PS Business Parks (PSBXP) 10-K 23 Feb 16 2015 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Feb. 15, 2016	Jun. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-K
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Registrant Name	PS BUSINESS PARKS INC/CA
Entity Central Index Key	866,368
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		27,034,073
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 1,408,830,193

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
ASSETS
Cash and cash equivalents	$ 188,912	$ 152,467
Real estate facilities, at cost:
Land	793,569	793,569
Buildings and improvements	2,215,515	2,182,993
Gross real estate investment property	3,009,084	2,976,562
Accumulated depreciation	(1,082,603)	(991,497)
Net real estate investment property	1,926,481	1,985,065
Properties held for disposition, net		25,937
Land and building held for development	6,081	24,442
Total real estate investments	1,932,562	2,035,444
Investment in unconsolidated joint venture	26,736
Rent receivable, net	2,234	2,838
Deferred rent receivable, net	28,327	26,050
Other assets	7,887	10,315
Total assets	2,186,658	2,227,114
LIABILITIES AND EQUITY
Accrued and other liabilities	76,059	68,905
Mortgage note payable	250,000	250,000
Total liabilities	$ 326,059	$ 318,905
Commitments and contingencies
PS Business Parks, Inc.'s shareholders' equity:
Preferred stock, $0.01 par value, 50,000,000 shares authorized, 36,800 and 39,800 shares issued and outstanding at December 31, 2015 and 2014, respectively	$ 920,000	$ 995,000
Common stock, $0.01 par value, 100,000,000 shares authorized, 27,034,073 and 26,919,161 shares issued and outstanding at December 31, 2015 and 2014, respectively	269	268
Paid-in capital	722,009	709,008
Cumulative net income	1,375,421	1,244,946
Cumulative distributions	(1,357,203)	(1,235,941)
Total PS Business Parks, Inc.'s shareholders' equity	1,660,496	1,713,281
Noncontrolling interests:
Common units	200,103	194,928
Total noncontrolling interests	200,103	194,928
Total equity	1,860,599	1,908,209
Total liabilities and equity	$ 2,186,658	$ 2,227,114

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Consolidated Balance Sheets [Abstract]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares issued	36,800	39,800
Preferred stock, shares outstanding	36,800	39,800
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	27,034,073	26,919,161
Common stock, shares outstanding	27,034,073	26,919,161

Consolidated Statements Of Inco

Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues:
Rental income	$ 373,135	$ 376,255	$ 359,246
Facility management fees	540	660	639
Total operating revenues	373,675	376,915	359,885
Expenses:
Cost of operations	121,224	127,371	114,831
Depreciation and amortization	105,394	110,357	108,917
General and administrative	13,582	13,639	5,312
Total operating expenses	240,200	251,367	229,060
Other income and (expense):
Interest and other income	590	372	1,485
Interest and other expense	(13,330)	(13,593)	(16,166)
Total other income and (expense)	(12,740)	(13,221)	(14,681)
Gain on sale of real estate facilities	28,235	92,373
Net income	148,970	204,700	116,144
Net income allocable to noncontrolling interests:
Noncontrolling interests - common units	18,495	30,729	12,952
Total net income allocable to noncontrolling interests	18,495	30,729	12,952
Net income allocable to PS Business Parks, Inc.:
Preferred shareholders	61,885	60,488	59,216
Restricted stock unit holders	299	329	125
Common shareholders	68,291	113,154	43,851
Total net income allocable to PS Business Parks, Inc.	130,475	173,971	103,192
Net income	$ 148,970	$ 204,700	$ 116,144
Net income per common share:
Basic	$ 2.53	$ 4.21	$ 1.77
Diluted	$ 2.52	$ 4.19	$ 1.77
Weighted average common shares outstanding:
Basic	26,973	26,899	24,732
Diluted	27,051	27,000	24,833

Consolidated Statement Of Equit

Consolidated Statement Of Equity - USD ($) $ in Thousands	Preferred Stock [Member]	Common Stock [Member]	Paid-In Capital [Member]	Cumulative Net Income [Member]	Cumulative Distributions [Member]	Total PS Business Parks, Inc.'s Shareholders' Equity [Member]	Noncontrolling Interests [Member]	Total
Balances, value at Dec. 31, 2012	$ 885,000	$ 242	$ 537,091	$ 967,783	$ (944,427)	$ 1,445,689	$ 168,572	$ 1,614,261
Balances, shares at Dec. 31, 2012	35,400	24,298,475
Issuance of preferred stock, net of issuance costs, value	$ 110,000		(3,689)			106,311		106,311
Issuance of preferred stock, net of issuance costs, shares	4,400
Issurance of common stock, net of issurance costs, value		$ 24	192,305			192,329		192,329
Issurance of common stock, net of issurance costs, shares		2,445,000
Exercise of stock options, value		$ 1	4,681			4,682		4,682
Exercise of stock options, shares		97,800
Stock compensation, net, value			(3,043)			(3,043)		(3,043)
Stock compensation, net, shares		8,547
Net income				103,192		103,192	12,952	116,144
Distributions:
Preferred stock					(59,216)	(59,216)		(59,216)
Common stock					(43,972)	(43,972)		(43,972)
Noncontrolling interests							(12,856)	(12,856)
Adjustment to noncontrolling interests in underlying operating partnership			(28,031)			(28,031)	28,031
Balances, value at Dec. 31, 2013	$ 995,000	$ 267	699,314	1,070,975	(1,047,615)	1,717,941	196,699	1,914,640
Balances, shares at Dec. 31, 2013	39,800	26,849,822
Exercise of stock options, value		$ 1	3,053			3,054		3,054
Exercise of stock options, shares		61,273
Stock compensation, net, value			8,842			8,842		8,842
Stock compensation, net, shares		8,066
Net income				173,971		173,971	30,729	204,700
Distributions:
Preferred stock					(60,488)	(60,488)		(60,488)
Common stock					(127,838)	(127,838)		(127,838)
Noncontrolling interests							(34,701)	(34,701)
Adjustment to noncontrolling interests in underlying operating partnership			(2,201)			(2,201)	2,201
Balances, value at Dec. 31, 2014	$ 995,000	$ 268	709,008	1,244,946	(1,235,941)	1,713,281	194,928	1,908,209
Balances, shares at Dec. 31, 2014	39,800	26,919,161
Redemption of preferred stock, net of issuance costs, value	$ (75,000)		2,487		(2,487)	(75,000)		(75,000)
Redemption of preferred stock, net of issuance costs, shares	(3,000)
Exercise of stock options, value		$ 1	5,088			5,089		5,089
Exercise of stock options, shares		99,178
Stock compensation, net, value			8,178			8,178		8,178
Stock compensation, net, shares		15,734
Net income				130,475		130,475	18,495	148,970
Distributions:
Preferred stock					(59,398)	(59,398)		(59,398)
Common stock					(59,377)	(59,377)		(59,377)
Noncontrolling interests							(16,072)	(16,072)
Adjustment to noncontrolling interests in underlying operating partnership			(2,752)			(2,752)	2,752
Balances, value at Dec. 31, 2015	$ 920,000	$ 269	$ 722,009	$ 1,375,421	$ (1,357,203)	$ 1,660,496	$ 200,103	$ 1,860,599
Balances, shares at Dec. 31, 2015	36,800	27,034,073

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net income	$ 148,970	$ 204,700	$ 116,144
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	105,394	110,357	108,917
In-place lease adjustment	(1,251)	(901)	118
Tenant improvement reimbursements net of lease incentives	(1,861)	(1,580)	(1,414)
Gain on sale of real estate facilities	(28,235)	(92,373)
Stock compensation	9,245	9,580	(2,532)
Decrease (increase) in receivables and other assets	(989)	792	(247)
Increase (decrease) in accrued and other liabilities	6,799	(2,804)	1,308
Total adjustments	89,102	23,071	106,150
Net cash provided by operating activities	238,072	227,771	222,294
Cash flows from investing activities:
Capital expenditures to real estate facilities	(43,654)	(51,786)	(58,175)
Capital expenditures to land and building held for development	(2,809)	(2,189)	(752)
Investments in unconsolidated joint venture	(5,566)
Acquisition of real estate facilities		(45,021)	(112,955)
Acquisition of land held for development			(990)
Proceeds from sale of real estate facilities	55,160	212,184
Net cash provided by (used in) investing activities	3,131	113,188	(172,872)
Cash flows from financing activities:
Proceeds from the exercise of stock options	5,089	3,054	4,682
Redemption of preferred stock	(75,000)
Distributions paid to preferred shareholders	(59,398)	(60,488)	(59,216)
Distributions paid to common shareholders	(59,377)	(127,838)	(43,972)
Distributions paid to noncontrolling interests - common units	(16,072)	(34,701)	(12,856)
Borrowings on credit facility			115,000
Note receivable from affiliate			(100,000)
Repayment of borrowings on credit facility			(115,000)
Repayment of borrowings on term loan debt			(200,000)
Repayment of note receivable from affiliate			100,000
Principal payments on mortgage notes payable			(47)
Repayment of mortgage notes payable			(18,055)
Net proceeds from the issuance of preferred stock			106,311
Net proceeds from the issuance of common stock			192,329
Net cash used in financing activities	(204,758)	(219,973)	(30,824)
Net increase in cash and cash equivalents	36,445	120,986	18,598
Cash and cash equivalents at the beginning of the period	152,467	31,481	12,883
Cash and cash equivalents at the end of the period	188,912	152,467	31,481
Supplemental disclosures:
Interest paid	14,197	14,200	15,934
Adjustment to noncontrolling interests in underlying operating partnership:
Noncontrolling interests - common units	2,752	2,201	28,031
Paid-in capital	(2,752)	$ (2,201)	(28,031)
Non-cash distributions related to the redemption of preferred stock:
Paid-in capital	2,487
Cumulative distributions	(2,487)
Transfer to investment in unconsolidated joint venture:
Land and building held For development	(21,170)
Investment in unconsolidated joint venture	$ 21,170
Transfer to land and building held for development:
Land			(5,927)
Buildings and improvements			(10,270)
Accumulated depreciation			778
Land and building held for development			$ 15,419

Organization And Description Of

Organization And Description Of Business	12 Months Ended
	Dec. 31, 2015
Organization And Description Of Business [Abstract]
Organization And Description Of Business	1. Organization and description of business Organization PS Business Parks, Inc. (“PSB”) was incorporated in the state of California in 1990. As of December 31, 2015 , PSB owned 77.8 % of the common partnership units of PS Business Parks, L.P. (the “Operating Partnership”). The remaining common partnership units are owned by Public Storage (“PS”). PSB, as the sole general partner of the Operating Partnership, has full, exclusive and complete responsibility and discretion in managing and controlling the Operating Partnership. PSB and its subsidiaries, including the Operating Partnership are collectively referred to as the “Company.” Assuming issuance of the Company’s common stock upon redemption of its partnership units, PS would own 42. 1 % (or 14.5 million shares) of the outstanding shares of the Company’s common stock. Description of business The Company is a fully-integrated, self-advised and self-managed real estate investment trust (“REIT”) that owns, operates, acquires and develops commercial properties, primarily multi-tenant flex, office and industrial space. As of December 31, 2015 , the Company owned and operated 28.0 million rentable square feet of commercial space in six states. The Company also manages 813 ,000 rentable square feet on behalf of PS. References to the number of properties or square footage are unaudited and outside the scope of the Company’s independent registered public accounting firm's audit of the Company’s financial statements in accordance with the standards of the Public Company Accounting Oversight Board (United States).

Summary Of Significant Accounti

Summary Of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Summary Of Significant Accounting Policies [Abstract]
Summary Of Significant Accounting Policies	2. Summary of significant accounting policies Basis of presentation The accompanying consolidated financial statements include the accounts of PSB and the Operating Partnership. All significant inter-company balances and transactions have been eliminated in the consolidated financial statements. The financial statements are presented on an accrual basis in accordance with U.S. generally accepted accounting principles (“GAAP”). Consolidation and Equity Method of Accounting The Company accounts for an investment in a joint venture that it has significant influence over, but does not control, using the equity method of accounting eliminating intra-entity profits and losses as if the joint venture were a consolidated subsidiary. Noncontrolling interests The Company's noncontrolling interests are reported as a component of equity separate from the parent’s equity. Purchases or sales of equity interests that do not result in a change in control are accounted for as equity transactions. In addition, net income attributable to the noncontrolling interests is included in consolidated net income on the face of the income statement and, upon a gain or loss of control, the interests purchased or sold, as well as any interests retained, are recorded at fair value with any gain or loss recognized in earnings. At the end of each reporting period, the Company determines the amount of equity (book value of net assets) which is allocable to the noncontrolling interests based upon the ownership interest, and an adjustment is made to the noncontrolling interests, with a corresponding adjustment to paid-in capital, to reflect the noncontrolling interests’ equity interest in the Company. Use of estimates The preparation of the consolidated financial statements in conformity with GAAP principle requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from these estimates. Allowance for doubtful accounts The Company monitors the collectability of its receivable balances including the deferred rent receivable on an ongoing basis. Based on these reviews, the Company maintains an allowance for doubtful accounts for estimated losses resulting from the possible inability of tenants to make contractual rent payments to the Company. A provision for doubtful accounts is recorded during each period. The allowance for doubtful accounts is netted against tenant and other receivables on the consolidated balance sheets. Tenant receivables are net of an allowance for uncollectible accounts totaling $ 400,000 at December 31, 2015 and 2014 . Deferred rent receivable is net of an allowance for uncollectible accounts totaling $909,000 and $841,000 at December 31, 2015 and 2014 , respectively. Financial instruments The methods and assumptions used to estimate the fair value of financial instruments are described below. The Company has estimated the fair value of financial instruments using available market information and appropriate valuation methodologies. Considerable judgment is required in interpreting market data to develop estimates of market value. Accordingly, estimated fair values are not necessarily indicative of the amounts that could be realized in current market exchanges. The Company determines the estimated fair value of financial assets and liabilities utilizing a hierarchy of valuation techniques based on whether the inputs to a fair value measurement are considered to be observable or unobservable in a marketplace. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect market assumptions. This hierarchy requires the use of observable market data when available. The following is the fair value hierarchy: · Level 1 —quoted prices for identical instruments in active markets; · 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 —fair value measurements derived from valuation techniques in which one or more significant inputs or significant value drivers are unobservable. Financial assets that are exposed to credit risk consist primarily of cash and cash equivalents and receivables. The Company considers all highly liquid investments with a remaining maturity of three months or less at the date of purchase to be cash equivalents. Cash and cash equivalents, which consist primarily of money market investments, are only invested in entities with an investment grade rating. Receivables are comprised of balances due from a large number of customers. Balances that the Company expects to become uncollectible are reserved for or written off. Due to the short period to maturity of the Company’s cash and cash equivalents, accounts receivable, other assets and accrued and other liabilities, the carrying values as presented on the consolidated balance sheets are reasonable estimates of fair value. Carrying values of the Company’s mortgage note payable and unsecured credit facility approximate fair value. The characteristics of these financial instruments, market data and other comparative metrics utilized in determining these fair values are “Level 2” inputs. Real estate facilities Real estate facilities are recorded at cost. Costs related to the renovation or improvement of the properties are capitalized. Expenditures for repairs and maintenance are expensed as incurred. Expenditures that are expected to benefit a period greater than two years and exceed $ 2,000 are capitalized and depreciated over their estimated useful life. Buildings and improvements are depreciated using the straight-line method over their estimated useful lives, which generally range from five to 30 years. Transaction costs, which include tenant improvements and lease commissions, in excess of $ 1,000 for leases with terms greater than one year are capitalized and depreciated over their estimated useful lives. Transaction costs less than $ 1,000 or for leases of one year or less are expensed as incurred. Land and building held for development Property taxes, insurance, interest and costs essential to the development of property for its intended use are capitalized during the period of development. Upon classification of an asset as held for development, depreciation of the asset is ceased. Properties held for disposition An asset is classified as an asset held for disposition when it meets certain requirements, which include, among other criteria, the approval of the sale of the asset, the marketing of the asset for sale and the expectation by the Company that the sale will likely occur within the next 12 months. Upon classification of an asset as held for disposition, depreciation of the asset is ceased, and the net book value of the asset is included on the balance sheet as properties held for disposition. Intangible assets/liabilities Intangible assets and liabilities include above-market and below-market in-place lease values of acquired properties based on the present value (using an interest rate which reflects the risks associated with the leases acquired) of the difference between (i) the contractual amounts to be paid pursuant to the in-place leases and (ii) management’s estimate of fair market lease rates for the corresponding in-place leases, measured over a period equal to the remaining non-cancelable term of the lease. The capitalized above-market and below-market lease values (included in other assets and accrued liabilities in the accompanying consolidated balance sheets) are amortized to rental income over the remaining non-cancelable terms of the respective leases. The Company recorded a net increase in rental income of $1.3 million and $901,000 during the years end December 31, 2015 and 2014 , respectively, related to the amortization of net intangible liabilities resulting from the above-market and below-market lease values. The Company recorded net reductions to rental income of $118,000 during the year ended December 31, 2013 tied to the amortization of net intangible assets resulting from the above-market and below-market lease values. As of December 31, 2015 , the value of in-place leases resulted in net intangible assets of $ 1. 7 million, net of $ 8. 6 million of accumulated amortization with a weighted average amortization period of 8. 7 years and net intangible liabilities of $ 1. 8 million, net of $ 9. 0 million of accumulated amortization with a weighted average amortization period of 5. 4 years. As of December 31, 2014 , the value of in-place leases resulted in net intangible assets of $ 2. 5 million, net of $ 7. 8 million of accumulated amortization and net intangible liabilities of $ 3. 9 million, net of $ 6. 9 million of accumulated amortization. Evaluation of asset impairment The Company evaluates its assets used in operations for impairment by identifying indicators of impairment and by comparing the sum of the estimated undiscounted future cash flows for each asset to the asset’s carrying value. When indicators of impairment are present and the sum of the estimated undiscounted future cash flows is less than the carrying value of such asset, an impairment loss is recorded equal to the difference between the asset’s current carrying value and its value based on discounting its estimated future cash flows. In addition, the Company evaluates its assets held for disposition for impairment. Assets held for disposition are reported at the lower of their carrying value or fair value, less cost of disposition. At December 31, 2015 , the Company did not consider any assets to be impaired. Asset impairment due to casualty loss It is the Company’s policy to record as a casualty loss or gain, in the period the casualty occurs, the differential between (a) the book value of assets destroyed and (b) any insurance proceeds that the Company expects to receive in accordance with its insurance contracts. Potential proceeds from insurance that are subject to any uncertainties, such as interpretation of deductible provisions of the governing agreements, the estimation of costs of restoration, or other such items, are treated as contingent proceeds and not recorded until the uncertainties are satisfied. For the years ended December 31, 2015 , 2014 and 2013 no material casualty losses were incurred. Stock compensation All share-based payments to employees, including grants of employee stock options, are recognized as stock compensation in the Company’s income statement based on their grant date fair values. See Note 11. Revenue and expense recognition The Company must meet four basic criteria before revenue can be recognized: persuasive evidence of an arrangement exists; the delivery has occurred or services have been rendered; the fee is fixed or determinable; and collectability is reasonably assured. All leases are classified as operating leases. Rental income is recognized on a straight-line basis over the terms of the leases. Straight-line rent is recognized for all tenants with contractual fixed increases in rent that are not included on the Company’s credit watch list. Deferred rent receivable represents rental revenue recognized on a straight-line basis in excess of billed rents. Reimbursements from tenants for real estate taxes and other recoverable operating expenses are recognized as rental income in the period the applicable costs are incurred. Property management fees are recognized in the period earned. Costs incurred in connection with leasing (primarily tenant improvements and lease commissions) are capitalized and amortized over the lease period. Gains from sales of real estate facilities The Company recognizes gains from sales of real estate facilities at the time of sale using the full accrual method, provided that various criteria related to the terms of the transactions and any subsequent involvement by the Company with the properties sold are met. If the criteria are not met, the Company defers the gains and recognizes them when the criteria are met or uses the installment or cost recovery methods as appropriate under the circumstances. General and administrative expenses General and administrative expenses include executive and other compensation, office expenses, professional fees, acquisition transaction costs, state income taxes and other such administrative items. Income taxes The Company has qualified and intends to continue to qualify as a REIT, as defined in Section 856 of the Internal Revenue Code of 1986, as amended. As a REIT, the Company is not subject to federal income tax to the extent that it distributes its REIT taxable income to its shareholders. A REIT must distribute at least 90 % of its taxable income each year. In addition, REITs are subject to a number of organizational and operating requirements. The Company may be subject to certain state and local taxes on its income and property and to federal income and excise taxes on its undistributed taxable income. The Company believes it met all organization and operating requirements to maintain its REIT status during 2015 , 2014 and 2013 and intends to continue to meet such requirements. Accordingly, no provision for income taxes has been made in the accompanying consolidated financial statements. The Company can recognize a tax benefit only if it is “more likely than not” that a particular tax position will be sustained upon examination or audit. To the extent that the “more likely than not” standard has been satisfied, the benefit associated with a position is measured as the largest amount that is greater than 50 % likely of being recognized upon settlement. As of December 31, 2015 , the Company did not recognize any tax benefit for uncertain tax positions. Accounting for preferred equity issuance costs The Company records issuance costs as a reduction to paid-in capital on its balance sheet at the time the preferred securities are issued and reflects the carrying value of the preferred equity at the stated value. Such issuance costs are recorded as non-cash preferred equity distributions at the time the Company notifies the holders of preferred stock of its intent to redeem such shares. Net income allocation Net income was allocated as follows for the years ended December 31, (in thousands) : 2015 2014 2013 Net income allocable to noncontrolling interests: Noncontrolling interests — common units $ 18,495 $ 30,729 $ 12,952 Total net income allocable to noncontrolling interests 18,495 30,729 12,952 Net income allocable to PS Business Parks, Inc.: Preferred shareholders: Distributions to preferred shareholders 59,398 60,488 59,216 Non-cash distributions related to the redemption of preferred stock 2,487 — — Total net income allocable to preferred shareholders 61,885 60,488 59,216 Restricted stock unit holders 299 329 125 Common shareholders 68,291 113,154 43,851 Total net income allocable to PS Business Parks, Inc. 130,475 173,971 103,192 Net income $ 148,970 $ 204,700 $ 116,144 Net income per common share Per share amounts are computed using the number of weighted average common shares outstanding. “Diluted” weighted average common shares outstanding includes the dilutive effect of stock options and restricted stock units under the treasury stock method. “Basic” weighted average common shares outstanding excludes such effect. The Company's restricted stock units are participating securities and are included in the computation of basic and diluted weighted average common shares outstanding. The Company’s restricted stock unit holders are paid non-forfeitable dividends in excess of the expense recorded which results in a reduction in net income allocable to common shareholders and unit holders. Earnings per share has been calculated as follows for the years ended December 31, (in thousands, except per share amounts): 2015 2014 2013 Net income allocable to common shareholders $ 68,291 $ 113,154 $ 43,851 Weighted average common shares outstanding: Basic weighted average common shares outstanding 26,973 26,899 24,732 Net effect of dilutive stock compensation — based on treasury stock method using average market price 78 101 101 Diluted weighted average common shares outstanding 27,051 27,000 24,833 Net income per common share — Basic $ 2.53 $ 4.21 $ 1.77 Net income per common share — Diluted $ 2.52 $ 4.19 $ 1.77 Options to purchase 32,000 , 16,000 and 14,000 shares for the years ended December 31, 2015 , 2014 and 2013 , respectively, were not included in the computation of diluted net income per share because such options were considered anti-dilutive. Segment reporting The Company views its operations as one segment. Reclassifications Certain reclassifications have been made to the consolidated financial statements for 2014 and 2013 in order to conform to the 2015 presentation. Recently issued accounting standards In May, 2014, the FASB issued new accounting guidance which amended the existing accounting standards for revenue recognition. The new accounting guidance establishes principles for recognizing revenue upon the transfer of promised goods or services to customers, in an amount that reflects the expected consideration received in exchange for those goods or services. This guidance is currently effective for the Company’s fiscal year beginning January 1, 2018. Early adoption is permitted for the Company’s fiscal year beginning January 1, 2017. The amendment allows for full retrospective adoption applied to all periods presented or modified retrospective adoption with the cumulative effect of initially applying the standard recognized at the date of initial application. The Company is currently in the process of evaluating the impact of adoption of the new accounting guidance on its consolidated financial statements.

Real Estate Facilities

Real Estate Facilities	12 Months Ended
	Dec. 31, 2015
Real Estate Facilities [Abstract]
Real Estate Facilities	3. Real estate facilities The activity in real estate facilities for the years ended December 31, 2015 , 2014 and 2013 is as follows (in thousands) : Buildings and Accumulated Land Improvements Depreciation Total Balances at December 31, 2012 $ 738,421 $ 2,005,943 $ (811,045) $ 1,933,319 Acquisition of real estate facilities 39,667 76,943 — 116,610 Capital expenditures — 60,228 — 60,228 Disposals — (15,391) 15,391 — Depreciation and amortization — — (108,917) (108,917) Transfer to properties sold — (1,466) 7,604 6,138 Transfer to land and building held for development (5,927) (10,270) 778 (15,419) Balances at December 31, 2013 772,161 2,115,987 (896,189) 1,991,959 Acquisition of real estate facilities 21,408 24,890 — 46,298 Capital expenditures — 54,462 — 54,462 Disposals — (10,587) 10,587 — Depreciation and amortization — — (110,357) (110,357) Transfer to properties sold — (1,759) 4,462 2,703 Balances at December 31, 2014 793,569 2,182,993 (991,497) 1,985,065 Capital expenditures — 46,777 — 46,777 Disposals — (13,990) 13,990 — Depreciation and amortization — — (105,394) (105,394) Transfer to properties sold — (265) 298 33 Balances at December 31, 2015 $ 793,569 $ 2,215,515 $ (1,082,603) $ 1,926,481 The unaudited basis of real estate facilities for federal income tax purposes was approximately $1. 9 billion at December 31, 2015 . The Company had approximately 21.7% of its properties, in terms of net book value, encumbered by mortgage debt at December 31, 2015 . The purchase price of acquired properties is recorded to land, buildings and improvements (including tenant improvements, unamortized lease commissions, acquired in-place lease values, and tenant relationships, if any) and intangible assets and liabilities associated with the value of above-market and below-market leases based on their respective estimated fair values. Acquisition-related costs are expensed as incurred. In determining the fair value of the tangible assets of the acquired properties, management considers the value of the properties as if vacant as of the acquisition date. Management must make significant assumptions in determining the value of assets acquired and liabilities assumed. Using different assumptions in the recording of the purchase cost of the acquired properties would affect the timing of recognition of the related revenue and expenses. Amounts recorded to land are derived from comparable sales of land within the same region. Amounts recorded to buildings and improvements, tenant improvements and unamortized lease commissions are based on current market replacement costs and other market information. The amount recorded to acquired in-place leases is determined based on management’s assessment of current market conditions and the estimated lease-up periods for the respective spaces. On December 30, 2014 , the Company acquired Charcot Business Park II, an eight -building, 119,000 square foot multi-tenant flex park in San Jose, California, for $ 16.0 million. The park is contiguous to the Company’s existing 164,000 square foot Charcot Business Park. On November 3, 2014 , the Company acquired a 246,000 square foot multi-tenant industrial building in Austin, Texas, for a purchase price of $ 10.6 million. On August 21, 2014 , the Company acquired a 145,000 square foot multi-tenant flex park consisting of six single-story buildings located in Dallas, Texas, for a purchase price of $ 5.1 million. On July 28, 2014 , the Company acquired a 19,000 square foot building in Dallas, Texas, for $ 1.1 million. The flex building is located in the Company’s 389,000 square foot Arapaho Business Park. On July 24, 2014 , the Company acquired a 149,000 square foot building in Miami, Florida, for $ 12.7 million. The building is located within the Company’s 3.3 million square foot Miami Industrial Commerce Center. The Company incurred and expensed acquisition transaction costs of $ 350,000 for the year ended December 31, 2014. On December 20, 2013 , the Company acquired Bayshore Corporate Center, an eight -building, 340,000 square foot, office park in San Mateo, California, for $60.5 million . On November 8, 2013 , the Company acquired nine multi-tenant flex buildings in the Valwood submarket of Dallas, Texas, aggregating 245,000 square feet for $12.4 million . On October 15, 2013 , the Company acquired four multi-tenant flex parks along with a four - acre parcel of land aggregating 559,000 square feet of single-story flex buildings located in Dallas, Texas, for a purchase price of $ 27. 9 million. On July 26, 2013 , the Company acquired a 389,000 square foot multi-tenant flex park consisting of 18 single-story buildings located in Dallas, Texas, for a purchase price of $14.8 million. The Company incurred and expensed acquisition transaction costs of $ 854,000 for the year ended December 31, 2013. The Company did not acquire any assets or assume any liabilities during the year ended December 31, 2015. The following table summarizes the assets acquired and liabilities assumed for the years ended December 31, (in thousands) : 2014 2013 Land $ 21,408 $ 39,667 Land held for development — 990 Buildings and improvements 24,890 76,943 Above-market in-place lease value — 403 Below-market in-place lease value (666) (2,428) Total purchase price 45,632 115,575 Net operating assets acquired and liabilities assumed (611) (1,630) Total cash paid $ 45,021 $ 113,945 On September 28, 2015 , the Company completed the sale of McKellips Business Park located in Tempe, Arizona, aggregating 23,000 square feet, for net proceeds of $1.3 million, which resulted in a gain of $759,000 . In July, 2015 , the Company completed the sale of two business parks located in Sacramento, California, for net proceeds of $29.3 million, which resulted in a gain of $15.0 million. On July 24, 2015 , the Company disposed of North Pointe Business Park, which consists of five multi-tenant flex buildings aggregating 213,000 square feet. On July 31, 2015 , the Company disposed of Northgate Business Park, which consists of 12 multi-tenant flex buildings comprising 154,000 square feet. On February 27, 2015 , as part of an eminent domain process with the Central Puget Sound Regional Transit Authority, the Company sold five buildings, aggregating 82,000 square feet, at the Company’s Overlake Business Park located in Redmond, Washington, for $13.9 million, which resulted in a gain of $4.8 million. On February 13, 2015 , the Company completed the sale of Milwaukie Business Park located in Milwaukie, Oregon, for net proceeds of $10.6 million, which resulted in a gain of $7.6 million. The park consists of six multi-tenant flex buildings aggregating 102,000 square feet. The assets sold in 2015, aggregating 574,000 square feet, have been classified as properties held for disposition as of December 31, 2014. On November 21, 2014 , the Company completed the sale of three business parks, consisting of 42 buildings aggregating 656,000 square feet, located in Phoenix, Arizona, for net proceeds of $ 52.2 million, resulting in a gain of $ 29.6 million. On October 1, 2014 , the Company completed the sale of two business parks, Cornell Oaks Corporate Center and Creekside Corporate Park along with 11.5 acres of adjacent land, located in Beaverton, Oregon, for net proceeds of $ 159. 9 million, resulting in a gain of $ 62.8 million. The parks consist of 18 buildings aggregating 1.2 million square feet.

Investment in Unconsolidated Jo

Investment in Unconsolidated Joint Venture	12 Months Ended
	Dec. 31, 2015
Investment in Unconsolidated Joint Venture [Abstract]
Investment in Unconsolidated Joint Venture	4 . Investment in unconsolidated joint venture In 2013, the Company entered into a joint venture, in which it has a 95.0% economic interest, known as Amherst JV LLC, (the “Joint Venture”) with an unrelated real estate development company for the purpose of developing a 395 -unit multi-family building on a five -acre site within its Westpark Business Park in Tysons, Virginia. The Company contributed the site, along with capitalized improvements, to the Joint Venture on October 5, 2015 and has reflected the land and costs to date as investment in unconsolidated joint venture as of December 31, 2015. Previously the land and costs were reflected in land and building held for development. The Company’s partner in the Joint Venture will serve as the managing member, with mutual consent from both the Company and the managing member required for all significant decisions. As such, the Company accounts for its investment in the Joint Venture using the equity method. Demolition, site preparation and construction commenced in October, 2015. The Company’s investment in unconsolidated joint venture was $ 26. 7 million at December 31, 2015. From January 1, 2015 through October 5, 2015, the Company capitalized $2. 8 million of development costs, which included $813,000 of capitalized interest. Subsequent to October 5, 2015 through December 31, 2015, the Company made cash contributions of $ 5. 2 million to the Joint Venture and capitalized $346,000 of interest on its investment in the Joint Venture. The land and capitalized development costs were $18. 4 million at December 31, 2014. For the year ended De cember 31, 2014, the Company capitalized $ 2.2 million of development costs, which included $ 944,000 of capitalized interest.

Leasing Activity

Leasing Activity	12 Months Ended
	Dec. 31, 2015
Leasing Activity [Abstract]
Leasing Activity	5 . Leasing activity The Company leases space in its real estate facilities to tenants primarily under non-cancelable leases generally ranging from one to 10 years. Future minimum rental revenues, excluding recovery of operating expenses under these leases, are as follows as of December 31, 2015 (in thousands) : 2016 $ 265,816 2017 201,788 2018 146,980 2019 99,678 2020 63,771 Thereafter 122,574 Total $ 900,607 In addition to minimum rental payments, certain tenants reimburse the Company for their pro rata share of specified operating expenses. Such reimbursements amounted to $78. 9 million, $80. 7 million and $75. 1 million for the years ended December 31, 2015 , 2014 and 2013 , respectively. These amounts are included as rental income in the accompanying consolidated statements of income. Leases accounting for 2. 9 % of total leased square footage are subject to termination options, of which 1. 6 % of total leased square footage have termination options exercisable through December 31, 2016 (unaudited). In general, these leases provide for termination payments should the termination options be exercised. The future minimum rental revenues in the above table assume such options are not exercised.

Bank Loans

Bank Loans	12 Months Ended
	Dec. 31, 2015
Bank Loans [Abstract]
Bank Loans	6 . Bank loans The Company has a line of credit (the “Credit Facility”) with Wells Fargo Bank, National Association (“Wells Fargo”). The Credit Facility has a borrowing limit of $ 250.0 million and expires May 1, 2019 . The rate of interest charged on borrowings is based on the London Interbank Offered Rate (“LIBOR”) plus 0.875 % to LIBOR plus 1.70 % depending on the Company’s credit ratings. Currently, the Company’s rate under the Credit Facility is LIBOR plus 0. 875 %. In addition, the Company is required to pay an annual facility fee ranging from 0.125 % to 0.30 % of the borrowing limit depending on the Company’s credit ratings (currently 0.1 25 %). The Company had no balance outstanding on the Credit Facility at December 31, 2015 and 2014 . The Company had $ 769,000 and $ 1.0 million of unamortized commitment fees as of December 31, 2015 and 2014 , respectively. The Credit Facility requires the Company to meet certain covenants, all of which the Company was in compliance with at December 31, 2015 . Interest on outstanding borrowings is payable monthly . The Company had a term loan with Wells Fargo (the “Term Loan”) in the amount of $ 250.0 million that was scheduled to mature on December 31, 2014 . The Term Loan was repaid in full in November, 2013 . Interest under the Term Loan was accrued based on an applicable rate ranging from LIBOR plus 1.15 % to LIBOR plus 2.25 % depending on the Company’s credit ratings. During 2013, the Company’s rate under the Term Loan was LIBOR plus 1.20 %. The Company had $ 383,000 of unamortized commitment fees as of December 31, 2012 and amortized such amount in full in 2013 as a result of the repayment.

Mortgage Note Payable

Mortgage Note Payable	12 Months Ended
	Dec. 31, 2015
Mortgage Note Payable [Abstract]
Mortgage Note Payable	7 . Mortgage note payable The Company has a $250.0 million mortgage note payable with a fixed interest rate of 5.45 %, secured by 4.8 million square feet of commercial properties with a net book value of $ 417. 7 million at December 31, 2015. The interest is payable monthly with a maturity date of December 1, 2016 , prepayable without penalty on June 1, 2016 . In January, 2013 , the Company repaid two mortgage notes payable totaling $18.1 million with a combined stated interest rate of 5.60% .

Noncontrolling Interests

Noncontrolling Interests	12 Months Ended
	Dec. 31, 2015
Noncontrolling Interests [Abstract]
Noncontrolling Interests	8 . Noncontrolling interests As described in Note 2, the Company reports noncontrolling interests within equity in the consolidated financial statements, but separate from the Company’s shareholders’ equity. In addition, net income allocable to noncontrolling interests is shown as a reduction from net income in calculating net income allocable to common shareholders. Common partnership units The Company presents the accounts of PSB and the Operating Partnership on a consolidated basis. Ownership interests in the Operating Partnership that can be redeemed for common stock, other than PSB’s interest, are classified as noncontrolling interests — common units in the consolidated financial statements. Net income allocable to noncontrolling interests — common units consists of the common units’ share of the consolidated operating results after allocation to preferred units and shares. Beginning one year from the date of admission as a limited partner (common units) and subject to certain limitations described below, each limited partner other than PSB has the right to require the redemption of its partnership interest. A limited partner (common units) that exercises its redemption right will receive cash from the Operating Partnership in an amount equal to the market value (as defined in the Operating Partnership Agreement) of the partnership interests redeemed. In lieu of the Operating Partnership redeeming the common units for cash, PSB, as general partner, has the right to elect to acquire the partnership interest directly from a limited partner exercising its redemption right, in exchange for cash in the amount specified above or by issuance of one share of PSB common stock for each unit of limited partnership interest redeemed. A limited partner (common units) cannot exercise its redemption right if delivery of shares of PSB common stock would be prohibited under the applicable articles of incorporation, or if the general partner believes that there is a risk that delivery of shares of common stock would cause the general partner to no longer qualify as a REIT, would cause a violation of the applicable securities laws, or would result in the Operating Partnership no longer being treated as a partnership for federal income tax purposes. On December 30, 2014, the Company paid a one-time special cash dividend of $ 2.75 per share along with the fourth quarter regular dividend of $ 0.50 per share. Holders of the common partnership units received the same distribution. At December 31, 2015 , there were 7,305,355 common units owned by PS, which are accounted for as noncontrolling interests. Combined with PS’s existing common stock ownership, on a fully converted basis, PS has a combined ownership of 42.1 % (or 14.5 million shares) of the Company’s common equity.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2015
Related Party Transactions [Abstract]
Related Party Transactions	9 . Related party transactions The Operating Partnership manages industrial, office and retail facilities for PS. These facilities, all located in the United States, operate under the “Public Storage” or “PS Business Parks” names. The PS Business Parks name and logo are owned by PS and licensed to the Company under a non-exclusive, royalty-free license agreement. The license can be terminated by either party for any reason with six months written notice. Under the property management contract with PS, the Operating Partnership is compensated based on a percentage of the gross revenues of the facilities managed. Under the supervision of the property owners, the Operating Partnership coordinates rental policies, rent collections, marketing activities, the purchase of equipment and supplies, maintenance activities, and the selection and engagement of vendors, suppliers and independent contractors. In addition, the Operating Partnership assists and advises the property owners in establishing policies for the hire, discharge and supervision of employees for the operation of these facilities, including property managers and leasing, billing and maintenance personnel. The property management contract with PS is for a seven -year term with the agreement automatically extending for an additional one -year period upon each one-year anniversary of its commencement (unless cancelled by either party). Either party can give notice of its intent to cancel the agreement upon expiration of its current term. Management fee revenues under this contract were $ 540,000 , $660,000 and $639,000 for the years ended December 31, 2015 , 2014 and 2013 , respectively. PS also provides property management services for the self-storage component of two assets owned by the Company. These self-storage facilities, located in Palm Beach County, Florida, operate under the “Public Storage” name. Under the property management contract, PS is compensated based on a percentage of the gross revenues of th e facilities managed. Under the supervision of the Company, PS coordinates rental policies, rent collections, marketing activities, the purchase of equipment and supplies, maintenance activities, and the selection and engagement of vendors, suppliers and independent contractors. In addition, PS is responsible for establishing the policies for the hire, discharge and supervision of employees for the operation of these facilities, including on-site managers, assistant managers and associate managers. Either the Company or PS can cancel the property management contract upon 60 days’ notice. Management fee expenses under the contract were $ 79,000 , $ 70,000 and $ 59,000 for the years ended December 31, 2015 , 2014 and 2013 , respectively. Pursuant to a cost sharing and administrative services agreement, the Company shares costs with PS for certain administrative services and rental of corporate office space, which are allocated to PS in accordance with a methodology intended to fairly allocate those costs. These costs totaled $469,000 , $451,000 and $432,000 for the years ended December 31, 2015 , 2014 and 2013 , respectively. The Company had net amounts due from PS of $ 57,000 and $166,000 at December 31, 2015 and 2014, respectively, for these contracts, as well as for certain operating expenses paid by the Company on behalf of PS. Concurrent with the Company’s public offering of common stock in 2013, as discussed in Note 1 0, the C ompany sold 950,000 shares of common stock at the public offering price to PS for net proceeds of $ 75.3 million. During 2013, the Company sold to PS its ownership interest in STOR-Re Mutual Insurance Company, Inc. (“STOR-Re”) for $ 1.1 million, representing a 4.0 % ownership interest, and accordingly, the Company recorded a gain on sale of the ownership interest of such amount as interest and other income. As of December 31, 2013, the Company had no ownership interest in STOR-Re. On October 1, 2013, PS borrowed $ 100.0 million from the Company pursuant to the terms of a term loan agreement. The loan, which could be repaid without penalty at any point prior to its maturity date of November 29, 2013 , was repaid in full on October 18, 2013 . Interest on the loan was at a rate of 1.3 88 % per annum. The loan was funded, in part, with borrowings on the Credit Facility. Interest income, under this note receivable, was $ 66,000 for the year ended December 31, 2013.

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2015
Shareholders' Equity [Abstract]
Shareholders' Equity	10 . Shareholders’ equity Preferred stock As of December 31, 2015 and 2014 , the Company had the following series of preferred stock outstanding: December 31, 2015 December 31, 2014 Earliest Potential Dividend Shares Amount Shares Amount Series Issuance Date Redemption Date Rate Outstanding (in thousands) Outstanding (in thousands) Series S January, 2012 January, 2017 6.450% 9,200 $ 230,000 9,200 $ 230,000 Series T May, 2012 May, 2017 6.000% 14,000 350,000 14,000 350,000 Series U September, 2012 September, 2017 5.750% 9,200 230,000 9,200 230,000 Series V March, 2013 March, 2018 5.700% 4,400 110,000 4,400 110,000 Series R October, 2010 October, 2015 6.875% — — 3,000 75,000 Total 36,800 $ 920,000 39,800 $ 995,000 On October 15, 2015, the Company completed the redemption of its 6.875% Cumulative Preferred Stock, Series R, at its par value of $75.0 million. The Company reported the non-cash distributions of $2.5 million, representing the original issuance costs, as a reduction of net income allocable to common shareholders and unit holders for the year ended December 31, 2015. On March 14, 2013 , the Company issued $ 110.0 million or 4.4 million depositary shares, each representing 1/1,000 of a share of the 5.70 % Cumulative Preferred Stock, Series V, at $ 25.00 per depositary share. The Company paid $59.4 million, $60.5 million and $59.2 million in distributions to its preferred shareholders for the years ended December 31, 2015 , 2014 and 2013 , respectively. Holders of the Company’s preferred stock will not be entitled to vote on most matters, except under certain conditions. In the event of a cumulative arrearage equal to six quarterly dividends, the holders of the preferred stock will have the right to elect two additional members to serve on the Company’s Board of Directors until all events of default have been cured. At December 31, 2015 , there were no dividends in arrears. Except under certain conditions relating to the Company’s qualification as a REIT, the preferred stock is not redeemable prior to the previously noted redemption dates. On or after the respective redemption dates, the respective series of preferred stock will be redeemable, at the option of the Company, in whole or in part, at $ 25.00 per depositary share, plus any accrued and unpaid dividends. The Company had $29.3 million and $ 31. 8 million of deferred costs in connection with the issuance of preferred stock as of December 31, 2015 and 2014, respectively, which the Company will report as additional non-cash distributions upon notice of its intent to redeem such shares. Common stock Subsequent to December 31, 2015, the Company’s Board of Directors increased its quarterly dividend from $0.60 per common share to $0.75 per common share, increasing quarterly distributions by $5. 2 million per quarter. Dividends declared for the three months ended December 31, 2014 included a one-time special cash dividend of $ 2.75 per share (the “Special Cash Dividend”) along with the fourth quarter regular dividend of $ 0.50 per share. The Special Cash Dividend was declared to distribute a portion of the excess income attributable to gains on sales from asset dispositions during 2014, as discussed in Note 3 . The Company paid $59.4 million ($ 2. 20 per common share), $127.8 million ($ 4.7 5 per common share) and $44.0 million ($ 1.76 per common share) in distributions to its common shareholders for the years ended December 31, 2015 , 2014 and 2013 , respectively. The portion of the distributions classified as ordinary income was 89.4% , 70.5% and 98.9% for the years ended December 31, 2015, 2014 and 2013, respectively. The portion of the distributions classified as long-term capital gain income was 10.6% , 29.5% and 1.1% for the years ended December 31, 2015, 2014 and 2013, respectively. The percentages in the two preceding sentences are unaudited. On November 7, 2013, the Company sold 1,495,000 shares of common stock in a public offering and concurrently sold 950,000 shares of common stock at the public offering price to PS. The aggregate net proceeds were $ 192.3 million. No shares of common stock were repurchased under the board approved common stock repurchase program during the years ended December 31, 2015, 2014 and 2013. Equity stock In addition to common and preferred stock, the Company is authorized to issue 100.0 million shares of Equity Stock. The Articles of Incorporation provide that Equity Stock may be issued from time to time in one or more series and give the Board of Directors broad authority to fix the dividend and distribution rights, conversion and voting rights, redemption provisions and liquidation rights of each series of Equity Stock.

Stock Compensation

Stock Compensation	12 Months Ended
	Dec. 31, 2015
Stock Compensation [Abstract]
Stock Compensation	11. Stock compensation PSB has a 2003 Stock Option and Incentive Plan (the “2003 Plan”) and a 2012 Equity and Performance-Based Incentive Compensation Plan (the “2012 Plan”) covering 1.5 million and 1.0 million shares of PSB’s common stock, respectively. Under the 2003 Plan and 2012 Plan, PSB has granted non-qualified options to certain directors, officers and key employees to purchase shares of PSB’s common stock at a price not less than the fair market value of the common stock at the date of grant. Additionally, under the 2003 Plan and 2012 Plan, PSB has granted restricted shares of common stock to certain directors and restricted stock units to officers and key employees. Options under the 2003 Plan and 2012 Plan vest over a five -year period from the date of grant at the rate of one fifth per year and expire 10 years after the date of grant. Generally, restricted stock units granted are subject to a six -year vesting schedule, none in year one and 20% for each of the next five years. The weighted average grant date fair value of options granted during the years ended December 31, 2015 , 2014 and 2013 was $ 8. 49 per share, $ 10. 95 per share and $ 9. 18 per share, respectively. The Company has calculated the fair value of each option grant on the date of grant using the Black-Scholes option-pricing model with the following weighted average assumptions used for grants during the years ended December 31, 2015 , 2014 and 2013 , respectively: a dividend yield of 2. 5 %, 2. 3 % and 2. 2 %; expected volatility of 16. 1 %, 17. 7 % and 17. 5 %; expected life of five years; and risk-free interest rates of 1. 4 %, 1. 7 % and 1. 0 %. The weighted average grant date fair value of restricted stock units granted during the years ended December 31, 2015 , 2014 and 2013 was $ 82. 78 , $ 81. 47 and $ 73. 85 , r espectively . The Company calculated the fair value of each restricted stock unit grant using the market value on the date of grant. At December 31, 2015 , there was a combined total of 1.3 million options and restricted stock units authorized to be granted. In connection with the 2014 Special Cash Dividend discussed in Note 10, the number of options and exercise prices of all outstanding options as of December 31, 2014 were adjusted pursuant to the anti-dilution provisions of the applicable plans so that the option holders would be neither advantaged nor disadvantaged as a result of the Special Cash Dividend. Information with respect to outstanding options and nonvested restricted stock units granted under the 2003 Plan and 2012 Plan is as follows : Weighted Aggregate Weighted Average Intrinsic Number of Average Remaining Value Options: Options Exercise Price Contract Life (in thousands) Outstanding at December 31, 2012 454,573 $ 53.41 Granted 24,000 $ 78.99 Exercised (97,800) $ 47.87 Forfeited — $ — Outstanding at December 31, 2013 380,773 $ 56.45 Granted 16,000 $ 82.84 Exercised (61,273) $ 49.84 Forfeited (4,000) $ 52.35 Special cash dividend adjustment (1) 10,352 N/A Outstanding at December 31, 2014 341,852 $ 57.11 Granted 16,000 $ 80.13 Exercised (99,178) $ 51.31 Forfeited — $ — Outstanding at December 31, 2015 258,674 $ 60.76 5.01 Years $ 6,899 Exercisable at December 31, 2015 194,999 $ 56.23 4.14 Years $ 6,084 (1) In accordance with the applicable equity award plan documents, the number and exercise price of outstanding options as of December 31, 2014 have been adjusted as a result of the Special Cash Dividend so that the option holder maintains their economic position with respect to the shareholders. Weighted Number of Average Grant Restricted Stock Units: Units Date Fair Value Nonvested at December 31, 2012 53,090 $ 55.69 Granted 8,350 $ 73.85 Vested (13,690) $ 53.84 Forfeited (2,650) $ 47.96 Nonvested at December 31, 2013 45,100 $ 60.07 Granted 6,800 $ 81.47 Vested (12,980) $ 53.65 Forfeited (3,750) $ 69.00 Nonvested at December 31, 2014 35,170 $ 65.62 Granted 75,606 $ 82.78 Vested (25,384) $ 74.19 Forfeited (6,740) $ 76.22 Nonvested at December 31, 2015 78,652 $ 78.44 Effective March, 2014, the Company entered into a performance-based restricted stock unit program, the Senior Management Long-Term Equity Incentive Program for 2014-2017 (“2014 LTEIP”), with certain employees of the Company. Under the 2014 LTEIP, the Company established three levels of targeted restricted stock unit awards for certain employees, which would be earned only if the Company achieved one of three defined targets during 2014 to 2017. Under the 2014 LTEIP there is an annual award following the end of each of the four years in the program, with the award subject to and based on the achievement of total return targets during the previous year, as well as an award based on achieving total return targets during the cumulative four-year period 2014-2017. In the event the minimum defined target is not achieved for an annual award, the shares allocated to be awarded for such year are added to the shares that may be received if the four-year target is achieved. All restricted stock unit awards under the 2014 LTEIP vest in four equal annual installments beginning from the date of award. Up to 96,650 restricted stock units would be granted for each of the four years assuming achievement was met and up to 82,846 restricted stock units would be granted for the cumulative four-year period assuming achievement was met. Compensation expense is recognized based on the shares expected to be awarded based on the target level that is expected to be achieved . Net compensation expense of $8.2 million and $ 7.4 million related to the 2014 LTEIP was recognized for the years ended December 31, 2015 and 2014, respectively. In connection with the 2014 LTEIP, targets for 2014 were achieved at the threshold total return level. As such, 66,506 restricted stock units were granted during the year ended December 31, 2015 at a weighted average grant date fair value of $8 3.47 . Effective January 1, 2012, the Company entered into a performance-based restricted stock unit program, the Senior Management Long-Term Equity Incentive Program for 2012-2015 (“2012 LTEIP”), with certain employees of the Company. The targets for 2012 and 2013 were not achieved and management determined in 2013 that it was not probable that the remaining targets under the 2012 LTEIP would be met. As such, the Company stopped recording amortization and recorded a reversal of all 2012 LTEIP amortization previously recorded in 2012 of $ 3.9 million during the year ended December 31, 2013. Net compensation expense of $261,000 , $1.1 million and $425,000 related to stock options was recognized during the years ended December 31, 2015 , 2014 and 2013 , respectively. Included in 2014 compensation expense relating to stock options was $ 644,000 of expense resulting from modifications made to outstanding stock options as a result of the Special Cash Dividend paid in December, 2014. Excluding the 2014 LTEIP amortization of $8.2 million and $7.4 million, net compensation expense of $433,000 and $ 526,000 related to restricted stock units was recognized during the years ended December 31, 2015 and 2014, respectively. Excluding the 2012 LTEIP reversal of $3.9 million, net compensation expense of $671,000 related to restricted stock units was recognized during the year ended December 31, 2013. As of December 31, 2015 , there was $ 412,000 of unamortized compensation expense related to stock options expected to be recognized over a weighted average period of 3. 0 years. As of December 31, 2015 , there was $ 20. 2 million (includes $ 18. 5 million from the 2014 LTEIP) of unamortized compensation expense related to restricted stock units expected to be recognized over a weighted average period of 4. 3 years. Cash received from 99,178 stock options exercised during the year ended December 31, 2015 was $5.1 million. Cash received from 61,273 stock options exercised during the year ended December 31, 2014 was $ 3. 1 million. Cash received from 97,800 stock options exercised during the year ended December 31, 2013 was $4.7 million. The aggregate intrinsic value of the stock options exercised was $ 2. 6 million, $ 2.1 million and $ 3. 1 million during the years ended December 31, 2015 , 2014 and 2013 , respectively. During the year ended December 31, 2015 , 25,38 4 restricted stock units vested ( 16,634 related to the 2014 LTEIP); in settlement of these units, 15,734 shares were issued ( 10,495 related to the 2014 LTEIP), net of shares applied to payroll taxes. The aggregate fair value of the shares vested for the year ended December 31, 2015 was $ 2. 0 million ( $1.3 million related to the 2014 LTEIP). During the year ended December 31, 2014 , 12,980 restricted stock units vested; in settlement of these units, 8,066 shares were issued, net of shares applied to payroll taxes. The aggregate fair value of the shares vested for the year ended December 31, 2014 was $ 1. 1 million. During the year ended December 31, 2013 , 13,690 restricted stock units vested; in settlement of these units, 8, 547 shares were issued, net of shares applied to payroll taxes. The aggregate fair value of the shares vested for the year ended December 31, 2013 was $ 1. 0 million. In April, 2015, the shareholders of the Compan y approved the issuance of an additional 130,000 shares of common stock under the Retirement Plan for Non-Employee Directors (the “Director Plan”). Under the Director Plan, the Company grants 1,000 shares of common stock for each year served as a director up to a maximum of 8,000 shares issued upon retirement. The Company recognizes compensation expense over the requisite service period. As a result, included in the Company’s consolidated statements of income was compensation expense of $ 316,000 , $ 550,000 and $ 264,000 for the years ended December 31, 2015 , 2014 and 2013 , respectively. Included in 2014 compensation expense relating to the retirement shares was $ 243,000 of expense resulting from the increase in maximum shares. As of December 31, 2015 , 2014 and 2013 , there was $ 1. 2 million, $ 1. 5 million and $ 1. 4 million, respectively, of unamortized compensation expense related to these shares. No shares were issued during the years ended December 31, 2015, 2014 and 2013.

Supplementary Quarterly Financi

Supplementary Quarterly Financial Data	12 Months Ended
	Dec. 31, 2015
Supplementary Quarterly Financial Data [Abstract]
Supplementary Quarterly Financial Data	12. Supplementary quarterly financial data (unaudited, in thousands, except per share data) : Three Months Ended March 31, 2015 June 30, 2015 September 30, 2015 December 31, 2015 Rental income $ 92,315 $ 92,948 $ 93,322 $ 94,550 Cost of operations $ 31,746 $ 30,057 $ 30,448 $ 28,973 Net income allocable to common shareholders $ 19,771 $ 11,129 $ 22,484 $ 14,906 Net income per share: Basic $ 0.73 $ 0.41 $ 0.83 $ 0.55 Diluted $ 0.73 $ 0.41 $ 0.83 $ 0.55 Three Months Ended March 31, 2014 June 30, 2014 September 30, 2014 December 31, 2014 Rental income $ 95,321 $ 93,986 $ 95,627 $ 91,321 Cost of operations $ 33,444 $ 31,535 $ 33,102 $ 29,290 Net income allocable to common shareholders $ 9,940 $ 9,826 $ 11,268 $ 82,131 Net income per share: Basic $ 0.37 $ 0.37 $ 0.42 $ 3.05 Diluted $ 0.37 $ 0.36 $ 0.42 $ 3.04

Commitments And Contingencies

Commitments And Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments And Contingencies [Abstract]
Commitments And Contingencies	13 . Commitments and contingencies The Company currently is neither subject to any other material litigation nor, to management’s knowledge, is any material litigation currently threatened against the Company other than routine litigation and administrative proceedings arising in the ordinary course of business.

401(k) Plan

401(k) Plan	12 Months Ended
	Dec. 31, 2015
Stock Compensation [Abstract]
401(k) Plan	14 . 401(k) Plan The Company has a 401(k) savings plan (the “ Plan”) in which all eligible employees may participate. The Plan provides for the Company to make matching contributions to all eligible employees up to 4 % of their annual salary dependent on the employee’s level of participation. For the years ended December 31, 2015 , 2014 and 2013 , $ 410,000 , $ 417,000 , and $ 362,000 , respectively, was charged as expense related to this plan.

Real Estate And Accumulated Dep

Real Estate And Accumulated Depreciation	12 Months Ended
	Dec. 31, 2015
Real Estate And Accumulated Depreciation [Abstract]
Real Estate and Accumulated Depreciation	PS BUSINESS PARKS, INC. SCHEDULE III - REAL ESTATE AND ACCUMULATED DEPRECIATION DECEMBER 31, 2015 (DOLLARS IN THOUSANDS) Cost Capitalized Subsequent to Gross Amount at Which Carried at Initial Cost to Company Acquisition December 31, 2015 Buildings Buildings Buildings Depreciable and and and Accumulated Lives Description Location Square Feet Encumbrances Land Improvements Improvements Land Improvements Total Depreciation Year(s) Acquired (Years) Buena Park Industrial Center Buena Park, CA 317 $ — $ 3,245 $ 7,703 $ 2,667 $ 3,245 $ 10,370 $ 13,615 $ 6,595 1997 5- 30 Carson Carson, CA 77 — 990 2,496 1,451 990 3,947 4,937 2,698 1997 5- 30 Cerritos Business Center Cerritos, CA 395 — 4,218 10,273 4,129 4,218 14,402 18,620 9,428 1997 5- 30 Cerritos/Edwards Cerritos, CA 31 — 450 1,217 1,407 450 2,624 3,074 1,816 1997 5- 30 Concord Business Park Concord, CA 246 — 12,454 20,491 844 12,454 21,335 33,789 4,185 2011 5- 30 Culver City Culver City, CA 147 — 3,252 8,157 5,951 3,252 14,108 17,360 10,052 1997 5- 30 Bayview Business Park Fremont, CA 104 7,300 4,990 4,831 234 4,990 5,065 10,055 1,307 2011 5- 30 Christy Business Park Fremont, CA 334 14,200 11,451 16,254 1,435 11,451 17,689 29,140 4,069 2011 5- 30 Industrial Drive Distribution Center Fremont, CA 199 5,300 7,482 6,812 787 7,482 7,599 15,081 1,453 2011 5- 30 Bay Center Business Park Hayward, CA 463 27,500 19,052 50,501 3,522 19,052 54,023 73,075 10,532 2011 5- 30 Cabot Distribution Center Hayward, CA 249 9,300 5,859 10,811 374 5,859 11,185 17,044 2,153 2011 5- 30 Diablo Business Park Hayward, CA 271 — 9,102 15,721 825 9,102 16,546 25,648 3,396 2011 5- 30 Eden Landing Hayward, CA 83 4,800 3,275 6,174 131 3,275 6,305 9,580 1,334 2011 5- 30 Hayward Business Park Hayward, CA 1,091 46,400 28,256 54,418 2,424 28,256 56,842 85,098 10,696 2011 5- 30 Huntwood Business Park Hayward, CA 176 11,600 7,391 11,819 964 7,391 12,783 20,174 2,868 2011 5- 30 Parkway Commerce Hayward, CA 407 — 4,398 10,433 4,727 4,398 15,160 19,558 9,962 1997 5- 30 Corporate Pointe Irvine, CA 161 — 6,876 18,519 6,529 6,876 25,048 31,924 16,246 2000 5- 30 Laguna Hills Commerce Center Laguna Hills, CA 513 — 16,261 39,559 7,028 16,261 46,587 62,848 28,681 1997 5- 30 Plaza Del Lago Laguna Hills, CA 101 — 2,037 5,051 3,951 2,037 9,002 11,039 6,186 1997 5- 30 Canada Lake Forest, CA 297 — 5,508 13,785 5,675 5,508 19,460 24,968 12,616 1997 5- 30 Dixon Landing Business Park Milpitas, CA 505 30,000 26,301 21,121 3,235 26,301 24,356 50,657 5,710 2011 5- 30 Monterey/Calle Monterey, CA 12 — 288 706 336 288 1,042 1,330 717 1997 5- 30 Monterey Park Monterey Park, CA 199 — 3,078 7,862 1,566 3,078 9,428 12,506 6,261 1997 5- 30 Port of Oakland Oakland, CA 200 10,800 5,638 11,066 661 5,638 11,727 17,365 2,447 2011 5- 30 Orangewood Orange County, CA 107 — 2,637 12,291 3,429 2,637 15,720 18,357 8,625 2003 5- 30 Orange County Business Center Orange County, CA 437 — 9,405 35,746 18,093 9,405 53,839 63,244 39,421 2003 5- 30 Kearney Mesa San Diego, CA 164 — 2,894 7,089 2,808 2,894 9,897 12,791 6,574 1997 5- 30 Lusk San Diego, CA 371 — 5,711 14,049 5,419 5,711 19,468 25,179 13,046 1997 5- 30 Rose Canyon Business Park San Diego, CA 233 — 15,129 20,054 2,202 15,129 22,256 37,385 11,416 2005 5- 30 Charcot Business Park San Jose, CA 283 10,300 18,654 17,580 1,560 18,654 19,140 37,794 4,115 2011/2014 5- 30 Las Plumas San Jose, CA 214 — 4,379 12,889 6,691 4,379 19,580 23,959 13,742 1998 5- 30 Little Orchard Distribution Center San Jose, CA 213 5,900 7,725 3,846 51 7,725 3,897 11,622 1,115 2011 5- 30 Montague Industrial Park San Jose, CA 316 14,200 14,476 12,807 444 14,476 13,251 27,727 3,761 2011 5- 30 Oakland Road San Jose, CA 177 — 3,458 8,765 3,132 3,458 11,897 15,355 7,833 1997 5- 30 Rogers Ave San Jose, CA 67 — 3,540 4,896 573 3,540 5,469 9,009 2,452 2006 5- 30 Doolittle Business Park San Leandro, CA 113 4,500 3,929 6,231 361 3,929 6,592 10,521 1,507 2011 5- 30 Cost Capitalized Subsequent to Gross Amount at Which Carried at Initial Cost to Company Acquisition December 31, 2015 Buildings Buildings Buildings Depreciable and and and Accumulated Lives Description Location Square Feet Encumbrances Land Improvements Improvements Land Improvements Total Depreciation Year(s) Acquired (Years) Bayshore Corporate Center San Mateo, CA 340 — 25,108 36,891 5,615 25,108 42,506 67,614 7,433 2013 5- 30 San Ramon/Norris Canyon San Ramon, CA 52 — 1,486 3,642 1,263 1,486 4,905 6,391 3,212 1997 5- 30 Commerce Park Santa Clara, CA 251 — 17,218 21,914 3,693 17,218 25,607 42,825 15,462 2007 5- 30 Santa Clara Tech Park Santa Clara, CA 178 — 7,673 15,645 4,359 7,673 20,004 27,677 12,765 2000 5- 30 Walsh at Lafayette Santa Clara, CA 321 19,300 13,439 17,890 292 13,439 18,182 31,621 4,496 2011 5- 30 Signal Hill Signal Hill, CA 269 — 6,693 12,699 2,672 6,693 15,371 22,064 8,697 1997/2006 5- 30 Airport Boulevard So San Francisco, CA 52 — 899 2,387 682 899 3,069 3,968 2,020 1997 5- 30 South San Francisco/Produce So San Francisco, CA 41 — 776 1,886 526 776 2,412 3,188 1,540 1997 5- 30 Studio City/Ventura Studio City, CA 22 — 621 1,530 607 621 2,137 2,758 1,340 1997 5- 30 Kifer Industrial Park Sunnyvale, CA 287 28,600 13,227 37,874 1,395 13,227 39,269 52,496 7,656 2011 5- 30 Torrance Torrance, CA 147 — 2,318 6,069 3,180 2,318 9,249 11,567 6,276 1997 5- 30 Boca Commerce Boca Raton, FL 135 — 7,795 9,258 2,394 7,795 11,652 19,447 4,220 2006 5- 30 MICC Miami, FL 3,468 — 95,115 112,583 40,030 95,115 152,613 247,728 83,721 2003/2011/2014 5- 30 Wellington Wellington, FL 263 — 10,845 18,560 2,510 10,845 21,070 31,915 8,162 2006 5- 30 Ammendale Beltsville, MD 309 — 4,278 18,380 10,702 4,278 29,082 33,360 20,856 1998 5- 30 Gaithersburg/Christopher Gaithersburg, MD 29 — 475 1,203 629 475 1,832 2,307 1,267 1997 5- 30 Metro Park Rockville, MD 898 — 33,995 94,463 37,270 33,995 131,733 165,728 83,239 2001 5- 30 Parklawn Business Park Rockville, MD 232 — 3,387 19,628 3,786 3,387 23,414 26,801 7,728 2010 5- 30 Shady Grove Rockville, MD 352 — 5,372 50,727 9,224 5,372 59,951 65,323 17,931 2010 5- 30 Westech Business Park Silver Spring, MD 532 — 25,261 74,572 16,170 25,261 90,742 116,003 50,215 2006 5- 30 Ben White Austin, TX 108 — 1,550 7,015 1,941 1,550 8,956 10,506 5,954 1998 5- 30 Lamar Business Park Austin, TX 145 — 2,528 6,596 4,331 2,528 10,927 13,455 9,185 1997 5- 30 McKalla Austin, TX 236 — 1,945 13,212 2,178 1,945 15,390 17,335 6,949 1998/2012 5- 30 McNeil Austin, TX 525 — 5,477 24,495 4,140 5,477 28,635 34,112 9,041 1999/2010/2012/2014 5- 30 Rutland Austin, TX 288 — 2,022 9,397 3,857 2,022 13,254 15,276 7,607 1998/1999 5- 30 Waterford Austin, TX 106 — 2,108 9,649 3,840 2,108 13,489 15,597 8,877 1999 5- 30 Braker Business Park Austin, TX 257 — 1,874 13,990 1,608 1,874 15,598 17,472 5,749 2010 5- 30 Mopac Business Park Austin, TX 117 — 719 3,579 694 719 4,273 4,992 1,449 2010 5- 30 Southpark Business Park Austin, TX 181 — 1,266 9,882 2,306 1,266 12,188 13,454 4,475 2010 5- 30 Valwood Business Center Carrolton, TX 356 — 2,510 13,859 1,476 2,510 15,335 17,845 2,969 2013 5- 30 Empire Commerce Dallas, TX 44 — 304 1,545 819 304 2,364 2,668 1,691 1998 5- 30 Northgate Dallas, TX 194 — 1,274 5,505 3,946 1,274 9,451 10,725 6,423 1998 5- 30 Northway Plaza Farmers Branch, TX 131 — 1,742 4,503 738 1,742 5,241 6,983 1,032 2013 5- 30 Springlake Business Center Farmers Branch, TX 206 — 2,607 5,715 1,646 2,607 7,361 9,968 1,185 2013/2014 5- 30 Westwood Business Park Farmers Branch, TX 112 — 941 6,884 2,364 941 9,248 10,189 5,146 2003 5- 30 Eastgate Garland, TX 36 — 480 1,203 499 480 1,702 2,182 1,176 1997 5- 30 Freeport Business Park Irving, TX 256 — 4,564 9,506 1,989 4,564 11,495 16,059 2,053 2013 5- 30 NFTZ (1) Irving, TX 231 — 1,517 6,499 3,496 1,517 9,995 11,512 6,449 1998 5- 30 Royal Tech Irving, TX 794 — 13,989 54,113 22,713 13,989 76,826 90,815 47,803 1998-2000/2011 5- 30 La Prada Mesquite, TX 56 — 495 1,235 601 495 1,836 2,331 1,296 1997 5- 30 The Summit Plano, TX 184 — 1,536 6,654 4,264 1,536 10,918 12,454 7,718 1998 5- 30 Arapaho Business Park Richardson, TX 408 — 5,226 10,661 2,938 5,226 13,599 18,825 3,304 2013/2014 5- 30 Richardson Business Park Richardson, TX 117 — 799 3,568 2,805 799 6,373 7,172 4,641 1998 5- 30 Bren Mar Alexandria, VA 113 — 2,197 5,380 3,782 2,197 9,162 11,359 6,391 1997 5- 30 Eisenhower Alexandria, VA 95 — 1,440 3,635 2,337 1,440 5,972 7,412 4,404 1997 5- 30 Beaumont Chantilly, VA 107 — 4,736 11,051 2,156 4,736 13,207 17,943 6,969 2006 5- 30 Dulles South/Sullyfield Chantilly, VA 99 — 1,373 6,810 3,074 1,373 9,884 11,257 6,361 1999 5- 30 Lafayette Chantilly, VA 197 — 1,680 13,398 4,941 1,680 18,339 20,019 12,194 1999/2000 5- 30 Cost Capitalized Subsequent to Gross Amount at Which Carried at Initial Cost to Company Acquisition December 31, 2015 Buildings Buildings Buildings Depreciable and and and Accumulated Lives Description Location Square Feet Encumbrances Land Improvements Improvements Land Improvements Total Depreciation Year(s) Acquired (Years) Park East Chantilly, VA 198 — 3,851 18,029 10,232 3,851 28,261 32,112 18,036 1999 5- 30 Fair Oaks Business Campus Fairfax, VA 290 — 13,598 36,232 8,028 13,598 44,260 57,858 24,257 2004/2007 5- 30 Monroe Herndon, VA 244 — 6,737 18,911 10,233 6,737 29,144 35,881 20,044 1997/1999 5- 30 Gunston Lorton, VA 247 — 4,146 17,872 8,995 4,146 26,867 31,013 15,227 1998 5- 30 Westpark Business Campus McLean, VA 751 — 47,955 101,847 21,328 47,955 123,175 171,130 38,783 2010/2011 5- 30 Prosperity Business Campus Merrifield, VA 659 — 23,147 67,575 30,011 23,147 97,586 120,733 58,680 2001 5- 30 Alban Road Springfield, VA 150 — 1,935 4,736 5,014 1,935 9,750 11,685 7,159 1997 5- 30 I-95 Springfield, VA 210 — 3,535 15,672 11,579 3,535 27,251 30,786 19,751 2000 5- 30 Northpointe Sterling, VA 147 — 2,767 8,778 4,503 2,767 13,281 16,048 9,567 1997/1998 5- 30 Shaw Road Sterling, VA 149 — 2,969 10,008 4,286 2,969 14,294 17,263 10,371 1998 5- 30 Tysons Corporate Center Vienna, VA 270 — 9,885 25,302 9,289 9,885 34,591 44,476 11,655 2010 5- 30 Woodbridge Woodbridge, VA 114 — 1,350 3,398 1,858 1,350 5,256 6,606 3,762 1997 5- 30 212th Business Park Kent, WA 951 — 19,573 17,695 12,014 19,573 29,709 49,282 6,177 2012 5- 30 Overlake Redmond, WA 411 — 23,122 41,106 6,086 23,122 47,192 70,314 26,383 2007 5- 30 Renton Renton, WA 28 — 330 889 552 330 1,441 1,771 1,009 1997 5- 30 27,969 $ 250,000 $ 793,569 $ 1,727,413 $ 488,102 $ 793,569 $ 2,215,515 $ 3,009,084 $ 1,082,603 (1) The Company owns two properties that are subject to ground leases in Las Colinas, Texas, expiring in 2019 and 2020 , each with one 10 -year extension option .

Summary Of Significant Accoun22

Summary Of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2015
Summary Of Significant Accounting Policies [Abstract]
Basis Of Presentation	Basis of presentation The accompanying consolidated financial statements include the accounts of PSB and the Operating Partnership. All significant inter-company balances and transactions have been eliminated in the consolidated financial statements. The financial statements are presented on an accrual basis in accordance with U.S. generally accepted accounting principles (“GAAP”).
Consolidation And Equity Method Of Accounting	Consolidation and Equity Method of Accounting The Company accounts for an investment in a joint venture that it has significant influence over, but does not control, using the equity method of accounting eliminating intra-entity profits and losses as if the joint venture were a consolidated subsidiary.
Noncontrolling Interests	Noncontrolling interests The Company's noncontrolling interests are reported as a component of equity separate from the parent’s equity. Purchases or sales of equity interests that do not result in a change in control are accounted for as equity transactions. In addition, net income attributable to the noncontrolling interests is included in consolidated net income on the face of the income statement and, upon a gain or loss of control, the interests purchased or sold, as well as any interests retained, are recorded at fair value with any gain or loss recognized in earnings. At the end of each reporting period, the Company determines the amount of equity (book value of net assets) which is allocable to the noncontrolling interests based upon the ownership interest, and an adjustment is made to the noncontrolling interests, with a corresponding adjustment to paid-in capital, to reflect the noncontrolling interests’ equity interest in the Company.
Use Of Estimates	Use of estimates The preparation of the consolidated financial statements in conformity with GAAP principle requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from these estimates.
Allowance For Doubtful Accounts	Allowance for doubtful accounts The Company monitors the collectability of its receivable balances including the deferred rent receivable on an ongoing basis. Based on these reviews, the Company maintains an allowance for doubtful accounts for estimated losses resulting from the possible inability of tenants to make contractual rent payments to the Company. A provision for doubtful accounts is recorded during each period. The allowance for doubtful accounts is netted against tenant and other receivables on the consolidated balance sheets. Tenant receivables are net of an allowance for uncollectible accounts totaling $ 400,000 at December 31, 2015 and 2014 . Deferred rent receivable is net of an allowance for uncollectible accounts totaling $909,000 and $841,000 at December 31, 2015 and 2014 , respectively.
Financial Instruments	Financial instruments The methods and assumptions used to estimate the fair value of financial instruments are described below. The Company has estimated the fair value of financial instruments using available market information and appropriate valuation methodologies. Considerable judgment is required in interpreting market data to develop estimates of market value. Accordingly, estimated fair values are not necessarily indicative of the amounts that could be realized in current market exchanges. The Company determines the estimated fair value of financial assets and liabilities utilizing a hierarchy of valuation techniques based on whether the inputs to a fair value measurement are considered to be observable or unobservable in a marketplace. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect market assumptions. This hierarchy requires the use of observable market data when available. The following is the fair value hierarchy: · Level 1 —quoted prices for identical instruments in active markets; · 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 —fair value measurements derived from valuation techniques in which one or more significant inputs or significant value drivers are unobservable. Financial assets that are exposed to credit risk consist primarily of cash and cash equivalents and receivables. The Company considers all highly liquid investments with a remaining maturity of three months or less at the date of purchase to be cash equivalents. Cash and cash equivalents, which consist primarily of money market investments, are only invested in entities with an investment grade rating. Receivables are comprised of balances due from a large number of customers. Balances that the Company expects to become uncollectible are reserved for or written off. Due to the short period to maturity of the Company’s cash and cash equivalents, accounts receivable, other assets and accrued and other liabilities, the carrying values as presented on the consolidated balance sheets are reasonable estimates of fair value. Carrying values of the Company’s mortgage note payable and unsecured credit facility approximate fair value. The characteristics of these financial instruments, market data and other comparative metrics utilized in determining these fair values are “Level 2” inputs.
Real Estate Facilities	Real estate facilities Real estate facilities are recorded at cost. Costs related to the renovation or improvement of the properties are capitalized. Expenditures for repairs and maintenance are expensed as incurred. Expenditures that are expected to benefit a period greater than two years and exceed $ 2,000 are capitalized and depreciated over their estimated useful life. Buildings and improvements are depreciated using the straight-line method over their estimated useful lives, which generally range from five to 30 years. Transaction costs, which include tenant improvements and lease commissions, in excess of $ 1,000 for leases with terms greater than one year are capitalized and depreciated over their estimated useful lives. Transaction costs less than $ 1,000 or for leases of one year or less are expensed as incurred.
Land And Building Held For Development	Land and building held for development Property taxes, insurance, interest and costs essential to the development of property for its intended use are capitalized during the period of development. Upon classification of an asset as held for development, depreciation of the asset is ceased.
Properties Held For Disposition	Properties held for disposition An asset is classified as an asset held for disposition when it meets certain requirements, which include, among other criteria, the approval of the sale of the asset, the marketing of the asset for sale and the expectation by the Company that the sale will likely occur within the next 12 months. Upon classification of an asset as held for disposition, depreciation of the asset is ceased, and the net book value of the asset is included on the balance sheet as properties held for disposition.
Intangible Assets/Liabilities	Intangible assets/liabilities Intangible assets and liabilities include above-market and below-market in-place lease values of acquired properties based on the present value (using an interest rate which reflects the risks associated with the leases acquired) of the difference between (i) the contractual amounts to be paid pursuant to the in-place leases and (ii) management’s estimate of fair market lease rates for the corresponding in-place leases, measured over a period equal to the remaining non-cancelable term of the lease. The capitalized above-market and below-market lease values (included in other assets and accrued liabilities in the accompanying consolidated balance sheets) are amortized to rental income over the remaining non-cancelable terms of the respective leases. The Company recorded a net increase in rental income of $1.3 million and $901,000 during the years end December 31, 2015 and 2014 , respectively, related to the amortization of net intangible liabilities resulting from the above-market and below-market lease values. The Company recorded net reductions to rental income of $118,000 during the year ended December 31, 2013 tied to the amortization of net intangible assets resulting from the above-market and below-market lease values. As of December 31, 2015 , the value of in-place leases resulted in net intangible assets of $ 1. 7 million, net of $ 8. 6 million of accumulated amortization with a weighted average amortization period of 8. 7 years and net intangible liabilities of $ 1. 8 million, net of $ 9. 0 million of accumulated amortization with a weighted average amortization period of 5. 4 years. As of December 31, 2014 , the value of in-place leases resulted in net intangible assets of $ 2. 5 million, net of $ 7. 8 million of accumulated amortization and net intangible liabilities of $ 3. 9 million, net of $ 6. 9 million of accumulated amortization.
Evaluation Of Asset Impairment	Evaluation of asset impairment The Company evaluates its assets used in operations for impairment by identifying indicators of impairment and by comparing the sum of the estimated undiscounted future cash flows for each asset to the asset’s carrying value. When indicators of impairment are present and the sum of the estimated undiscounted future cash flows is less than the carrying value of such asset, an impairment loss is recorded equal to the difference between the asset’s current carrying value and its value based on discounting its estimated future cash flows. In addition, the Company evaluates its assets held for disposition for impairment. Assets held for disposition are reported at the lower of their carrying value or fair value, less cost of disposition. At December 31, 2015 , the Company did not consider any assets to be impaired.
Asset Impairment Due to Casualty Loss	Asset impairment due to casualty loss It is the Company’s policy to record as a casualty loss or gain, in the period the casualty occurs, the differential between (a) the book value of assets destroyed and (b) any insurance proceeds that the Company expects to receive in accordance with its insurance contracts. Potential proceeds from insurance that are subject to any uncertainties, such as interpretation of deductible provisions of the governing agreements, the estimation of costs of restoration, or other such items, are treated as contingent proceeds and not recorded until the uncertainties are satisfied. For the years ended December 31, 2015 , 2014 and 2013 no material casualty losses were incurred.
Stock Compensation	Stock compensation All share-based payments to employees, including grants of employee stock options, are recognized as stock compensation in the Company’s income statement based on their grant date fair values. See Note 11.
Revenue And Expense Recognition	Revenue and expense recognition The Company must meet four basic criteria before revenue can be recognized: persuasive evidence of an arrangement exists; the delivery has occurred or services have been rendered; the fee is fixed or determinable; and collectability is reasonably assured. All leases are classified as operating leases. Rental income is recognized on a straight-line basis over the terms of the leases. Straight-line rent is recognized for all tenants with contractual fixed increases in rent that are not included on the Company’s credit watch list. Deferred rent receivable represents rental revenue recognized on a straight-line basis in excess of billed rents. Reimbursements from tenants for real estate taxes and other recoverable operating expenses are recognized as rental income in the period the applicable costs are incurred. Property management fees are recognized in the period earned. Costs incurred in connection with leasing (primarily tenant improvements and lease commissions) are capitalized and amortized over the lease period.
Gains From Sales Of Real Estate Facilities	Gains from sales of real estate facilities The Company recognizes gains from sales of real estate facilities at the time of sale using the full accrual method, provided that various criteria related to the terms of the transactions and any subsequent involvement by the Company with the properties sold are met. If the criteria are not met, the Company defers the gains and recognizes them when the criteria are met or uses the installment or cost recovery methods as appropriate under the circumstances.
General And Administrative Expenses	General and administrative expenses General and administrative expenses include executive and other compensation, office expenses, professional fees, acquisition transaction costs, state income taxes and other such administrative items.
Income Taxes	Income taxes The Company has qualified and intends to continue to qualify as a REIT, as defined in Section 856 of the Internal Revenue Code of 1986, as amended. As a REIT, the Company is not subject to federal income tax to the extent that it distributes its REIT taxable income to its shareholders. A REIT must distribute at least 90 % of its taxable income each year. In addition, REITs are subject to a number of organizational and operating requirements. The Company may be subject to certain state and local taxes on its income and property and to federal income and excise taxes on its undistributed taxable income. The Company believes it met all organization and operating requirements to maintain its REIT status during 2015 , 2014 and 2013 and intends to continue to meet such requirements. Accordingly, no provision for income taxes has been made in the accompanying consolidated financial statements. The Company can recognize a tax benefit only if it is “more likely than not” that a particular tax position will be sustained upon examination or audit. To the extent that the “more likely than not” standard has been satisfied, the benefit associated with a position is measured as the largest amount that is greater than 50 % likely of being recognized upon settlement. As of December 31, 2015 , the Company did not recognize any tax benefit for uncertain tax positions.
Accounting For Preferred Equity Issuance Costs	Accounting for preferred equity issuance costs The Company records issuance costs as a reduction to paid-in capital on its balance sheet at the time the preferred securities are issued and reflects the carrying value of the preferred equity at the stated value. Such issuance costs are recorded as non-cash preferred equity distributions at the time the Company notifies the holders of preferred stock of its intent to redeem such shares.
Net Income Allocation	Net income allocation Net income was allocated as follows for the years ended December 31, (in thousands) : 2015 2014 2013 Net income allocable to noncontrolling interests: Noncontrolling interests — common units $ 18,495 $ 30,729 $ 12,952 Total net income allocable to noncontrolling interests 18,495 30,729 12,952 Net income allocable to PS Business Parks, Inc.: Preferred shareholders: Distributions to preferred shareholders 59,398 60,488 59,216 Non-cash distributions related to the redemption of preferred stock 2,487 — — Total net income allocable to preferred shareholders 61,885 60,488 59,216 Restricted stock unit holders 299 329 125 Common shareholders 68,291 113,154 43,851 Total net income allocable to PS Business Parks, Inc. 130,475 173,971 103,192 Net income $ 148,970 $ 204,700 $ 116,144
Net Income Per Common Share	Net income per common share Per share amounts are computed using the number of weighted average common shares outstanding. “Diluted” weighted average common shares outstanding includes the dilutive effect of stock options and restricted stock units under the treasury stock method. “Basic” weighted average common shares outstanding excludes such effect. The Company's restricted stock units are participating securities and are included in the computation of basic and diluted weighted average common shares outstanding. The Company’s restricted stock unit holders are paid non-forfeitable dividends in excess of the expense recorded which results in a reduction in net income allocable to common shareholders and unit holders. Earnings per share has been calculated as follows for the years ended December 31, (in thousands, except per share amounts): 2015 2014 2013 Net income allocable to common shareholders $ 68,291 $ 113,154 $ 43,851 Weighted average common shares outstanding: Basic weighted average common shares outstanding 26,973 26,899 24,732 Net effect of dilutive stock compensation — based on treasury stock method using average market price 78 101 101 Diluted weighted average common shares outstanding 27,051 27,000 24,833 Net income per common share — Basic $ 2.53 $ 4.21 $ 1.77 Net income per common share — Diluted $ 2.52 $ 4.19 $ 1.77 Options to purchase 32,000 , 16,000 and 14,000 shares for the years ended December 31, 2015 , 2014 and 2013 , respectively, were not included in the computation of diluted net income per share because such options were considered anti-dilutive.
Segment Reporting	Segment reporting The Company views its operations as one segment.
Reclassifications	Reclassifications Certain reclassifications have been made to the consolidated financial statements for 2014 and 2013 in order to conform to the 2015 presentation.
Recently Issued Accounting Standards	Recently issued accounting standards In May, 2014, the FASB issued new accounting guidance which amended the existing accounting standards for revenue recognition. The new accounting guidance establishes principles for recognizing revenue upon the transfer of promised goods or services to customers, in an amount that reflects the expected consideration received in exchange for those goods or services. This guidance is currently effective for the Company’s fiscal year beginning January 1, 2018. Early adoption is permitted for the Company’s fiscal year beginning January 1, 2017. The amendment allows for full retrospective adoption applied to all periods presented or modified retrospective adoption with the cumulative effect of initially applying the standard recognized at the date of initial application. The Company is currently in the process of evaluating the impact of adoption of the new accounting guidance on its consolidated financial statements.

Summary Of Significant Accoun23

Summary Of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2015
Summary Of Significant Accounting Policies [Abstract]
Net Income Allocation	2015 2014 2013 Net income allocable to noncontrolling interests: Noncontrolling interests — common units $ 18,495 $ 30,729 $ 12,952 Total net income allocable to noncontrolling interests 18,495 30,729 12,952 Net income allocable to PS Business Parks, Inc.: Preferred shareholders: Distributions to preferred shareholders 59,398 60,488 59,216 Non-cash distributions related to the redemption of preferred stock 2,487 — — Total net income allocable to preferred shareholders 61,885 60,488 59,216 Restricted stock unit holders 299 329 125 Common shareholders 68,291 113,154 43,851 Total net income allocable to PS Business Parks, Inc. 130,475 173,971 103,192 Net income $ 148,970 $ 204,700 $ 116,144
Calculation Of Earnings Per Share	2015 2014 2013 Net income allocable to common shareholders $ 68,291 $ 113,154 $ 43,851 Weighted average common shares outstanding: Basic weighted average common shares outstanding 26,973 26,899 24,732 Net effect of dilutive stock compensation — based on treasury stock method using average market price 78 101 101 Diluted weighted average common shares outstanding 27,051 27,000 24,833 Net income per common share — Basic $ 2.53 $ 4.21 $ 1.77 Net income per common share — Diluted $ 2.52 $ 4.19 $ 1.77

Real Estate Facilities (Tables)

Real Estate Facilities (Tables)	12 Months Ended
	Dec. 31, 2015
Real Estate Facilities [Abstract]
Activity In Real Estate Facilities	Buildings and Accumulated Land Improvements Depreciation Total Balances at December 31, 2012 $ 738,421 $ 2,005,943 $ (811,045) $ 1,933,319 Acquisition of real estate facilities 39,667 76,943 — 116,610 Capital expenditures — 60,228 — 60,228 Disposals — (15,391) 15,391 — Depreciation and amortization — — (108,917) (108,917) Transfer to properties sold — (1,466) 7,604 6,138 Transfer to land and building held for development (5,927) (10,270) 778 (15,419) Balances at December 31, 2013 772,161 2,115,987 (896,189) 1,991,959 Acquisition of real estate facilities 21,408 24,890 — 46,298 Capital expenditures — 54,462 — 54,462 Disposals — (10,587) 10,587 — Depreciation and amortization — — (110,357) (110,357) Transfer to properties sold — (1,759) 4,462 2,703 Balances at December 31, 2014 793,569 2,182,993 (991,497) 1,985,065 Capital expenditures — 46,777 — 46,777 Disposals — (13,990) 13,990 — Depreciation and amortization — — (105,394) (105,394) Transfer to properties sold — (265) 298 33 Balances at December 31, 2015 $ 793,569 $ 2,215,515 $ (1,082,603) $ 1,926,481
Summary Of Real Estate Assets Acquired And Liabilities Assumed	2014 2013 Land $ 21,408 $ 39,667 Land held for development — 990 Buildings and improvements 24,890 76,943 Above-market in-place lease value — 403 Below-market in-place lease value (666) (2,428) Total purchase price 45,632 115,575 Net operating assets acquired and liabilities assumed (611) (1,630) Total cash paid $ 45,021 $ 113,945

Leasing Activity (Tables)

Leasing Activity (Tables)	12 Months Ended
	Dec. 31, 2015
Leasing Activity [Abstract]
Summary Of Future Minimum Rental Revenues Excluding Recovery Of Operating Expenses	2016 $ 265,816 2017 201,788 2018 146,980 2019 99,678 2020 63,771 Thereafter 122,574 Total $ 900,607

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2015
Shareholders' Equity [Abstract]
Schedule Of Preferred Stock Outstanding	December 31, 2015 December 31, 2014 Earliest Potential Dividend Shares Amount Shares Amount Series Issuance Date Redemption Date Rate Outstanding (in thousands) Outstanding (in thousands) Series S January, 2012 January, 2017 6.450% 9,200 $ 230,000 9,200 $ 230,000 Series T May, 2012 May, 2017 6.000% 14,000 350,000 14,000 350,000 Series U September, 2012 September, 2017 5.750% 9,200 230,000 9,200 230,000 Series V March, 2013 March, 2018 5.700% 4,400 110,000 4,400 110,000 Series R October, 2010 October, 2015 6.875% — — 3,000 75,000 Total 36,800 $ 920,000 39,800 $ 995,000

Stock Compensation (Tables)

Stock Compensation (Tables)	12 Months Ended
	Dec. 31, 2015
Stock Compensation [Abstract]
Summary Of Stock Options Activity	Weighted Aggregate Weighted Average Intrinsic Number of Average Remaining Value Options: Options Exercise Price Contract Life (in thousands) Outstanding at December 31, 2012 454,573 $ 53.41 Granted 24,000 $ 78.99 Exercised (97,800) $ 47.87 Forfeited — $ — Outstanding at December 31, 2013 380,773 $ 56.45 Granted 16,000 $ 82.84 Exercised (61,273) $ 49.84 Forfeited (4,000) $ 52.35 Special cash dividend adjustment (1) 10,352 N/A Outstanding at December 31, 2014 341,852 $ 57.11 Granted 16,000 $ 80.13 Exercised (99,178) $ 51.31 Forfeited — $ — Outstanding at December 31, 2015 258,674 $ 60.76 5.01 Years $ 6,899 Exercisable at December 31, 2015 194,999 $ 56.23 4.14 Years $ 6,084 (1) In accordance with the applicable equity award plan documents, the number and exercise price of outstanding options as of December 31, 2014 have been adjusted as a result of the Special Cash Dividend so that the option holder maintains their economic position with respect to the shareholders.
Nonvested Restricted Stock Units	Weighted Number of Average Grant Restricted Stock Units: Units Date Fair Value Nonvested at December 31, 2012 53,090 $ 55.69 Granted 8,350 $ 73.85 Vested (13,690) $ 53.84 Forfeited (2,650) $ 47.96 Nonvested at December 31, 2013 45,100 $ 60.07 Granted 6,800 $ 81.47 Vested (12,980) $ 53.65 Forfeited (3,750) $ 69.00 Nonvested at December 31, 2014 35,170 $ 65.62 Granted 75,606 $ 82.78 Vested (25,384) $ 74.19 Forfeited (6,740) $ 76.22 Nonvested at December 31, 2015 78,652 $ 78.44

Supplementary Quarterly Finan28

Supplementary Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2015
Supplementary Quarterly Financial Data [Abstract]
Schedule Of Supplemental Quarterly Financial Data	Three Months Ended March 31, 2015 June 30, 2015 September 30, 2015 December 31, 2015 Rental income $ 92,315 $ 92,948 $ 93,322 $ 94,550 Cost of operations $ 31,746 $ 30,057 $ 30,448 $ 28,973 Net income allocable to common shareholders $ 19,771 $ 11,129 $ 22,484 $ 14,906 Net income per share: Basic $ 0.73 $ 0.41 $ 0.83 $ 0.55 Diluted $ 0.73 $ 0.41 $ 0.83 $ 0.55 Three Months Ended March 31, 2014 June 30, 2014 September 30, 2014 December 31, 2014 Rental income $ 95,321 $ 93,986 $ 95,627 $ 91,321 Cost of operations $ 33,444 $ 31,535 $ 33,102 $ 29,290 Net income allocable to common shareholders $ 9,940 $ 9,826 $ 11,268 $ 82,131 Net income per share: Basic $ 0.37 $ 0.37 $ 0.42 $ 3.05 Diluted $ 0.37 $ 0.36 $ 0.42 $ 3.04

Organization And Description 29

Organization And Description Of Business (Details) ft² in Thousands, shares in Millions	Dec. 31, 2015ft²stateshares
Organization And Description Of Business [Abstract]
The Company's ownership percentage of the limited partnership	77.80%
Affiliate's percent ownership of the Company's common equity	42.10%
Shares owned by Public Storage | shares	14.5
Owned and operated properties (in rentable square feet)	28,000
Number of states with rentable commercial space | state	6
Managed properties (in rentable square feet)	813

Summary Of Significant Accoun30

Summary Of Significant Accounting Policies (Narrative) (Details)	12 Months Ended
	Dec. 31, 2015USD ($)segmentshares	Dec. 31, 2014USD ($)shares	Dec. 31, 2013USD ($)shares
Property, Plant and Equipment [Line Items]
Allowance for uncollectible accounts	$ 400,000	$ 400,000
Allowance for uncollectable deferred rent receivables	$ 909,000	841,000
Cash and cash equivalents maximum benchmark (in months)	3 months
Minimum expenditure costs subject to capitalization and depreciation	$ 2,000
Minimum expected future benefit period on expenditures cost to be capitalized and depreciated (in years)	2 years
Minimum transaction cost subject to capitalization and depreciation	$ 1,000
Minimum expected future benefit period on transaction cost to be capitalized and depreciated (in years)	1 year
Maximum transaction costs subject to being expensed as incurred	$ 1,000
Maximum length of lease period for transaction costs to be expensed as incurred	1 year
Length of time criteria for expected sale of assets to be classified as properties held for disposition	12 months
Increase (decrease) in rental income due to amortization of net intangible assets or liabilities	$ 1,251,000	901,000	$ (118,000)
Value of in-place leases resulting in a net intangible asset	1,700,000	2,500,000
Accumulated amortization - intangible assets	$ 8,600,000	7,800,000
Intangible assets, weighted average amortization period (in years)	8 years 8 months 12 days
Value of in-place leases resulting in a net intangible liability	$ 1,800,000	3,900,000
Accumulated amortization - intangible liabilities	$ 9,000,000	$ 6,900,000
Intangible liability, weighted average amortization period (in years)	5 years 4 months 24 days
Distribution of taxable income requirement	90.00%
Income tax provision	$ 0
Odds of a particular tax position will be sustained upon examination or audit	50.00%
Anti-dilutive share options to purchase | shares	32,000	16,000	14,000
Number of operating segments | segment	1
Maximum [Member] | Building And Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	30 years
Minimum [Member] | Building And Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	5 years

Summary Of Significant Accoun31

Summary Of Significant Accounting Policies (Net Income Allocation) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Summary Of Significant Accounting Policies [Abstract]
Noncontrolling interests - common units									$ 18,495	$ 30,729	$ 12,952
Total net income allocable to noncontrolling interests - common units									18,495	30,729	12,952
Total net income allocable to noncontrolling interests									18,495	30,729	12,952
Distributions to preferred shareholders									59,398	60,488	59,216
Preferred shareholders: Non-cash distributions related to the redemption of preferred stock									2,487
Total net income allocable to preferred shareholders									61,885	60,488	59,216
Restricted stock unit holders									299	329	125
Common shareholders	$ 14,906	$ 22,484	$ 11,129	$ 19,771	$ 82,131	$ 11,268	$ 9,826	$ 9,940	68,291	113,154	43,851
Total net income allocable to PS Business Parks, Inc.									130,475	173,971	103,192
Net income									$ 148,970	$ 204,700	$ 116,144

Summary Of Significant Accoun32

Summary Of Significant Accounting Policies (Calculation Of Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Summary Of Significant Accounting Policies [Abstract]
Net income allocable to common shareholders	$ 14,906	$ 22,484	$ 11,129	$ 19,771	$ 82,131	$ 11,268	$ 9,826	$ 9,940	$ 68,291	$ 113,154	$ 43,851
Basic weighted average common shares outstanding									26,973	26,899	24,732
Net effect of dilutive stock compensation - based on treasury stock method using average market price									78	101	101
Diluted weighted average common shares outstanding									27,051	27,000	24,833
Net income per common share - Basic	$ 0.55	$ 0.83	$ 0.41	$ 0.73	$ 3.05	$ 0.42	$ 0.37	$ 0.37	$ 2.53	$ 4.21	$ 1.77
Net income per common share - Diluted	$ 0.55	$ 0.83	$ 0.41	$ 0.73	$ 3.04	$ 0.42	$ 0.36	$ 0.37	$ 2.52	$ 4.19	$ 1.77

Real Estate Facilities (Narrati

Real Estate Facilities (Narrative) (Details)

Sep. 28, 2015USD ($)ft²

Feb. 27, 2015USD ($)ft²item

Feb. 13, 2015USD ($)ft²item

Nov. 21, 2014USD ($)ft²item

Oct. 01, 2014USD ($)aft²item

Jul. 31, 2015USD ($)ft²item

Dec. 31, 2015USD ($)ft²

Dec. 31, 2014USD ($)ft²

Dec. 31, 2013USD ($)

Jul. 24, 2015ft²item

Dec. 30, 2014USD ($)ft²item

Nov. 03, 2014USD ($)ft²

Aug. 21, 2014USD ($)ft²item

Jul. 28, 2014USD ($)ft²

Jul. 24, 2014USD ($)ft²

Dec. 20, 2013USD ($)ft²property

Nov. 08, 2013USD ($)ft²property

Oct. 15, 2013USD ($)aft²property

Jul. 26, 2013USD ($)ft²property

Real Estate Facilities [Line Items]

Federal income tax basis of real estate facilities

$ 1,900,000,000

Percentage of properties encumbered by mortgage debt

21.70%

Leasable space (in square feet) | ft²

27,969

Acquisition transaction costs

$ 350,000

$ 854,000

Area of property held for disposition | ft²

574,000

Charcot Business Park II [Member]

Real Estate Facilities [Line Items]

Acquisition date of real estate

Dec. 30, 2014

Number of buildings acquired | item

8

Leasable space (in square feet) | ft²

119,000

Purchase price

$ 16,000,000

Charcot Business Park [Member]

Real Estate Facilities [Line Items]

Leasable space (in square feet) | ft²

164,000

McNeil I [Member]

Real Estate Facilities [Line Items]

Acquisition date of real estate

Nov. 3, 2014

Leasable space (in square feet) | ft²

246,000

Purchase price

$ 10,600,000

Bayshore Corporate Center [Member]

Real Estate Facilities [Line Items]

Acquisition date of real estate

Dec. 20, 2013

Number of buildings acquired | property

8

Leasable space (in square feet) | ft²

340,000

Purchase price

$ 60,500,000

MICC Center 23 [Member]

Real Estate Facilities [Line Items]

Acquisition date of real estate

Jul. 24, 2014

Leasable space (in square feet) | ft²

149,000

Purchase price

$ 12,700,000

MICC [Member]

Real Estate Facilities [Line Items]

Leasable space (in square feet) | ft²

3,300,000

Arapaho Business Park 9 [Member]

Real Estate Facilities [Line Items]

Acquisition date of real estate

Jul. 28, 2014

Leasable space (in square feet) | ft²

19,000

Purchase price

$ 1,100,000

Springlake Business Center II [Member]

Real Estate Facilities [Line Items]

Acquisition date of real estate

Aug. 21, 2014

Number of buildings acquired | item

6

Leasable space (in square feet) | ft²

145,000

Purchase price

$ 5,100,000

Arapaho Business Park [Member]

Real Estate Facilities [Line Items]

Acquisition date of real estate

Jul. 26, 2013

Number of buildings acquired | property

18

Leasable space (in square feet) | ft²

389,000

389,000

Purchase price

$ 14,800,000

Dallas Multi-Tenant Flex Parks [Member]

Real Estate Facilities [Line Items]

Acquisition date of real estate

Oct. 15, 2013

Number of parks acquired | property

4

Number of acres acquired | a

4

Leasable space (in square feet) | ft²

559,000

Purchase price

$ 27,900,000

Valwood Business Center [Member]

Real Estate Facilities [Line Items]

Acquisition date of real estate

Nov. 8, 2013

Number of buildings acquired | property

9

Leasable space (in square feet) | ft²

245,000

Purchase price

$ 12,400,000

McKellips Business Park [Member]

Real Estate Facilities [Line Items]

Leasable space (in square feet) | ft²

23,000

Disposal date of real estate

Sep. 28, 2015

Proceeds from the sale of real estate facility

$ 1,300,000

Gain on sale of real estate facilities

$ 759,000

North Pointe Business Park [Member]

Real Estate Facilities [Line Items]

Leasable space (in square feet) | ft²

213,000

Disposal date of real estate

Jul. 24, 2015

Number of buildings sold | item

5

Northgate Business Park [Member]

Real Estate Facilities [Line Items]

Leasable space (in square feet) | ft²

154,000

Disposal date of real estate

Jul. 31, 2015

Number of buildings sold | item

12

Overlake [Member]

Real Estate Facilities [Line Items]

Leasable space (in square feet) | ft²

82,000

Disposal date of real estate

Feb. 27, 2015

Proceeds from the sale of real estate facility

$ 13,900,000

Number of buildings sold | item

5

Gain on sale of real estate facilities

$ 4,800,000

Milwaukie Business Park [Member]

Real Estate Facilities [Line Items]

Leasable space (in square feet) | ft²

102,000

Disposal date of real estate

Feb. 13, 2015

Proceeds from the sale of real estate facility

$ 10,600,000

Number of buildings sold | item

6

Gain on sale of real estate facilities

$ 7,600,000

Sacramento Business Parks [Member]

Real Estate Facilities [Line Items]

Disposal date of real estate

Jul. 1, 2015

Number of business parks sold | item

2

Proceeds from the sale of real estate facility

$ 29,300,000

Gain on sale of real estate facilities

$ 15,000,000

Phoenix Business Parks [Member]

Real Estate Facilities [Line Items]

Leasable space (in square feet) | ft²

656,000

Disposal date of real estate

Nov. 21, 2014

Number of business parks sold | item

3

Proceeds from the sale of real estate facility

$ 52,200,000

Number of buildings sold | item

42

Gain on sale of real estate facilities

$ 29,600,000

Beaverton Business Parks [Member]

Real Estate Facilities [Line Items]

Leasable space (in square feet) | ft²

1,200,000

Disposal date of real estate

Oct. 1, 2014

Number of acres | a

11.5

Number of business parks sold | item

2

Proceeds from the sale of real estate facility

$ 159,900,000

Number of buildings sold | item

18

Gain on sale of real estate facilities

$ 62,800,000

Real Estate Facilities (Activit

Real Estate Facilities (Activity In Real Estate Facilities) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Balances	$ 1,985,065	$ 1,991,959	$ 1,933,319
Acquisition of real estate facilities		46,298	116,610
Capital expenditures	46,777	54,462	60,228
Depreciation and amortization	(105,394)	(110,357)	(108,917)
Transfer to properties sold	33	2,703	6,138
Transfer to land and building held for development			(15,419)
Balances	1,926,481	1,985,065	1,991,959
Land [Member]
Property, Plant and Equipment [Line Items]
Balances	$ 793,569	772,161	738,421
Acquisition of real estate facilities		$ 21,408	$ 39,667
Capital expenditures
Disposals
Depreciation and amortization
Transfer to properties sold
Transfer to land and building held for development			$ (5,927)
Balances	$ 793,569	$ 793,569	772,161
Building And Improvements [Member]
Property, Plant and Equipment [Line Items]
Balances	2,182,993	2,115,987	2,005,943
Acquisition of real estate facilities		24,890	76,943
Capital expenditures	46,777	54,462	60,228
Disposals	(13,990)	(10,587)	(15,391)
Transfer to properties sold	(265)	(1,759)	(1,466)
Transfer to land and building held for development			(10,270)
Balances	2,215,515	2,182,993	2,115,987
Accumulated Depreciation [Member]
Property, Plant and Equipment [Line Items]
Balances	(991,497)	(896,189)	(811,045)
Disposals	13,990	10,587	15,391
Depreciation and amortization	(105,394)	(110,357)	(108,917)
Transfer to properties sold	298	4,462	7,604
Transfer to land and building held for development			778
Balances	$ (1,082,603)	$ (991,497)	$ (896,189)

Real Estate Facilities (Summary

Real Estate Facilities (Summary Of Real Estate Assets Acquired And Liabilities Assumed) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Real Estate Facilities [Abstract]
Land	$ 21,408	$ 39,667
Land held for development		990
Buildings and improvements	24,890	76,943
Above-market in-place lease value		403
Below-market in-place lease value	(666)	(2,428)
Total purchase price	45,632	115,575
Net operating assets acquired and liabilities assumed	(611)	(1,630)
Total cash paid	$ 45,021	$ 113,945

Investment in Unconsolidated 36

Investment in Unconsolidated Joint Venture (Details)	3 Months Ended	10 Months Ended	12 Months Ended
	Dec. 31, 2015USD ($)a	Oct. 31, 2015USD ($)	Dec. 31, 2015USD ($)aproperty	Dec. 31, 2014USD ($)
Investment in unconsolidated joint venture	$ 26,736,000		$ 26,736,000
Land and building held for development	$ 6,081,000		$ 6,081,000	$ 24,442,000
Investment in Unconsolidated Joint Venture [Member]
Economic interest in joint venture, percentage	95.00%		95.00%
Number of units to be developed | property			395
Area of land | a	5		5
Contribution date			Oct. 5, 2015
Cash contribution to unconsolidated joint venture	$ 5,200,000
Interest costs on investment in the joint venture	$ 346,000
Northern Virginia Redeveloped Land [Member]
Land and building held for development				18,400,000
Capitalized cost		$ 2,800,000		2,200,000
Capitalized interest expense		$ 813,000		$ 944,000

Leasing Activity (Narrative) (D

Leasing Activity (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Tenant reimbursements	$ 78.9	$ 80.7	$ 75.1
Percentage of leased asset subjected to termination options	2.90%
Percentage of leased asset exercisable in period	1.60%
Maximum [Member]
Non-cancelable leases term (in years)	10 years
Minimum [Member]
Non-cancelable leases term (in years)	1 year

Leasing Activity (Summary Of Fu

Leasing Activity (Summary Of Future Minimum Rental Revenues Excluding Recovery Of Operating Expenses) (Details) $ in Thousands	Dec. 31, 2015USD ($)
Leasing Activity [Abstract]
2,016	$ 265,816
2,017	201,788
2,018	146,980
2,019	99,678
2,020	63,771
Thereafter	122,574
Total	$ 900,607

Bank Loans (Details)

Bank Loans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2012	Dec. 20, 2011
Line of Credit Facility [Line Items]
Line of credit, expiration date	May 1, 2019
Credit Facility, borrowing limit	$ 250,000,000
Credit Facility, frequency of interest payment	monthly
Spread over LIBOR	0.875%
Credit Facility, percentage of commitment fees	0.125%
Credit Facility, amount outstanding	$ 0		$ 0
Unamortized commitment fees	$ 769,000		$ 1,000,000
Maximum [Member]
Line of Credit Facility [Line Items]
Spread over LIBOR	1.70%
Credit Facility, percentage of commitment fees	0.30%
Minimum [Member]
Line of Credit Facility [Line Items]
Spread over LIBOR	0.875%
Credit Facility, percentage of commitment fees	0.125%
Term Loan Agreement [Member]
Line of Credit Facility [Line Items]
Spread over LIBOR		1.20%
Unsecured debt					$ 250,000,000
Unamortized commitment fees				$ 383,000
Accelerated amortization of commitment fees		$ 383,000
Debt instrument, maturity date	Dec. 31, 2014
Debt instrument, repayment date	Nov. 1, 2013
Term Loan Agreement [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Spread over LIBOR	2.25%
Term Loan Agreement [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Spread over LIBOR	1.15%

Mortgage Note Payable (Details)

Mortgage Note Payable (Details) $ in Thousands, ft² in Millions	1 Months Ended	12 Months Ended
	Jan. 31, 2013USD ($)item	Dec. 31, 2015USD ($)ft²	Dec. 31, 2014USD ($)
Debt Instrument [Line Items]
Mortgage notes payable, carrying amount		$ 250,000	$ 250,000
5.45% Mortgage Note [Member]
Debt Instrument [Line Items]
Interest rate		5.45%
Secured by square feet of real estate facilities | ft²		4.8
Net book value of secured property		$ 417,700
Mortgage note, frequency of interest payment		monthly
Mortgage note due date		Dec. 1, 2016
Mortgage note, earliest prepayment date without penalty		Jun. 1, 2016
Two Repaid Mortgage Notes [Member]
Debt Instrument [Line Items]
Interest rate	5.60%
Debt Instrument, Repayment Date		Jan. 1, 2013
Number of mortgage notes repaid | item	2
Mortgage note repayment amount	$ 18,100

Noncontrolling Interests (Detai

Noncontrolling Interests (Details) - $ / shares	Dec. 30, 2014	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Noncontrolling Interests [Line Items]
Number of years from date of admission as a limited partner for redemption of partnership interest			1 year
Number of common stock per unit of limited partnership interest redeemed			1
Common units owned by affiliate			7,305,355
Affiliate's percent ownership of the Company's common equity			42.10%
Shares owned by Public Storage			14,500,000
Dividends declared per common share			$ 2.20	$ 4.75	$ 1.76
Special Cash Dividend Paid [Member]
Noncontrolling Interests [Line Items]
Dividends declared per common share	$ 2.75
Fourth Quarter Dividend [Member]
Noncontrolling Interests [Line Items]
Dividends declared per common share		$ 0.50

Related Party Transactions (Det

Related Party Transactions (Details)	Nov. 07, 2013USD ($)shares	Dec. 31, 2015USD ($)item	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)	Oct. 31, 2013	Oct. 01, 2013USD ($)
Related Party Transaction [Line Items]
Number of common stock shares sold to PS | shares	950,000
Proceeds from sale of common stock shares sold to PS	$ 75,300,000
Royalty-free license agreement written notice of termination period minimum (in months)		6 months
Property management contract term (in years)		7 years
Extended property management contract period (in years)		1 year
Management fee revenues		$ 540,000	$ 660,000	$ 639,000
Number of assets owned that are maintained by Public Storage | item		2
Property management contract written notice of termination period minimum (in days)		60 days
Management fee expenses		$ 79,000	70,000	59,000
Administrative services costs		469,000	451,000	432,000
Due from related parties		$ 57,000	$ 166,000
PS [Member]
Related Party Transaction [Line Items]
Proceeds from sale of ownership interest				$ 1,100,000
Ownership percentage during period				4.00%
Ownership percentage				0.00%
PS Loan Receivable [Member]
Related Party Transaction [Line Items]
Amount lent to related party						$ 100,000,000
Debt instrument, maturity date		Nov. 29, 2013
Term loan, repayment date		Oct. 18, 2013
Term loan, interest rate					1.388%
Interest income from related party				$ 66,000

Shareholders' Equity (Narrative

Shareholders' Equity (Narrative) (Details) $ / shares in Units, shares in Millions	Oct. 15, 2015USD ($)	Mar. 14, 2013USD ($)$ / sharesshares	Dec. 31, 2015USD ($)item$ / shares	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Class of Stock [Line Items]
Redemption/repurchase of preferred stock			$ 75,000,000
Non-cash distributions related to the redemption of preferred stock			2,487,000
Preferred Stock, Value, Outstanding			920,000,000	$ 995,000,000
Distributions paid to preferred shareholders			$ 59,398,000	60,488,000	$ 59,216,000
Number of quarterly dividends in arrearage before preferred shareholders can elect additional board members | item			6
Number of additional board members the preferred shareholders can elect in the case of an excess arrearage of quarterly dividends | item			2
Dividends in arrears			$ 0
Redeemable preferred stock, redemption price per share | $ / shares			$ 25
Preferred stock, aggregate deferred issuance costs outstanding			$ 29,300,000	$ 31,800,000
Series R [Member]
Class of Stock [Line Items]
Cumulative preferred stock, dividend rate	6.875%		6.875%	6.875%
Redemption/repurchase of preferred stock	$ 75,000,000
Issuance Date			Oct. 1, 2010	Oct. 1, 2010
Preferred Stock, Value, Outstanding				$ 75,000,000
Redemption date			Oct. 1, 2015	Oct. 1, 2015
Series V [Member]
Class of Stock [Line Items]
Cumulative preferred stock, dividend rate		5.70%	5.70%	5.70%
Issuance Date			Mar. 1, 2013	Mar. 1, 2013
Preferred Stock, Value, Outstanding		$ 110,000,000	$ 110,000,000	$ 110,000,000
Depositary shares issued | shares		4.4
Depository shares conversion ratio to preferred share		0.10%
Depositary shares issued price per share | $ / shares		$ 25
Redemption date			Mar. 1, 2018	Mar. 1, 2018

Shareholders' Equity (Common An

Shareholders' Equity (Common And Equity Stock) (Details) - USD ($) $ / shares in Units, $ in Thousands	Nov. 07, 2013	Feb. 19, 2016	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Shareholders' Equity [Line Items]
Shares issued or sold	1,495,000
Proceeds from issuance of common stock						$ 192,329
Increase in Distributions paid to common shareholders per quarter				$ 59,377	$ 127,838	$ 43,972
Dividends declared per common share				$ 2.20	$ 4.75	$ 1.76
Percentage of distributions classified as ordinary income				89.40%	70.50%	98.90%
Percentage of distributions classified as long-term capital gain income				10.60%	29.50%	1.10%
Equity stock, shares authorized				100,000,000
Common Stock [Member]
Shareholders' Equity [Line Items]
Aggregate number of common stock repurchased in the period				0	0	0
PS [Member]
Shareholders' Equity [Line Items]
Shares issued or sold	950,000
Special Cash Dividend [Member]
Shareholders' Equity [Line Items]
Dividends declared per common share			$ 2.75
Fourth Quarter Dividend [Member]
Shareholders' Equity [Line Items]
Dividends declared per common share			$ 0.50
Subsequent Event [Member]
Shareholders' Equity [Line Items]
Previous dividends declared per common share		$ 0.60
Increase in Distributions paid to common shareholders per quarter		$ 5,200
Dividends declared per common share		$ 0.75

Shareholders' Equity (Schedule

Shareholders' Equity (Schedule Of Preferred Stock Outstanding) (Details) - USD ($) $ in Thousands	Oct. 15, 2015	Mar. 14, 2013	Dec. 31, 2015	Dec. 31, 2014
Class of Stock [Line Items]
Shares Outstanding			36,800	39,800
Amount			$ 920,000	$ 995,000
Series S [Member]
Class of Stock [Line Items]
Issuance Date			Jan. 1, 2012	Jan. 1, 2012
Earliest Potential Redemption Date			Jan. 1, 2017	Jan. 1, 2017
Dividend Rate			6.45%	6.45%
Shares Outstanding			9,200	9,200
Amount			$ 230,000	$ 230,000
Series T [Member]
Class of Stock [Line Items]
Issuance Date			May 1, 2012	May 1, 2012
Earliest Potential Redemption Date			May 1, 2017	May 1, 2017
Dividend Rate			6.00%	6.00%
Shares Outstanding			14,000	14,000
Amount			$ 350,000	$ 350,000
Series U [Member]
Class of Stock [Line Items]
Issuance Date			Sep. 1, 2012	Sep. 1, 2012
Earliest Potential Redemption Date			Sep. 1, 2017	Sep. 1, 2017
Dividend Rate			5.75%	5.75%
Shares Outstanding			9,200	9,200
Amount			$ 230,000	$ 230,000
Series V [Member]
Class of Stock [Line Items]
Issuance Date			Mar. 1, 2013	Mar. 1, 2013
Earliest Potential Redemption Date			Mar. 1, 2018	Mar. 1, 2018
Dividend Rate		5.70%	5.70%	5.70%
Shares Outstanding			4,400	4,400
Amount		$ 110,000	$ 110,000	$ 110,000
Series R [Member]
Class of Stock [Line Items]
Issuance Date			Oct. 1, 2010	Oct. 1, 2010
Earliest Potential Redemption Date			Oct. 1, 2015	Oct. 1, 2015
Dividend Rate	6.875%		6.875%	6.875%
Shares Outstanding				3,000
Amount				$ 75,000

Stock Compensation (Narrative)

Stock Compensation (Narrative) (Details)	12 Months Ended
	Dec. 31, 2015USD ($)item$ / sharesshares	Dec. 31, 2014USD ($)$ / sharesshares	Dec. 31, 2013USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options and restricted stock units authorized to grant	1,300,000
Proceeds from the exercise of stock options | $	$ 5,089,000	$ 3,054,000	$ 4,682,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	5 years
Vesting percentage, year one	20.00%
Vesting percentage, year two	20.00%
Vesting percentage, year three	20.00%
Vesting percentage, year four	20.00%
Vesting percentage, year five	20.00%
Expiration period (in years)	10 years
Weighted average grant date fair value of options granted | $ / shares	$ 8.49	$ 10.95	$ 9.18
Dividend yield	2.50%	2.30%	2.20%
Expected volatility	16.10%	17.70%	17.50%
Expected life (in years)	5 years	5 years	5 years
Risk-free interest rate	1.40%	1.70%	1.00%
Stock options expense | $	$ 261,000	$ 1,100,000	$ 425,000
Unamortized compensation expense | $	$ 412,000
Weighted average recognized period of unamortized compensation expenses (in years)	3 years
Exercise of stock options, shares	99,178	61,273	97,800
Aggregate intrinsic value of the stock options exercised | $	$ 2,600,000	$ 2,100,000	$ 3,100,000
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	6 years
Vesting percentage, year one	0.00%
Vesting percentage, year two	20.00%
Vesting percentage, year three	20.00%
Vesting percentage, year four	20.00%
Vesting percentage, year five	20.00%
Vesting percentage, year six	20.00%
Restricted stock units granted	75,606	6,800	8,350
Weighted average grant date fair value of stock granted | $ / shares	$ 82.78	$ 81.47	$ 73.85
Restricted stock units expense | $	$ 433,000	$ 526,000	$ 671,000
Unamortized compensation expense | $	$ 20,200,000
Weighted average recognized period of unamortized compensation expenses (in years)	4 years 3 months 18 days
Number of units vested	25,384	12,980	13,690
Number of units issued	15,734	8,066	8,547
Aggregate fair value of the shares vested | $	$ 2,000,000	$ 1,100,000	$ 1,000,000
Special Cash Dividend [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options expense | $		644,000
2003 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares covered under Stock Option and Incentive Plan	1,500,000
2012 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares covered under Stock Option and Incentive Plan	1,000,000
Vesting period (in years)	5 years
Expiration period (in years)	10 years
2014 Performance-Based Restricted Stock Unit Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units granted	66,506
Weighted average grant date fair value of stock granted | $ / shares	$ 83.47
Number of defined targets to achieve for restricted stock unit awards, maximum | item	3
Number of defined targets to achieve for restricted stock unit awards, minimum | item	1
Length of Restricted Stock Unit program (in years)	4 years
Number of annual vesting installments | item	4
Approximate number of restricted stock units granted per year, maximum	96,650
Maximum shares for cumulative four-year period	82,846
Compensation expense | $	$ 8,200,000	7,400,000
Unamortized compensation expense | $	$ 18,500,000
Number of units vested	16,634
Number of units issued	10,495
Aggregate fair value of the shares vested | $	$ 1,300,000
2012 Performance-Based Restricted Stock Unit Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reversal of LTEIP amortization | $			3,900,000
Retirement Plan For Non-Employee Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $	316,000	550,000	264,000
Additional compensation expense | $	243,000
Unamortized compensation expense | $	$ 1,200,000	$ 1,500,000	$ 1,400,000
Number of units issued	0	0	0
Shares approved for issuance	130,000
Number of shares granted for each year served	1,000
Maximum number of shares issued upon retirement	8,000

Stock Compensation (Summary Of

Stock Compensation (Summary Of Stock Options Activity) (Details) - Stock Options [Member] - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options, Outstanding		341,852	380,773	454,573
Number of Options, Granted		16,000	16,000	24,000
Number of Options, Exercised		(99,178)	(61,273)	(97,800)
Number of Options, Forfeited			(4,000)
Number of options, Special dividend adjustment	[1]		10,352
Number of Options, Outstanding		258,674	341,852	380,773
Number of Options, Exercisable at December 31, 2015		194,999
Weighted Average Exercise Price, Outstanding		$ 57.11	$ 56.45	$ 53.41
Weighted Average Exercise Price, Granted		80.13	82.84	78.99
Weighted Average Exercise Price, Exercised		51.31	49.84	47.87
Weighted Average Exercise Price, Forfeited			52.35
Weighted Average Exercise Price, Outstanding		60.76	$ 57.11	$ 56.45
Weighted Average Exercise Price, Exercisable at December 31, 2015		$ 56.23
Weighted Average Remaining Contract Life, Outstanding at December 31, 2015		5 years 4 days
Weighted Average Remaining Contract Life, Exercisable at December 31, 2015		4 years 1 month 21 days
Aggregate Intrinsic Value, Outstanding at December 31, 2015		$ 6,899
Aggregate Intrinsic Value, Exercisable at December 31, 2015		$ 6,084
[1]	In accordance with the applicable equity award plan documents, the number and exercise price of outstanding options as of December 31, 2014 have been adjusted as a result of the Special Cash Dividend so that the option holder maintains their economic position with respect to the shareholders.

Stock Compensation (Nonvested R

Stock Compensation (Nonvested Restricted Stock Units) (Details) - Restricted Stock [Member] - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Units, Nonvested	35,170	45,100	53,090
Number of Units, Granted	75,606	6,800	8,350
Number of Units, Vested	(25,384)	(12,980)	(13,690)
Number of Units, Forfeited	(6,740)	(3,750)	(2,650)
Number of Units, Nonvested	78,652	35,170	45,100
Weighted Average Grant Date Fair Value, Nonvested	$ 65.62	$ 60.07	$ 55.69
Weighted Average Grant Date Fair Value, Granted	82.78	81.47	73.85
Weighted Average Grant Date Fair Value, Vested	74.19	53.65	53.84
Weighted Average Grant Date Fair Value, Forfeited	76.22	69	47.96
Weighted Average Grant Date Fair Value, Nonvested	$ 78.44	$ 65.62	$ 60.07

Supplementary Quarterly Finan49

Supplementary Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Supplementary Quarterly Financial Data [Abstract]
Rental income	$ 94,550	$ 93,322	$ 92,948	$ 92,315	$ 91,321	$ 95,627	$ 93,986	$ 95,321	$ 373,135	$ 376,255	$ 359,246
Cost of operations	28,973	30,448	30,057	31,746	29,290	33,102	31,535	33,444	121,224	127,371	114,831
Net income allocable to common shareholders	$ 14,906	$ 22,484	$ 11,129	$ 19,771	$ 82,131	$ 11,268	$ 9,826	$ 9,940	$ 68,291	$ 113,154	$ 43,851
Net income per share: Basic	$ 0.55	$ 0.83	$ 0.41	$ 0.73	$ 3.05	$ 0.42	$ 0.37	$ 0.37	$ 2.53	$ 4.21	$ 1.77
Net income per share: Diluted	$ 0.55	$ 0.83	$ 0.41	$ 0.73	$ 3.04	$ 0.42	$ 0.36	$ 0.37	$ 2.52	$ 4.19	$ 1.77

401(k) Plan (Details)

401(k) Plan (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stock Compensation [Abstract]
Matching contributions by employer, percentage	4.00%
Expenses related to 401(k) savings plan	$ 410,000	$ 417,000	$ 362,000

Real Estate And Accumulated D51

Real Estate And Accumulated Depreciation (Real Estate And Accumulated Depreciation) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)ft²property
Real Estate and Accumulated Depreciation [Line Items]
Square Feet | ft²	27,969
Encumbrances	$ 250,000
Initial Cost to Company, Land	793,569
Initial Cost to Company, Buildings and Improvements	1,727,413
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	488,102
Gross Amount at Which Carried at December 31, 2015, Land	793,569
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	2,215,515
Gross Amount at Which Carried at December 31, 2015, Total	3,009,084
Accumulated Depreciation	$ 1,082,603
Number of properties subject to ground leases | property	2
Las Colinas Lease Expiring In 2019 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ground leases expiration, extension option period (in years)	10 years
Las Colinas Lease Expiring In 2020 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ground leases expiration, extension option period (in years)	10 years
Buena Park Industrial Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Buena Park, CA
Square Feet | ft²	317
Initial Cost to Company, Land	$ 3,245
Initial Cost to Company, Buildings and Improvements	7,703
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	2,667
Gross Amount at Which Carried at December 31, 2015, Land	3,245
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	10,370
Gross Amount at Which Carried at December 31, 2015, Total	13,615
Accumulated Depreciation	$ 6,595
Year(s) Acquired	1,997
Carson [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Carson, CA
Square Feet | ft²	77
Initial Cost to Company, Land	$ 990
Initial Cost to Company, Buildings and Improvements	2,496
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	1,451
Gross Amount at Which Carried at December 31, 2015, Land	990
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	3,947
Gross Amount at Which Carried at December 31, 2015, Total	4,937
Accumulated Depreciation	$ 2,698
Year(s) Acquired	1,997
Cerritos Business Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Cerritos, CA
Square Feet | ft²	395
Initial Cost to Company, Land	$ 4,218
Initial Cost to Company, Buildings and Improvements	10,273
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	4,129
Gross Amount at Which Carried at December 31, 2015, Land	4,218
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	14,402
Gross Amount at Which Carried at December 31, 2015, Total	18,620
Accumulated Depreciation	$ 9,428
Year(s) Acquired	1,997
Cerritos/Edwards [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Cerritos, CA
Square Feet | ft²	31
Initial Cost to Company, Land	$ 450
Initial Cost to Company, Buildings and Improvements	1,217
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	1,407
Gross Amount at Which Carried at December 31, 2015, Land	450
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	2,624
Gross Amount at Which Carried at December 31, 2015, Total	3,074
Accumulated Depreciation	$ 1,816
Year(s) Acquired	1,997
Concord Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Concord, CA
Square Feet | ft²	246
Initial Cost to Company, Land	$ 12,454
Initial Cost to Company, Buildings and Improvements	20,491
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	844
Gross Amount at Which Carried at December 31, 2015, Land	12,454
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	21,335
Gross Amount at Which Carried at December 31, 2015, Total	33,789
Accumulated Depreciation	$ 4,185
Year(s) Acquired	2,011
Culver City [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Culver City, CA
Square Feet | ft²	147
Initial Cost to Company, Land	$ 3,252
Initial Cost to Company, Buildings and Improvements	8,157
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	5,951
Gross Amount at Which Carried at December 31, 2015, Land	3,252
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	14,108
Gross Amount at Which Carried at December 31, 2015, Total	17,360
Accumulated Depreciation	$ 10,052
Year(s) Acquired	1,997
Bayview Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Fremont, CA
Square Feet | ft²	104
Encumbrances	$ 7,300
Initial Cost to Company, Land	4,990
Initial Cost to Company, Buildings and Improvements	4,831
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	234
Gross Amount at Which Carried at December 31, 2015, Land	4,990
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	5,065
Gross Amount at Which Carried at December 31, 2015, Total	10,055
Accumulated Depreciation	$ 1,307
Year(s) Acquired	2,011
Christy Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Fremont, CA
Square Feet | ft²	334
Encumbrances	$ 14,200
Initial Cost to Company, Land	11,451
Initial Cost to Company, Buildings and Improvements	16,254
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	1,435
Gross Amount at Which Carried at December 31, 2015, Land	11,451
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	17,689
Gross Amount at Which Carried at December 31, 2015, Total	29,140
Accumulated Depreciation	$ 4,069
Year(s) Acquired	2,011
Industrial Drive Distribution Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Fremont, CA
Square Feet | ft²	199
Encumbrances	$ 5,300
Initial Cost to Company, Land	7,482
Initial Cost to Company, Buildings and Improvements	6,812
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	787
Gross Amount at Which Carried at December 31, 2015, Land	7,482
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	7,599
Gross Amount at Which Carried at December 31, 2015, Total	15,081
Accumulated Depreciation	$ 1,453
Year(s) Acquired	2,011
Bay Center Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hayward, CA
Square Feet | ft²	463
Encumbrances	$ 27,500
Initial Cost to Company, Land	19,052
Initial Cost to Company, Buildings and Improvements	50,501
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	3,522
Gross Amount at Which Carried at December 31, 2015, Land	19,052
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	54,023
Gross Amount at Which Carried at December 31, 2015, Total	73,075
Accumulated Depreciation	$ 10,532
Year(s) Acquired	2,011
Cabot Distribution Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hayward, CA
Square Feet | ft²	249
Encumbrances	$ 9,300
Initial Cost to Company, Land	5,859
Initial Cost to Company, Buildings and Improvements	10,811
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	374
Gross Amount at Which Carried at December 31, 2015, Land	5,859
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	11,185
Gross Amount at Which Carried at December 31, 2015, Total	17,044
Accumulated Depreciation	$ 2,153
Year(s) Acquired	2,011
Diablo Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hayward, CA
Square Feet | ft²	271
Initial Cost to Company, Land	$ 9,102
Initial Cost to Company, Buildings and Improvements	15,721
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	825
Gross Amount at Which Carried at December 31, 2015, Land	9,102
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	16,546
Gross Amount at Which Carried at December 31, 2015, Total	25,648
Accumulated Depreciation	$ 3,396
Year(s) Acquired	2,011
Eden Landing [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hayward, CA
Square Feet | ft²	83
Encumbrances	$ 4,800
Initial Cost to Company, Land	3,275
Initial Cost to Company, Buildings and Improvements	6,174
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	131
Gross Amount at Which Carried at December 31, 2015, Land	3,275
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	6,305
Gross Amount at Which Carried at December 31, 2015, Total	9,580
Accumulated Depreciation	$ 1,334
Year(s) Acquired	2,011
Hayward Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hayward, CA
Square Feet | ft²	1,091
Encumbrances	$ 46,400
Initial Cost to Company, Land	28,256
Initial Cost to Company, Buildings and Improvements	54,418
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	2,424
Gross Amount at Which Carried at December 31, 2015, Land	28,256
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	56,842
Gross Amount at Which Carried at December 31, 2015, Total	85,098
Accumulated Depreciation	$ 10,696
Year(s) Acquired	2,011
Huntwood Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hayward, CA
Square Feet | ft²	176
Encumbrances	$ 11,600
Initial Cost to Company, Land	7,391
Initial Cost to Company, Buildings and Improvements	11,819
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	964
Gross Amount at Which Carried at December 31, 2015, Land	7,391
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	12,783
Gross Amount at Which Carried at December 31, 2015, Total	20,174
Accumulated Depreciation	$ 2,868
Year(s) Acquired	2,011
Parkway Commerce [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hayward, CA
Square Feet | ft²	407
Initial Cost to Company, Land	$ 4,398
Initial Cost to Company, Buildings and Improvements	10,433
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	4,727
Gross Amount at Which Carried at December 31, 2015, Land	4,398
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	15,160
Gross Amount at Which Carried at December 31, 2015, Total	19,558
Accumulated Depreciation	$ 9,962
Year(s) Acquired	1,997
Corporate Pointe [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Irvine, CA
Square Feet | ft²	161
Initial Cost to Company, Land	$ 6,876
Initial Cost to Company, Buildings and Improvements	18,519
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	6,529
Gross Amount at Which Carried at December 31, 2015, Land	6,876
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	25,048
Gross Amount at Which Carried at December 31, 2015, Total	31,924
Accumulated Depreciation	$ 16,246
Year(s) Acquired	2,000
Laguna Hills Commerce Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Laguna Hills, CA
Square Feet | ft²	513
Initial Cost to Company, Land	$ 16,261
Initial Cost to Company, Buildings and Improvements	39,559
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	7,028
Gross Amount at Which Carried at December 31, 2015, Land	16,261
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	46,587
Gross Amount at Which Carried at December 31, 2015, Total	62,848
Accumulated Depreciation	$ 28,681
Year(s) Acquired	1,997
Plaza Del Lago [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Laguna Hills, CA
Square Feet | ft²	101
Initial Cost to Company, Land	$ 2,037
Initial Cost to Company, Buildings and Improvements	5,051
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	3,951
Gross Amount at Which Carried at December 31, 2015, Land	2,037
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	9,002
Gross Amount at Which Carried at December 31, 2015, Total	11,039
Accumulated Depreciation	$ 6,186
Year(s) Acquired	1,997
Canada [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Lake Forest, CA
Square Feet | ft²	297
Initial Cost to Company, Land	$ 5,508
Initial Cost to Company, Buildings and Improvements	13,785
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	5,675
Gross Amount at Which Carried at December 31, 2015, Land	5,508
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	19,460
Gross Amount at Which Carried at December 31, 2015, Total	24,968
Accumulated Depreciation	$ 12,616
Year(s) Acquired	1,997
Dixon Landing Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Milpitas, CA
Square Feet | ft²	505
Encumbrances	$ 30,000
Initial Cost to Company, Land	26,301
Initial Cost to Company, Buildings and Improvements	21,121
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	3,235
Gross Amount at Which Carried at December 31, 2015, Land	26,301
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	24,356
Gross Amount at Which Carried at December 31, 2015, Total	50,657
Accumulated Depreciation	$ 5,710
Year(s) Acquired	2,011
Monterey/Calle [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Monterey, CA
Square Feet | ft²	12
Initial Cost to Company, Land	$ 288
Initial Cost to Company, Buildings and Improvements	706
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	336
Gross Amount at Which Carried at December 31, 2015, Land	288
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	1,042
Gross Amount at Which Carried at December 31, 2015, Total	1,330
Accumulated Depreciation	$ 717
Year(s) Acquired	1,997
Monterey Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Monterey Park, CA
Square Feet | ft²	199
Initial Cost to Company, Land	$ 3,078
Initial Cost to Company, Buildings and Improvements	7,862
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	1,566
Gross Amount at Which Carried at December 31, 2015, Land	3,078
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	9,428
Gross Amount at Which Carried at December 31, 2015, Total	12,506
Accumulated Depreciation	$ 6,261
Year(s) Acquired	1,997
Port Of Oakland [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Oakland, CA
Square Feet | ft²	200
Encumbrances	$ 10,800
Initial Cost to Company, Land	5,638
Initial Cost to Company, Buildings and Improvements	11,066
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	661
Gross Amount at Which Carried at December 31, 2015, Land	5,638
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	11,727
Gross Amount at Which Carried at December 31, 2015, Total	17,365
Accumulated Depreciation	$ 2,447
Year(s) Acquired	2,011
Orangewood [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orange County, CA
Square Feet | ft²	107
Initial Cost to Company, Land	$ 2,637
Initial Cost to Company, Buildings and Improvements	12,291
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	3,429
Gross Amount at Which Carried at December 31, 2015, Land	2,637
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	15,720
Gross Amount at Which Carried at December 31, 2015, Total	18,357
Accumulated Depreciation	$ 8,625
Year(s) Acquired	2,003
Orange County Business Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orange County, CA
Square Feet | ft²	437
Initial Cost to Company, Land	$ 9,405
Initial Cost to Company, Buildings and Improvements	35,746
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	18,093
Gross Amount at Which Carried at December 31, 2015, Land	9,405
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	53,839
Gross Amount at Which Carried at December 31, 2015, Total	63,244
Accumulated Depreciation	$ 39,421
Year(s) Acquired	2,003
Kearney Mesa [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	San Diego, CA
Square Feet | ft²	164
Initial Cost to Company, Land	$ 2,894
Initial Cost to Company, Buildings and Improvements	7,089
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	2,808
Gross Amount at Which Carried at December 31, 2015, Land	2,894
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	9,897
Gross Amount at Which Carried at December 31, 2015, Total	12,791
Accumulated Depreciation	$ 6,574
Year(s) Acquired	1,997
Lusk [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	San Diego, CA
Square Feet | ft²	371
Initial Cost to Company, Land	$ 5,711
Initial Cost to Company, Buildings and Improvements	14,049
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	5,419
Gross Amount at Which Carried at December 31, 2015, Land	5,711
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	19,468
Gross Amount at Which Carried at December 31, 2015, Total	25,179
Accumulated Depreciation	$ 13,046
Year(s) Acquired	1,997
Rose Canyon Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	San Diego, CA
Square Feet | ft²	233
Initial Cost to Company, Land	$ 15,129
Initial Cost to Company, Buildings and Improvements	20,054
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	2,202
Gross Amount at Which Carried at December 31, 2015, Land	15,129
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	22,256
Gross Amount at Which Carried at December 31, 2015, Total	37,385
Accumulated Depreciation	$ 11,416
Year(s) Acquired	2,005
Charcot Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	San Jose, CA
Square Feet | ft²	283
Encumbrances	$ 10,300
Initial Cost to Company, Land	18,654
Initial Cost to Company, Buildings and Improvements	17,580
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	1,560
Gross Amount at Which Carried at December 31, 2015, Land	18,654
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	19,140
Gross Amount at Which Carried at December 31, 2015, Total	37,794
Accumulated Depreciation	$ 4,115
Year(s) Acquired	2011/2014
Las Plumas [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	San Jose, CA
Square Feet | ft²	214
Initial Cost to Company, Land	$ 4,379
Initial Cost to Company, Buildings and Improvements	12,889
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	6,691
Gross Amount at Which Carried at December 31, 2015, Land	4,379
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	19,580
Gross Amount at Which Carried at December 31, 2015, Total	23,959
Accumulated Depreciation	$ 13,742
Year(s) Acquired	1,998
Little Orchard Distribution Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	San Jose, CA
Square Feet | ft²	213
Encumbrances	$ 5,900
Initial Cost to Company, Land	7,725
Initial Cost to Company, Buildings and Improvements	3,846
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	51
Gross Amount at Which Carried at December 31, 2015, Land	7,725
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	3,897
Gross Amount at Which Carried at December 31, 2015, Total	11,622
Accumulated Depreciation	$ 1,115
Year(s) Acquired	2,011
Montague Industrial Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	San Jose, CA
Square Feet | ft²	316
Encumbrances	$ 14,200
Initial Cost to Company, Land	14,476
Initial Cost to Company, Buildings and Improvements	12,807
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	444
Gross Amount at Which Carried at December 31, 2015, Land	14,476
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	13,251
Gross Amount at Which Carried at December 31, 2015, Total	27,727
Accumulated Depreciation	$ 3,761
Year(s) Acquired	2,011
Oakland Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	San Jose, CA
Square Feet | ft²	177
Initial Cost to Company, Land	$ 3,458
Initial Cost to Company, Buildings and Improvements	8,765
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	3,132
Gross Amount at Which Carried at December 31, 2015, Land	3,458
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	11,897
Gross Amount at Which Carried at December 31, 2015, Total	15,355
Accumulated Depreciation	$ 7,833
Year(s) Acquired	1,997
Rogers Ave [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	San Jose, CA
Square Feet | ft²	67
Initial Cost to Company, Land	$ 3,540
Initial Cost to Company, Buildings and Improvements	4,896
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	573
Gross Amount at Which Carried at December 31, 2015, Land	3,540
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	5,469
Gross Amount at Which Carried at December 31, 2015, Total	9,009
Accumulated Depreciation	$ 2,452
Year(s) Acquired	2,006
Doolittle Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	San Leandro, CA
Square Feet | ft²	113
Encumbrances	$ 4,500
Initial Cost to Company, Land	3,929
Initial Cost to Company, Buildings and Improvements	6,231
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	361
Gross Amount at Which Carried at December 31, 2015, Land	3,929
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	6,592
Gross Amount at Which Carried at December 31, 2015, Total	10,521
Accumulated Depreciation	$ 1,507
Year(s) Acquired	2,011
Bayshore Corporate Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	San Mateo, CA
Square Feet | ft²	340
Initial Cost to Company, Land	$ 25,108
Initial Cost to Company, Buildings and Improvements	36,891
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	5,615
Gross Amount at Which Carried at December 31, 2015, Land	25,108
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	42,506
Gross Amount at Which Carried at December 31, 2015, Total	67,614
Accumulated Depreciation	$ 7,433
Year(s) Acquired	2,013
San Ramon/Norris Canyon [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	San Ramon, CA
Square Feet | ft²	52
Initial Cost to Company, Land	$ 1,486
Initial Cost to Company, Buildings and Improvements	3,642
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	1,263
Gross Amount at Which Carried at December 31, 2015, Land	1,486
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	4,905
Gross Amount at Which Carried at December 31, 2015, Total	6,391
Accumulated Depreciation	$ 3,212
Year(s) Acquired	1,997
Commerce Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Santa Clara, CA
Square Feet | ft²	251
Initial Cost to Company, Land	$ 17,218
Initial Cost to Company, Buildings and Improvements	21,914
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	3,693
Gross Amount at Which Carried at December 31, 2015, Land	17,218
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	25,607
Gross Amount at Which Carried at December 31, 2015, Total	42,825
Accumulated Depreciation	$ 15,462
Year(s) Acquired	2,007
Santa Clara Tech Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Santa Clara, CA
Square Feet | ft²	178
Initial Cost to Company, Land	$ 7,673
Initial Cost to Company, Buildings and Improvements	15,645
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	4,359
Gross Amount at Which Carried at December 31, 2015, Land	7,673
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	20,004
Gross Amount at Which Carried at December 31, 2015, Total	27,677
Accumulated Depreciation	$ 12,765
Year(s) Acquired	2,000
Walsh At Lafayette [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Santa Clara, CA
Square Feet | ft²	321
Encumbrances	$ 19,300
Initial Cost to Company, Land	13,439
Initial Cost to Company, Buildings and Improvements	17,890
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	292
Gross Amount at Which Carried at December 31, 2015, Land	13,439
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	18,182
Gross Amount at Which Carried at December 31, 2015, Total	31,621
Accumulated Depreciation	$ 4,496
Year(s) Acquired	2,011
Signal Hill [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Signal Hill, CA
Square Feet | ft²	269
Initial Cost to Company, Land	$ 6,693
Initial Cost to Company, Buildings and Improvements	12,699
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	2,672
Gross Amount at Which Carried at December 31, 2015, Land	6,693
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	15,371
Gross Amount at Which Carried at December 31, 2015, Total	22,064
Accumulated Depreciation	$ 8,697
Year(s) Acquired	1997/2006
Airport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	So San Francisco, CA
Square Feet | ft²	52
Initial Cost to Company, Land	$ 899
Initial Cost to Company, Buildings and Improvements	2,387
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	682
Gross Amount at Which Carried at December 31, 2015, Land	899
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	3,069
Gross Amount at Which Carried at December 31, 2015, Total	3,968
Accumulated Depreciation	$ 2,020
Year(s) Acquired	1,997
South San Francisco/Produce [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	So San Francisco, CA
Square Feet | ft²	41
Initial Cost to Company, Land	$ 776
Initial Cost to Company, Buildings and Improvements	1,886
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	526
Gross Amount at Which Carried at December 31, 2015, Land	776
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	2,412
Gross Amount at Which Carried at December 31, 2015, Total	3,188
Accumulated Depreciation	$ 1,540
Year(s) Acquired	1,997
Studio City/Ventura [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Studio City, CA
Square Feet | ft²	22
Initial Cost to Company, Land	$ 621
Initial Cost to Company, Buildings and Improvements	1,530
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	607
Gross Amount at Which Carried at December 31, 2015, Land	621
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	2,137
Gross Amount at Which Carried at December 31, 2015, Total	2,758
Accumulated Depreciation	$ 1,340
Year(s) Acquired	1,997
Kifer Industrial Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Sunnyvale, CA
Square Feet | ft²	287
Encumbrances	$ 28,600
Initial Cost to Company, Land	13,227
Initial Cost to Company, Buildings and Improvements	37,874
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	1,395
Gross Amount at Which Carried at December 31, 2015, Land	13,227
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	39,269
Gross Amount at Which Carried at December 31, 2015, Total	52,496
Accumulated Depreciation	$ 7,656
Year(s) Acquired	2,011
Torrance [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Torrance, CA
Square Feet | ft²	147
Initial Cost to Company, Land	$ 2,318
Initial Cost to Company, Buildings and Improvements	6,069
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	3,180
Gross Amount at Which Carried at December 31, 2015, Land	2,318
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	9,249
Gross Amount at Which Carried at December 31, 2015, Total	11,567
Accumulated Depreciation	$ 6,276
Year(s) Acquired	1,997
Boca Commerce [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Boca Raton, FL
Square Feet | ft²	135
Initial Cost to Company, Land	$ 7,795
Initial Cost to Company, Buildings and Improvements	9,258
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	2,394
Gross Amount at Which Carried at December 31, 2015, Land	7,795
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	11,652
Gross Amount at Which Carried at December 31, 2015, Total	19,447
Accumulated Depreciation	$ 4,220
Year(s) Acquired	2,006
MICC [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Miami, FL
Square Feet | ft²	3,468
Initial Cost to Company, Land	$ 95,115
Initial Cost to Company, Buildings and Improvements	112,583
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	40,030
Gross Amount at Which Carried at December 31, 2015, Land	95,115
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	152,613
Gross Amount at Which Carried at December 31, 2015, Total	247,728
Accumulated Depreciation	$ 83,721
Year(s) Acquired	2003/2011/2014
Wellington [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Wellington, FL
Square Feet | ft²	263
Initial Cost to Company, Land	$ 10,845
Initial Cost to Company, Buildings and Improvements	18,560
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	2,510
Gross Amount at Which Carried at December 31, 2015, Land	10,845
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	21,070
Gross Amount at Which Carried at December 31, 2015, Total	31,915
Accumulated Depreciation	$ 8,162
Year(s) Acquired	2,006
Ammendale [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Beltsville, MD
Square Feet | ft²	309
Initial Cost to Company, Land	$ 4,278
Initial Cost to Company, Buildings and Improvements	18,380
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	10,702
Gross Amount at Which Carried at December 31, 2015, Land	4,278
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	29,082
Gross Amount at Which Carried at December 31, 2015, Total	33,360
Accumulated Depreciation	$ 20,856
Year(s) Acquired	1,998
Gaithersburgh/Christopher [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Gaithersburg, MD
Square Feet | ft²	29
Initial Cost to Company, Land	$ 475
Initial Cost to Company, Buildings and Improvements	1,203
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	629
Gross Amount at Which Carried at December 31, 2015, Land	475
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	1,832
Gross Amount at Which Carried at December 31, 2015, Total	2,307
Accumulated Depreciation	$ 1,267
Year(s) Acquired	1,997
Metro Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Rockville, MD
Square Feet | ft²	898
Initial Cost to Company, Land	$ 33,995
Initial Cost to Company, Buildings and Improvements	94,463
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	37,270
Gross Amount at Which Carried at December 31, 2015, Land	33,995
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	131,733
Gross Amount at Which Carried at December 31, 2015, Total	165,728
Accumulated Depreciation	$ 83,239
Year(s) Acquired	2,001
Parklawn Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Rockville, MD
Square Feet | ft²	232
Initial Cost to Company, Land	$ 3,387
Initial Cost to Company, Buildings and Improvements	19,628
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	3,786
Gross Amount at Which Carried at December 31, 2015, Land	3,387
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	23,414
Gross Amount at Which Carried at December 31, 2015, Total	26,801
Accumulated Depreciation	$ 7,728
Year(s) Acquired	2,010
Shady Grove [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Rockville, MD
Square Feet | ft²	352
Initial Cost to Company, Land	$ 5,372
Initial Cost to Company, Buildings and Improvements	50,727
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	9,224
Gross Amount at Which Carried at December 31, 2015, Land	5,372
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	59,951
Gross Amount at Which Carried at December 31, 2015, Total	65,323
Accumulated Depreciation	$ 17,931
Year(s) Acquired	2,010
Westech Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Silver Spring, MD
Square Feet | ft²	532
Initial Cost to Company, Land	$ 25,261
Initial Cost to Company, Buildings and Improvements	74,572
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	16,170
Gross Amount at Which Carried at December 31, 2015, Land	25,261
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	90,742
Gross Amount at Which Carried at December 31, 2015, Total	116,003
Accumulated Depreciation	$ 50,215
Year(s) Acquired	2,006
Ben White [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Austin, TX
Square Feet | ft²	108
Initial Cost to Company, Land	$ 1,550
Initial Cost to Company, Buildings and Improvements	7,015
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	1,941
Gross Amount at Which Carried at December 31, 2015, Land	1,550
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	8,956
Gross Amount at Which Carried at December 31, 2015, Total	10,506
Accumulated Depreciation	$ 5,954
Year(s) Acquired	1,998
Lamar Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Austin, TX
Square Feet | ft²	145
Initial Cost to Company, Land	$ 2,528
Initial Cost to Company, Buildings and Improvements	6,596
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	4,331
Gross Amount at Which Carried at December 31, 2015, Land	2,528
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	10,927
Gross Amount at Which Carried at December 31, 2015, Total	13,455
Accumulated Depreciation	$ 9,185
Year(s) Acquired	1,997
McKalla [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Austin, TX
Square Feet | ft²	236
Initial Cost to Company, Land	$ 1,945
Initial Cost to Company, Buildings and Improvements	13,212
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	2,178
Gross Amount at Which Carried at December 31, 2015, Land	1,945
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	15,390
Gross Amount at Which Carried at December 31, 2015, Total	17,335
Accumulated Depreciation	$ 6,949
Year(s) Acquired	1998/2012
McNeil [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Austin, TX
Square Feet | ft²	525
Initial Cost to Company, Land	$ 5,477
Initial Cost to Company, Buildings and Improvements	24,495
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	4,140
Gross Amount at Which Carried at December 31, 2015, Land	5,477
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	28,635
Gross Amount at Which Carried at December 31, 2015, Total	34,112
Accumulated Depreciation	$ 9,041
Year(s) Acquired	1999/2010/2012/2014
Rutland [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Austin, TX
Square Feet | ft²	288
Initial Cost to Company, Land	$ 2,022
Initial Cost to Company, Buildings and Improvements	9,397
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	3,857
Gross Amount at Which Carried at December 31, 2015, Land	2,022
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	13,254
Gross Amount at Which Carried at December 31, 2015, Total	15,276
Accumulated Depreciation	$ 7,607
Year(s) Acquired	1998/1999
Waterford [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Austin, TX
Square Feet | ft²	106
Initial Cost to Company, Land	$ 2,108
Initial Cost to Company, Buildings and Improvements	9,649
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	3,840
Gross Amount at Which Carried at December 31, 2015, Land	2,108
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	13,489
Gross Amount at Which Carried at December 31, 2015, Total	15,597
Accumulated Depreciation	$ 8,877
Year(s) Acquired	1,999
Braker Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Austin, TX
Square Feet | ft²	257
Initial Cost to Company, Land	$ 1,874
Initial Cost to Company, Buildings and Improvements	13,990
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	1,608
Gross Amount at Which Carried at December 31, 2015, Land	1,874
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	15,598
Gross Amount at Which Carried at December 31, 2015, Total	17,472
Accumulated Depreciation	$ 5,749
Year(s) Acquired	2,010
Mopac Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Austin, TX
Square Feet | ft²	117
Initial Cost to Company, Land	$ 719
Initial Cost to Company, Buildings and Improvements	3,579
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	694
Gross Amount at Which Carried at December 31, 2015, Land	719
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	4,273
Gross Amount at Which Carried at December 31, 2015, Total	4,992
Accumulated Depreciation	$ 1,449
Year(s) Acquired	2,010
Southpark Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Austin, TX
Square Feet | ft²	181
Initial Cost to Company, Land	$ 1,266
Initial Cost to Company, Buildings and Improvements	9,882
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	2,306
Gross Amount at Which Carried at December 31, 2015, Land	1,266
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	12,188
Gross Amount at Which Carried at December 31, 2015, Total	13,454
Accumulated Depreciation	$ 4,475
Year(s) Acquired	2,010
Valwood Business Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Carrolton, TX
Square Feet | ft²	356
Initial Cost to Company, Land	$ 2,510
Initial Cost to Company, Buildings and Improvements	13,859
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	1,476
Gross Amount at Which Carried at December 31, 2015, Land	2,510
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	15,335
Gross Amount at Which Carried at December 31, 2015, Total	17,845
Accumulated Depreciation	$ 2,969
Year(s) Acquired	2,013
Empire Commerce [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Dallas, TX
Square Feet | ft²	44
Initial Cost to Company, Land	$ 304
Initial Cost to Company, Buildings and Improvements	1,545
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	819
Gross Amount at Which Carried at December 31, 2015, Land	304
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	2,364
Gross Amount at Which Carried at December 31, 2015, Total	2,668
Accumulated Depreciation	$ 1,691
Year(s) Acquired	1,998
Northgate [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Dallas, TX
Square Feet | ft²	194
Initial Cost to Company, Land	$ 1,274
Initial Cost to Company, Buildings and Improvements	5,505
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	3,946
Gross Amount at Which Carried at December 31, 2015, Land	1,274
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	9,451
Gross Amount at Which Carried at December 31, 2015, Total	10,725
Accumulated Depreciation	$ 6,423
Year(s) Acquired	1,998
Northway Plaza [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Farmers Branch, TX
Square Feet | ft²	131
Initial Cost to Company, Land	$ 1,742
Initial Cost to Company, Buildings and Improvements	4,503
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	738
Gross Amount at Which Carried at December 31, 2015, Land	1,742
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	5,241
Gross Amount at Which Carried at December 31, 2015, Total	6,983
Accumulated Depreciation	$ 1,032
Year(s) Acquired	2,013
Springlake Business Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Farmers Branch, TX
Square Feet | ft²	206
Initial Cost to Company, Land	$ 2,607
Initial Cost to Company, Buildings and Improvements	5,715
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	1,646
Gross Amount at Which Carried at December 31, 2015, Land	2,607
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	7,361
Gross Amount at Which Carried at December 31, 2015, Total	9,968
Accumulated Depreciation	$ 1,185
Year(s) Acquired	2013/2014
Westwood Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Farmers Branch, TX
Square Feet | ft²	112
Initial Cost to Company, Land	$ 941
Initial Cost to Company, Buildings and Improvements	6,884
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	2,364
Gross Amount at Which Carried at December 31, 2015, Land	941
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	9,248
Gross Amount at Which Carried at December 31, 2015, Total	10,189
Accumulated Depreciation	$ 5,146
Year(s) Acquired	2,003
Eastgate [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Garland, TX
Square Feet | ft²	36
Initial Cost to Company, Land	$ 480
Initial Cost to Company, Buildings and Improvements	1,203
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	499
Gross Amount at Which Carried at December 31, 2015, Land	480
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	1,702
Gross Amount at Which Carried at December 31, 2015, Total	2,182
Accumulated Depreciation	$ 1,176
Year(s) Acquired	1,997
Freeport Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Irving, TX
Square Feet | ft²	256
Initial Cost to Company, Land	$ 4,564
Initial Cost to Company, Buildings and Improvements	9,506
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	1,989
Gross Amount at Which Carried at December 31, 2015, Land	4,564
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	11,495
Gross Amount at Which Carried at December 31, 2015, Total	16,059
Accumulated Depreciation	$ 2,053
Year(s) Acquired	2,013
NFTZ [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Irving, TX	[1]
Square Feet | ft²	231	[1]
Initial Cost to Company, Land	$ 1,517	[1]
Initial Cost to Company, Buildings and Improvements	6,499	[1]
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	3,496	[1]
Gross Amount at Which Carried at December 31, 2015, Land	1,517	[1]
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	9,995	[1]
Gross Amount at Which Carried at December 31, 2015, Total	11,512	[1]
Accumulated Depreciation	$ 6,449	[1]
Year(s) Acquired	1,998	[1]
Royal Tech [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Irving, TX
Square Feet | ft²	794
Initial Cost to Company, Land	$ 13,989
Initial Cost to Company, Buildings and Improvements	54,113
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	22,713
Gross Amount at Which Carried at December 31, 2015, Land	13,989
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	76,826
Gross Amount at Which Carried at December 31, 2015, Total	90,815
Accumulated Depreciation	$ 47,803
Year(s) Acquired	1998-2000/2011
La Prada [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Mesquite, TX
Square Feet | ft²	56
Initial Cost to Company, Land	$ 495
Initial Cost to Company, Buildings and Improvements	1,235
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	601
Gross Amount at Which Carried at December 31, 2015, Land	495
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	1,836
Gross Amount at Which Carried at December 31, 2015, Total	2,331
Accumulated Depreciation	$ 1,296
Year(s) Acquired	1,997
The Summit [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Plano, TX
Square Feet | ft²	184
Initial Cost to Company, Land	$ 1,536
Initial Cost to Company, Buildings and Improvements	6,654
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	4,264
Gross Amount at Which Carried at December 31, 2015, Land	1,536
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	10,918
Gross Amount at Which Carried at December 31, 2015, Total	12,454
Accumulated Depreciation	$ 7,718
Year(s) Acquired	1,998
Arapaho Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richardson, TX
Square Feet | ft²	408
Initial Cost to Company, Land	$ 5,226
Initial Cost to Company, Buildings and Improvements	10,661
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	2,938
Gross Amount at Which Carried at December 31, 2015, Land	5,226
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	13,599
Gross Amount at Which Carried at December 31, 2015, Total	18,825
Accumulated Depreciation	$ 3,304
Year(s) Acquired	2013/2014
Richardson Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richardson, TX
Square Feet | ft²	117
Initial Cost to Company, Land	$ 799
Initial Cost to Company, Buildings and Improvements	3,568
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	2,805
Gross Amount at Which Carried at December 31, 2015, Land	799
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	6,373
Gross Amount at Which Carried at December 31, 2015, Total	7,172
Accumulated Depreciation	$ 4,641
Year(s) Acquired	1,998
Bren Mar [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Alexandria, VA
Square Feet | ft²	113
Initial Cost to Company, Land	$ 2,197
Initial Cost to Company, Buildings and Improvements	5,380
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	3,782
Gross Amount at Which Carried at December 31, 2015, Land	2,197
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	9,162
Gross Amount at Which Carried at December 31, 2015, Total	11,359
Accumulated Depreciation	$ 6,391
Year(s) Acquired	1,997
Eisenhower [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Alexandria, VA
Square Feet | ft²	95
Initial Cost to Company, Land	$ 1,440
Initial Cost to Company, Buildings and Improvements	3,635
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	2,337
Gross Amount at Which Carried at December 31, 2015, Land	1,440
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	5,972
Gross Amount at Which Carried at December 31, 2015, Total	7,412
Accumulated Depreciation	$ 4,404
Year(s) Acquired	1,997
Beaumont [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Chantilly, VA
Square Feet | ft²	107
Initial Cost to Company, Land	$ 4,736
Initial Cost to Company, Buildings and Improvements	11,051
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	2,156
Gross Amount at Which Carried at December 31, 2015, Land	4,736
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	13,207
Gross Amount at Which Carried at December 31, 2015, Total	17,943
Accumulated Depreciation	$ 6,969
Year(s) Acquired	2,006
Dulles South/Sullyfield [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Chantilly, VA
Square Feet | ft²	99
Initial Cost to Company, Land	$ 1,373
Initial Cost to Company, Buildings and Improvements	6,810
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	3,074
Gross Amount at Which Carried at December 31, 2015, Land	1,373
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	9,884
Gross Amount at Which Carried at December 31, 2015, Total	11,257
Accumulated Depreciation	$ 6,361
Year(s) Acquired	1,999
Lafayette [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Chantilly, VA
Square Feet | ft²	197
Initial Cost to Company, Land	$ 1,680
Initial Cost to Company, Buildings and Improvements	13,398
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	4,941
Gross Amount at Which Carried at December 31, 2015, Land	1,680
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	18,339
Gross Amount at Which Carried at December 31, 2015, Total	20,019
Accumulated Depreciation	$ 12,194
Year(s) Acquired	1999/2000
Park East [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Chantilly, VA
Square Feet | ft²	198
Initial Cost to Company, Land	$ 3,851
Initial Cost to Company, Buildings and Improvements	18,029
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	10,232
Gross Amount at Which Carried at December 31, 2015, Land	3,851
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	28,261
Gross Amount at Which Carried at December 31, 2015, Total	32,112
Accumulated Depreciation	$ 18,036
Year(s) Acquired	1,999
Fair Oaks Business Campus [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Fairfax, VA
Square Feet | ft²	290
Initial Cost to Company, Land	$ 13,598
Initial Cost to Company, Buildings and Improvements	36,232
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	8,028
Gross Amount at Which Carried at December 31, 2015, Land	13,598
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	44,260
Gross Amount at Which Carried at December 31, 2015, Total	57,858
Accumulated Depreciation	$ 24,257
Year(s) Acquired	2004/2007
Monroe [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Herndon, VA
Square Feet | ft²	244
Initial Cost to Company, Land	$ 6,737
Initial Cost to Company, Buildings and Improvements	18,911
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	10,233
Gross Amount at Which Carried at December 31, 2015, Land	6,737
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	29,144
Gross Amount at Which Carried at December 31, 2015, Total	35,881
Accumulated Depreciation	$ 20,044
Year(s) Acquired	1997/1999
Gunston [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Lorton, VA
Square Feet | ft²	247
Initial Cost to Company, Land	$ 4,146
Initial Cost to Company, Buildings and Improvements	17,872
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	8,995
Gross Amount at Which Carried at December 31, 2015, Land	4,146
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	26,867
Gross Amount at Which Carried at December 31, 2015, Total	31,013
Accumulated Depreciation	$ 15,227
Year(s) Acquired	1,998
Westpark Business Campus [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	McLean, VA
Square Feet | ft²	751
Initial Cost to Company, Land	$ 47,955
Initial Cost to Company, Buildings and Improvements	101,847
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	21,328
Gross Amount at Which Carried at December 31, 2015, Land	47,955
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	123,175
Gross Amount at Which Carried at December 31, 2015, Total	171,130
Accumulated Depreciation	$ 38,783
Year(s) Acquired	2010/2011
Prosperity Business Campus [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Merrifield, VA
Square Feet | ft²	659
Initial Cost to Company, Land	$ 23,147
Initial Cost to Company, Buildings and Improvements	67,575
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	30,011
Gross Amount at Which Carried at December 31, 2015, Land	23,147
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	97,586
Gross Amount at Which Carried at December 31, 2015, Total	120,733
Accumulated Depreciation	$ 58,680
Year(s) Acquired	2,001
Alban Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Springfield, VA
Square Feet | ft²	150
Initial Cost to Company, Land	$ 1,935
Initial Cost to Company, Buildings and Improvements	4,736
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	5,014
Gross Amount at Which Carried at December 31, 2015, Land	1,935
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	9,750
Gross Amount at Which Carried at December 31, 2015, Total	11,685
Accumulated Depreciation	$ 7,159
Year(s) Acquired	1,997
I-95 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Springfield, VA
Square Feet | ft²	210
Initial Cost to Company, Land	$ 3,535
Initial Cost to Company, Buildings and Improvements	15,672
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	11,579
Gross Amount at Which Carried at December 31, 2015, Land	3,535
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	27,251
Gross Amount at Which Carried at December 31, 2015, Total	30,786
Accumulated Depreciation	$ 19,751
Year(s) Acquired	2,000
Northpointe [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Sterling, VA
Square Feet | ft²	147
Initial Cost to Company, Land	$ 2,767
Initial Cost to Company, Buildings and Improvements	8,778
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	4,503
Gross Amount at Which Carried at December 31, 2015, Land	2,767
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	13,281
Gross Amount at Which Carried at December 31, 2015, Total	16,048
Accumulated Depreciation	$ 9,567
Year(s) Acquired	1997/1998
Shaw Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Sterling, VA
Square Feet | ft²	149
Initial Cost to Company, Land	$ 2,969
Initial Cost to Company, Buildings and Improvements	10,008
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	4,286
Gross Amount at Which Carried at December 31, 2015, Land	2,969
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	14,294
Gross Amount at Which Carried at December 31, 2015, Total	17,263
Accumulated Depreciation	$ 10,371
Year(s) Acquired	1,998
Tysons Corporate Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Vienna, VA
Square Feet | ft²	270
Initial Cost to Company, Land	$ 9,885
Initial Cost to Company, Buildings and Improvements	25,302
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	9,289
Gross Amount at Which Carried at December 31, 2015, Land	9,885
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	34,591
Gross Amount at Which Carried at December 31, 2015, Total	44,476
Accumulated Depreciation	$ 11,655
Year(s) Acquired	2,010
Woodbridge [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Woodbridge, VA
Square Feet | ft²	114
Initial Cost to Company, Land	$ 1,350
Initial Cost to Company, Buildings and Improvements	3,398
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	1,858
Gross Amount at Which Carried at December 31, 2015, Land	1,350
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	5,256
Gross Amount at Which Carried at December 31, 2015, Total	6,606
Accumulated Depreciation	$ 3,762
Year(s) Acquired	1,997
212th Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Kent, WA
Square Feet | ft²	951
Initial Cost to Company, Land	$ 19,573
Initial Cost to Company, Buildings and Improvements	17,695
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	12,014
Gross Amount at Which Carried at December 31, 2015, Land	19,573
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	29,709
Gross Amount at Which Carried at December 31, 2015, Total	49,282
Accumulated Depreciation	$ 6,177
Year(s) Acquired	2,012
Overlake [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Redmond, WA
Square Feet | ft²	411
Initial Cost to Company, Land	$ 23,122
Initial Cost to Company, Buildings and Improvements	41,106
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	6,086
Gross Amount at Which Carried at December 31, 2015, Land	23,122
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	47,192
Gross Amount at Which Carried at December 31, 2015, Total	70,314
Accumulated Depreciation	$ 26,383
Year(s) Acquired	2,007
Renton [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Renton, WA
Square Feet | ft²	28
Initial Cost to Company, Land	$ 330
Initial Cost to Company, Buildings and Improvements	889
Cost Capitalized Subsequent to Acquisition, Buildings and Improvements	552
Gross Amount at Which Carried at December 31, 2015, Land	330
Gross Amount at Which Carried at December 31, 2015, Buildings and Improvements	1,441
Gross Amount at Which Carried at December 31, 2015, Total	1,771
Accumulated Depreciation	$ 1,009
Year(s) Acquired	1,997
Minimum [Member] | Buena Park Industrial Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Carson [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Cerritos Business Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Cerritos/Edwards [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Concord Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Culver City [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Bayview Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Christy Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Industrial Drive Distribution Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Bay Center Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Cabot Distribution Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Diablo Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Eden Landing [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Hayward Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Huntwood Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Parkway Commerce [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Corporate Pointe [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Laguna Hills Commerce Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Plaza Del Lago [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Canada [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Dixon Landing Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Monterey/Calle [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Monterey Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Port Of Oakland [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Orangewood [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Orange County Business Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Kearney Mesa [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Lusk [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Rose Canyon Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Charcot Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Las Plumas [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Little Orchard Distribution Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Montague Industrial Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Oakland Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Rogers Ave [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Doolittle Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Bayshore Corporate Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | San Ramon/Norris Canyon [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Commerce Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Santa Clara Tech Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Walsh At Lafayette [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Signal Hill [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Airport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | South San Francisco/Produce [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Studio City/Ventura [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Kifer Industrial Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Torrance [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Boca Commerce [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | MICC [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Wellington [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Ammendale [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Gaithersburgh/Christopher [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Metro Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Parklawn Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Shady Grove [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Westech Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Ben White [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Lamar Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | McKalla [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | McNeil [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Rutland [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Waterford [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Braker Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Mopac Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Southpark Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Valwood Business Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Empire Commerce [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Northgate [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Northway Plaza [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Springlake Business Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Westwood Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Eastgate [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Freeport Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | NFTZ [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years	[1]
Minimum [Member] | Royal Tech [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | La Prada [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | The Summit [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Arapaho Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Richardson Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Bren Mar [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Eisenhower [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Beaumont [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Dulles South/Sullyfield [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Lafayette [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Park East [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Fair Oaks Business Campus [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Monroe [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Gunston [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Westpark Business Campus [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Prosperity Business Campus [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Alban Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | I-95 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Northpointe [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Shaw Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Tysons Corporate Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Woodbridge [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | 212th Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Overlake [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Minimum [Member] | Renton [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	5 years
Maximum [Member] | Buena Park Industrial Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Carson [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Cerritos Business Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Cerritos/Edwards [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Concord Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Culver City [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Bayview Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Christy Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Industrial Drive Distribution Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Bay Center Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Cabot Distribution Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Diablo Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Eden Landing [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Hayward Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Huntwood Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Parkway Commerce [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Corporate Pointe [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Laguna Hills Commerce Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Plaza Del Lago [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Canada [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Dixon Landing Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Monterey/Calle [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Monterey Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Port Of Oakland [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Orangewood [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Orange County Business Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Kearney Mesa [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Lusk [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Rose Canyon Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Charcot Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Las Plumas [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Little Orchard Distribution Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Montague Industrial Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Oakland Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Rogers Ave [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Doolittle Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Bayshore Corporate Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | San Ramon/Norris Canyon [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Commerce Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Santa Clara Tech Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Walsh At Lafayette [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Signal Hill [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Airport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | South San Francisco/Produce [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Studio City/Ventura [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Kifer Industrial Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Torrance [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Boca Commerce [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | MICC [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Wellington [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Ammendale [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Gaithersburgh/Christopher [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Metro Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Parklawn Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Shady Grove [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Westech Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Ben White [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Lamar Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | McKalla [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | McNeil [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Rutland [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Waterford [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Braker Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Mopac Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Southpark Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Valwood Business Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Empire Commerce [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Northgate [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Northway Plaza [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Springlake Business Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Westwood Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Eastgate [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Freeport Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | NFTZ [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years	[1]
Maximum [Member] | Royal Tech [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | La Prada [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | The Summit [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Arapaho Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Richardson Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Bren Mar [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Eisenhower [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Beaumont [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Dulles South/Sullyfield [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Lafayette [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Park East [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Fair Oaks Business Campus [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Monroe [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Gunston [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Westpark Business Campus [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Prosperity Business Campus [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Alban Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | I-95 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Northpointe [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Shaw Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Tysons Corporate Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Woodbridge [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | 212th Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Overlake [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
Maximum [Member] | Renton [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable Lives (Years)	30 years
[1]	The Company owns two properties that are subject to ground leases in Las Colinas, Texas, expiring in 2019 and 2020, each with one 10-year extension option.