 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 $85,000 and $173,000 for the three and six months ended June 30, 2018 , respectively, and $55,000 and $120,000 for the three and six months ended June 30, 2017 , respectively, and were the only type of employee costs reimbursed under the Advisory Agreement for the three and six months ended June 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) 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 six months ended June 30, 2017 , the Advisor incurred $0.1 million for the costs of the supplemental coverage obtained by the Company. During each of the six months ended June 30, 2018 and 2017 , the Advisor paid the Company a $0.2 million property insurance rebate. 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 June 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 six months ended June 30, 2018 , the Company recognized $60,000 and $120,000 of revenue related to this lease, respectively. During the three and six months ended June 30, 2017 , the Company recognized $60,000 and $120,000 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 June 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	6 Months Ended
	Jun. 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 June 30, 2018 .

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	6 Months Ended
	Jun. 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 July 3, 2018 , the Company paid distributions of $9.5 million , which related to distributions declared for daily record dates for each day in the period from June 1, 2018 through June 30, 2018 . On August 1, 2018 , the Company paid distributions of $9.7 million , which related to distributions declared for daily record dates for each day in the period from July 1, 2018 through July 31, 2018 . Distributions Authorized On July 27, 2018 , the Company’s board of directors authorized distributions based on daily record dates for the period from August 1, 2018 through August 31, 2018 , which the Company expects to pay in September 2018 . On August 7, 2018 , the Company’s board of directors authorized distributions based on daily record dates for the period from September 1, 2018 through September 30, 2018 , which the Company expects to pay in October 2018 and distributions based on daily record dates for the period from October 1, 2018 through October 31, 2018 , which the Company expects to pay in November 2018 . 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 .

SUMMARY OF SIGNIFICANT ACCOUN20

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	6 Months Ended
	Jun. 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 six months ended June 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 six months ended June 30, 2018 , tenant reimbursements for substantial services accounted for under ASU No. 2014-09 were $1.9 million and $3.5 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 six months ended June 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 June 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. The Company is currently evaluating the impact of adopting the new lease accounting standard on its consolidated financial statements. 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. 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.

REAL ESTATE (Tables)

REAL ESTATE (Tables)	6 Months Ended
	Jun. 30, 2018
Real Estate [Abstract]
Schedule of Real Estate Investments	The following table summarizes the Company’s investments in real estate as of June 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 $ 47,755 $ (14,612 ) $ 33,143 Town Center 03/27/2012 Plano TX Office 116,063 (27,006 ) 89,057 McEwen Building 04/30/2012 Franklin TN Office 37,130 (7,843 ) 29,287 Gateway Tech Center 05/09/2012 Salt Lake City UT Office 24,480 (6,006 ) 18,474 Tower on Lake Carolyn 12/21/2012 Irving TX Office 53,419 (11,554 ) 41,865 RBC Plaza 01/31/2013 Minneapolis MN Office 153,392 (34,491 ) 118,901 One Washingtonian Center 06/19/2013 Gaithersburg MD Office 91,814 (17,198 ) 74,616 Preston Commons 06/19/2013 Dallas TX Office 117,914 (21,640 ) 96,274 Sterling Plaza 06/19/2013 Dallas TX Office 79,113 (12,340 ) 66,773 201 Spear Street 12/03/2013 San Francisco CA Office 143,555 (14,487 ) 129,068 500 West Madison 12/16/2013 Chicago IL Office 434,460 (63,935 ) 370,525 222 Main 02/27/2014 Salt Lake City UT Office 164,562 (27,797 ) 136,765 Anchor Centre 05/22/2014 Phoenix AZ Office 95,772 (14,941 ) 80,831 171 17th Street 08/25/2014 Atlanta GA Office 133,093 (24,324 ) 108,769 Reston Square 12/03/2014 Reston VA Office 46,817 (7,818 ) 38,999 Ten Almaden 12/05/2014 San Jose CA Office 122,908 (15,266 ) 107,642 Towers at Emeryville 12/23/2014 Emeryville CA Office 271,818 (30,710 ) 241,108 101 South Hanley 12/24/2014 St. Louis MO Office 72,010 (10,281 ) 61,729 3003 Washington Boulevard 12/30/2014 Arlington VA Office 151,150 (17,709 ) 133,441 Village Center Station 05/20/2015 Greenwood Village CO Office 77,406 (11,456 ) 65,950 Park Place Village 06/18/2015 Leawood KS Office/Retail 128,671 (16,041 ) 112,630 201 17th Street 06/23/2015 Atlanta GA Office 102,679 (12,625 ) 90,054 Promenade I & II at Eilan 07/14/2015 San Antonio TX Office 62,644 (8,208 ) 54,436 CrossPoint at Valley Forge 08/18/2015 Wayne PA Office 90,352 (10,155 ) 80,197 515 Congress 08/31/2015 Austin TX Office 119,934 (12,675 ) 107,259 The Almaden 09/23/2015 San Jose CA Office 168,337 (14,686 ) 153,651 3001 Washington Boulevard 11/06/2015 Arlington VA Office 58,882 (4,016 ) 54,866 Carillon 01/15/2016 Charlotte NC Office 153,097 (14,819 ) 138,278 Hardware Village (1) 08/26/2016 Salt Lake City UT Development/Apartment 91,158 — 91,158 $ 3,410,385 $ (484,639 ) $ 2,925,746 _____________________ (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.
Schedules of Concentration of Risk, by Risk Factor	As of June 30, 2018 , the Company’s real estate properties were leased to approximately 900 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 153 $ 61,902 20.1 % _____________________ (1) Annualized base rent represents annualized contractual base rental income as of June 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 June 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 $ 370,525 11.5 % $ 33,746 $ 28.13 82.3 % _____________________ (1) Annualized base rent represents annualized contractual base rental income as of June 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 June 30, 2018 , the future minimum rental income from the Company’s properties under its non-cancelable operating leases was as follows (in thousands): July 1, 2018 through December 31, 2018 $ 148,952 2019 288,725 2020 258,983 2021 231,126 2022 197,819 Thereafter 564,996 $ 1,690,601
Schedule of Revenue and Expenses of Real Estate Held-for-Sale	The results of operations for the property sold during the six months ended June 30, 2018 and gain on sale as of June 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 six months ended June 30, 2018 and 2017 (in thousands): For the Three Months Ended June 30, For the Six Months Ended June 30, 2018 2017 2018 2017 Revenues Rental income $ 674 $ 1,125 $ 1,802 $ 2,240 Tenant reimbursements and other operating income 26 41 110 71 Total revenues $ 700 $ 1,166 $ 1,912 $ 2,311 Expenses Operating, maintenance, and management $ 142 $ 319 $ 462 $ 622 Real estate taxes and insurance 71 109 213 217 Asset management fees to affiliate 39 66 105 131 Depreciation and amortization — 537 — 1,062 Interest expense 127 163 320 307 Total expenses $ 379 $ 1,194 $ 1,100 $ 2,339
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 June 30, 2018 and December 31, 2017 (in thousands): June 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 ABSORP22

TENANT ORIGINATION AND ABSORPTION COSTS, ABOVE-MARKET LEASE ASSETS AND BELOW-MARKET LEASE LIABILITIES (Tables)	6 Months Ended
	Jun. 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 June 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 June 30, 2018 December 31, 2017 June 30, 2018 December 31, 2017 June 30, 2018 December 31, 2017 Cost $ 219,080 $ 230,576 $ 11,956 $ 12,301 $ (43,602 ) $ (47,459 ) Accumulated Amortization (112,581 ) (108,078 ) (6,963 ) (6,440 ) 22,469 22,849 Net Amount $ 106,499 $ 122,498 $ 4,993 $ 5,861 $ (21,133 ) $ (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 six months ended June 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 June 30, For the Three Months Ended June 30, For the Three Months Ended June 30, 2018 2017 2018 2017 2018 2017 Amortization $ (7,856 ) $ (11,013 ) $ (439 ) $ (544 ) $ 1,655 $ 2,505 Tenant Origination and Absorption Costs Above-Market Lease Assets Below-Market Lease Liabilities For the Six Months Ended June 30, For the Six Months Ended June 30, For the Six Months Ended June 30, 2018 2017 2018 2017 2018 2017 Amortization $ (15,998 ) $ (22,119 ) $ (895 ) $ (1,247 ) $ 3,482 $ 4,779

INVESTMENT IN UNCONSOLIDATED 23

INVESTMENT IN UNCONSOLIDATED JOINT VENTURE (Tables)	6 Months Ended
	Jun. 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): June 30, 2018 Assets: Real estate, net $ 105,080 Cash and cash equivalents 805 Other assets 3,821 Total assets $ 109,706 Liabilities and equity: Accounts payable $ 5,346 Notes payable, net 61,372 Other liabilities 336 Members’ capital 42,652 Total liabilities and equity $ 109,706 Six Months Ended June 30, 2018 Revenues $ 769 Expenses: Operating, maintenance, and management 2 Real estate taxes and insurance 42 Depreciation and amortization 770 Interest expense 407 Total expenses 1,221 Net loss $ (452 ) Company ’s equity in loss of unconsolidated joint venture $ (348 )

NOTES PAYABLE (Tables)

NOTES PAYABLE (Tables)	6 Months Ended
	Jun. 30, 2018
Notes Payable [Abstract]
Schedule of Long-term Debt Instruments	As of June 30, 2018 and December 31, 2017 , the Company’s notes payable consisted of the following (dollars in thousands): Book Value as of June 30, 2018 Book Value as of December 31, 2017 Contractual Interest Rate as of (1) Effective Interest Rate as of June 30, 2018 (1) Payment Type Maturity Date (2) Portfolio Loan (3) $ 188,460 $ 188,460 One-month LIBOR + 1.90% 3.88% Interest Only 06/01/2019 222 Main Mortgage Loan 98,506 99,471 3.97% 3.97% Principal & Interest 03/01/2021 Anchor Centre Mortgage Loan 49,950 50,000 One-month LIBOR + 1.50% 3.48% Principal & Interest 06/01/2019 171 17th Street Mortgage Loan (4) 84,876 85,292 One-month LIBOR + 1.45% 2.97% Principal & Interest 09/01/2018 Reston Square Mortgage Loan 29,654 29,800 One-month LIBOR + 1.50% 3.78% Principal & Interest 02/01/2019 101 South Hanley Mortgage Loan 42,526 40,557 One-month LIBOR + 1.55% 3.85% 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 — 21,689 (5) (5) (5) (5) 201 17th Street Mortgage Loan (6) 64,428 64,428 One-month LIBOR + 1.40% 3.51% Interest Only 08/01/2018 CrossPoint at Valley Forge Mortgage Loan 51,000 51,000 One-month LIBOR + 1.50% 3.33% Interest Only (7) 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 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% 3.65% Interest Only 01/01/2019 Carillon Mortgage Loan 91,675 90,248 One-month LIBOR + 1.65% 3.37% Interest Only 02/01/2020 3001 Washington Boulevard Mortgage Loan 28,404 28,404 One-month LIBOR + 1.60% 3.08% Interest Only 02/01/2019 Hardware Village Loan Facility (8) 35,322 21,011 One-month LIBOR + 3.25% 5.24% Interest Only 02/23/2020 Portfolio Loan Facility (9) 888,500 797,500 One-month LIBOR + 1.80% 3.83% Interest Only 11/03/2020 Total notes payable principal outstanding 2,043,821 1,956,919 Deferred financing costs, net (11,972 ) (15,133 ) Total notes payable, net $ 2,031,849 $ 1,941,786 _____________________ (1) Contractual interest rate represents the interest rate in effect under the loan as of June 30, 2018 . Effective interest rate is calculated as the actual interest rate in effect as of June 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 June 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 June 30, 2018 ; subject to certain conditions, the maturity dates of certain loans may be extended beyond the dates shown. (3) As of June 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 June 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 June 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. (4) Subsequent to June 30, 2018 , the 171 17th Street Mortgage Loan maturity date was extended to September 1, 2019. (5) On May 25, 2018 , in connection with the disposition of Rocklin Corporate Center, the Company paid off the Rocklin Corporate Center Mortgage Loan. (6) Subsequent to June 30, 2018 , the 201 17th Street Mortgage Loan maturity date was extended to August 1, 2019. (7) Represents the payment type required under the loan as of June 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. (8) As of June 30, 2018 , $35.3 million had been disbursed and $38.7 million remained available for future disbursements, subject to certain conditions contained in the loan documents. (9) As of June 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 June 30, 2018 , the outstanding balance under the loan consisted of $757.5 million of term debt and $131.0 million of revolving debt. As of June 30, 2018 , an additional $121.5 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 June 30, 2018 (in thousands): July 1, 2018 through December 31, 2018 $ 151,030 2019 398,572 2020 1,219,673 2021 93,956 2022 180,590 $ 2,043,821

DERIVATIVE INSTRUMENTS (Tables)

DERIVATIVE INSTRUMENTS (Tables)	6 Months Ended
	Jun. 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 as of June 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): June 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 June 30, 2018 Derivative instruments designated as hedging instruments Interest Rate Swaps 1 $ 68,400 2 $ 118,400 One-month LIBOR/ Fixed at 1.41% 1.41% 0.2 Derivative instruments not designated as hedging instruments Interest Rate Swaps 14 $ 1,209,329 16 $ 1,209,643 One-month LIBOR/ 2.03% 3.4
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 June 30, 2018 and December 31, 2017 (dollars in thousands): June 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 $ 85 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 $ 30,035 10 $ 6,386 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 June 30, For the Six Months Ended June 30, 2018 2017 2018 2017 Income statement related Derivatives designated as hedging instruments Amount of (income) expense recognized on interest rate swaps (effective portion) $ (96 ) $ 570 $ (108 ) $ 1,464 (96 ) 570 (108 ) 1,464 Derivatives not designated as hedging instruments Realized loss recognized on interest rate swaps 201 1,315 1,309 2,858 Unrealized (gain) loss on interest rate swaps (7,289 ) 963 (25,326 ) (1,575 ) (7,088 ) 2,278 (24,017 ) 1,283 (Decrease) increase in interest expense as a result of derivatives $ (7,184 ) $ 2,848 $ (24,125 ) $ 2,747 Other comprehensive income related Unrealized (losses) income on derivative instruments $ (1 ) $ (136 ) $ 83 $ 589

FAIR VALUE DISCLOSURES (Tables)

FAIR VALUE DISCLOSURES (Tables)	6 Months Ended
	Jun. 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 June 30, 2018 and December 31, 2017 , which carrying amounts generally do not approximate the fair values (in thousands): June 30, 2018 December 31, 2017 Face Value Carrying Amount Fair Value Face Value Carrying Amount Fair Value Financial liabilities: Notes payable $ 2,043,821 $ 2,031,849 $ 2,050,669 $ 1,956,919 $ 1,941,786 $ 1,950,965
Schedule of Assets and Liabilities at Fair Value	As of June 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 $ 30,120 $ — $ 30,120 $ —

RELATED PARTY TRANSACTIONS (Tab

RELATED PARTY TRANSACTIONS (Tables)	6 Months Ended
	Jun. 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 six months ended June 30, 2018 and 2017 , respectively, and any related amounts payable as of June 30, 2018 and December 31, 2017 (in thousands): Incurred Payable as of Three Months Ended June 30, Six Months Ended June 30, June 30, December 31, 2018 2017 2018 2017 2018 2017 Expensed Asset management fees $ 6,738 $ 6,431 $ 13,358 $ 12,637 $ 2,214 $ 2,262 Reimbursement of operating expenses (1) 956 55 1,102 196 864 121 Disposition fees (2) 429 — 429 — — — Capitalized Acquisition fee on development project 110 60 179 170 745 566 Acquisition fee on unconsolidated joint venture 69 53 162 377 451 290 Asset management fee on development project — — — 48 — — Asset management fee on unconsolidated joint venture — — — 14 — — $ 8,302 $ 6,599 $ 15,230 $ 13,442 $ 4,274 $ 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 $85,000 and $173,000 for the three and six months ended June 30, 2018 , respectively, and $55,000 and $120,000 for the three and six months ended June 30, 2017 , respectively, and were the only type of employee costs reimbursed under the Advisory Agreement for the three and six months ended June 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) 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 ($)shares	Jun. 30, 2018USD ($)propertyshares	Dec. 31, 2017USD ($)shares	May 29, 2016USD ($)shares	Jun. 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)		175,274,174	180,864,707		175,274,174
Issuance of common stock | $		$ 28,501	$ 59,785
Redemptions of common stock | $		$ 93,371	$ 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)		2,556,146	5,919,223	169,006,162
Issuance of common stock | $		$ 25	$ 59	$ 1,700,000
Shares of common stock sold under dividend reinvestment plan, shares					25,448,597
Shares of common stock sold under dividend reinvestment plan, value | $					$ 253,200
Redemptions of common stock (in shares)		8,146,679	5,945,088		19,459,048
Redemptions of common stock | $		$ 81	$ 59		$ 207,800
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 ACCOUN29

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018USD ($)$ / shares	Jun. 30, 2017USD ($)$ / shares	Jun. 30, 2018USD ($)segment$ / shares	Jun. 30, 2017USD ($)$ / shares
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Tenant reimbursements | $	$ 21,613	$ 19,484	$ 41,113	$ 38,589
Distributions declared per share (in dollars per share) | $ / shares	$ 0.162	$ 0.162	$ 0.322	$ 0.322
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 | $	$ 1,900		$ 3,500

REAL ESTATE (Narrative) (Detail

REAL ESTATE (Narrative) (Details) ft² in Millions	Jun. 30, 2018ft²property
Real Estate Properties [Line Items]
Rentable square feet | ft²	10.9
Percentage of portfolio occupied	92.00%
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) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017	Aug. 26, 2016
Real Estate Properties [Line Items]
Total Real Estate at Cost	$ 3,410,385	$ 3,369,925
Accumulated Depreciation and Amortization	(484,639)	(435,808)
Total real estate held for investment, net	$ 2,925,746	$ 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	$ 47,755
Accumulated Depreciation and Amortization	(14,612)
Total real estate held for investment, net	$ 33,143
Town Center | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Mar. 27, 2012
Total Real Estate at Cost	$ 116,063
Accumulated Depreciation and Amortization	(27,006)
Total real estate held for investment, net	$ 89,057
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	(7,843)
Total real estate held for investment, net	$ 29,287
Gateway Tech Center | Office Properties
Real Estate Properties [Line Items]
Date Acquired	May 9, 2012
Total Real Estate at Cost	$ 24,480
Accumulated Depreciation and Amortization	(6,006)
Total real estate held for investment, net	$ 18,474
Tower on Lake Carolyn | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Dec. 21, 2012
Total Real Estate at Cost	$ 53,419
Accumulated Depreciation and Amortization	(11,554)
Total real estate held for investment, net	$ 41,865
RBC Plaza | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Jan. 31, 2013
Total Real Estate at Cost	$ 153,392
Accumulated Depreciation and Amortization	(34,491)
Total real estate held for investment, net	$ 118,901
One Washingtonian Center | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Jun. 19, 2013
Total Real Estate at Cost	$ 91,814
Accumulated Depreciation and Amortization	(17,198)
Total real estate held for investment, net	$ 74,616
Preston Commons | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Jun. 19, 2013
Total Real Estate at Cost	$ 117,914
Accumulated Depreciation and Amortization	(21,640)
Total real estate held for investment, net	$ 96,274
Sterling Plaza | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Jun. 19, 2013
Total Real Estate at Cost	$ 79,113
Accumulated Depreciation and Amortization	(12,340)
Total real estate held for investment, net	$ 66,773
201 Spear Street | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Dec. 3, 2013
Total Real Estate at Cost	$ 143,555
Accumulated Depreciation and Amortization	(14,487)
Total real estate held for investment, net	$ 129,068
500 West Madison | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Dec. 16, 2013
Total Real Estate at Cost	$ 434,460
Accumulated Depreciation and Amortization	(63,935)
Total real estate held for investment, net	$ 370,525
222 Main | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Feb. 27, 2014
Total Real Estate at Cost	$ 164,562
Accumulated Depreciation and Amortization	(27,797)
Total real estate held for investment, net	$ 136,765
Anchor Centre | Office Properties
Real Estate Properties [Line Items]
Date Acquired	May 22, 2014
Total Real Estate at Cost	$ 95,772
Accumulated Depreciation and Amortization	(14,941)
Total real estate held for investment, net	$ 80,831
171 17th Street | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Aug. 25, 2014
Total Real Estate at Cost	$ 133,093
Accumulated Depreciation and Amortization	(24,324)
Total real estate held for investment, net	$ 108,769
Reston Square | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Dec. 3, 2014
Total Real Estate at Cost	$ 46,817
Accumulated Depreciation and Amortization	(7,818)
Total real estate held for investment, net	$ 38,999
Ten Almaden | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Dec. 5, 2014
Total Real Estate at Cost	$ 122,908
Accumulated Depreciation and Amortization	(15,266)
Total real estate held for investment, net	$ 107,642
Towers at Emeryville | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Dec. 23, 2014
Total Real Estate at Cost	$ 271,818
Accumulated Depreciation and Amortization	(30,710)
Total real estate held for investment, net	$ 241,108
101 South Hanley | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Dec. 24, 2014
Total Real Estate at Cost	$ 72,010
Accumulated Depreciation and Amortization	(10,281)
Total real estate held for investment, net	$ 61,729
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	(17,709)
Total real estate held for investment, net	$ 133,441
Village Center Station | Office Properties
Real Estate Properties [Line Items]
Date Acquired	May 20, 2015
Total Real Estate at Cost	$ 77,406
Accumulated Depreciation and Amortization	(11,456)
Total real estate held for investment, net	$ 65,950
Park Place Village | Office/Retail
Real Estate Properties [Line Items]
Date Acquired	Jun. 18, 2015
Total Real Estate at Cost	$ 128,671
Accumulated Depreciation and Amortization	(16,041)
Total real estate held for investment, net	$ 112,630
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	(12,625)
Total real estate held for investment, net	$ 90,054
Promenade I & II at Eilan | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Jul. 14, 2015
Total Real Estate at Cost	$ 62,644
Accumulated Depreciation and Amortization	(8,208)
Total real estate held for investment, net	$ 54,436
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	(10,155)
Total real estate held for investment, net	$ 80,197
515 Congress | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Aug. 31, 2015
Total Real Estate at Cost	$ 119,934
Accumulated Depreciation and Amortization	(12,675)
Total real estate held for investment, net	$ 107,259
The Almaden | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Sep. 23, 2015
Total Real Estate at Cost	$ 168,337
Accumulated Depreciation and Amortization	(14,686)
Total real estate held for investment, net	$ 153,651
3001 Washington Boulevard | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Nov. 6, 2015
Total Real Estate at Cost	$ 58,882
Accumulated Depreciation and Amortization	(4,016)
Total real estate held for investment, net	$ 54,866
Carillon | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Jan. 15, 2016
Total Real Estate at Cost	$ 153,097
Accumulated Depreciation and Amortization	(14,819)
Total real estate held for investment, net	$ 138,278
Hardware Village | Development/Apartment
Real Estate Properties [Line Items]
Date Acquired	Aug. 26, 2016
Total Real Estate at Cost	$ 91,158
Accumulated Depreciation and Amortization	0
Total real estate held for investment, net	$ 91,158

REAL ESTATE (Properties Represe

REAL ESTATE (Properties Represented More than 10% of Company’s Total Assets) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018USD ($)ft²$ / ft²	Dec. 31, 2017USD ($)
Real Estate Properties [Line Items]
Rentable Square Feet | ft²	10,900,000
Total Real Estate, Net	$ 2,925,746	$ 2,934,117
Occupancy	92.00%
500 West Madison | Assets, Total
Real Estate Properties [Line Items]
Rentable Square Feet | ft²	1,457,724
Total Real Estate, Net	$ 370,525
Percentage of Total Assets	11.50%
Annualized Base Rent	$ 33,746
Average Annualized Base Rent per sq. ft. | $ / ft²	28.13
Occupancy	82.30%

REAL ESTATE (Operating Leases)

REAL ESTATE (Operating Leases) (Narrative) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018USD ($)tenant	Jun. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Operating Leased Assets [Line Items]
Deferred rent recognized	$ 4,947	$ 5,504
Deferred rent receivables	80,500		$ 74,400
Incentive to Lessee	$ 9,600		9,300
Number of tenants | tenant	900
Other Liabilities
Operating Leased Assets [Line Items]
Security deposit liability	$ 11,100		$ 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	Jun. 30, 2018USD ($)
Real Estate [Abstract]
July 1, 2018 through December 31, 2018	$ 148,952
2,019	288,725
2,020	258,983
2,021	231,126
2,022	197,819
Thereafter	564,996
Future minimum rental income	$ 1,690,601

REAL ESTATE (Highes Tenant Indu

REAL ESTATE (Highes Tenant Industry Concentrations- Grater than 10% of Annual Base Rent) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018USD ($)tenant
Concentration Risk [Line Items]
Number of Tenants	900
Finance
Concentration Risk [Line Items]
Number of Tenants	153
Annualized Base Rent | $	$ 61,902
Percentage of Annualized Base Rent	20.10%

REAL ESTATE REAL ESTATE (Geogra

REAL ESTATE REAL ESTATE (Geographic Concentration Risk) (Narrative) (Details) - Assets, Total	6 Months Ended
	Jun. 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	12.00%

REAL ESTATE (Property Damage) (

REAL ESTATE (Property Damage) (Details) - USD ($)	6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Real Estate Properties [Line Items]
Insurance proceeds received for property damage	$ 3,928,000	$ 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	3,900,000
Reduction in estimated insurance damages	1,900,000
Business interruption insurance recorded	600,000
Business interruption insurance received	1,100,000
Insurance recoveries	2,300,000
Physical Damage | Fiscal Year 2017
Real Estate Properties [Line Items]
Business interruption insurance received	700,000
Physical Damage | January and February 2018
Real Estate Properties [Line Items]
Business interruption insurance received	$ 400,000

REAL ESTATE (Revenue and Expens

REAL ESTATE (Revenue and Expenses of Real Estate Sales) (Details) - Disposed of by Sale $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)property	Jun. 30, 2017USD ($)	Dec. 31, 2017property
Real Estate Properties [Line Items]
Number of real estate properties disposed | property			1		0
Revenues
Rental income	$ 674	$ 1,125	$ 1,802	$ 2,240
Tenant reimbursements and other operating income	26	41	110	71
Total revenues	700	1,166	1,912	2,311
Expenses
Operating, maintenance, and management	142	319	462	622
Real estate taxes and insurance	71	109	213	217
Asset management fees to affiliate	39	66	105	131
Depreciation and amortization	0	537	0	1,062
Interest expense	127	163	320	307
Total expenses	$ 379	$ 1,194	$ 1,100	$ 2,339

REAL ESTATE (Schedule of Assets

REAL ESTATE (Schedule of Assets and Liabilities Related to Real Estate Held for Sale) (Details) - Held-for-sale - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
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 ABSORP40

TENANT ORIGINATION AND ABSORPTION COSTS, ABOVE-MARKET LEASE ASSETS AND BELOW-MARKET LEASE LIABILITIES (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 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	$ 219,080		$ 219,080		$ 230,576
Tenant Origination and Absorption Costs, Accumulated Amortization	(112,581)		(112,581)		(108,078)
Tenant Origination and Absorption Costs, Net Amount	106,499		106,499		122,498
Tenant Origination and Absorption Costs, Amortization expense	(7,856)	$ (11,013)	(15,998)	$ (22,119)
Above-Market Lease Assets, Cost	11,956		11,956		12,301
Above-Market Lease Assets, Accumulated Amortization	(6,963)		(6,963)		(6,440)
Above-Market Lease Assets, Net Amount	4,993		4,993		5,861
Above-Market Lease Assets, Amortization expense	(439)	(544)	(895)	(1,247)
Below-Market Lease Liabilities, Cost	(43,602)		(43,602)		(47,459)
Below-Market Lease Liabilities, Accumulated Amortization	22,469		22,469		22,849
Below-Market Lease Liabilities, Net Amount	(21,133)		(21,133)		$ (24,610)
Below-Market Lease Liabilities, Amortization expense	$ 1,655	$ 2,505	$ 3,482	$ 4,779

INVESTMENT IN UNCONSOLIDATED 41

INVESTMENT IN UNCONSOLIDATED JOINT VENTURE (Narrative) (Details) - USD ($)	Mar. 03, 2017	Jun. 30, 2018	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Amount drawn		$ 2,043,821,000	$ 1,956,919,000
Equity method investments		34,239,000	$ 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		$ 61,400,000
Village Center Station II Joint Venture | Village Center Station II
Schedule of Equity Method Investments [Line Items]
Equity interest in joint venture	75.00%
Payments to acquire investments	$ 113,100,000
Contributed capital	$ 32,300,000
Additional capital contributions required, percent		75.00%
Equity interest in joint venture to be purchased	25.00%
Equity interest in joint venture to be purchased, value	$ 25,000,000
Equity method investments		$ 34,200,000
Equity method investments, acquisition cost		$ 2,200,000

INVESTMENT IN UNCONSOLIDATED 42

INVESTMENT IN UNCONSOLIDATED JOINT VENTURE (Summarized Financial Information) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2016
Assets
Real estate, net	$ 2,925,746		$ 2,925,746		$ 2,962,134
Cash and cash equivalents	63,831	$ 69,261	63,831	$ 69,261	65,486	$ 72,068
Total assets	3,210,385		3,210,385		3,220,807
Liabilities and equity
Accounts payable	65,775		65,775		71,012
Notes payable, net	2,031,849		2,031,849		1,941,786
Other liabilities	26,655		26,655		30,935
Total liabilities and equity	3,210,385		3,210,385		$ 3,220,807
Income Statement [Abstract]
Revenues	107,576	103,019	211,755	208,418
Expenses:
Operating, maintenance, and management	24,301	22,983	47,455	45,472
Real estate taxes and insurance	18,487	16,338	35,261	32,260
Depreciation and amortization	39,025	41,524	78,006	83,219
Interest expense	12,517	16,896	13,327	29,797
Total expenses	103,080	105,289	190,942	205,726
Net income (loss) attributable to common stockholders	17,749	(1,568)	34,379	3,418
Company’s equity in loss of unconsolidated joint venture	(348)	$ 0	(348)	$ (1)
Village Center Station II Joint Venture
Assets
Real estate, net	105,080		105,080
Cash and cash equivalents	805		805
Other assets	3,821		3,821
Total assets	109,706		109,706
Liabilities and equity
Accounts payable	5,346		5,346
Notes payable, net	61,372		61,372
Other liabilities	336		336
Members’ capital	42,652		42,652
Total liabilities and equity	$ 109,706		109,706
Income Statement [Abstract]
Revenues			769
Expenses:
Operating, maintenance, and management			2
Real estate taxes and insurance			42
Depreciation and amortization			770
Interest expense			407
Total expenses			1,221
Net income (loss) attributable to common stockholders			(452)
Company’s equity in loss of unconsolidated joint venture			$ (348)

NOTES PAYABLE (Schedule of Long

NOTES PAYABLE (Schedule of Long-term Debt Instruments) (Details) - USD ($)	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Total notes payable principal outstanding	$ 2,043,821,000	$ 1,956,919,000
Deferred financing costs, net	(11,972,000)	(15,133,000)
Total notes payable, net	2,031,849,000	1,941,786,000
Portfolio Loan | Secured Debt
Debt Instrument [Line Items]
Total notes payable, net	127,500,000
Portfolio Loan Facility | Secured Debt
Debt Instrument [Line Items]
Total notes payable, net	757,500,000
Mortgages | Portfolio Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding	$ 188,460,000	188,460,000
Effective Interest Rate	3.88%
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	$ 98,506,000	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	$ 49,950,000	50,000,000
Effective Interest Rate	3.48%
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 (4)
Debt Instrument [Line Items]
Total notes payable principal outstanding	$ 84,876,000	85,292,000
Effective Interest Rate	2.97%
Maturity Date	Sep. 1, 2018
Mortgages | 171 17th Street Mortgage Loan (4) | 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	$ 29,654,000	29,800,000
Effective Interest Rate	3.78%
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	$ 42,526,000	40,557,000
Effective Interest Rate	3.85%
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
Debt Instrument [Line Items]
Total notes payable principal outstanding	$ 0	21,689,000
Mortgages | 201 17th Street Mortgage Loan (6)
Debt Instrument [Line Items]
Total notes payable principal outstanding	$ 64,428,000	64,428,000
Effective Interest Rate	3.51%
Maturity Date	Aug. 1, 2018
Mortgages | 201 17th Street Mortgage Loan (6) | 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	3.65%
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	$ 91,675,000	90,248,000
Effective Interest Rate	3.37%
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	$ 28,404,000	28,404,000
Effective Interest Rate	3.08%
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	$ 35,322,000	21,011,000
Effective Interest Rate	5.24%
Maturity Date	Feb. 23, 2020
Loan, amount outstanding	$ 35,300,000
Unused borrowing capacity, amount	$ 38,700,000
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	$ 888,500,000	$ 797,500,000
Effective Interest Rate	3.83%
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	131,000,000
Unused borrowing capacity, amount	$ 121,500,000
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		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Debt Instrument [Line Items]
Interest expense	$ 12,517	$ 16,896	$ 13,327	$ 29,797
Amortization of deferred financing costs			3,091	2,410
Interest expense incurred as a result of derivative instruments	7,200	2,800	24,100	2,700
Interest capitalized			2,150	820
Interest payable, current	6,500		6,500		$ 6,100
Construction in Progress
Debt Instrument [Line Items]
Interest capitalized	1,100	700	2,100	800
Interest Expense
Debt Instrument [Line Items]
Amortization of deferred financing costs	$ 1,600	$ 1,300	$ 3,300	$ 2,500

NOTES PAYABLE (Schedule of Matu

NOTES PAYABLE (Schedule of Maturities of Long-term Debt) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Notes Payable [Abstract]
July 1, 2018 through December 31, 2018	$ 151,030
2,019	398,572
2,020	1,219,673
2,021	93,956
2,022	180,590
Total notes payable	$ 2,043,821	$ 1,956,919

DERIVATIVE INSTRUMENTS (Notiona

DERIVATIVE INSTRUMENTS (Notional Amount) (Details) - Interest Rate Swaps $ in Thousands	6 Months Ended
	Jun. 30, 2018USD ($)investment	Dec. 31, 2017USD ($)investment
Derivative instruments designated as hedging instruments
Derivative [Line Items]
Number of Instruments | investment	1	2
Notional Amount | $	$ 68,400	$ 118,400
Weighted-Average Fix Pay Rate	1.41%
Weighted-Average Remaining Term in Years	1 month 29 days
Derivative instruments designated as hedging instruments | One-month LIBOR
Derivative [Line Items]
Reference Rate	1.41%
Derivative instruments not designated as hedging instruments
Derivative [Line Items]
Number of Instruments | investment	14	16
Notional Amount | $	$ 1,209,329	$ 1,209,643
Weighted-Average Fix Pay Rate	2.03%
Weighted-Average Remaining Term in Years	3 years 5 months 6 days
Derivative instruments not designated as hedging instruments | Minimum | One-month LIBOR
Derivative [Line Items]
Reference Rate	1.39%
Derivative instruments not designated as hedging instruments | Maximum | One-month LIBOR
Derivative [Line Items]
Reference Rate	2.37%

DERIVATIVE INSTRUMENTS (Balance

DERIVATIVE INSTRUMENTS (Balance Sheet) (Details) - Interest Rate Swaps $ in Thousands	Jun. 30, 2018USD ($)investmentInvestments	Dec. 31, 2017USD ($)investmentInvestments
Derivative instruments designated as hedging instruments
Derivative [Line Items]
Number of Instruments	1	2
Derivative instruments designated as hedging instruments | Prepaid Expenses and Other Current Assets
Derivative [Line Items]
Number of Instruments	1	1
Asset, Fair Value | $	$ 85	$ 128
Derivative instruments designated as hedging instruments | Other Liabilities
Derivative [Line Items]
Number of Instruments	0	1
Liability, Fair Value | $	$ 0	$ (18)
Derivative instruments not designated as hedging instruments
Derivative [Line Items]
Number of Instruments	14	16
Derivative instruments not designated as hedging instruments | Prepaid Expenses and Other Current Assets
Derivative [Line Items]
Number of Instruments | Investments	14	10
Asset, Fair Value | $	$ 30,035	$ 6,386
Derivative instruments not designated as hedging instruments | Other Liabilities
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		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Derivative [Line Items]
Unrealized (losses) income on derivative instruments	$ (1)	$ (136)	$ 83	$ 589
Derivative instruments designated as hedging instruments
Derivative [Line Items]
Amount of (income) expense recognized on interest rate swaps (effective portion)	(96)	570	(108)	1,464
(Decrease) increase in interest expense as a result of derivatives	(96)	570	(108)	1,464
Derivative instruments not designated as hedging instruments
Derivative [Line Items]
(Decrease) increase in interest expense as a result of derivatives	(7,184)	2,848	(24,125)	2,747
Derivative instruments not designated as hedging instruments | Interest Rate Swaps
Derivative [Line Items]
Realized loss recognized on interest rate swaps	201	1,315	1,309	2,858
Unrealized (gain) loss on interest rate swaps	(7,289)	963	(25,326)	(1,575)
(Decrease) increase in interest expense as a result of derivatives	$ (7,088)	$ 2,278	$ (24,017)	$ 1,283

DERIVATIVE INSTRUMENTS (Narrati

DERIVATIVE INSTRUMENTS (Narrative) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2018USD ($)
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Additional interest expense expected to be recognized over the next 12 months related to derivative instruments designated as cash flow hedges	$ 0.1

FAIR VALUE DISCLOSURES (Schedul

FAIR VALUE DISCLOSURES (Schedule of Face Value, Carrying Amounts and Fair Value) (Details) - USD ($)	Jun. 30, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt face amount	$ 2,043,821,000	$ 1,956,919,000
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable, Value	2,031,849,000	1,941,786,000
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable, Value	$ 2,050,669,000	$ 1,950,965,000

FAIR VALUE DISCLOSURES (Assets

FAIR VALUE DISCLOSURES (Assets and Liabilities at Fair value) (Details) - Recurring Basis: - Interest Rate Swaps $ in Thousands	Jun. 30, 2018USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset derivatives	$ 30,120
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
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset derivatives	30,120
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		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Related Party Transaction [Line Items]
Payable as of	$ 4,274		$ 4,274		$ 3,239
Administrative fees, amount paid	85	$ 55	173	$ 120
Advisor and Dealer Manager
Related Party Transaction [Line Items]
Incurred	8,302	6,599	15,230	13,442
Payable as of	4,274		4,274		3,239
Advisor and Dealer Manager | Asset management fees
Related Party Transaction [Line Items]
Expenses	6,738	6,431	13,358	12,637
Payable as of	2,214		2,214		2,262
Advisor and Dealer Manager | Reimbursement of operating expenses
Related Party Transaction [Line Items]
Expenses	956	55	1,102	196
Payable as of	864		864		121
Advisor and Dealer Manager | Disposition fees
Related Party Transaction [Line Items]
Expenses	429	0	429	0
Payable as of	0		0		0
Advisor and Dealer Manager | Acquisition fee on development project
Related Party Transaction [Line Items]
Incurred	110	60	179	170
Payable as of	745		745		566
Advisor and Dealer Manager | Acquisition fee on unconsolidated joint venture
Related Party Transaction [Line Items]
Incurred	69	53	162	377
Payable as of	451		451		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		6 Months Ended
	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	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	$ 60	$ 120	$ 120
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	Aug. 07, 2018	Aug. 01, 2018	Jul. 03, 2018	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 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]
Paid distributions		$ 9.7	$ 9.5
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%