KBS Real Estate Investment Trust III (KBSR) 10-Q 14 Nov 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Nov. 09, 2017
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Entity Registrant Name	KBS Real Estate Investment Trust III, Inc.
Entity Central Index Key	1,482,430
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		180,420,256

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Real estate:
Land	$ 395,133	$ 395,133
Buildings and improvements	2,695,238	2,651,690
Construction in progress	56,124	21,853
Tenant origination and absorption costs	243,102	264,973
Total real estate, cost	3,389,597	3,333,649
Less accumulated depreciation and amortization	(423,322)	(344,794)
Total real estate, net	2,966,275	2,988,855
Cash and cash equivalents	44,575	72,068
Investment in unconsolidated joint venture	33,593	0
Rents and other receivables, net	76,632	64,654
Above-market leases, net	6,417	8,191
Prepaid expenses and other assets	65,789	48,908
Total assets	3,193,281	3,182,676
Liabilities and equity
Notes payable, net	1,891,442	1,783,468
Accounts payable and accrued liabilities	71,327	56,210
Due to affiliate	2,756	2,397
Distributions payable	9,657	10,000
Below-market leases, net	26,692	33,655
Other liabilities	31,526	41,699
Total liabilities	2,033,400	1,927,429
Commitments and contingencies (Note 10)
Redeemable common stock	52,300	61,871
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, 180,102,670 and 180,890,572 shares issued and outstanding as of September 30, 2017 and December 31, 2016, respectively	1,801	1,809
Additional paid-in capital	1,591,659	1,591,652
Cumulative distributions and net losses	(485,971)	(398,087)
Accumulated other comprehensive income (loss)	21	(2,298)
Total KBS Real Estate Investment Trust III, Inc. stockholders’ equity	1,107,510	1,193,076
Noncontrolling interest	71	300
Total equity	1,107,581	1,193,376
Total liabilities and equity	$ 3,193,281	$ 3,182,676

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 2017	Dec. 31, 2016
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)	180,102,670	180,890,572
Common stock, shares outstanding (in shares)	180,102,670	180,890,572

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues:
Rental income	$ 77,798	$ 76,998	$ 236,200	$ 228,783
Tenant reimbursements	19,063	19,258	57,652	54,849
Other operating income	5,697	5,549	17,124	15,504
Interest income from real estate loan receivable	0	5	0	831
Total revenues	102,558	101,810	310,976	299,967
Expenses:
Operating, maintenance and management	25,293	24,009	70,765	68,627
Real estate taxes and insurance	16,460	16,359	48,721	47,675
Asset management fees to affiliate	6,587	6,286	19,223	18,646
Real estate acquisition fees to affiliate	0	0	0	1,473
Real estate acquisition fees and expenses	0	5	0	306
General and administrative expenses	983	1,289	3,324	4,115
Depreciation and amortization	41,151	39,978	124,370	120,088
Interest expense	15,460	10,042	45,257	53,948
Total expenses	105,934	97,968	311,660	314,878
Other income (loss):
Other income	0	0	650	0
Other interest income	23	17	73	39
Equity in loss of unconsolidated joint venture	0	0	(1)	0
Total other income, net	23	17	722	39
Net (loss) income	(3,353)	3,859	38	(14,872)
Net loss attributable to noncontrolling interest	202	0	229	0
Net (loss) income attributable to common stockholders	$ (3,151)	$ 3,859	$ 267	$ (14,872)
Net (loss) income per common share, basic and diluted (in dollars per share)	$ (0.02)	$ 0.02	$ 0	$ (0.08)
Weighted-average number of common shares outstanding, basic and diluted (in shares)	180,975,877	180,433,084	181,320,425	179,758,697

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (3,151)	$ 3,859	$ 267	$ (14,872)
Other comprehensive income (loss):
Unrealized income (losses) on derivative instruments	13	1,784	602	(6,695)
Reclassification adjustment realized in net income (effective portion)	253	1,363	1,717	4,252
Total other comprehensive income (loss)	266	3,147	2,319	(2,443)
Total comprehensive (loss) income	(2,885)	7,006	2,586	(17,315)
Total comprehensive loss attributable to noncontrolling interest	202	0	229	0
Total comprehensive (loss) income attributable to common stockholders	$ (2,683)	$ 7,006	$ 2,815	$ (17,315)

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 Losses	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest
Balance (in shares) at Dec. 31, 2015			177,943,238
Balance at Dec. 31, 2015	$ 1,286,832	$ 1,286,832	$ 1,779	$ 1,571,107	$ (281,825)	$ (4,229)	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	763	763			763
Other comprehensive income	1,931	1,931				1,931
Issuance of common stock (in shares)			6,485,383
Issuance of common stock	61,871	61,871	$ 65	61,806
Transfers to redeemable common stock	(6,504)	(6,504)		(6,504)
Redemptions of common stock (in shares)			(3,538,049)
Redemptions of common stock	(34,767)	(34,767)	$ (35)	(34,732)
Distributions declared	(117,025)	(117,025)			(117,025)
Other offering costs	(25)	(25)		(25)
Noncontrolling interest contribution	$ 300						300
Balance (in shares) at Dec. 31, 2016	180,890,572		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 (loss)	38	267			267		(229)
Other comprehensive income	2,319	2,319				2,319
Issuance of common stock (in shares)			4,465,177
Issuance of common stock	45,098	45,098	$ 45	45,053
Transfers from redeemable common stock	9,571	9,571		9,571
Redemptions of common stock (in shares)			(5,253,079)
Redemptions of common stock	(54,669)	(54,669)	$ (53)	(54,616)
Distributions declared	(88,151)	(88,151)			(88,151)
Other offering costs	$ (1)	(1)		(1)
Balance (in shares) at Sep. 30, 2017	180,102,670		180,102,670
Balance at Sep. 30, 2017	$ 1,107,581	$ 1,107,510	$ 1,801	$ 1,591,659	$ (485,971)	$ 21	$ 71

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash Flows from Operating Activities:
Net income (loss)	$ 38	$ (14,872)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	124,370	120,088
Equity in loss of unconsolidated joint venture	1	0
Noncash interest income on real estate-related investment	0	15
Deferred rents	(8,527)	(13,943)
Loss due to property damage	371	0
Allowance for doubtful accounts	1,065	1,023
Amortization of above- and below-market leases, net	(5,189)	(6,869)
Amortization of deferred financing costs	3,537	3,838
Unrealized (gains) losses on derivative instruments	(2,579)	14,813
Changes in operating assets and liabilities:
Rents and other receivables	(4,168)	(3,868)
Prepaid expenses and other assets	(18,881)	(16,391)
Accounts payable and accrued liabilities	5,709	6,694
Other liabilities	(5,145)	(477)
Due to affiliates	(37)	(7,969)
Net cash provided by operating activities	90,565	82,082
Cash Flows from Investing Activities:
Acquisitions of real estate	0	(141,760)
Improvements to real estate	(54,070)	(50,412)
Payments for construction in progress	(32,967)	(7,793)
Investment in unconsolidated joint venture	(33,421)	0
Advances on real estate loan receivable	0	(544)
Principal repayments on real estate loan receivable	0	22,526
Escrow deposits for tenant improvements	(3,762)	0
Net cash used in investing activities	(124,220)	(177,983)
Cash Flows from Financing Activities:
Proceeds from notes payable	107,385	139,071
Principal payments on notes payable	(1,893)	(31,900)
Payments of deferred financing costs	(1,264)	(1,339)
Payments to redeem common stock	(54,669)	(26,146)
Return of contingent consideration related to acquisition of real estate	0	228
Payments of other offering costs	(1)	(21)
Noncontrolling interest contribution	0	300
Distributions paid to common stockholders	(43,396)	(41,039)
Net cash provided by financing activities	6,162	39,154
Net decrease in cash and cash equivalents	(27,493)	(56,747)
Cash and cash equivalents, beginning of period	72,068	108,242
Cash and cash equivalents, end of period	44,575	51,495
Supplemental Disclosure of Cash Flow Information:
Interest paid, net of capitalized interest of $1,543 and $64 for the nine months ended September 30, 2017 and 2016, respectively	43,101	34,625
Supplemental Disclosure of Noncash Investing and Financing Activities:
Distributions paid to common stockholders through common stock issuances pursuant to the dividend reinvestment plan	45,098	46,543
Increase in accrued improvements to real estate	8,149	2,869
Application of escrow deposits to acquisition of real estate	0	4,350
Increase in construction in progress payable	856	1,865
Increase in acquisition fee related to construction in progress due to affiliate	234	87
Increase in acquisition fee on unconsolidated joint venture due to affiliate	173	0
Transfer of land to construction in progress	$ 0	$ 4,183

CONSOLIDATED STATEMENTS OF CAS8

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Cash Flows [Abstract]
Interest capitalized	$ 700	$ 100	$ 1,543	$ 64

ORGANIZATION

ORGANIZATION	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
ORGANIZATION	ORGANIZATION KBS Real Estate Investment Trust III, Inc. (the “Company”) was formed on December 22, 2009 as a Maryland corporation that elected to be taxed as a real estate investment trust (“REIT”) beginning with the taxable year ended December 31, 2011 and it intends to continue to operate in such manner. Substantially all of the Company’s business is conducted through KBS Limited Partnership III (the “Operating Partnership”), a Delaware limited partnership. The Company is the sole general partner of and owns a 0.1% partnership interest in the Operating Partnership. KBS REIT Holdings III LLC (“REIT Holdings III”), the limited partner of the Operating Partnership, owns the remaining 99.9% interest in the Operating Partnership and is its sole limited partner. The Company is the sole member and manager of REIT Holdings III. Subject to certain restrictions and limitations, the business of the Company is externally managed by KBS Capital Advisors LLC (the “Advisor”), an affiliate of the Company, pursuant to an advisory agreement the Company entered into with the Advisor (the “Advisory Agreement”). On January 26, 2010, the Company issued 20,000 shares of its common stock to the Advisor at a purchase price of $10.00 per share. As of September 30, 2017 , the Advisor owned 20,000 shares of the Company’s common stock. The Company owns a diverse portfolio of real estate investments. As of September 30, 2017 , the Company owned 28 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, which is currently under construction. Additionally, as of September 30, 2017 , the Company had entered into a consolidated joint venture to develop and subsequently operate a multifamily apartment project, which is currently under construction. The Company commenced its initial public offering (the “Offering”) on October 26, 2010. Upon commencing the Offering, the Company retained KBS Capital Markets Group LLC (the “Dealer Manager”), an affiliate of the Company, to serve as the dealer manager of the Offering pursuant to a dealer manager agreement, as amended and restated (the “Dealer Manager Agreement”). The Company ceased offering shares of common stock in the primary Offering on May 29, 2015 and terminated the primary Offering on July 28, 2015. The Company sold 169,006,162 shares of common stock in the primary Offering for gross proceeds of $1.7 billion . As of September 30, 2017 , the Company had also sold 21,438,406 shares of common stock under its dividend reinvestment plan for gross offering proceeds of $210.1 million . Also as of September 30, 2017 , the Company had redeemed 10,620,360 shares sold in the Offering for $107.2 million . Additionally, on October 3, 2014, the Company issued 258,462 shares of common stock for $2.4 million in private transactions exempt from the registration requirements pursuant to Section 4(a)(2) of the Securities Act of 1933. The Company continues to offer shares of common stock under its dividend reinvestment plan. In some states, the Company will need to renew the registration statement annually or file a new registration statement to continue its dividend reinvestment plan offering. The Company may terminate its dividend reinvestment plan offering at any time.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 2017
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, 2016 , except for the addition of an accounting policy with respect to investments in unconsolidated joint ventures under the equity method. 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, 2016 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 Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) and the rules and regulations of the SEC, including the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, the unaudited consolidated financial statements do not include all of the information and footnotes required by GAAP for audited financial statements. In the opinion of management, the financial statements for the unaudited interim periods presented include all adjustments, which are of a normal and recurring nature, necessary for a fair and consistent presentation of the results for such periods. Operating results for the three and nine and months ended September 30, 2017 are not necessarily indicative of the results that may be expected for the year ending December 31, 2017. 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. Investments in Unconsolidated Joint Ventures The Company accounts for investments in unconsolidated joint ventures over which the Company may exercise significant influence, but does not control, using the equity method of accounting. Under the equity method, the investment is initially recorded at cost and subsequently adjusted to reflect additional contributions or distributions and the Company’s proportionate share of equity in the joint venture’s income (loss). The Company recognizes its proportionate share of the ongoing income or loss of the unconsolidated joint venture as equity in income (loss) of unconsolidated joint venture on the consolidated statements of operations. On a quarterly basis, the Company evaluates its investment in an unconsolidated joint venture for other-than-temporary impairments. As of September 30, 2017 , the Company did not identify any indicators of impairment related to its unconsolidated real estate joint venture accounted for under the equity method. Per Share Data Basic net income (loss) per share of common stock is calculated by dividing net income (loss) attributable to common stockholders by the weighted-average number of shares of common stock issued and outstanding during such period. Diluted net income (loss) per share of common stock equals basic net income (loss) per share of common stock as there were no potentially dilutive securities outstanding during the three and nine months ended September 30, 2017 and 2016 , respectively. Distributions declared per common share were $0.164 and $ 0.486 for the three and nine months ended September 30, 2017 , respectively. Distributions declared per common share were $ 0.164 and $ 0.486 for the three and nine months ended September 30, 2016 , respectively. Distributions declared per common share assumes each share was issued and outstanding each day during the three and nine months ended September 30, 2017 and 2016 , respectively. For each day that was a record date for distributions during the three and nine months ended September 30, 2017 and 2016 , distributions were calculated at a rate of $0.00178082 per share per day. Each day during the periods from January 1, 2016 through February 28, 2016, March 1, 2016 through September 30, 2016 and January 1, 2017 through September 30, 2017 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 investments exhibit similar long-term financial performance and have similar economic characteristics to each other. As of September 30, 2017 , the Company aggregated its investments in real estate into one reportable business segment. Recently Issued Accounting Standards Update In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) (“ASU No. 2014-09”). ASU No. 2014-09 requires an entity to recognize the revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods and services. ASU No. 2014-09 supersedes the revenue requirements in Revenue Recognition (Topic 605) and most industry-specific guidance throughout the Industry Topics of the Codification. ASU No. 2014-09 does not apply to lease contracts within the scope of Leases (Topic 840). ASU No. 2014-09 was to be effective for fiscal years, and interim periods within those years, beginning after December 15, 2016, and is to be applied retrospectively, with early application not permitted. In August 2015, the FASB issued ASU No. 2015-14, Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date (“ASU No. 2015-14”), which defers the effective date of ASU No. 2014-09 by one year. Early adoption is permitted but not before the original effective date. The primary source of revenue for the Company is generated through leasing arrangements, which are excluded from this standard. The Company’s revenues that may be impacted by this standard primarily include other operating income, sales of real estate and other ancillary income earned at its properties. In 2016, other operating income and other ancillary income were approximately 7% of consolidated revenue. The Company is in process of evaluating how this standard will impact sales of real estate. The Company continues to evaluate the impact that the standard will have on its consolidated financial statements. The Company expects to adopt the standard using the modified retrospective approach, which requires a cumulative effect adjustment as of the date of the adoption. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU No. 2016-01”). The amendments in ASU No. 2016-01 address certain aspects of recognition, measurement, presentation and disclosure of financial instruments. ASU No. 2016-01 primarily affects accounting for equity investments and financial liabilities where the fair value option has been elected. ASU No. 2016-01 also requires entities to present financial assets and financial liabilities separately, grouped by measurement category and form of financial asset in the balance sheet or in the accompanying notes to the financial statements. ASU No. 2016-01 is effective for annual periods beginning after December 15, 2017, including interim periods within those fiscal years. Early application of certain provisions of the standard is permitted for financial statements that have not been previously issued. The Company does not expect the adoption of ASU No. 2016-01 to have a significant impact on its financial statements. 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. The new leases standard 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 leases standard on its consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses of Financial Instruments (“ASU No. 2016-13”). ASU No. 2016-13 affects entities holding financial assets and net investments in leases that are not accounted for at fair value through net income. The amendments in ASU No. 2016-13 require a financial asset (or a group of financial assets) measured at amortized cost basis to be presented at the net amount expected to be collected. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial asset(s) to present the net carrying value at the amount expected to be collected on the financial asset. ASU No. 2016-13 also amends the impairment model for available-for-sale securities. An entity will recognize an allowance for credit losses on available-for-sale debt securities as a contra-account to the amortized cost basis rather than as a direct reduction of the amortized cost basis of the investment, as is currently required. ASU No. 2016-13 also requires new disclosures. For financial assets measured at amortized cost, an entity will be required to disclose information about how it developed its allowance for credit losses, including changes in the factors that influenced management’s estimate of expected credit losses and the reasons for those changes. For financing receivables and net investments in leases measured at amortized cost, an entity will be required to further disaggregate the information it currently discloses about the credit quality of these assets by year of the asset’s origination for as many as five annual periods. For available for sale securities, an entity will be required to provide a roll-forward of the allowance for credit losses and an aging analysis for securities that are past due. ASU No. 2016-13 is effective for annual periods beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company is still evaluating the impact of adopting ASU No. 2016-13 on its financial statements, but does not expect the adoption of ASU No. 2016-13 to have a material impact on its financial statements. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (“ASU No. 2016-15”). ASU No. 2016-15 is intended to reduce diversity in practice in how certain transactions are classified in the statement of cash flows. The amendments in ASU No. 2016-15 provide guidance on eight specific cash flow issues, including the following that are or may be relevant to the Company: (a) Cash payments for debt prepayment or debt extinguishment costs should be classified as cash outflows for financing activities; (b) Cash payments relating to contingent consideration made soon after an acquisition’s consummation date (i.e., approximately three months or less) should be classified as cash outflows for investing activities. Payments made thereafter should be classified as cash outflows for financing activities up to the amount of the original contingent consideration liability. Payments made in excess of the amount of the original contingent consideration liability should be classified as cash outflows for operating activities; (c) Cash payments received from the settlement of insurance claims should be classified on the basis of the nature of the loss (or each component loss, if an entity receives a lump-sum settlement); (d) Relating to distributions received from equity method investments, ASU No. 2016-15 provides an accounting policy election for classifying distributions received from equity method investments. Such amounts can be classified using a (1) cumulative earnings approach, or (2) nature of distribution approach. Under the cumulative earnings approach, an investor would compare the distributions received to its cumulative equity method earnings since inception. Any distributions received up to the amount of cumulative equity earnings would be considered a return on investment and classified in operating activities. Any excess distributions would be considered a return of investment and classified in investing activities. Alternatively, an investor can choose to classify the distributions based on the nature of activities of the investee that generated the distribution. If the necessary information is subsequently not available for an investee to determine the nature of the activities, the entity should use the cumulative earnings approach for that investee and report a change in accounting principle on a retrospective basis; and (e) In the absence of specific guidance, an entity should classify each separately identifiable cash source and use on the basis of the nature of the underlying cash flows. For cash flows with aspects of more than one class that cannot be separated, the classification should be based on the activity that is likely to be the predominant source or use of cash flow. ASU No. 2016-15 is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. The Company is still evaluating the impact of adopting ASU No. 2016-15 on its financial statements, but does not expect the adoption of ASU No. 2016-15 to have a material impact on its financial statements. In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash (“ASU No. 2016-18”). ASU No. 2016-18 requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, restricted cash and restricted cash equivalents. Therefore, amounts generally described as restricted cash should be included with cash and cash equivalents when reconciling the beginning of period and end of period total amounts shown on the statement of cash flows. ASU No. 2016-18 is effective for annual periods beginning after December 15, 2017, including interim periods within those fiscal years. The Company elected to early adopt ASU No. 2016-18 for the reporting period ended December 31, 2016 and applied it retrospectively. As a result of the adoption of ASU No. 2016-18, the Company no longer presents the changes within restricted cash in the consolidated statements of cash flows. In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business (“ASU No. 2017-01”) to add guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. ASU No. 2017-01 provides a screen to determine when an integrated set of assets and activities (collectively referred to as a “set”) is not a business. The screen requires that when substantially all of the fair value of the gross assets acquired (or disposed of) is concentrated in a single identifiable asset or a group of similar identifiable assets, the set is not a business. If the screen is not met, ASU No. 2017-01 (1) requires that to be considered a business, a set must include, at a minimum, an input and a substantive process that together significantly contribute to the ability to create output and (2) removes the evaluation of whether a market participant could replace missing elements. ASU No. 2017-01 provides a framework to assist entities in evaluating whether both an input and a substantive process are present. The framework includes two sets of criteria to consider that depend on whether a set has outputs. Although outputs are not required for a set to be a business, outputs generally are a key element of a business; therefore, the FASB has developed more stringent criteria for sets without outputs. ASU No. 2017-01 is effective for annual periods beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is permitted. The amendments can be applied to transactions occurring before the guidance was issued (January 5, 2017) as long as the applicable financial statements have not been issued. The Company elected to early adopt ASU No. 2017-01 for the reporting period beginning January 1, 2017. As a result of the adoption of ASU No. 2017-01, the Company’s acquisitions of investment properties beginning January 1, 2017 could qualify as asset acquisitions (as opposed to business combinations). Transaction costs associated with asset acquisitions are capitalized, while transaction costs associated with business combinations will continue to be expensed as incurred.

REAL ESTATE

REAL ESTATE	9 Months Ended
	Sep. 30, 2017
Real Estate [Abstract]
REAL ESTATE	REAL ESTATE As of September 30, 2017 , the Company’s real estate portfolio was composed of 28 office properties and one mixed-use office/retail property encompassing in the aggregate approximately 11.1 million rentable square feet. In addition, the Company had entered into a consolidated joint venture to develop and subsequently operate a multifamily apartment project, which is currently under construction. As of September 30, 2017 , the Company’s real estate portfolio was collectively 92% occupied. The following table summarizes the Company’s investments in real estate as of September 30, 2017 (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 $ 47,373 $ (12,999 ) $ 34,374 Town Center 03/27/2012 Plano TX Office 116,133 (23,752 ) 92,381 McEwen Building 04/30/2012 Franklin TN Office 36,873 (6,868 ) 30,005 Gateway Tech Center 05/09/2012 Salt Lake City UT Office 24,749 (5,863 ) 18,886 Tower on Lake Carolyn 12/21/2012 Irving TX Office 52,625 (11,679 ) 40,946 RBC Plaza 01/31/2013 Minneapolis MN Office 151,277 (29,773 ) 121,504 One Washingtonian Center 06/19/2013 Gaithersburg MD Office 90,635 (14,453 ) 76,182 Preston Commons 06/19/2013 Dallas TX Office 117,959 (18,774 ) 99,185 Sterling Plaza 06/19/2013 Dallas TX Office 79,662 (10,969 ) 68,693 201 Spear Street 12/03/2013 San Francisco CA Office 140,040 (11,421 ) 128,619 500 West Madison 12/16/2013 Chicago IL Office 440,607 (68,666 ) 371,941 222 Main 02/27/2014 Salt Lake City UT Office 166,331 (23,434 ) 142,897 Anchor Centre 05/22/2014 Phoenix AZ Office 93,901 (12,582 ) 81,319 171 17th Street 08/25/2014 Atlanta GA Office 133,176 (19,638 ) 113,538 Rocklin Corporate Center 11/06/2014 Rocklin CA Office 33,515 (5,311 ) 28,204 Reston Square 12/03/2014 Reston VA Office 46,561 (6,141 ) 40,420 Ten Almaden 12/05/2014 San Jose CA Office 120,351 (12,795 ) 107,556 Towers at Emeryville 12/23/2014 Emeryville CA Office 262,312 (26,218 ) 236,094 101 South Hanley 12/24/2014 St. Louis MO Office 70,692 (7,859 ) 62,833 3003 Washington Boulevard 12/30/2014 Arlington VA Office 151,096 (13,832 ) 137,264 Village Center Station 05/20/2015 Greenwood Village CO Office 78,259 (8,630 ) 69,629 Park Place Village 06/18/2015 Leawood KS Office/Retail 128,857 (12,607 ) 116,250 201 17th Street 06/23/2015 Atlanta GA Office 103,379 (9,587 ) 93,792 Promenade I & II at Eilan 07/14/2015 San Antonio TX Office 62,643 (6,076 ) 56,567 CrossPoint at Valley Forge 08/18/2015 Wayne PA Office 90,252 (7,469 ) 82,783 515 Congress 08/31/2015 Austin TX Office 117,420 (10,444 ) 106,976 The Almaden 09/23/2015 San Jose CA Office 167,833 (11,828 ) 156,005 3001 Washington Boulevard 11/06/2015 Arlington VA Office 56,608 (2,663 ) 53,945 Carillon 01/15/2016 Charlotte NC Office 152,354 (10,991 ) 141,363 Hardware Village (1) 08/26/2016 Salt Lake City UT Development/Apartment 56,124 — 56,124 $ 3,389,597 $ (423,322 ) $ 2,966,275 _____________________ (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 September 30, 2017 , 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 $ 371,941 11.6 % $ 34,883 $ 27.80 86.1 % _____________________ (1) Annualized base rent represents annualized contractual base rental income as of September 30, 2017 , adjusted to straight-line any contractual tenant concessions (including free rent), rent increases and rent decreases from the lease’s inception through the balance of the lease term. Operating Leases The Company’s real estate properties are leased to tenants under operating leases for which the terms and expirations vary. As of September 30, 2017 , the leases had remaining terms, excluding options to extend, of up to 14.3 years with a weighted-average remaining term of 4.6 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 $11.6 million and $12.7 million as of September 30, 2017 and December 31, 2016 , respectively. During the nine months ended September 30, 2017 and 2016 , the Company recognized deferred rent from tenants of $8.5 million and $13.9 million , respectively. As of September 30, 2017 and December 31, 2016 , the cumulative deferred rent balance was $69.8 million and $58.6 million , respectively, and is included in rents and other receivables on the accompanying balance sheets. The cumulative deferred rent balance included $7.6 million and $5.2 million of unamortized lease incentives as of September 30, 2017 and December 31, 2016 , respectively. As of September 30, 2017 , the future minimum rental income from the Company’s properties under its non-cancelable operating leases was as follows (in thousands): October 1, 2017 through December 31, 2017 $ 71,113 2018 289,600 2019 269,676 2020 235,674 2021 203,589 Thereafter 649,360 $ 1,719,012 As of September 30, 2017 , 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 156 $ 61,946 20.5 % _____________________ (1) Annualized base rent represents annualized contractual base rental income as of September 30, 2017 , adjusted to straight-line any contractual tenant concessions (including free rent), rent increases and rent decreases from the lease’s inception through the balance of the lease term. As of September 30, 2017 , no other tenant industries accounted for more than 10% of annualized base rent and no tenant accounted for more than 10% of annualized base rent. No material tenant credit issues have been identified at this time. Geographic Concentration Risk As of September 30, 2017 , the Company’s net investments in real estate in California, Texas and Illinois represented 21% , 16% 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.

TENANT ORIGINATION AND ABSORPTI

TENANT ORIGINATION AND ABSORPTION COSTS, ABOVE-MARKET LEASE ASSETS AND BELOW-MARKET LEASE LIABILITIES	9 Months Ended
	Sep. 30, 2017
Tenant Origination and Absorption Costs, Above-Market Lease Assets and Below-Market Lease Liabilities [Abstract]
TENANT ORIGINATION AND ABSORPTION COSTS, ABOVE-MARKET LEASE ASSETS AND BELOW-MARKET LEASE LIABILITIES	TENANT ORIGINATION AND ABSORPTION COSTS, ABOVE-MARKET LEASE ASSETS AND BELOW-MARKET LEASE LIABILITIES As of September 30, 2017 and December 31, 2016 , the Company’s tenant origination and absorption costs, above-market lease assets and below-market lease liabilities (excluding fully amortized assets and liabilities and accumulated amortization) were as follows (in thousands): Tenant Origination and Absorption Costs Above-Market Lease Assets Below-Market Lease Liabilities September 30, 2017 December 31, 2016 September 30, 2017 December 31, 2016 September 30, 2017 December 31, 2016 Cost $ 243,102 $ 264,973 $ 13,576 $ 14,383 $ (49,401 ) $ (55,438 ) Accumulated Amortization (110,207 ) (99,757 ) (7,159 ) (6,192 ) 22,709 21,783 Net Amount $ 132,895 $ 165,216 $ 6,417 $ 8,191 $ (26,692 ) $ (33,655 ) Increases (decreases) in net income as a result of amortization of the Company’s tenant origination and absorption costs, above-market lease assets and below-market lease liabilities for the three and nine months ended September 30, 2017 and 2016 were as follows (in thousands): Tenant Origination and Absorption Costs Above-Market Lease Assets Below-Market Lease Liabilities For the Three Months Ended September 30, For the Three Months Ended September 30, For the Three Months Ended September 30, 2017 2016 2017 2016 2017 2016 Amortization $ (10,202 ) $ (11,208 ) $ (527 ) $ (718 ) $ 2,184 $ 2,474 Tenant Origination and Absorption Costs Above-Market Lease Assets Below-Market Lease Liabilities For the Nine Months Ended September 30, For the Nine Months Ended September 30, For the Nine Months Ended September 30, 2017 2016 2017 2016 2017 2016 Amortization $ (32,321 ) $ (35,100 ) $ (1,774 ) $ (2,186 ) $ 6,963 $ 9,055

INVESTMENT IN UNCONSOLIDATED JO

INVESTMENT IN UNCONSOLIDATED JOINT VENTURE	9 Months Ended
	Sep. 30, 2017
Equity Method Investments and Joint Ventures [Abstract]
INVESTMENT IN UNCONSOLIDATED JOINT VENTURE	INVESTMENT IN UNCONSOLIDATED JOINT VENTURE Village Center Station II Equity Method Investment 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 with an unaffiliated developer, Shea Village Center Station II, LLC (the “Developer”) (the “Village Center Station II Joint Venture”) 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 September 30, 2017 , $23.1 million has 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 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. Upon completion of Village Center Station II, the Company expects to purchase the Developer’s 25% equity interest. 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 September 30, 2017 , the book value of the Company’s investment in the Village Center Station II Joint Venture was $33.6 million which includes $1.2 million of acquisition costs and capitalized interest incurred directly by the Company. As of September 30, 2017 , 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 $33.6 million investment. Summarized financial information for the Village Center Station II Joint Venture follows (in thousands): September 30, 2017 Assets: Construction in progress $ 73,400 Cash and cash equivalents 1 Other assets 2,591 Total assets $ 75,992 Liabilities and equity: Accounts payable $ 9,615 Notes payable, net 23,004 Other liabilities 258 Members’ capital 43,115 Total liabilities and equity $ 75,992

NOTES PAYABLE

NOTES PAYABLE	9 Months Ended
	Sep. 30, 2017
Notes Payable [Abstract]
NOTES PAYABLE	NOTES PAYABLE As of September 30, 2017 and December 31, 2016 , the Company’s notes payable consisted of the following (dollars in thousands): Book Value as of September 30, 2017 Book Value as of December 31, 2016 Contractual Interest Rate as of (1) Effective Interest Rate as of September 30, 2017 (1) Payment Type Maturity Date (2) Town Center Mortgage Loan $ 75,000 $ 75,000 One-month LIBOR + 1.85% 2.87% Interest Only 03/27/2018 (3) Portfolio Loan (5) 163,460 127,500 One-month LIBOR + 1.90% 3.14% Interest Only 06/01/2019 RBC Plaza Mortgage Loan 75,434 75,930 One-month LIBOR + 1.80% 3.04% Principal & Interest 02/01/2018 (3) National Office Portfolio Mortgage Loan (6) 170,602 170,602 One-month LIBOR + 1.50% 2.84% Interest Only 07/01/2018 (3) 500 West Madison Mortgage Loan (7) 235,000 215,000 One-month LIBOR + 1.65% 3.13% Interest Only 12/16/2018 (3) 222 Main Mortgage Loan 99,946 101,343 3.97% 3.97% Principal & Interest 03/01/2021 Anchor Centre Mortgage Loan 50,000 50,000 One-month LIBOR + 1.50% 3.18% Interest Only 06/01/2018 171 17th Street Mortgage Loan 85,479 83,778 One-month LIBOR + 1.45% 2.83% Interest Only (4) 09/01/2018 Reston Square Mortgage Loan 29,800 23,840 One-month LIBOR + 1.50% 3.63% Interest Only 02/01/2018 Ten Almaden Mortgage Loan 66,555 65,853 One-month LIBOR + 1.65% 3.43% Interest Only 01/01/2018 (3) Towers at Emeryville Mortgage Loan (8) 153,524 145,379 One-month LIBOR + 1.75% 3.96% Interest Only 01/15/2018 (3) 101 South Hanley Mortgage Loan 40,557 37,502 One-month LIBOR + 1.55% 3.75% Interest Only (4) 01/01/2020 3003 Washington Boulevard Mortgage Loan 90,378 90,378 One-month LIBOR + 1.55% 3.54% Interest Only 02/01/2020 Rocklin Corporate Center Mortgage Loan 21,689 20,868 One-month LIBOR + 1.50% 2.74% Interest Only 06/05/2018 201 17th Street Mortgage Loan 64,428 58,063 One-month LIBOR + 1.40% 3.32% Interest Only 08/01/2018 CrossPoint at Valley Forge Mortgage Loan 51,000 51,000 One-month LIBOR + 1.50% 3.33% Interest Only (4) 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 68,381 67,500 One-month LIBOR + 1.70% 2.94% Interest Only 11/01/2020 201 Spear Street Mortgage Loan 100,000 100,000 One-month LIBOR + 1.66% 2.90% Interest Only 01/01/2019 Carillon Mortgage Loan 90,248 76,440 One-month LIBOR + 1.65% 3.25% Interest Only 02/01/2020 3001 Washington Boulevard Mortgage Loan 28,404 27,129 One-month LIBOR + 1.60% 2.84% Interest Only 02/01/2019 Hardware Village Loan Facility (9) 8,712 — One-month LIBOR + 3.25% 4.49% Interest Only 02/23/2020 Total notes payable principal outstanding 1,898,897 1,793,405 Deferred financing costs, net (7,455 ) (9,937 ) Total notes payable, net $ 1,891,442 $ 1,783,468 _____________________ (1) Contractual interest rate represents the interest rate in effect under the loan as of September 30, 2017 . Effective interest rate is calculated as the actual interest rate in effect as of September 30, 2017 (consisting of the contractual interest rate and the effect of interest rate swaps and caps, if applicable), using interest rate indices as of September 30, 2017 , where applicable. For further information regarding the Company's derivative instruments, see Note 7, “Derivative Instruments.” (2) Represents the maturity date as of September 30, 2017 ; subject to certain conditions, the maturity dates of certain loans may be extended beyond the dates shown. (3) On November 3, 2017, the Company paid off the outstanding balances under these loans using proceeds from the Portfolio Loan Facility. See Note 11,“Subsequent Events - Financing Subsequent to September 30, 2017 - Portfolio Loan Facility.” (4) Represents the payment type required under the loan as of September 30, 2017 . Certain future monthly payments due under these loans 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. (5) As of September 30, 2017 , the Portfolio Loan was secured by Domain Gateway, the McEwen Building, Gateway Tech Center, the Tower on Lake Carolyn, Park Place Village and Village Center Station. The face amount of the Portfolio Loan is $ 255.0 million , of which $ 127.5 million is term debt and $ 127.5 million is revolving debt. As of September 30, 2017 , the outstanding balance under the loan consisted of $127.5 million of term debt and $36.0 million of revolving debt. As of September 30, 2017 , an additional $90.5 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. (6) The National Office Portfolio Mortgage Loan was secured by One Washingtonian Center, Preston Commons and Sterling Plaza. See footnote 3 above. (7) As of September 30, 2017 , $235.0 million of term debt was outstanding and $20.0 million remained available for future disbursements, subject to certain terms and conditions contained in the loan documents. See footnote 3 above. (8) As of September 30, 2017 , $153.5 million had been disbursed to the Company and $21.5 million remained available for future disbursements, subject to certain conditions contained in the loan documents. See footnote 3 above. (9) As of September 30, 2017 , $8.7 million had been disbursed and $65.3 million remained available for future disbursements, subject to certain conditions contained in the loan documents. As of September 30, 2017 , the Company’s deferred financing costs were $7.6 million , net of amortization, of which $7.5 million was included in notes payable, net, and $0.1 million was included in prepaid expenses and other assets on the accompanying consolidated balance sheets. As of December 31, 2016 , the Company’s deferred financing costs were $10.0 million , net of amortization, of which $9.9 million was included in notes payable, net, and $0.1 million was included in prepaid expenses and other assets on the accompanying consolidated balance sheets. During the three and nine months ended September 30, 2017 , the Company incurred $15.5 million and $45.3 million of interest expense, respectively. During the three and nine months ended September 30, 2016 , the Company incurred $10.0 million and $53.9 million of interest expense, respectively. Included in interest expense was: (i) the amortization of deferred financing costs of $1.3 million and $3.8 million for three and nine months ended September 30, 2017 and $1.3 million and $3.8 million for the three and nine months ended September 30, 2016 , respectively, (ii) the capitalization of interest to construction in progress, which decreased interest expense by $0.7 million and $1.5 million for the three and nine months ended September 30, 2017 and $0.1 million and $0.1 million for the three and nine months ended September 30, 2016 , respectively, (iii) the interest expense (including gains and losses) incurred as a result of the Company’s derivative instruments, which increased interest expense by $0.4 million and $3.1 million for the three and nine months ended September 30, 2017 , respectively, and $20.5 million for the nine months ended September 30, 2016 , and decreased interest expense by $1.3 million for the three months ended September 30, 2016 . As of September 30, 2017 and December 31, 2016 , $5.3 million and $4.3 million of interest expense were payable, respectively. The following is a schedule of maturities, including principal amortization payments, for all notes payable outstanding as of September 30, 2017 (in thousands): October 1, 2017 through December 31, 2017 $ 874 2018 1,029,540 2019 294,445 2020 299,491 2021 93,957 Thereafter 180,590 $ 1,898,897 The Company’s notes payable contain financial debt covenants. As of September 30, 2017 , the Company was in compliance with these debt covenants.

DERIVATIVE INSTRUMENTS

DERIVATIVE INSTRUMENTS	9 Months Ended
	Sep. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE INSTRUMENTS	DERIVATIVE INSTRUMENTS The Company enters into derivative instruments for risk management purposes to hedge its exposure to cash flow variability caused by changing interest rates. The primary goal of the Company’s risk management practices related to interest rate risk is to prevent changes in interest rates from adversely impacting the Company’s ability to achieve its investment return objectives. The Company does not enter into derivatives for speculative purposes. The Company enters into interest rate swaps as a fixed rate payer to mitigate its exposure to rising interest rates on its variable rate notes payable. The value of interest rate swaps is primarily impacted by interest rates, market expectations about interest rates, and the remaining life of the instrument. In general, increases in interest rates, or anticipated increases in interest rates, will increase the value of the fixed rate payer position and decrease the value of the variable rate payer position. As the remaining life of the interest rate swap decreases, the value of both positions will generally move towards zero. The Company enters into interest rate caps to mitigate its exposure to rising interest rates on its variable rate notes payable. The values of interest rate caps are primarily impacted by interest rates, market expectations about interest rates, and the remaining life of the instrument. In general, increases in interest rates, or anticipated increases in interest rates, will increase the value of interest rate caps. As the remaining life of an interest rate cap decreases, the value of the instrument will generally decrease towards zero. The following table summarizes the notional amount and other information related to the Company’s interest rate swaps and cap as of September 30, 2017 and December 31, 2016 . The notional amount is an indication of the extent of the Company’s involvement in each instrument at that time, but does not represent exposure to credit, interest rate or market risks (dollars in thousands): September 30, 2017 December 31, 2016 Weighted-Average Fix Pay Rate Weighted-Average Remaining Term in Years Derivative Instruments Number of Instruments Notional Amount Number of Instruments Notional Amount Reference Rate as of September 30, 2017 Derivative instruments designated as hedging instruments Interest Rate Swaps 6 $ 508,400 7 $ 625,130 One-month LIBOR/ Fixed at 0.86% - 1.68% 1.42% 0.9 Derivative instruments not designated as hedging instruments Interest Rate Swaps (1) 12 $ 658,183 12 $ 658,183 One-month LIBOR/ 1.99% 2.9 Interest Rate Cap (2) — $ — 1 $ 147,340 (2) (2) (2) _____________________ (1) Included in these amounts are two forward interest rate swaps with an aggregate notional amount of $91.5 million that were not yet in effect as of September 30, 2017 . These two interest rate swaps will become effective at various times during the remainder of 2017 through 2018. (2) The interest rate cap matured on January 1, 2017. The following table sets forth the fair value of the Company’s derivative instruments as well as their classification on the consolidated balance sheets as of September 30, 2017 and December 31, 2016 (dollars in thousands): September 30, 2017 December 31, 2016 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 3 $ 142 1 $ 42 Interest Rate Swaps Other liabilities, at fair value 3 $ (121 ) 6 $ (2,340 ) Derivative instruments not designated as hedging instruments Interest Rate Swaps Prepaid expenses and other assets, at fair value 4 $ 1,358 4 $ 1,588 Interest Rate Swaps Other liabilities, at fair value 8 $ (4,579 ) 8 $ (7,388 ) Interest Rate Cap Prepaid expenses and other assets, at fair value — $ — 1 $ — The change in fair value of the effective portion of a derivative instrument that is designated as a cash flow hedge is recorded as other comprehensive income (loss) on the accompanying consolidated statements of comprehensive income (loss) and as other comprehensive income on the accompanying consolidated statements of equity. Amounts in other comprehensive income (loss) will be reclassified into earnings in the periods in which earnings are affected by the hedged cash flows. The change in fair value of the ineffective portion is recognized directly in earnings. With respect to swap agreements that are terminated for which it remains probable that the original hedged forecasted transactions (i.e., LIBOR-based debt service payments) will occur, the loss related to the termination of these swap agreements is included in accumulated other comprehensive income (loss) and is reclassified into earnings over the period of the original forecasted hedged transaction. The change in fair value of a derivative instrument that is not designated as a cash flow hedge is recorded as interest expense in the accompanying consolidated statements of operations. The following table summarizes the effects of derivative instruments on the Company’s consolidated statements of operations (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2017 2016 2017 2016 Income statement related Derivatives designated as hedging instruments Amount of expense recognized on interest rate swaps (effective portion) $ 253 $ 1,363 $ 1,717 $ 4,252 253 1,363 1,717 4,252 Derivatives not designated as hedging instruments Realized loss recognized on interest rate swaps 1,108 1,040 3,966 1,398 Unrealized (gain) loss on interest rate swaps (1,004 ) (3,745 ) (2,579 ) 14,810 Unrealized loss on interest rate cap — — — 3 104 (2,705 ) 1,387 16,211 Increase (decrease) in interest expense as a result of derivatives $ 357 $ (1,342 ) $ 3,104 $ 20,463 Other comprehensive income related Unrealized income (losses) on derivative instruments $ 13 $ 1,784 $ 602 $ (6,695 ) During the three and nine months ended September 30, 2017 and 2016 , 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 expense related to derivative instruments designated as cash flow hedges. The present value of the additional interest expense expected to be recognized over the next 12 months related to derivative instruments designated as cash flow hedges totaled $0.1 million as of September 30, 2017 and was included in accumulated other comprehensive income (loss).

FAIR VALUE DISCLOSURES

FAIR VALUE DISCLOSURES	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
FAIR VALUE DISCLOSURES	FAIR VALUE DISCLOSURES Under GAAP, the Company is required to measure certain financial instruments at fair value on a recurring basis. In addition, the Company is required to measure other non-financial and financial assets at fair value on a non-recurring basis (e.g., carrying value of impaired real estate loans receivable and long-lived assets). Fair value is defined as the price that would be received upon the sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The GAAP fair value framework uses a three-tiered approach. Fair value measurements are classified and disclosed in one of the following three categories: • Level 1: unadjusted quoted prices in active markets that are accessible at the measurement date for identical assets or liabilities; • Level 2: quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-derived valuations in which significant inputs and significant value drivers are observable in active markets; and • Level 3: prices or valuation techniques where little or no market data is available that requires inputs that are both significant to the fair value measurement and unobservable. The fair value for certain financial instruments is derived using a combination of market quotes, pricing models and other valuation techniques that involve significant management judgment. The price transparency of financial instruments is a key determinant of the degree of judgment involved in determining the fair value of the Company’s financial instruments. Financial instruments for which actively quoted prices or pricing parameters are available and for which markets contain orderly transactions will generally have a higher degree of price transparency than financial instruments for which markets are inactive or consist of non-orderly trades. The Company evaluates several factors when determining if a market is inactive or when market transactions are not orderly. The following is a summary of the methods and assumptions used by management in estimating the fair value of each class of assets and liabilities for which it is practicable to estimate the fair value: Cash and cash equivalents, rent and other receivables, and accounts payable and accrued liabilities: These balances approximate their fair values due to the short maturities of these items. Derivative instruments: The Company’s derivative instruments are presented at fair value on the accompanying consolidated balance sheets. The valuation of these instruments is determined using a proprietary model that utilizes observable inputs. As such, the Company classifies these inputs as Level 2 inputs. The proprietary model uses the contractual terms of the derivatives, including the period to maturity, as well as observable market-based inputs, including interest rate curves and volatility. The fair values of interest rate swaps are estimated using the market standard methodology of netting the discounted fixed cash payments and the discounted expected variable cash receipts. The variable cash receipts are based on an expectation of interest rates (forward curves) derived from observable market interest rate curves. In addition, credit valuation adjustments, which consider the impact of any credit risks to the contracts, are incorporated in the fair values to account for potential nonperformance risk. The fair value of interest rate caps (floors) are determined using the market standard methodology of discounting the future expected cash payments (receipts) which would occur if variable interest rates rise above (below) the strike rate of the caps (floors). The variable interest rates used in the calculation of projected payments (receipts) on the cap (floors) are based on an expectation of future interest rates derived from observed market interest rate curves and volatilities. Notes payable: The fair values of the Company’s notes payable are estimated using a discounted cash flow analysis based on management’s estimates of current market interest rates for instruments with similar characteristics, including remaining loan term, loan-to-value ratio, type of collateral and other credit enhancements. Additionally, when determining the fair value of a liability in circumstances in which a quoted price in an active market for an identical liability is not available, the Company measures fair value using (i) a valuation technique that uses the quoted price of the identical liability when traded as an asset or quoted prices for similar liabilities when traded as assets or (ii) another valuation technique that is consistent with the principles of fair value measurement, such as the income approach or the market approach. The Company classifies these inputs as Level 3 inputs. The following were the face values, carrying amounts and fair values of the Company’s notes payable as of September 30, 2017 and December 31, 2016 , which carrying amounts generally do not approximate the fair values (in thousands): September 30, 2017 December 31, 2016 Face Value Carrying Amount Fair Value Face Value Carrying Amount Fair Value Financial liabilities: Notes payable $ 1,898,897 $ 1,891,442 $ 1,889,296 $ 1,793,405 $ 1,783,468 $ 1,775,953 Disclosure of the fair values of financial instruments is based on pertinent information available to the Company as of the period end and requires a significant amount of judgment. Low levels of transaction volume for certain financial instruments have made the estimation of fair values difficult and, therefore, both the actual results and the Company’s estimate of value at a future date could be materially different. As of September 30, 2017 , the Company measured the following assets and liabilities 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 $ 1,500 $ — $ 1,500 $ — Liability derivatives - interest rate swaps (4,700 ) — (4,700 ) —

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS	9 Months Ended
	Sep. 30, 2017
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 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 Strategic Opportunity REIT, Inc., KBS Legacy Partners Apartment REIT, Inc., KBS Strategic Opportunity REIT II, Inc. and KBS Growth & Income REIT, Inc. On January 6, 2014, the Company, together with KBS REIT I, KBS Real Estate Investment Trust II, Inc., KBS Strategic Opportunity REIT, Inc., KBS Legacy Partners Apartment REIT, Inc., KBS Strategic Opportunity REIT II, Inc., 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, Inc. was added to the insurance program at terms similar to those described above. In June 2017, the Company renewed its participation in the program, and the program is effective through June 30, 2018. As KBS REIT I is implementing its plan of liquidation, at renewal in June 2017, KBS REIT I elected to cease participation in the program and obtain separate insurance coverage. During the three and nine months ended September 30, 2017 and 2016 , no other business transactions occurred between the Company and KBS Real Estate Investment Trust, Inc., KBS Real Estate Investment Trust II, Inc., KBS Strategic Opportunity REIT, Inc., KBS Legacy Partners Apartment REIT, Inc., KBS Strategic Opportunity REIT II, Inc. and KBS Growth & Income REIT, Inc. Pursuant to the terms of these agreements, summarized below are the related-party costs incurred by the Company for the three and nine months ended September 30, 2017 and 2016 , respectively, and any related amounts payable as of September 30, 2017 and December 31, 2016 (in thousands): Incurred Payable as of Three Months Ended September 30, Nine Months Ended September 30, September 30, December 31, 2017 2016 2017 2016 2017 2016 Expensed Asset management fees $ 6,587 $ 6,286 $ 19,223 $ 18,646 $ 2,158 $ 2,126 Reimbursement of operating expenses (1) 59 68 255 261 70 139 Real estate acquisition fees — — — 1,473 — — Capitalized Acquisition fee on development project 64 28 234 87 355 121 Acquisition fee on unconsolidated joint venture 120 — 497 — 173 — Asset management fee on development project — — 48 — — 11 Asset management fee on unconsolidated joint venture — — 14 — — — $ 6,830 $ 6,382 $ 20,271 $ 20,467 $ 2,756 $ 2,397 _____________________ (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 $49,000 and $169,000 for the three and nine months ended September 30, 2017 , respectively, and $51,000 and $145,000 for the three and nine months ended September 30, 2016 , respectively, and were the only type of employee costs reimbursed under the Advisory Agreement for the three and nine months ended September 30, 2017 and 2016 , 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. In connection with the Offering, the Company’s sponsors 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 sponsors’ obligations under this indemnification agreement in exchange for reimbursement by the sponsors to the Company for all costs, expenses and premiums related to this supplemental coverage. During the nine months ended September 30, 2017 , the Advisor incurred $0.1 million for the costs of the supplemental coverage obtained by the Company. During the nine months ended September 30, 2016 , the Advisor incurred $0.1 million for the costs of the supplemental coverage obtained by the Company. During the nine months ended September 30, 2017 , the Advisor paid the Company a $0.2 million property insurance rebate. During the nine months ended September 30, 2016 , the Advisor paid the Company a $0.2 million property insurance rebate and $0.1 million for legal and professional fees due from the Advisor. Lease to Affiliate On May 29, 2015, the indirect wholly owned subsidiary of the Company that owns 3003 Washington Boulevard entered into a lease with an affiliate of the Advisor for 5,046 rentable square feet, or approximately 2.3% of the total rentable square feet, at 3003 Washington Boulevard. The lease commenced on October 1, 2015 and terminates on August 31, 2019. The annualized base rent, which represents annualized contractual base rental income as of September 30, 2017 , adjusted to straight-line any contractual tenant concessions (including free rent) and rent increases from the lease’s inception through the balance of the lease term, for this lease is approximately $0.2 million , and the average annual rental rate (net of rental abatements) over the lease term is $46.38 per square foot. During the three and nine months ended September 30, 2017 , the Company recognized $61,000 and $180,000 of revenue related to this lease, respectively. During the three and nine months ended September 30, 2016 , the Company recognized $59,000 and $176,000 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.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Economic Dependency The Company is dependent on the Advisor for certain services that are essential to the Company, including the identification, evaluation, negotiation, origination, acquisition and disposition of investments; management of the daily operations of the Company’s investment portfolio; and other general and administrative responsibilities. In the event that the Advisor is unable to provide the respective services, the Company will be required to obtain such services from other sources. Legal Matters From time to time, the Company may be party to legal proceedings that arise in the ordinary course of its business. Management is not aware of any legal proceedings of which the outcome is probable or reasonably possible to have a material adverse effect on the Company’s results of operations or financial condition, which would require accrual or disclosure of the contingency and possible range of loss. Additionally, the Company has not recorded any loss contingencies related to legal proceedings in which the potential loss is deemed to be remote. Environmental As an owner of real estate, the Company is subject to various environmental laws of federal, state and local governments. Compliance with existing environmental laws is not expected to have a material adverse effect on the Company’s financial condition and results of operations as of September 30, 2017 .

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	9 Months Ended
	Sep. 30, 2017
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS The Company evaluates subsequent events up until the date the consolidated financial statements are issued. Distributions Paid On October 2, 2017 , the Company paid distributions of $9.7 million , which related to distributions declared for daily record dates for each day in the period from September 1, 2017 through September 30, 2017 . On November 1, 2017 , the Company paid distributions of $10.0 million , which related to distributions declared for daily record dates for each day in the period from October 1, 2017 through October 31, 2017 . Distributions Declared On October 9, 2017 , the Company’s board of directors authorized distributions based on daily record dates for the period from November 1, 2017 through November 30, 2017 , which the Company expects to pay in December 2017 . On November 14, 2017 , the Company’s board of directors authorized distributions based on daily record dates for the period from December 1, 2017 through December 31, 2017 , which the Company expects to pay in January 2018 , and distributions based on daily record dates for the period from January 1, 2018 through January 31, 2018 , which the Company expects to pay in February 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 6.11% annualized rate based on the Company's December 9, 2016 estimated value per share of $10.63 . Financing Subsequent to September 30, 2017 Portfolio Loan Facility On November 3, 2017, the Company, through indirect wholly owned subsidiaries (each a “Borrower”), entered into a three -year loan facility with Bank of America, N.A., as administrative agent; Merril Lynch Pierce Fenner & Smith Incorporated, Wells Fargo Securities, LLC and U.S. Bank, N.A., as joint lead arrangers and joint book runners; Wells Fargo Bank, NA, as syndication agent, and each of the financial institutions a signatory thereto (the “Lenders”), for an amount of up to $1.01 billion (the “Portfolio Loan Facility”), of which $757.5 million is term debt and $252.5 million is revolving debt. Proceeds from the term debt were used to pay off and address the upcoming 2018 loan maturities for the existing Town Center Mortgage Loan, RBC Plaza Mortgage Loan, National Office Portfolio Mortgage Loan, 500 West Madison Mortgage Loan, Ten Almaden Mortgage Loan and Towers at Emeryville Mortgage Loan. At closing, $787.5 million was funded, of which $776.0 million was used to pay off the existing mortgage loans (listed above) and the remaining amount was used to pay origination fees and accrued interest. The $787.5 million funded consisted of $757.5 million of term debt and $30.0 million of revolving debt. The Portfolio Loan Facility may be used for the repayment of debt, for tenant improvements, leasing commissions and capital improvements, for working capital or liquidity management of the Company and for other purposes described in the loan agreement. During the term of the Portfolio Loan Facility, the Company has an option to increase the aggregate loan amount by up to an additional $400.0 million in increments of $25.0 million , to a maximum of $1.41 billion , 25% of which would be revolving debt and 75% of which would be term debt, subject to certain conditions contained in the loan agreement. The Portfolio Loan Facility matures on November 3, 2020, with two 12 -month extension options, subject to certain terms and conditions contained in the loan documents. The Portfolio Loan Facility bears interest at a floating rate of 180 basis points over one-month LIBOR during the initial term of the loan and monthly payments are interest only with the entire balance and all outstanding interest and fees due at maturity, assuming no prior prepayment. The Company will have the right to prepay all of the Portfolio Loan Facility, subject to certain expenses potentially incurred by the Lenders as a result of the prepayment and subject to certain conditions contained in the loan documents. In addition, the Portfolio Loan Facility contains customary representations and warranties, financial and other affirmative and negative covenants (including maintenance of an ongoing debt service coverage ratio), events of default and remedies typical for this type of facility. On November 3, 2017, KBS REIT Properties III, LLC (“REIT Properties III”), an indirect wholly owned subsidiary of the Company, entered into three interest rate swap agreements with a current aggregate notional amount of $451.5 million . As of November 3, 2017, the Company had three existing interest rate swaps related to the paid off loans with a current notional amount in the aggregate of $306.0 million . As the existing interest rate swaps expire at various times from January 1, 2018 through January 1, 2020, the notional amount of the new interest rate swaps in the aggregate will increase to maintain a notional amount of $757.5 million . The new and existing interest rate swaps, in the aggregate, effectively fix the interest rate on the term portion of the Portfolio Loan Facility at a blended rate of 3.861% , effective from November 3, 2017 through November 1, 2022. The Portfolio Loan Facility is secured by RBC Plaza, Preston Commons, Sterling Plaza, One Washingtonian Center, Towers at Emeryville, Ten Almaden, Town Center and 500 West Madison. The Company has the right to substitute properties securing the Portfolio Loan Facility at any time, subject to approval of the Lenders and compliance with the terms and conditions described in the loan agreement. Under the guaranty agreement related to the Portfolio Loan Facility (the “Guaranty”), REIT Properties III (i) provides a guaranty of, among other sums described in the Guaranty, all principal and interest outstanding under the Portfolio Loan Facility in the event of certain bankruptcy or insolvency proceedings involving REIT Properties III, any Borrower or any of their affiliates and (ii) guarantees payment of, and agrees to protect, defend, indemnify and hold harmless each Lender for, from and against, any deficiency, loss or damage suffered by any Lender because of (a) certain intentional acts committed by any Borrower or (b) certain bankruptcy or insolvency proceedings involving REIT Properties III, any Borrower or any of their affiliates, as such acts are described in the Guaranty.

SUMMARY OF SIGNIFICANT ACCOUN20

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2017
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 Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) and the rules and regulations of the SEC, including the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, the unaudited consolidated financial statements do not include all of the information and footnotes required by GAAP for audited financial statements. In the opinion of management, the financial statements for the unaudited interim periods presented include all adjustments, which are of a normal and recurring nature, necessary for a fair and consistent presentation of the results for such periods. Operating results for the three and nine and months ended September 30, 2017 are not necessarily indicative of the results that may be expected for the year ending December 31, 2017.
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.
Investments in Unconsolidated Joint Ventures	The Company accounts for investments in unconsolidated joint ventures over which the Company may exercise significant influence, but does not control, using the equity method of accounting. Under the equity method, the investment is initially recorded at cost and subsequently adjusted to reflect additional contributions or distributions and the Company’s proportionate share of equity in the joint venture’s income (loss). The Company recognizes its proportionate share of the ongoing income or loss of the unconsolidated joint venture as equity in income (loss) of unconsolidated joint venture on the consolidated statements of operations. On a quarterly basis, the Company evaluates its investment in an unconsolidated joint venture for other-than-temporary impairments. As of September 30, 2017 , the Company did not identify any indicators of impairment related to its unconsolidated real estate joint venture accounted for under the equity method.
Per Share Data	Basic net income (loss) per share of common stock is calculated by dividing net income (loss) attributable to common stockholders by the weighted-average number of shares of common stock issued and outstanding during such period. Diluted net income (loss) per share of common stock equals basic net income (loss) per share of common stock as there were no potentially dilutive securities outstanding during the three and nine months ended September 30, 2017 and 2016 , respectively. Distributions declared per common share were $0.164 and $ 0.486 for the three and nine months ended September 30, 2017 , respectively. Distributions declared per common share were $ 0.164 and $ 0.486 for the three and nine months ended September 30, 2016 , respectively. Distributions declared per common share assumes each share was issued and outstanding each day during the three and nine months ended September 30, 2017 and 2016 , respectively. For each day that was a record date for distributions during the three and nine months ended September 30, 2017 and 2016 , distributions were calculated at a rate of $0.00178082 per share per day. Each day during the periods from January 1, 2016 through February 28, 2016, March 1, 2016 through September 30, 2016 and January 1, 2017 through September 30, 2017 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 investments exhibit similar long-term financial performance and have similar economic characteristics to each other. As of September 30, 2017 , the Company aggregated its investments in real estate into one reportable business segment.
Recently Issued Accounting Standards Update	In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) (“ASU No. 2014-09”). ASU No. 2014-09 requires an entity to recognize the revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods and services. ASU No. 2014-09 supersedes the revenue requirements in Revenue Recognition (Topic 605) and most industry-specific guidance throughout the Industry Topics of the Codification. ASU No. 2014-09 does not apply to lease contracts within the scope of Leases (Topic 840). ASU No. 2014-09 was to be effective for fiscal years, and interim periods within those years, beginning after December 15, 2016, and is to be applied retrospectively, with early application not permitted. In August 2015, the FASB issued ASU No. 2015-14, Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date (“ASU No. 2015-14”), which defers the effective date of ASU No. 2014-09 by one year. Early adoption is permitted but not before the original effective date. The primary source of revenue for the Company is generated through leasing arrangements, which are excluded from this standard. The Company’s revenues that may be impacted by this standard primarily include other operating income, sales of real estate and other ancillary income earned at its properties. In 2016, other operating income and other ancillary income were approximately 7% of consolidated revenue. The Company is in process of evaluating how this standard will impact sales of real estate. The Company continues to evaluate the impact that the standard will have on its consolidated financial statements. The Company expects to adopt the standard using the modified retrospective approach, which requires a cumulative effect adjustment as of the date of the adoption. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU No. 2016-01”). The amendments in ASU No. 2016-01 address certain aspects of recognition, measurement, presentation and disclosure of financial instruments. ASU No. 2016-01 primarily affects accounting for equity investments and financial liabilities where the fair value option has been elected. ASU No. 2016-01 also requires entities to present financial assets and financial liabilities separately, grouped by measurement category and form of financial asset in the balance sheet or in the accompanying notes to the financial statements. ASU No. 2016-01 is effective for annual periods beginning after December 15, 2017, including interim periods within those fiscal years. Early application of certain provisions of the standard is permitted for financial statements that have not been previously issued. The Company does not expect the adoption of ASU No. 2016-01 to have a significant impact on its financial statements. 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. The new leases standard 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 leases standard on its consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses of Financial Instruments (“ASU No. 2016-13”). ASU No. 2016-13 affects entities holding financial assets and net investments in leases that are not accounted for at fair value through net income. The amendments in ASU No. 2016-13 require a financial asset (or a group of financial assets) measured at amortized cost basis to be presented at the net amount expected to be collected. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial asset(s) to present the net carrying value at the amount expected to be collected on the financial asset. ASU No. 2016-13 also amends the impairment model for available-for-sale securities. An entity will recognize an allowance for credit losses on available-for-sale debt securities as a contra-account to the amortized cost basis rather than as a direct reduction of the amortized cost basis of the investment, as is currently required. ASU No. 2016-13 also requires new disclosures. For financial assets measured at amortized cost, an entity will be required to disclose information about how it developed its allowance for credit losses, including changes in the factors that influenced management’s estimate of expected credit losses and the reasons for those changes. For financing receivables and net investments in leases measured at amortized cost, an entity will be required to further disaggregate the information it currently discloses about the credit quality of these assets by year of the asset’s origination for as many as five annual periods. For available for sale securities, an entity will be required to provide a roll-forward of the allowance for credit losses and an aging analysis for securities that are past due. ASU No. 2016-13 is effective for annual periods beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company is still evaluating the impact of adopting ASU No. 2016-13 on its financial statements, but does not expect the adoption of ASU No. 2016-13 to have a material impact on its financial statements. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (“ASU No. 2016-15”). ASU No. 2016-15 is intended to reduce diversity in practice in how certain transactions are classified in the statement of cash flows. The amendments in ASU No. 2016-15 provide guidance on eight specific cash flow issues, including the following that are or may be relevant to the Company: (a) Cash payments for debt prepayment or debt extinguishment costs should be classified as cash outflows for financing activities; (b) Cash payments relating to contingent consideration made soon after an acquisition’s consummation date (i.e., approximately three months or less) should be classified as cash outflows for investing activities. Payments made thereafter should be classified as cash outflows for financing activities up to the amount of the original contingent consideration liability. Payments made in excess of the amount of the original contingent consideration liability should be classified as cash outflows for operating activities; (c) Cash payments received from the settlement of insurance claims should be classified on the basis of the nature of the loss (or each component loss, if an entity receives a lump-sum settlement); (d) Relating to distributions received from equity method investments, ASU No. 2016-15 provides an accounting policy election for classifying distributions received from equity method investments. Such amounts can be classified using a (1) cumulative earnings approach, or (2) nature of distribution approach. Under the cumulative earnings approach, an investor would compare the distributions received to its cumulative equity method earnings since inception. Any distributions received up to the amount of cumulative equity earnings would be considered a return on investment and classified in operating activities. Any excess distributions would be considered a return of investment and classified in investing activities. Alternatively, an investor can choose to classify the distributions based on the nature of activities of the investee that generated the distribution. If the necessary information is subsequently not available for an investee to determine the nature of the activities, the entity should use the cumulative earnings approach for that investee and report a change in accounting principle on a retrospective basis; and (e) In the absence of specific guidance, an entity should classify each separately identifiable cash source and use on the basis of the nature of the underlying cash flows. For cash flows with aspects of more than one class that cannot be separated, the classification should be based on the activity that is likely to be the predominant source or use of cash flow. ASU No. 2016-15 is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. The Company is still evaluating the impact of adopting ASU No. 2016-15 on its financial statements, but does not expect the adoption of ASU No. 2016-15 to have a material impact on its financial statements. In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash (“ASU No. 2016-18”). ASU No. 2016-18 requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, restricted cash and restricted cash equivalents. Therefore, amounts generally described as restricted cash should be included with cash and cash equivalents when reconciling the beginning of period and end of period total amounts shown on the statement of cash flows. ASU No. 2016-18 is effective for annual periods beginning after December 15, 2017, including interim periods within those fiscal years. The Company elected to early adopt ASU No. 2016-18 for the reporting period ended December 31, 2016 and applied it retrospectively. As a result of the adoption of ASU No. 2016-18, the Company no longer presents the changes within restricted cash in the consolidated statements of cash flows. In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business (“ASU No. 2017-01”) to add guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. ASU No. 2017-01 provides a screen to determine when an integrated set of assets and activities (collectively referred to as a “set”) is not a business. The screen requires that when substantially all of the fair value of the gross assets acquired (or disposed of) is concentrated in a single identifiable asset or a group of similar identifiable assets, the set is not a business. If the screen is not met, ASU No. 2017-01 (1) requires that to be considered a business, a set must include, at a minimum, an input and a substantive process that together significantly contribute to the ability to create output and (2) removes the evaluation of whether a market participant could replace missing elements. ASU No. 2017-01 provides a framework to assist entities in evaluating whether both an input and a substantive process are present. The framework includes two sets of criteria to consider that depend on whether a set has outputs. Although outputs are not required for a set to be a business, outputs generally are a key element of a business; therefore, the FASB has developed more stringent criteria for sets without outputs. ASU No. 2017-01 is effective for annual periods beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is permitted. The amendments can be applied to transactions occurring before the guidance was issued (January 5, 2017) as long as the applicable financial statements have not been issued. The Company elected to early adopt ASU No. 2017-01 for the reporting period beginning January 1, 2017. As a result of the adoption of ASU No. 2017-01, the Company’s acquisitions of investment properties beginning January 1, 2017 could qualify as asset acquisitions (as opposed to business combinations). Transaction costs associated with asset acquisitions are capitalized, while transaction costs associated with business combinations will continue to be expensed as incurred.

REAL ESTATE (Tables)

REAL ESTATE (Tables)	9 Months Ended
	Sep. 30, 2017
Real Estate [Abstract]
Schedule of Real Estate Investments	The following table summarizes the Company’s investments in real estate as of September 30, 2017 (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 $ 47,373 $ (12,999 ) $ 34,374 Town Center 03/27/2012 Plano TX Office 116,133 (23,752 ) 92,381 McEwen Building 04/30/2012 Franklin TN Office 36,873 (6,868 ) 30,005 Gateway Tech Center 05/09/2012 Salt Lake City UT Office 24,749 (5,863 ) 18,886 Tower on Lake Carolyn 12/21/2012 Irving TX Office 52,625 (11,679 ) 40,946 RBC Plaza 01/31/2013 Minneapolis MN Office 151,277 (29,773 ) 121,504 One Washingtonian Center 06/19/2013 Gaithersburg MD Office 90,635 (14,453 ) 76,182 Preston Commons 06/19/2013 Dallas TX Office 117,959 (18,774 ) 99,185 Sterling Plaza 06/19/2013 Dallas TX Office 79,662 (10,969 ) 68,693 201 Spear Street 12/03/2013 San Francisco CA Office 140,040 (11,421 ) 128,619 500 West Madison 12/16/2013 Chicago IL Office 440,607 (68,666 ) 371,941 222 Main 02/27/2014 Salt Lake City UT Office 166,331 (23,434 ) 142,897 Anchor Centre 05/22/2014 Phoenix AZ Office 93,901 (12,582 ) 81,319 171 17th Street 08/25/2014 Atlanta GA Office 133,176 (19,638 ) 113,538 Rocklin Corporate Center 11/06/2014 Rocklin CA Office 33,515 (5,311 ) 28,204 Reston Square 12/03/2014 Reston VA Office 46,561 (6,141 ) 40,420 Ten Almaden 12/05/2014 San Jose CA Office 120,351 (12,795 ) 107,556 Towers at Emeryville 12/23/2014 Emeryville CA Office 262,312 (26,218 ) 236,094 101 South Hanley 12/24/2014 St. Louis MO Office 70,692 (7,859 ) 62,833 3003 Washington Boulevard 12/30/2014 Arlington VA Office 151,096 (13,832 ) 137,264 Village Center Station 05/20/2015 Greenwood Village CO Office 78,259 (8,630 ) 69,629 Park Place Village 06/18/2015 Leawood KS Office/Retail 128,857 (12,607 ) 116,250 201 17th Street 06/23/2015 Atlanta GA Office 103,379 (9,587 ) 93,792 Promenade I & II at Eilan 07/14/2015 San Antonio TX Office 62,643 (6,076 ) 56,567 CrossPoint at Valley Forge 08/18/2015 Wayne PA Office 90,252 (7,469 ) 82,783 515 Congress 08/31/2015 Austin TX Office 117,420 (10,444 ) 106,976 The Almaden 09/23/2015 San Jose CA Office 167,833 (11,828 ) 156,005 3001 Washington Boulevard 11/06/2015 Arlington VA Office 56,608 (2,663 ) 53,945 Carillon 01/15/2016 Charlotte NC Office 152,354 (10,991 ) 141,363 Hardware Village (1) 08/26/2016 Salt Lake City UT Development/Apartment 56,124 — 56,124 $ 3,389,597 $ (423,322 ) $ 2,966,275 _____________________ (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 September 30, 2017 , 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 156 $ 61,946 20.5 % _____________________ (1) Annualized base rent represents annualized contractual base rental income as of September 30, 2017 , adjusted to straight-line any contractual tenant concessions (including free rent), rent increases and rent decreases from the lease’s inception through the balance of the lease term. As of September 30, 2017 , 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 $ 371,941 11.6 % $ 34,883 $ 27.80 86.1 % _____________________ (1) Annualized base rent represents annualized contractual base rental income as of September 30, 2017 , adjusted to straight-line any contractual tenant concessions (including free rent), rent increases and rent decreases from the lease’s inception through the balance of the lease term.
Schedule of Future Minimum Rental Income for Company's Properties	As of September 30, 2017 , the future minimum rental income from the Company’s properties under its non-cancelable operating leases was as follows (in thousands): October 1, 2017 through December 31, 2017 $ 71,113 2018 289,600 2019 269,676 2020 235,674 2021 203,589 Thereafter 649,360 $ 1,719,012

TENANT ORIGINATION AND ABSORP22

TENANT ORIGINATION AND ABSORPTION COSTS, ABOVE-MARKET LEASE ASSETS AND BELOW-MARKET LEASE LIABILITIES (Tables)	9 Months Ended
	Sep. 30, 2017
Tenant Origination and Absorption Costs, Above-Market Lease Assets and Below-Market Lease Liabilities [Abstract]
Tenant Origination and Absorption Costs, Above-Market Lease Assets and Below-Market Lease Liabilities	As of September 30, 2017 and December 31, 2016 , the Company’s tenant origination and absorption costs, above-market lease assets and below-market lease liabilities (excluding fully amortized assets and liabilities and accumulated amortization) were as follows (in thousands): Tenant Origination and Absorption Costs Above-Market Lease Assets Below-Market Lease Liabilities September 30, 2017 December 31, 2016 September 30, 2017 December 31, 2016 September 30, 2017 December 31, 2016 Cost $ 243,102 $ 264,973 $ 13,576 $ 14,383 $ (49,401 ) $ (55,438 ) Accumulated Amortization (110,207 ) (99,757 ) (7,159 ) (6,192 ) 22,709 21,783 Net Amount $ 132,895 $ 165,216 $ 6,417 $ 8,191 $ (26,692 ) $ (33,655 )
Amortization of Tenant Origination and Absorption Costs, Above-Market Leases and Below-Market Lease Liabilities	Increases (decreases) in net income as a result of amortization of the Company’s tenant origination and absorption costs, above-market lease assets and below-market lease liabilities for the three and nine months ended September 30, 2017 and 2016 were as follows (in thousands): Tenant Origination and Absorption Costs Above-Market Lease Assets Below-Market Lease Liabilities For the Three Months Ended September 30, For the Three Months Ended September 30, For the Three Months Ended September 30, 2017 2016 2017 2016 2017 2016 Amortization $ (10,202 ) $ (11,208 ) $ (527 ) $ (718 ) $ 2,184 $ 2,474 Tenant Origination and Absorption Costs Above-Market Lease Assets Below-Market Lease Liabilities For the Nine Months Ended September 30, For the Nine Months Ended September 30, For the Nine Months Ended September 30, 2017 2016 2017 2016 2017 2016 Amortization $ (32,321 ) $ (35,100 ) $ (1,774 ) $ (2,186 ) $ 6,963 $ 9,055

INVESTMENT IN UNCONSOLIDATED 23

INVESTMENT IN UNCONSOLIDATED JOINT VENTURE (Tables)	9 Months Ended
	Sep. 30, 2017
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 follows (in thousands): September 30, 2017 Assets: Construction in progress $ 73,400 Cash and cash equivalents 1 Other assets 2,591 Total assets $ 75,992 Liabilities and equity: Accounts payable $ 9,615 Notes payable, net 23,004 Other liabilities 258 Members’ capital 43,115 Total liabilities and equity $ 75,992

NOTES PAYABLE (Tables)

NOTES PAYABLE (Tables)	9 Months Ended
	Sep. 30, 2017
Notes Payable [Abstract]
Schedule of Long-term Debt Instruments	As of September 30, 2017 and December 31, 2016 , the Company’s notes payable consisted of the following (dollars in thousands): Book Value as of September 30, 2017 Book Value as of December 31, 2016 Contractual Interest Rate as of (1) Effective Interest Rate as of September 30, 2017 (1) Payment Type Maturity Date (2) Town Center Mortgage Loan $ 75,000 $ 75,000 One-month LIBOR + 1.85% 2.87% Interest Only 03/27/2018 (3) Portfolio Loan (5) 163,460 127,500 One-month LIBOR + 1.90% 3.14% Interest Only 06/01/2019 RBC Plaza Mortgage Loan 75,434 75,930 One-month LIBOR + 1.80% 3.04% Principal & Interest 02/01/2018 (3) National Office Portfolio Mortgage Loan (6) 170,602 170,602 One-month LIBOR + 1.50% 2.84% Interest Only 07/01/2018 (3) 500 West Madison Mortgage Loan (7) 235,000 215,000 One-month LIBOR + 1.65% 3.13% Interest Only 12/16/2018 (3) 222 Main Mortgage Loan 99,946 101,343 3.97% 3.97% Principal & Interest 03/01/2021 Anchor Centre Mortgage Loan 50,000 50,000 One-month LIBOR + 1.50% 3.18% Interest Only 06/01/2018 171 17th Street Mortgage Loan 85,479 83,778 One-month LIBOR + 1.45% 2.83% Interest Only (4) 09/01/2018 Reston Square Mortgage Loan 29,800 23,840 One-month LIBOR + 1.50% 3.63% Interest Only 02/01/2018 Ten Almaden Mortgage Loan 66,555 65,853 One-month LIBOR + 1.65% 3.43% Interest Only 01/01/2018 (3) Towers at Emeryville Mortgage Loan (8) 153,524 145,379 One-month LIBOR + 1.75% 3.96% Interest Only 01/15/2018 (3) 101 South Hanley Mortgage Loan 40,557 37,502 One-month LIBOR + 1.55% 3.75% Interest Only (4) 01/01/2020 3003 Washington Boulevard Mortgage Loan 90,378 90,378 One-month LIBOR + 1.55% 3.54% Interest Only 02/01/2020 Rocklin Corporate Center Mortgage Loan 21,689 20,868 One-month LIBOR + 1.50% 2.74% Interest Only 06/05/2018 201 17th Street Mortgage Loan 64,428 58,063 One-month LIBOR + 1.40% 3.32% Interest Only 08/01/2018 CrossPoint at Valley Forge Mortgage Loan 51,000 51,000 One-month LIBOR + 1.50% 3.33% Interest Only (4) 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 68,381 67,500 One-month LIBOR + 1.70% 2.94% Interest Only 11/01/2020 201 Spear Street Mortgage Loan 100,000 100,000 One-month LIBOR + 1.66% 2.90% Interest Only 01/01/2019 Carillon Mortgage Loan 90,248 76,440 One-month LIBOR + 1.65% 3.25% Interest Only 02/01/2020 3001 Washington Boulevard Mortgage Loan 28,404 27,129 One-month LIBOR + 1.60% 2.84% Interest Only 02/01/2019 Hardware Village Loan Facility (9) 8,712 — One-month LIBOR + 3.25% 4.49% Interest Only 02/23/2020 Total notes payable principal outstanding 1,898,897 1,793,405 Deferred financing costs, net (7,455 ) (9,937 ) Total notes payable, net $ 1,891,442 $ 1,783,468 _____________________ (1) Contractual interest rate represents the interest rate in effect under the loan as of September 30, 2017 . Effective interest rate is calculated as the actual interest rate in effect as of September 30, 2017 (consisting of the contractual interest rate and the effect of interest rate swaps and caps, if applicable), using interest rate indices as of September 30, 2017 , where applicable. For further information regarding the Company's derivative instruments, see Note 7, “Derivative Instruments.” (2) Represents the maturity date as of September 30, 2017 ; subject to certain conditions, the maturity dates of certain loans may be extended beyond the dates shown. (3) On November 3, 2017, the Company paid off the outstanding balances under these loans using proceeds from the Portfolio Loan Facility. See Note 11,“Subsequent Events - Financing Subsequent to September 30, 2017 - Portfolio Loan Facility.” (4) Represents the payment type required under the loan as of September 30, 2017 . Certain future monthly payments due under these loans 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. (5) As of September 30, 2017 , the Portfolio Loan was secured by Domain Gateway, the McEwen Building, Gateway Tech Center, the Tower on Lake Carolyn, Park Place Village and Village Center Station. The face amount of the Portfolio Loan is $ 255.0 million , of which $ 127.5 million is term debt and $ 127.5 million is revolving debt. As of September 30, 2017 , the outstanding balance under the loan consisted of $127.5 million of term debt and $36.0 million of revolving debt. As of September 30, 2017 , an additional $90.5 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. (6) The National Office Portfolio Mortgage Loan was secured by One Washingtonian Center, Preston Commons and Sterling Plaza. See footnote 3 above. (7) As of September 30, 2017 , $235.0 million of term debt was outstanding and $20.0 million remained available for future disbursements, subject to certain terms and conditions contained in the loan documents. See footnote 3 above. (8) As of September 30, 2017 , $153.5 million had been disbursed to the Company and $21.5 million remained available for future disbursements, subject to certain conditions contained in the loan documents. See footnote 3 above. (9) As of September 30, 2017 , $8.7 million had been disbursed and $65.3 million remained available for future disbursements, subject to certain conditions contained in the loan documents.
Schedule of Maturities of Long-term Debt	The following is a schedule of maturities, including principal amortization payments, for all notes payable outstanding as of September 30, 2017 (in thousands): October 1, 2017 through December 31, 2017 $ 874 2018 1,029,540 2019 294,445 2020 299,491 2021 93,957 Thereafter 180,590 $ 1,898,897

DERIVATIVE INSTRUMENTS (Tables)

DERIVATIVE INSTRUMENTS (Tables)	9 Months Ended
	Sep. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Notional and Fair Value of Interest Rate Swaps Designated as Cash Flow Hedges	The following table summarizes the notional amount and other information related to the Company’s interest rate swaps and cap as of September 30, 2017 and December 31, 2016 . The notional amount is an indication of the extent of the Company’s involvement in each instrument at that time, but does not represent exposure to credit, interest rate or market risks (dollars in thousands): September 30, 2017 December 31, 2016 Weighted-Average Fix Pay Rate Weighted-Average Remaining Term in Years Derivative Instruments Number of Instruments Notional Amount Number of Instruments Notional Amount Reference Rate as of September 30, 2017 Derivative instruments designated as hedging instruments Interest Rate Swaps 6 $ 508,400 7 $ 625,130 One-month LIBOR/ Fixed at 0.86% - 1.68% 1.42% 0.9 Derivative instruments not designated as hedging instruments Interest Rate Swaps (1) 12 $ 658,183 12 $ 658,183 One-month LIBOR/ 1.99% 2.9 Interest Rate Cap (2) — $ — 1 $ 147,340 (2) (2) (2) _____________________ (1) Included in these amounts are two forward interest rate swaps with an aggregate notional amount of $91.5 million that were not yet in effect as of September 30, 2017 . These two interest rate swaps will become effective at various times during the remainder of 2017 through 2018. (2) The interest rate cap matured on January 1, 2017.
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	The following table sets forth the fair value of the Company’s derivative instruments as well as their classification on the consolidated balance sheets as of September 30, 2017 and December 31, 2016 (dollars in thousands): September 30, 2017 December 31, 2016 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 3 $ 142 1 $ 42 Interest Rate Swaps Other liabilities, at fair value 3 $ (121 ) 6 $ (2,340 ) Derivative instruments not designated as hedging instruments Interest Rate Swaps Prepaid expenses and other assets, at fair value 4 $ 1,358 4 $ 1,588 Interest Rate Swaps Other liabilities, at fair value 8 $ (4,579 ) 8 $ (7,388 ) Interest Rate Cap Prepaid expenses and other assets, at fair value — $ — 1 $ —
Schedule of Derivative Instruments in Statement of Operations	The following table summarizes the effects of derivative instruments on the Company’s consolidated statements of operations (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2017 2016 2017 2016 Income statement related Derivatives designated as hedging instruments Amount of expense recognized on interest rate swaps (effective portion) $ 253 $ 1,363 $ 1,717 $ 4,252 253 1,363 1,717 4,252 Derivatives not designated as hedging instruments Realized loss recognized on interest rate swaps 1,108 1,040 3,966 1,398 Unrealized (gain) loss on interest rate swaps (1,004 ) (3,745 ) (2,579 ) 14,810 Unrealized loss on interest rate cap — — — 3 104 (2,705 ) 1,387 16,211 Increase (decrease) in interest expense as a result of derivatives $ 357 $ (1,342 ) $ 3,104 $ 20,463 Other comprehensive income related Unrealized income (losses) on derivative instruments $ 13 $ 1,784 $ 602 $ (6,695 )

FAIR VALUE DISCLOSURES (Tables)

FAIR VALUE DISCLOSURES (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Schedule of Face Value, Carrying Amounts and Fair Value	The following were the face values, carrying amounts and fair values of the Company’s notes payable as of September 30, 2017 and December 31, 2016 , which carrying amounts generally do not approximate the fair values (in thousands): September 30, 2017 December 31, 2016 Face Value Carrying Amount Fair Value Face Value Carrying Amount Fair Value Financial liabilities: Notes payable $ 1,898,897 $ 1,891,442 $ 1,889,296 $ 1,793,405 $ 1,783,468 $ 1,775,953
Schedule of Assets and Liabilities at Fair Value	As of September 30, 2017 , the Company measured the following assets and liabilities 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 $ 1,500 $ — $ 1,500 $ — Liability derivatives - interest rate swaps (4,700 ) — (4,700 ) —

RELATED PARTY TRANSACTIONS (Tab

RELATED PARTY TRANSACTIONS (Tables)	9 Months Ended
	Sep. 30, 2017
Related Party Transactions [Abstract]
Schedule of Related Party Costs	Pursuant to the terms of these agreements, summarized below are the related-party costs incurred by the Company for the three and nine months ended September 30, 2017 and 2016 , respectively, and any related amounts payable as of September 30, 2017 and December 31, 2016 (in thousands): Incurred Payable as of Three Months Ended September 30, Nine Months Ended September 30, September 30, December 31, 2017 2016 2017 2016 2017 2016 Expensed Asset management fees $ 6,587 $ 6,286 $ 19,223 $ 18,646 $ 2,158 $ 2,126 Reimbursement of operating expenses (1) 59 68 255 261 70 139 Real estate acquisition fees — — — 1,473 — — Capitalized Acquisition fee on development project 64 28 234 87 355 121 Acquisition fee on unconsolidated joint venture 120 — 497 — 173 — Asset management fee on development project — — 48 — — 11 Asset management fee on unconsolidated joint venture — — 14 — — — $ 6,830 $ 6,382 $ 20,271 $ 20,467 $ 2,756 $ 2,397 _____________________ (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 $49,000 and $169,000 for the three and nine months ended September 30, 2017 , respectively, and $51,000 and $145,000 for the three and nine months ended September 30, 2016 , respectively, and were the only type of employee costs reimbursed under the Advisory Agreement for the three and nine months ended September 30, 2017 and 2016 , 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.

ORGANIZATION (Details)

ORGANIZATION (Details) $ / shares in Units, $ in Thousands	Oct. 03, 2014USD ($)shares	Sep. 30, 2017USD ($)propertyshares	Dec. 31, 2016USD ($)shares	May 29, 2016USD ($)shares	Sep. 30, 2017USD ($)propertyshares	Jan. 26, 2010$ / 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)		180,102,670	180,890,572		180,102,670
Issuance of common stock | $		$ 45,098	$ 61,871
Redemptions of common stock | $		$ 54,669	$ 34,767
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		28			28
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)		4,465,177	6,485,383	169,006,162
Issuance of common stock | $		$ 45	$ 65	$ 1,700,000
Shares of common stock sold under dividend reinvestment plan, shares					21,438,406
Shares of common stock sold under dividend reinvestment plan, value | $					$ 210,100
Redemptions of common stock (in shares)		5,253,079	3,538,049		10,620,360
Redemptions of common stock | $		$ 53	$ 35		$ 107,200
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)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017$ / shares	Sep. 30, 2016$ / shares	Sep. 30, 2017segment$ / shares	Sep. 30, 2016$ / shares	Dec. 31, 2016
Accounting Policies [Abstract]
Distributions declared per share (in dollars per share)	$ 0.164	$ 0.164	$ 0.486	$ 0.486
Distribution rate per share per day, declared (in dollars per share)	$ 0.00178082	$ 0.00178082	$ 0.00178082	$ 0.00178082
Number of reportable segments | segment			1
Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other operating income and other ancillary income as percent of consolidated revenue					7.00%

REAL ESTATE (Narrative) (Detail

REAL ESTATE (Narrative) (Details) ft² in Millions	Sep. 30, 2017ft²property
Real Estate Properties [Line Items]
Rentable square feet | ft²	11.1
Percentage of portfolio occupied	92.00%
Office Properties
Real Estate Properties [Line Items]
Number of real estate properties	28
Mixed-use Office/Retail Property
Real Estate Properties [Line Items]
Number of real estate properties	1

REAL ESTATE (Schedule of Real E

REAL ESTATE (Schedule of Real Estate Investments) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016	Aug. 26, 2016
Real Estate Properties [Line Items]
Total Real Estate at Cost	$ 3,389,597	$ 3,333,649
Accumulated Depreciation and Amortization	(423,322)	(344,794)
Total real estate, net	$ 2,966,275	$ 2,988,855
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	$ 47,373
Accumulated Depreciation and Amortization	(12,999)
Total real estate, net	$ 34,374
Town Center | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Mar. 27, 2012
Total Real Estate at Cost	$ 116,133
Accumulated Depreciation and Amortization	(23,752)
Total real estate, net	$ 92,381
McEwen Building | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Apr. 30, 2012
Total Real Estate at Cost	$ 36,873
Accumulated Depreciation and Amortization	(6,868)
Total real estate, net	$ 30,005
Gateway Tech Center | Office Properties
Real Estate Properties [Line Items]
Date Acquired	May 9, 2012
Total Real Estate at Cost	$ 24,749
Accumulated Depreciation and Amortization	(5,863)
Total real estate, net	$ 18,886
Tower on Lake Carolyn | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Dec. 21, 2012
Total Real Estate at Cost	$ 52,625
Accumulated Depreciation and Amortization	(11,679)
Total real estate, net	$ 40,946
RBC Plaza | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Jan. 31, 2013
Total Real Estate at Cost	$ 151,277
Accumulated Depreciation and Amortization	(29,773)
Total real estate, net	$ 121,504
One Washingtonian Center | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Jun. 19, 2013
Total Real Estate at Cost	$ 90,635
Accumulated Depreciation and Amortization	(14,453)
Total real estate, net	$ 76,182
Preston Commons | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Jun. 19, 2013
Total Real Estate at Cost	$ 117,959
Accumulated Depreciation and Amortization	(18,774)
Total real estate, net	$ 99,185
Sterling Plaza | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Jun. 19, 2013
Total Real Estate at Cost	$ 79,662
Accumulated Depreciation and Amortization	(10,969)
Total real estate, net	$ 68,693
201 Spear Street | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Dec. 3, 2013
Total Real Estate at Cost	$ 140,040
Accumulated Depreciation and Amortization	(11,421)
Total real estate, net	$ 128,619
500 West Madison | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Dec. 16, 2013
Total Real Estate at Cost	$ 440,607
Accumulated Depreciation and Amortization	(68,666)
Total real estate, net	$ 371,941
222 Main | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Feb. 27, 2014
Total Real Estate at Cost	$ 166,331
Accumulated Depreciation and Amortization	(23,434)
Total real estate, net	$ 142,897
Anchor Centre | Office Properties
Real Estate Properties [Line Items]
Date Acquired	May 22, 2014
Total Real Estate at Cost	$ 93,901
Accumulated Depreciation and Amortization	(12,582)
Total real estate, net	$ 81,319
171 17th Street | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Aug. 25, 2014
Total Real Estate at Cost	$ 133,176
Accumulated Depreciation and Amortization	(19,638)
Total real estate, net	$ 113,538
Rocklin Corporate Center | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Nov. 6, 2014
Total Real Estate at Cost	$ 33,515
Accumulated Depreciation and Amortization	(5,311)
Total real estate, net	$ 28,204
Reston Square | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Dec. 3, 2014
Total Real Estate at Cost	$ 46,561
Accumulated Depreciation and Amortization	(6,141)
Total real estate, net	$ 40,420
Ten Almaden | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Dec. 5, 2014
Total Real Estate at Cost	$ 120,351
Accumulated Depreciation and Amortization	(12,795)
Total real estate, net	$ 107,556
Towers at Emeryville | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Dec. 23, 2014
Total Real Estate at Cost	$ 262,312
Accumulated Depreciation and Amortization	(26,218)
Total real estate, net	$ 236,094
101 South Hanley | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Dec. 24, 2014
Total Real Estate at Cost	$ 70,692
Accumulated Depreciation and Amortization	(7,859)
Total real estate, net	$ 62,833
3003 Washington Boulevard | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Dec. 30, 2014
Total Real Estate at Cost	$ 151,096
Accumulated Depreciation and Amortization	(13,832)
Total real estate, net	$ 137,264
Village Center Station | Office Properties
Real Estate Properties [Line Items]
Date Acquired	May 20, 2015
Total Real Estate at Cost	$ 78,259
Accumulated Depreciation and Amortization	(8,630)
Total real estate, net	$ 69,629
Park Place Village | Office/Retail
Real Estate Properties [Line Items]
Date Acquired	Jun. 18, 2015
Total Real Estate at Cost	$ 128,857
Accumulated Depreciation and Amortization	(12,607)
Total real estate, net	$ 116,250
201 17th Street | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Jun. 23, 2015
Total Real Estate at Cost	$ 103,379
Accumulated Depreciation and Amortization	(9,587)
Total real estate, net	$ 93,792
Promenade I & II at Eilan | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Jul. 14, 2015
Total Real Estate at Cost	$ 62,643
Accumulated Depreciation and Amortization	(6,076)
Total real estate, net	$ 56,567
CrossPoint at Valley Forge | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Aug. 18, 2015
Total Real Estate at Cost	$ 90,252
Accumulated Depreciation and Amortization	(7,469)
Total real estate, net	$ 82,783
515 Congress | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Aug. 31, 2015
Total Real Estate at Cost	$ 117,420
Accumulated Depreciation and Amortization	(10,444)
Total real estate, net	$ 106,976
The Almaden | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Sep. 23, 2015
Total Real Estate at Cost	$ 167,833
Accumulated Depreciation and Amortization	(11,828)
Total real estate, net	$ 156,005
3001 Washington Boulevard | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Nov. 6, 2015
Total Real Estate at Cost	$ 56,608
Accumulated Depreciation and Amortization	(2,663)
Total real estate, net	$ 53,945
Carillon | Office Properties
Real Estate Properties [Line Items]
Date Acquired	Jan. 15, 2016
Total Real Estate at Cost	$ 152,354
Accumulated Depreciation and Amortization	(10,991)
Total real estate, net	$ 141,363
Hardware Village | Development/Apartment
Real Estate Properties [Line Items]
Date Acquired	Aug. 26, 2016
Total Real Estate at Cost	$ 56,124
Accumulated Depreciation and Amortization	0
Total real estate, net	$ 56,124

REAL ESTATE (Properties Represe

REAL ESTATE (Properties Represented More than 10% of Company’s Total Assets) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)ft²$ / ft²	Dec. 31, 2016USD ($)
Real Estate Properties [Line Items]
Rentable Square Feet | ft²	11,100,000
Total Real Estate, Net	$ 2,966,275	$ 2,988,855
Occupancy	92.00%
500 West Madison | Assets, Total
Real Estate Properties [Line Items]
Rentable Square Feet | ft²	1,457,724
Total Real Estate, Net	$ 371,941
Percentage of Total Assets	11.60%
Annualized Base Rent	$ 34,883
Average Annualized Base Rent per sq. ft. | $ / ft²	27.80
Occupancy	86.10%

REAL ESTATE (Operating Leases)

REAL ESTATE (Operating Leases) (Narrative) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)tenant	Sep. 30, 2016USD ($)	Dec. 31, 2016USD ($)
Operating Leased Assets [Line Items]
Deferred rent recognized	$ 8,527	$ 13,943
Deferred rent receivables	69,800		$ 58,600
Incentive to Lessee	$ 7,600		5,200
Number of tenants | tenant	900
Other Liabilities
Operating Leased Assets [Line Items]
Security deposit liability	$ 11,600		$ 12,700
Maximum
Operating Leased Assets [Line Items]
Operating lease, term	14 years 3 months 18 days
Weighted Average
Operating Leased Assets [Line Items]
Operating lease, term	4 years 7 months 6 days

REAL ESTATE (Future Minimum Ren

REAL ESTATE (Future Minimum Rental Income) (Details) $ in Thousands	Sep. 30, 2017USD ($)
Real Estate [Abstract]
October 1, 2017 through December 31, 2017	$ 71,113
2,018	289,600
2,019	269,676
2,020	235,674
2,021	203,589
Thereafter	649,360
Future minimum rental income	$ 1,719,012

REAL ESTATE (Highes Tenant Indu

REAL ESTATE (Highes Tenant Industry Concentrations- Grater than 10% of Annual Base Rent) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)tenant
Concentration Risk [Line Items]
Number of Tenants	900
Finance
Concentration Risk [Line Items]
Number of Tenants	156
Annualized Base Rent | $	$ 61,946
Percentage of Annualized Base Rent	20.50%

REAL ESTATE REAL ESTATE (Geogra

REAL ESTATE REAL ESTATE (Geographic Concentration Risk) (Narrative) (Details) - Assets, Total	9 Months Ended
	Sep. 30, 2017
California
Concentration Risk [Line Items]
Concentration risk, percentage	21.00%
Texas
Concentration Risk [Line Items]
Concentration risk, percentage	16.00%
Illinois
Concentration Risk [Line Items]
Concentration risk, percentage	12.00%

TENANT ORIGINATION AND ABSORP37

TENANT ORIGINATION AND ABSORPTION COSTS, ABOVE-MARKET LEASE ASSETS AND BELOW-MARKET LEASE LIABILITIES (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Tenant Origination and Absorption Costs, Above-Market Lease Assets and Below-Market Lease Liabilities [Abstract]
Tenant Origination and Absorption Costs, Cost	$ 243,102		$ 243,102		$ 264,973
Tenant Origination and Absorption Costs, Accumulated Amortization	(110,207)		(110,207)		(99,757)
Tenant Origination and Absorption Costs, Net Amount	132,895		132,895		165,216
Tenant Origination and Absorption Costs, Amortization expense	(10,202)	$ (11,208)	(32,321)	$ (35,100)
Above-Market Lease Assets, Cost	13,576		13,576		14,383
Above-Market Lease Assets, Accumulated Amortization	(7,159)		(7,159)		(6,192)
Above-Market Lease Assets, Net Amount	6,417		6,417		8,191
Above-Market Lease Assets, Amortization expense	(527)	(718)	(1,774)	(2,186)
Below-Market Lease Liabilities, Cost	(49,401)		(49,401)		(55,438)
Below-Market Lease Liabilities, Accumulated Amortization	22,709		22,709		21,783
Below-Market Lease Liabilities, Net Amount	(26,692)		(26,692)		$ (33,655)
Below-Market Lease Liabilities, Amortization expense	$ 2,184	$ 2,474	$ 6,963	$ 9,055

INVESTMENT IN UNCONSOLIDATED 38

INVESTMENT IN UNCONSOLIDATED JOINT VENTURE (Narrative) (Details) - USD ($)	Mar. 03, 2017	Sep. 30, 2017	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Amount drawn		$ 1,898,897,000	$ 1,793,405,000
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		$ 23,100,000
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		$ 33,600,000
Equity method investments, acquisition cost		$ 1,200,000

INVESTMENT IN UNCONSOLIDATED 39

INVESTMENT IN UNCONSOLIDATED JOINT VENTURE (Balance Sheets) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Assets
Cash and cash equivalents	$ 44,575	$ 72,068	$ 51,495	$ 108,242
Total assets	3,193,281	3,182,676
Liabilities and equity
Accounts payable	71,327	56,210
Notes payable, net	1,891,442	1,783,468
Other liabilities	31,526	41,699
Total liabilities and equity	3,193,281	$ 3,182,676
Village Center Station II Joint Venture
Assets
Construction in progress	73,400
Cash and cash equivalents	1
Other assets	2,591
Total assets	75,992
Liabilities and equity
Accounts payable	9,615
Notes payable, net	23,004
Other liabilities	258
Members’ capital	43,115
Total liabilities and equity	$ 75,992

NOTES PAYABLE (Narrative) (Deta

NOTES PAYABLE (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Debt Instrument [Line Items]
Deferred financing costs	$ 7,600		$ 7,600		$ 10,000
Interest expense	15,460	$ 10,042	45,257	$ 53,948
Interest payable, current	5,300		5,300		4,300
Amortization of deferred financing costs			3,537	3,838
Interest capitalized	700	100	1,543	64
Interest expense incurred as a result of derivative instruments	400	1,300	3,100	20,500
Interest Expense
Debt Instrument [Line Items]
Amortization of deferred financing costs	1,300	$ 1,300	3,800	$ 3,800
Notes Payable
Debt Instrument [Line Items]
Deferred financing costs	7,500		7,500		9,900
Prepaid Expenses and Other Current Assets
Debt Instrument [Line Items]
Deferred financing costs	$ 100		$ 100		$ 100

NOTES PAYABLE (Schedule of Long

NOTES PAYABLE (Schedule of Long-term Debt Instruments) (Details) - USD ($)	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Total notes payable principal outstanding	$ 1,898,897,000	$ 1,793,405,000
Deferred financing costs, net	(7,455,000)	(9,937,000)
Total notes payable, net	1,891,442,000	1,783,468,000
Portfolio Loan | Secured Debt
Debt Instrument [Line Items]
Total notes payable, net	127,500,000
500 West Madison Mortgage Loan
Debt Instrument [Line Items]
Total notes payable, net	235,000,000
500 West Madison Mortgage Loan | First Non-Revolver Tranche
Debt Instrument [Line Items]
Current borrowing capacity	20,000,000
Mortgages | Town Center Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding	$ 75,000,000	75,000,000
Effective Interest Rate	2.87%
Maturity Date	Mar. 27, 2018
Mortgages | Town Center Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.85%
Mortgages | Portfolio Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding	$ 163,460,000	127,500,000
Effective Interest Rate	3.14%
Maturity Date	Jun. 1, 2019
Mortgages | Portfolio Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.90%
Mortgages | RBC Plaza Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding	$ 75,434,000	75,930,000
Effective Interest Rate	3.04%
Maturity Date	Feb. 1, 2018
Mortgages | RBC Plaza Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.80%
Mortgages | National Office Portfolio Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding	$ 170,602,000	170,602,000
Effective Interest Rate	2.84%
Maturity Date	Jul. 1, 2018
Mortgages | National Office Portfolio Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.50%
Mortgages | 500 West Madison Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding	$ 235,000,000	215,000,000
Effective Interest Rate	3.13%
Maturity Date	Dec. 16, 2018
Mortgages | 500 West Madison Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.65%
Mortgages | 222 Main Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding	$ 99,946,000	101,343,000
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	$ 50,000,000	50,000,000
Effective Interest Rate	3.18%
Maturity Date	Jun. 1, 2018
Mortgages | Anchor Centre Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.50%
Mortgages | 171 17th Street Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding	$ 85,479,000	83,778,000
Effective Interest Rate	2.83%
Maturity Date	Sep. 1, 2018
Mortgages | 171 17th Street Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.45%
Mortgages | Reston Square Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding	$ 29,800,000	23,840,000
Effective Interest Rate	3.63%
Maturity Date	Feb. 1, 2018
Mortgages | Reston Square Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.50%
Mortgages | Ten Almaden Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding	$ 66,555,000	65,853,000
Effective Interest Rate	3.43%
Maturity Date	Jan. 1, 2018
Mortgages | Ten Almaden Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.65%
Mortgages | Towers at Emeryville Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding	$ 153,524,000	145,379,000
Effective Interest Rate	3.96%
Maturity Date	Jan. 15, 2018
Loan, amount outstanding	$ 153,500,000
Unused borrowing capacity, amount	$ 21,500,000
Mortgages | Towers at Emeryville Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.75%
Mortgages | 101 South Hanley Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding	$ 40,557,000	37,502,000
Effective Interest Rate	3.75%
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	3.54%
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	$ 21,689,000	20,868,000
Effective Interest Rate	2.74%
Maturity Date	Jun. 5, 2018
Mortgages | Rocklin Corporate Center Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.50%
Mortgages | 201 17th Street Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding	$ 64,428,000	58,063,000
Effective Interest Rate	3.32%
Maturity Date	Aug. 1, 2018
Mortgages | 201 17th Street Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.40%
Mortgages | CrossPoint at Valley Forge Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding	$ 51,000,000	51,000,000
Effective Interest Rate	3.33%
Maturity Date	Sep. 1, 2022
Mortgages | CrossPoint at Valley Forge Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.50%
Mortgages | The Almaden Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding	$ 93,000,000	93,000,000
Stated percentage	4.20%
Effective Interest Rate	4.20%
Maturity Date	Jan. 1, 2022
Mortgages | Promenade I & II at Eilan Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding	$ 37,300,000	37,300,000
Effective Interest Rate	3.57%
Maturity Date	Oct. 1, 2022
Mortgages | Promenade I & II at Eilan Mortgage Loan | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.75%
Mortgages | 515 Congress Mortgage Loan
Debt Instrument [Line Items]
Total notes payable principal outstanding	$ 68,381,000	67,500,000
Effective Interest Rate	2.94%
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	2.90%
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	$ 90,248,000	76,440,000
Effective Interest Rate	3.25%
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	27,129,000
Effective Interest Rate	2.84%
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	$ 8,712,000	$ 0
Effective Interest Rate	4.49%
Maturity Date	Feb. 23, 2020
Loan, amount outstanding	$ 8,700,000
Unused borrowing capacity, amount	$ 65,300,000
Mortgages | Hardware Village Loan Facility | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	3.25%
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	36,000,000
Unused borrowing capacity, amount	$ 90,500,000
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%

NOTES PAYABLE (Schedule of Matu

NOTES PAYABLE (Schedule of Maturities of Long-term Debt) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Notes Payable [Abstract]
October 1, 2017 through December 31, 2017	$ 874
2,018	1,029,540
2,019	294,445
2,020	299,491
2,021	93,957
Thereafter	180,590
Total notes payable	$ 1,898,897	$ 1,793,405

DERIVATIVE INSTRUMENTS (Notiona

DERIVATIVE INSTRUMENTS (Notional Amount) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)investment	Dec. 31, 2016USD ($)investment
Interest Rate Swaps | Exercised at Various Dates (2016-2018)
Derivative [Line Items]
Number of Instruments | investment	2
Notional Amount | $	$ 91,500
Derivative instruments designated as hedging instruments | Interest Rate Swaps
Derivative [Line Items]
Number of Instruments | investment	6	7
Notional Amount | $	$ 508,400	$ 625,130
Weighted-Average Fix Pay Rate	1.42%
Weighted-Average Remaining Term in Years	10 months 12 days
Derivative instruments designated as hedging instruments | Interest Rate Swaps | Minimum | One-month LIBOR
Derivative [Line Items]
Reference Rate	0.86%
Derivative instruments designated as hedging instruments | Interest Rate Swaps | Maximum | One-month LIBOR
Derivative [Line Items]
Reference Rate	1.68%
Derivative instruments not designated as hedging instruments | Interest Rate Swaps
Derivative [Line Items]
Number of Instruments | investment	12	12
Notional Amount | $	$ 658,183	$ 658,183
Weighted-Average Fix Pay Rate	1.99%
Weighted-Average Remaining Term in Years	2 years 11 months 6 days
Derivative instruments not designated as hedging instruments | Interest Rate Swaps | Minimum | One-month LIBOR
Derivative [Line Items]
Reference Rate	1.39%
Derivative instruments not designated as hedging instruments | Interest Rate Swaps | Maximum | One-month LIBOR
Derivative [Line Items]
Reference Rate	2.37%
Derivative instruments not designated as hedging instruments | Interest Rate Cap
Derivative [Line Items]
Number of Instruments | investment	0	1
Notional Amount | $	$ 0	$ 147,340

DERIVATIVE INSTRUMENTS (Balance

DERIVATIVE INSTRUMENTS (Balance Sheet) (Details) $ in Thousands	Sep. 30, 2017USD ($)investmentInvestments	Dec. 31, 2016USD ($)investmentInvestments
Derivative instruments designated as hedging instruments | Interest Rate Swaps
Derivative [Line Items]
Number of Instruments	6	7
Derivative instruments designated as hedging instruments | Prepaid Expenses and Other Current Assets | Interest Rate Swaps
Derivative [Line Items]
Number of Instruments	3	1
Asset, Fair Value | $	$ 142	$ 42
Derivative instruments designated as hedging instruments | Other Liabilities | Interest Rate Swaps
Derivative [Line Items]
Number of Instruments	3	6
Liability, Fair Value | $	$ (121)	$ (2,340)
Derivative instruments not designated as hedging instruments | Interest Rate Swaps
Derivative [Line Items]
Number of Instruments	12	12
Derivative instruments not designated as hedging instruments | Interest Rate Cap
Derivative [Line Items]
Number of Instruments	0	1
Derivative instruments not designated as hedging instruments | Prepaid Expenses and Other Current Assets | Interest Rate Swaps
Derivative [Line Items]
Number of Instruments | Investments	4	4
Asset, Fair Value | $	$ 1,358	$ 1,588
Derivative instruments not designated as hedging instruments | Prepaid Expenses and Other Current Assets | Interest Rate Cap
Derivative [Line Items]
Number of Instruments	0	1
Asset, Fair Value | $	$ 0	$ 0
Derivative instruments not designated as hedging instruments | Other Liabilities | Interest Rate Swaps
Derivative [Line Items]
Number of Instruments	8	8
Liability, Fair Value | $	$ (4,579)	$ (7,388)

DERIVATIVE INSTRUMENTS (Stateme

DERIVATIVE INSTRUMENTS (Statement of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Derivative [Line Items]
Increase (decrease) in interest expense as a result of derivatives	$ 357	$ (1,342)	$ 3,104	$ 20,463
Unrealized income (losses) on derivative instruments	13	1,784	602	(6,695)
Derivative instruments designated as hedging instruments
Derivative [Line Items]
Derivatives designated as hedging instruments	253	1,363	1,717	4,252
Increase (decrease) in interest expense as a result of derivatives	253	1,363	1,717	4,252
Derivative instruments not designated as hedging instruments
Derivative [Line Items]
Increase (decrease) in interest expense as a result of derivatives	104	(2,705)	1,387	16,211
Derivative instruments not designated as hedging instruments | Interest Rate Swaps
Derivative [Line Items]
Realized loss recognized on interest rate swaps	1,108	1,040	3,966	1,398
Unrealized income (losses) on derivative instruments	(1,004)	(3,745)	(2,579)	14,810
Derivative instruments not designated as hedging instruments | Interest Rate Cap
Derivative [Line Items]
Unrealized income (losses) on derivative instruments	$ 0	$ 0	$ 0	$ 3

DERIVATIVE INSTRUMENTS (Narrati

DERIVATIVE INSTRUMENTS (Narrative) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2017USD ($)
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 ($)	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt face amount	$ 1,898,897,000	$ 1,793,405,000
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable, Value	1,891,442,000	1,783,468,000
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable, Value	$ 1,889,296,000	$ 1,775,953,000

FAIR VALUE DISCLOSURES (Assets

FAIR VALUE DISCLOSURES (Assets and Liabilities at Fair value) (Details) - Recurring Basis: - Interest Rate Swaps $ in Thousands	Sep. 30, 2017USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset derivatives	$ 1,500
Liability derivatives	(4,700)
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
Liability derivatives	0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset derivatives	1,500
Liability derivatives	(4,700)
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset derivatives	0
Liability derivatives	$ 0

RELATED PARTY TRANSACTIONS (Cos

RELATED PARTY TRANSACTIONS (Costs) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Related Party Transaction [Line Items]
Payable as of	$ 2,756		$ 2,756		$ 2,397
Administrative fees, amount paid	49	$ 51	169	$ 145
Advisor and Dealer Manager
Related Party Transaction [Line Items]
Incurred	6,830	6,382	20,271	20,467
Payable as of	2,756		2,756		2,397
Advisor and Dealer Manager | Asset management fees
Related Party Transaction [Line Items]
Expenses	6,587	6,286	19,223	18,646
Payable as of	2,158		2,158		2,126
Advisor and Dealer Manager | Reimbursement of operating expenses
Related Party Transaction [Line Items]
Expenses	59	68	255	261
Payable as of	70		70		139
Advisor and Dealer Manager | Real estate acquisition fees
Related Party Transaction [Line Items]
Expenses	0	0	0	1,473
Payable as of	0		0		0
Advisor and Dealer Manager | Acquisition fee on development project
Related Party Transaction [Line Items]
Incurred	64	28	234	87
Payable as of	355		355		121
Advisor and Dealer Manager | Acquisition fee on unconsolidated joint venture
Related Party Transaction [Line Items]
Incurred	120	0	497	0
Payable as of	173		173		0
Advisor and Dealer Manager | Asset management fee on development project
Related Party Transaction [Line Items]
Incurred	0	0	48	0
Payable as of	0		0		11
Advisor and Dealer Manager | Asset management fee on unconsolidated joint venture
Related Party Transaction [Line Items]
Incurred	0	$ 0	14	$ 0
Payable as of	$ 0		$ 0		$ 0

RELATED PARTY TRANSACTIONS (Nar

RELATED PARTY TRANSACTIONS (Narrative) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	May 29, 2015USD ($)ft²$ / ft²
KBS Capital Advisors LLC
Related Party Transaction [Line Items]
Expenses			$ 100	$ 100
KBS Capital Advisors LLC | Property Insurance Rebate
Related Party Transaction [Line Items]
Incurred			200	200
KBS Capital Advisors LLC | Legal and Professional Fees Reimbursement
Related Party Transaction [Line Items]
Incurred				100
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	$ 61	$ 59	$ 180	$ 176

SUBSEQUENT EVENTS (Distribution

SUBSEQUENT EVENTS (Distributions) (Details) - USD ($) $ / shares in Units, $ in Millions	Nov. 01, 2017	Oct. 09, 2017	Oct. 02, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 09, 2016
Subsequent Event [Line Items]
Distribution rate per share per day, declared (in dollars per share)				$ 0.00178082	$ 0.00178082	$ 0.00178082	$ 0.00178082
Dividend Declared | Most Recent Primary Offering Purchase Price
Subsequent Event [Line Items]
Common stock, purchase price per share (in dollars per share)								$ 10.63
Subsequent Event | Dividend Paid
Subsequent Event [Line Items]
Paid distributions	$ 10		$ 9.7
Subsequent Event | Dividend Declared
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		6.11%

SUBSEQUENT EVENTS (Financing) (

SUBSEQUENT EVENTS (Financing) (Details)	Nov. 03, 2017USD ($)extension	Sep. 30, 2017USD ($)	Dec. 31, 2016USD ($)
Subsequent Event [Line Items]
Term debt		$ 1,898,897,000	$ 1,793,405,000
Long-term debt		1,891,442,000	$ 1,783,468,000
Portfolio Loan Facility | Revolving Credit Facility
Subsequent Event [Line Items]
Current borrowing capacity		$ 252,500,000
Subsequent Event | Portfolio Loan Facility
Subsequent Event [Line Items]
Term	3 years
Current borrowing capacity	$ 1,010,000,000
Loan, amount outstanding	787,500,000
Additional increase	400,000,000
Incremental increase	25,000,000
Maximum borrowing capacity	$ 1,410,000,000
Number of extensions | extension	2
Extension period	12 months
Subsequent Event | Portfolio Loan Facility | One-month LIBOR
Subsequent Event [Line Items]
Interest rate	1.80%
Subsequent Event | Portfolio Loan Facility | Revolving Credit Facility
Subsequent Event [Line Items]
Loan, amount outstanding	$ 30,000,000
Maximum borrowing capacity, percentage	25.00%
Subsequent Event | Portfolio Loan Facility | Term debt
Subsequent Event [Line Items]
Term debt	$ 757,500,000
Long-term debt	$ 757,500,000
Maximum borrowing capacity, percentage	75.00%
Subsequent Event | Town Center Mortgage Loan, RBC Plaza Mortgage Loan, National Office Portfolio Mortgage Loan, 500 West Madison Mortgage Loan, Ten Almaden Mortgage Loan and Towers at Emeryville Mortgage Loan
Subsequent Event [Line Items]
Extinguishment of debt, amount	$ 776,000,000

SUBSEQUENT EVENTS (Derivative)

SUBSEQUENT EVENTS (Derivative) (Details) - Subsequent Event - Interest Rate Swaps	Nov. 03, 2017USD ($)instrument
Subsequent Event [Line Items]
Number of Instruments | instrument	3
Notional amount	$ 306,000,000
Effective from November 3, 2017 through November 1, 2022
Subsequent Event [Line Items]
Notional amount	$ 757,500,000
Fixed interest rate	3.861%
REIT Properties III
Subsequent Event [Line Items]
Number of Instruments | instrument	3
Notional amount	$ 451,500,000