Whitestone REIT (WSR) 10-Q 1 Nov 21 2021 Q3 Quarterly report Financial data

Cover

Cover - shares	9 Months Ended
	Sep. 30, 2021	Oct. 28, 2021
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Amendment Flag	false
Document Transition Report	false
Entity File Number	001-34855
Entity Registrant Name	Whitestone REIT
Entity Central Index Key	0001175535
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	76-0594970
Entity Address, Address Line One	2600 South Gessner,
Entity Address, Address Line Two	Suite 500
Entity Address, City or Town	Houston,
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77063
City Area Code	713
Local Phone Number	827-9595
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		49,113,056
Common Stock
Entity Information [Line Items]
Title of 12(b) Security	Common Shares of Beneficial Interest, par value $0.001 per share
Trading Symbol	WSR
Security Exchange Name	NYSE
Preferred Stock
Entity Information [Line Items]
Title of 12(b) Security	Preferred Stock Purchase Rights
No Trading Symbol Flag	true
Security Exchange Name	NYSE

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands		Sep. 30, 2021	Dec. 31, 2020
Real estate assets, at cost
Property		$ 1,165,274	$ 1,106,426
Accumulated depreciation		(183,383)	(163,712)
Total real estate assets		981,891	942,714
Investment in real estate partnership		34,408	33,979
Cash and cash equivalents		10,858	25,777
Restricted cash		106	179
Escrows and acquisition deposits		10,437	9,274
Accrued rents and accounts receivable, net of allowance for doubtful accounts		21,991	23,009
Receivable due from related party		651	335
Unamortized lease commissions, legal fees and loan costs		8,356	7,686
Prepaid expenses and other assets	[1]	2,371	2,049
Total assets		1,071,069	1,045,002
Liabilities:
Notes payable		618,649	644,185
Accounts payable and accrued expenses	[2]	44,563	50,918
Payable due to related party		530	125
Tenants' security deposits		7,718	6,916
Dividends and distributions payable		5,333	4,532
Total liabilities		676,793	706,676
Commitments and contingencies:		0	0
Equity:
Preferred shares, $0.001 par value per share; 50,000,000 shares authorized; none issued and outstanding as of September 30, 2021 and December 31, 2020		0	0
Common shares, $0.001 par value per share; 400,000,000 shares authorized; 48,839,594 and 42,391,316 issued and outstanding as of September 30, 2021 and December 31, 2020, respectively		48	42
Additional paid-in capital		618,963	562,250
Accumulated deficit		(221,277)	(215,809)
Accumulated other comprehensive loss		(9,726)	(14,400)
Total Whitestone REIT shareholders' equity		388,008	332,083
Noncontrolling interest in subsidiary		6,268	6,243
Total equity		394,276	338,326
Total liabilities and equity		1,071,069	1,045,002
Operating lease right of use assets (net)		316	592
Operating lease liabilities		$ 323	$ 603
[1]	Operating lease right of use assets (net)
[2]	Operating lease liabilities

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Preferred shares, par value per share (in dollars per share)	$ 0.001	$ 0.001
Preferred shares, shares authorized (in shares)	50,000,000	50,000,000
Preferred shares, shares issued (in shares)	0	0
Preferred shares, shares outstanding (in shares)	0	0
Common shares, par value per share (in dollars per share)	$ 0.001	$ 0.001
Common shares, authorized (in shares)	400,000,000	400,000,000
Common shares, issued (in shares)	48,839,594	42,391,316
Common shares, outstanding (in shares)	48,839,594	42,391,316

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Income (Loss) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenues
Rental	$ 32,069	$ 28,868	$ 90,916	$ 86,116
Management, transaction, and other fees	375	1,032	1,191	1,965
Total revenues	32,444	29,900	92,107	88,081
Operating expenses
Depreciation and amortization	7,340	7,171	21,458	21,112
Operating and maintenance	5,789	5,029	16,072	15,021
Real estate taxes	4,589	4,670	12,787	13,591
General and administrative	5,672	5,860	16,036	15,604
Total operating expenses	23,390	22,730	66,353	65,328
Other expenses (income)
Interest expense	6,142	6,400	18,417	19,561
(Gain) loss on sale or disposal of assets, net	48	18	(177)	882
Interest, dividend and other investment income	(31)	(71)	(103)	(206)
Total other expenses	6,159	6,347	18,137	20,237
Income before equity investment in real estate partnership and income tax	2,895	823	7,617	2,516
Equity in earnings of real estate partnership	151	196	429	752
Provision for income tax	(100)	(105)	(274)	(288)
Income from continuing operations	2,946	914	7,772	2,980
Gain on sale of property from discontinued operations	0	0	1,833	0
Income from discontinued operations	0	0	1,833	0
Net income	2,946	914	9,605	2,980
Less: Net income attributable to noncontrolling interests	47	14	165	58
Net income attributable to Whitestone REIT	$ 2,899	$ 900	$ 9,440	$ 2,922
Basic Earnings Per Share:
Income from continuing operations attributable to Whitestone REIT excluding amounts attributable to unvested restricted shares (in dollars per share)	$ 0.06	$ 0.02	$ 0.17	$ 0.07
Income from discontinued operations attributable to Whitestone REIT (in dollars per share)	0	0	0.04	0
Net income attributable to common shareholders, excluding amounts attributable to unvested restricted shares (in dollars per share)	0.06	0.02	0.21	0.07
Diluted Earnings Per Share:
Income from continuing operations attributable to Whitestone REIT excluding amounts attributable to unvested restricted shares (in dollars per share)	0.06	0.02	0.17	0.07
Income from discontinued operations attributable to Whitestone REIT (in dollars per share)	0	0	0.04	0
Net income attributable to common shareholders, excluding amounts attributable to unvested restricted shares (in dollars per share)	$ 0.06	$ 0.02	$ 0.21	$ 0.07
Weighted average number of common shares outstanding:
Basic (in shares)	46,883	42,346	44,268	42,202
Diluted (in shares)	47,825	43,440	45,108	43,040
Consolidated Statements of Comprehensive Income (Loss)
Net income	$ 2,946	$ 914	$ 9,605	$ 2,980
Other comprehensive income (loss)
Unrealized gain (loss) on cash flow hedging activities	1,273	1,241	4,783	(10,395)
Comprehensive income (loss)	4,219	2,155	14,388	(7,415)
Less: Net income attributable to noncontrolling interests	47	14	165	58
Less: Comprehensive income (loss) attributable to noncontrolling interests	20	43	82	(203)
Comprehensive income (loss) attributable to Whitestone REIT	4,152	2,098	14,141	(7,270)
Rental Revenues
Rental revenues	23,177	21,808	67,041	65,591
Recoveries	8,720	8,339	24,375	24,976
Bad debt	172	(1,279)	(500)	(4,451)
Total rental	$ 32,069	$ 28,868	$ 90,916	$ 86,116

Consolidated Statement of Chang

Consolidated Statement of Changes in Equity - USD ($) $ in Thousands		Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Gain (Loss)	Total Shareholders' Equity	Noncontrolling Interests
Beginning Balance (in shares) at Dec. 31, 2019			41,492,000
Beginning Balance (in units) at Dec. 31, 2019								909,000
Beginning Balance at Dec. 31, 2019		$ 353,098	$ 41	$ 554,816	$ (204,049)	$ (5,491)	$ 345,317	$ 7,781
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exchange of noncontrolling interest OP units for common shares (in shares)			(5,000)					(5,000)
Exchange of noncontrolling interest OP units for common shares		0		44			44	$ (44)
Issuance of common shares - ATM Program, net of offering costs (in shares)			171,000
Issuance of common shares - ATM Program, net of offering costs		2,241		2,241			2,241
Exchange offer costs		(32)		(32)			(32)
Issuance of shares under dividend reinvestment plan (in shares)			4,000
Issuance of shares under dividend reinvestment plan		42		42			42
Repurchase of common shares (in shares)	[1]		(153,000)
Repurchase of common shares	[1]	(1,630)		(1,630)			(1,630)
Share-based compensation (in shares)			616,000
Share-based compensation		1,248		1,248			1,248
Distributions		(4,544)			(4,449)		(4,449)	(95)
Unrealized loss on change in value of cash flow hedge		(10,952)				(10,721)	(10,721)	(231)
Net income		1,647			1,612		1,612	$ 35
Ending Balance (in shares) at Mar. 31, 2020			42,135,000
Ending Balance (in units) at Mar. 31, 2020								904,000
Ending Balance at Mar. 31, 2020		341,118	$ 41	556,729	(206,886)	(16,212)	333,672	$ 7,446
Beginning Balance (in shares) at Dec. 31, 2019			41,492,000
Beginning Balance (in units) at Dec. 31, 2019								909,000
Beginning Balance at Dec. 31, 2019		353,098	$ 41	554,816	(204,049)	(5,491)	345,317	$ 7,781
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Unrealized loss on change in value of cash flow hedge		(10,395)
Net income		2,980
Ending Balance (in shares) at Sep. 30, 2020			42,353,000
Ending Balance (in units) at Sep. 30, 2020								776,000
Ending Balance at Sep. 30, 2020		336,260	$ 42	560,129	(214,468)	(15,707)	329,996	$ 6,264
Beginning Balance (in shares) at Mar. 31, 2020			42,135,000
Beginning Balance (in units) at Mar. 31, 2020								904,000
Beginning Balance at Mar. 31, 2020		341,118	$ 41	556,729	(206,886)	(16,212)	333,672	$ 7,446
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exchange of noncontrolling interest OP units for common shares (in shares)			(127,000)					(127,000)
Exchange of noncontrolling interest OP units for common shares		0	$ 1	1,082			1,083	$ (1,083)
Exchange offer costs		(11)		(11)			(11)
Issuance of shares under dividend reinvestment plan (in shares)			2,000
Issuance of shares under dividend reinvestment plan		16		16			16
Repurchase of common shares (in shares)			(23,000)
Repurchase of common shares	[1]	(440)		(440)			(440)
Share-based compensation (in shares)			103,000
Share-based compensation		1,140		1,140			1,140
Distributions		(4,527)			(4,446)		(4,446)	(81)
Unrealized loss on change in value of cash flow hedge		(684)				(669)	(669)	(15)
Reallocation of ownership between parent and subsidiary		0			1	(34)	(33)	33
Net income		419			410		410	$ 9
Ending Balance (in shares) at Jun. 30, 2020			42,344,000
Ending Balance (in units) at Jun. 30, 2020								777,000
Ending Balance at Jun. 30, 2020		337,031	$ 42	558,516	(210,921)	(16,915)	330,722	$ 6,309
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exchange of noncontrolling interest OP units for common shares (in shares)			(1,000)					(1,000)
Exchange of noncontrolling interest OP units for common shares		0	$ 0	11			11	$ (11)
Exchange offer costs		0		0			0
Issuance of shares under dividend reinvestment plan (in shares)			3,000
Issuance of shares under dividend reinvestment plan		16		16			16
Repurchase of common shares (in shares)	[1]		(2,000)
Repurchase of common shares	[1]	(6)		(6)			(6)
Share-based compensation (in shares)			7,000
Share-based compensation		1,592		1,592			1,592
Distributions		(4,528)			(4,446)		(4,446)	(82)
Unrealized loss on change in value of cash flow hedge		1,241				1,198	1,198	43
Reallocation of ownership between parent and subsidiary		0			(1)	10	9	(9)
Net income		914			900		900	$ 14
Ending Balance (in shares) at Sep. 30, 2020			42,353,000
Ending Balance (in units) at Sep. 30, 2020								776,000
Ending Balance at Sep. 30, 2020		$ 336,260	$ 42	560,129	(214,468)	(15,707)	329,996	$ 6,264
Beginning Balance (in shares) at Dec. 31, 2020		42,391,316	42,391,000
Beginning Balance (in units) at Dec. 31, 2020								773,000
Beginning Balance at Dec. 31, 2020		$ 338,326	$ 42	562,250	(215,809)	(14,400)	332,083	$ 6,243
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of shares under dividend reinvestment plan (in shares)			2,000
Issuance of shares under dividend reinvestment plan		15		15			15
Repurchase of common shares (in shares)	[1]		(37,000)
Repurchase of common shares	[1]	(324)		(324)			(324)
Share-based compensation (in shares)			223,000
Share-based compensation		1,398	$ 1	1,397			1,398
Distributions		(4,705)			(4,622)		(4,622)	(83)
Unrealized loss on change in value of cash flow hedge		2,221				2,180	2,180	41
Net income		1,441			1,415		1,415	$ 26
Ending Balance (in shares) at Mar. 31, 2021			42,579,000
Ending Balance (in units) at Mar. 31, 2021								773,000
Ending Balance at Mar. 31, 2021		$ 338,372	$ 43	563,338	(219,016)	(12,220)	332,145	$ 6,227
Beginning Balance (in shares) at Dec. 31, 2020		42,391,316	42,391,000
Beginning Balance (in units) at Dec. 31, 2020								773,000
Beginning Balance at Dec. 31, 2020		$ 338,326	$ 42	562,250	(215,809)	(14,400)	332,083	$ 6,243
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Unrealized loss on change in value of cash flow hedge		4,783
Net income		$ 9,605
Ending Balance (in shares) at Sep. 30, 2021		48,839,594	48,840,000
Ending Balance (in units) at Sep. 30, 2021								773,000
Ending Balance at Sep. 30, 2021		$ 394,276	$ 48	618,963	(221,277)	(9,726)	388,008	$ 6,268
Beginning Balance (in shares) at Mar. 31, 2021			42,579,000
Beginning Balance (in units) at Mar. 31, 2021								773,000
Beginning Balance at Mar. 31, 2021		338,372	$ 43	563,338	(219,016)	(12,220)	332,145	$ 6,227
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common shares - ATM Program, net of offering costs (in shares)			3,025,000
Issuance of common shares - ATM Program, net of offering costs		25,371	$ 2	25,369			25,371
Exchange offer costs		(31)		(31)			(31)
Issuance of shares under dividend reinvestment plan (in shares)			1,000
Issuance of shares under dividend reinvestment plan		15		15			15
Repurchase of common shares (in shares)	[1]		(13,000)
Repurchase of common shares	[1]	(104)		(104)			(104)
Share-based compensation (in shares)			101,000
Share-based compensation		1,177		1,177			1,177
Distributions		(5,035)			(4,952)		(4,952)	(83)
Unrealized loss on change in value of cash flow hedge		1,289				1,268	1,268	21
Reallocation of ownership between parent and subsidiary		0			0	(14)	(14)	14
Net income		5,218			5,126		5,126	$ 92
Ending Balance (in shares) at Jun. 30, 2021			45,693,000
Ending Balance (in units) at Jun. 30, 2021								773,000
Ending Balance at Jun. 30, 2021		366,272	$ 45	589,764	(218,842)	(10,966)	360,001	$ 6,271
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common shares - ATM Program, net of offering costs (in shares)			2,991,000
Issuance of common shares - ATM Program, net of offering costs		27,964	$ 3	27,961			27,964
Exchange offer costs		(18)		(18)			(18)
Issuance of shares under dividend reinvestment plan (in shares)			2,000
Issuance of shares under dividend reinvestment plan		15		15			15
Repurchase of common shares (in shares)	[1]		(28,000)
Repurchase of common shares	[1]	(250)		(250)			(250)
Share-based compensation (in shares)			182,000
Share-based compensation		1,491		1,491			1,491
Distributions		(5,417)			(5,334)		(5,334)	(83)
Unrealized loss on change in value of cash flow hedge		1,273				1,253	1,253	20
Reallocation of ownership between parent and subsidiary		0			0	(13)	(13)	13
Net income		$ 2,946			2,899		2,899	$ 47
Ending Balance (in shares) at Sep. 30, 2021		48,839,594	48,840,000
Ending Balance (in units) at Sep. 30, 2021								773,000
Ending Balance at Sep. 30, 2021		$ 394,276	$ 48	$ 618,963	$ (221,277)	$ (9,726)	$ 388,008	$ 6,268
[1]	The Company acquired common shares held by employees who tendered owned common shares to satisfy the tax withholding on the lapse of certain restrictions on restricted common shares.

Consolidated Statement of Cha_2

Consolidated Statement of Changes in Equity Consolidated Statement of Changes in Equity (Parenthetical) - $ / shares	3 Months Ended
	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020
Common Stock
Distributions (in usd per share)	$ 0.1075	$ 0.1075	$ 0.105	$ 0.105	$ 0.285
OP Units
Distributions (in usd per share)	$ 0.1075	$ 0.1075	$ 0.105	$ 0.105	$ 0.285

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities:
Net income from continuing operations		$ 7,772	$ 2,980
Income from discontinued operations		1,833	0
Net income		9,605	2,980
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		21,458	21,112
Amortization of deferred loan costs		822	839
(Gain) loss on sale or disposal of assets and loan forgiveness, net		(177)	882
Bad debt		500	4,451
Share-based compensation		4,066	3,980
Equity in earnings of real estate partnership		(429)	(752)
Changes in operating assets and liabilities:
Escrows and acquisition deposits		(1,163)	522
Accrued rents and accounts receivable		518	(6,123)
Receivable due from related party		(316)	(825)
Unamortized lease commissions, legal fees and loan costs		(2,531)	(958)
Prepaid expenses and other assets		1,548	2,145
Accounts payable and accrued expenses		(1,572)	131
Payable due to related party		405	538
Tenants' security deposits		802	298
Net cash provided by operating activities		31,703	29,220
Cash flows from investing activities:
Acquisitions of real estate		(53,364)	0
Additions to real estate		(6,058)	(5,808)
Proceeds from note receivable		0	922
Net cash used in investing activities		(59,422)	(4,886)
Gain on sale of property from discontinued operations		1,833	0
Cash flows from financing activities:
Distributions paid to common shareholders		(14,063)	(20,771)
Distributions paid to OP unit holders		(248)	(430)
Proceeds from issuance of common shares, net of offering costs		53,335	2,241
Payments of exchange offer costs		(49)	(43)
Proceeds from Notes Payable		0	1,734
Net proceeds from (payments of) credit facility		(25,000)	30,000
Repayments of notes payable		(2,403)	(11,514)
Repurchase of common shares		(678)	(2,076)
Net cash provided by (used in) financing activities		10,894	(859)
Net increase (decrease) in cash, cash equivalents and restricted cash		(14,992)	23,475
Cash, cash equivalents and restricted cash at beginning of period		25,956	15,643
Cash, cash equivalents and restricted cash at end of period	[1]	10,964	39,118
Supplemental disclosure of cash flow information:
Cash paid for interest		17,732	18,790
Cash paid for taxes		364	353
Non cash investing and financing activities:
Disposal of fully depreciated real estate		284	34
Financed insurance premiums		1,712	1,431
Value of shares issued under dividend reinvestment plan		45	74
Value of common shares exchanged for OP units		0	1,138
Change in fair value of cash flow hedge		4,783	(10,395)
Cash, cash equivalents and restricted cash
Cash and cash equivalents		10,858	38,990
Restricted cash		106	128
Total cash, cash equivalents and restricted cash	[1]	$ 10,964	$ 39,118
[1]	For a reconciliation of cash, cash equivalents and restricted cash, see supplemental disclosures below.

Interim Financial Statements

Interim Financial Statements	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Interim Financial Statements	INTERIM FINANCIAL STATEMENTS The consolidated financial statements included in this report are unaudited; however, amounts presented in the consolidated balance sheet as of December 31, 2020 are derived from our audited consolidated financial statements as of that date. The unaudited consolidated financial statements as of and for the period ended September 30, 2021 have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information on a basis consistent with the annual audited consolidated financial statements and with the instructions to Form 10-Q. The consolidated financial statements presented herein reflect all adjustments which, in the opinion of management, are necessary for a fair presentation of the financial position of Whitestone and our subsidiaries as of September 30, 2021 and December 31, 2020, and the results of operations for the three and nine month periods ended September 30, 2021 and 2020, the consolidated statements of changes in equity for the three months periods ended March 31, June 30, and September 30, 2021 and 2020 and cash flows for the nine month periods ended September 30, 2021 and 2020. All of these adjustments are of a normal recurring nature. The results of operations for the interim periods are not necessarily indicative of the results expected for a full year. The statements should be read in conjunction with the audited consolidated financial statements and the notes thereto which are included in our Annual Report on Form 10-K for the year ended December 31, 2020. Business . Whitestone was formed as a real estate investment trust (“REIT”) pursuant to the Texas Real Estate Investment Trust Act on August 20, 1998. In July 2004, we changed our state of organization from Texas to Maryland pursuant to a merger where we merged directly with and into a Maryland REIT formed for the sole purpose of the reorganization and the conversion of each of the outstanding common shares of beneficial interest of the Texas entity into 1.42857 common shares of beneficial interest of the Maryland entity. We serve as the general partner of Whitestone REIT Operating Partnership, L.P. (the “Operating Partnership”), which was formed on December 31, 1998 as a Delaware limited partnership. We currently conduct substantially all of our operations and activities through the Operating Partnership. As the general partner of the Operating Partnership, we have the exclusive power to manage and conduct the business of the Operating Partnership, subject to certain customary exceptions. As of September 30, 2021 and December 31, 2020, Whitestone wholly owned 59 and 58 commercial properties, respectively, in and around Austin, Chicago, Dallas-Fort Worth, Houston, Phoenix and San Antonio. As of September 30, 2021, these properties consist of: Consolidated Operating Portfolio • 53 wholly owned properties that meet our Community Centered Properties ® strategy; and Redevelopment, New Acquisitions Portfolio • one wholly owned property, Lakeside Market, that meets our Community Centered Properties ® strategy containing approximately 0.2 million square feet of GLA and having a total carrying amount (net of accumulated depreciation) of $52.9 million, and is classified as part of our new acquisition portfolio. Acquired properties are categorized in the new acquisition portfolio until the earlier of 90% occupancy or 18 months of ownership; and • five parcels of land held for future development. As of September 30, 2021, we, through our investment in Pillarstone Capital REIT Operating Partnership LP (“Pillarstone” or “Pillarstone OP”), owned a majority interest in eight properties that do not meet our Community Centered Property® strategy containing approximately 0.9 million square feet of GLA (the “Pillarstone Properties”). We own 81.4% of the total outstanding units of Pillarstone OP, which we account for using the equity method. We also manage the day-to-day operations of Pillarstone OP. We anticipate that the global health crisis caused by a novel strain of coronavirus (“COVID-19”) and the related responses intended to control its spread will continue to adversely affect business activity, particularly relating to our retail tenants, across the markets in which we operate. As part of the initial responses to the virus, many governmental authorities

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Consolidation. We are the sole general partner of the Operating Partnership and possess full legal control and authority over the operations of the Operating Partnership. As of September 30, 2021 and December 31, 2020, we owned a majority of the partnership interests in the Operating Partnership. Consequently, the accompanying consolidated financial statements include the accounts of the Operating Partnership. Noncontrolling interest in the accompanying consolidated financial statements represents the share of equity and earnings of the Operating Partnership allocable to holders of partnership interests other than us. Net income or loss is allocated to noncontrolling interests based on the weighted-average percentage ownership of the Operating Partnership during the period. Issuance of additional common shares of beneficial interest in Whitestone (the “common shares”) and units of limited partnership interest in the Operating Partnership that are convertible into cash or, at our option, common shares on a one-for-one basis (the “OP units”) changes the percentage of ownership interests of both the noncontrolling interests and Whitestone. Equity Method. For the years prior to December 31, 2017, Pillarstone OP was accounted for under the profit-sharing method. In accordance with the Financial Accounting Standards Board’s (“FASB”) guidance applicable to sales of real estate or interests therein, specifically FASB Accounting Standards Codification (“ASC”) 360-20, “ Real Estate Sales, ” Topic 606, “ Revenue from Contracts with Customers ” and ASC 610, “ Other Income–Gains and Losses from the Derecognition of Nonfinancial Assets ,” we adopted Topic 606 and ASC 610 as of January 1, 2018, resulting in the derecognition of the underlying assets and liabilities associated with the Contribution (defined below) as of January 1, 2018 and the recognition of the Company’s investment in Pillarstone OP under the equity method. See Note 6 (Investment in Real Estate Partnership) for additional disclosure on Pillarstone OP. In these financial statements, unless otherwise indicated, we do not include the Pillarstone Properties when we refer to our properties. Basis of Accounting. Our financial records are maintained on the accrual basis of accounting whereby revenues are recognized when earned and expenses are recorded when incurred. Use of Estimates. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent liabilities as of the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Significant estimates that we use include the estimated fair values of properties acquired, the estimated useful lives for depreciable and amortizable assets and costs, the grant date fair value of common share units included in share-based compensation expense, the estimated allowance for doubtful accounts, the estimated fair value of interest rate swaps and the estimates supporting our impairment analysis for the carrying values of our real estate assets. Actual results could differ from those estimates. In particular, the COVID-19 pandemic has adversely impacted and is likely to further adversely impact the Company’s business and markets, including the Company’s operations and the operations of its tenants. The full extent to which the pandemic will directly or indirectly impact the Company’s business, results of operations and financial condition, including revenues, expenses, reserves and allowances, fair value measurements, and asset impairment charges, will depend on future developments that are highly uncertain and difficult to predict. These developments include, but are not limited to, the duration and spread of the pandemic, its severity in our markets and elsewhere, the impact on our tenants’ businesses and financial condition, governmental actions to contain the spread of the pandemic and respond to the reduction in global economic activity, and how quickly and to what extent normal economic and operating conditions can resume. Reclassifications. We have reclassified certain prior period amounts in the accompanying consolidated financial statements in order to be consistent with the current period presentation. These reclassifications had no effect on net income, total assets, total liabilities or equity. Restricted Cash. We classify all cash pledged as collateral to secure certain obligations and all cash whose use is limited as restricted cash. During 2015, pursuant to the terms of our $15.1 million 4.99% Note, due January 6, 2024 (see Note 7 (Debt)), which is collateralized by our Anthem Marketplace property, we were required by the lenders thereunder to establish a cash management account controlled by the lenders to collect all amounts generated by our Anthem Marketplace property in order to collateralize such promissory note. Derivative Instruments and Hedging Activities. We utilize derivative financial instruments, principally interest rate swaps, to manage our exposure to fluctuations in interest rates. We have established policies and procedures for risk assessment, and the approval, reporting and monitoring of derivative financial instruments. We recognize our interest rate swaps as cash flow hedges with the effective portion of the changes in fair value recorded in comprehensive income (loss) and subsequently reclassified into earnings in the period that the hedged transaction affects earnings. Any ineffective portion of a cash flow hedges’ change in fair value is recorded immediately into earnings. Our cash flow hedges are determined using Level 2 inputs under ASC 820, “Fair Value Measurements and Disclosures.” Level 2 inputs represent quoted prices in active markets for similar assets or liabilities; quoted prices in markets that are not active; and model-derived valuations in which significant inputs and significant value drivers are observable. As of September 30, 2021, we consider our cash flow hedges to be highly effective. Development Properties. Land, buildings and improvements are recorded at cost. Expenditures related to the development of real estate are carried at cost which includes capitalized carrying charges and development costs. Carrying charges (interest, real estate taxes, loan fees, and direct and indirect development costs related to buildings under construction), are capitalized as part of construction in progress. The capitalization of such costs ceases when the property, or any completed portion, becomes available for occupancy. For the three months ended September 30, 2021, approximately $109,000 and $75,000 in interest expense and real estate taxes, respectively, were capitalized, and for the nine months ended September 30, 2021, approximately $312,000 and $225,000 in interest expense and real estate taxes, respectively, were capitalized. For the three months ended September 30, 2020, approximately $122,000 and $71,000 in interest expense and real estate taxes, respectively, were capitalized, and for the nine months ended September 30, 2020, approximately $362,000 and $231,000 in interest expense and real estate taxes, respectively, were capitalized. Share-Based Compensation. From time to time, we grant nonvested restricted common share awards or restricted common share unit awards, which may be converted into common shares, to executive officers and employees under our 2018 Long-Term Equity Incentive Ownership Plan (the “2018 Plan”). Awarded shares and units vest when certain performance conditions are met. We recognize compensation expense when achievement of the performance conditions is probable based on management’s most recent estimates using the fair value of the shares as of the grant date. We recognized $1,563,000 and $1,645,000 in share-based compensation for the three months ended September 30, 2021 and 2020, respectively, and we recognized $4,275,000 and $4,167,000 in share-based compensation for the nine months ended September 30, 2021 and 2020, respectively. We recognize forfeitures as they occur. Noncontrolling Interests. Noncontrolling interests are the portion of equity in a subsidiary not attributable to a parent. Accordingly, we have reported noncontrolling interests in equity on the consolidated balance sheets but separate from Whitestone’s equity. On the consolidated statements of operations and comprehensive income (loss), subsidiaries are reported at the consolidated amount, including both the amount attributable to Whitestone and noncontrolling interests. The consolidated statements of changes in equity is included for quarterly financial statements, including beginning balances, activity for the period and ending balances for shareholders’ equity, noncontrolling interests and total equity. Accrued Rents and Accounts Receivable. Included in accrued rents and accounts receivable are base rents, tenant reimbursements and receivables attributable to recording rents on a straight-line basis. We review the collectability of charges under our tenant operating leases on a regular basis, taking into consideration changes in factors such as the tenant’s payment history, the financial condition of the tenant, business conditions in the industry in which the tenant operates and economic conditions in the area where the property is located, including the impact of the COVID-19 pandemic on tenants’ businesses and financial condition. We recognize an adjustment to rental revenue if we deem it probable that the receivable will not be collected. Our review of collectability under our operating leases includes any accrued rental revenues related to the straight-line method of reporting rental revenue. As of September 30, 2021 and December 31, 2020, we had an allowance for uncollectible accounts of $15.9 million and $16.4 million, respectively. During the three months ending September 30, 2021 and 2020, we recorded an adjustment to rental revenue for bad debt, exclusive of straight-line rent reserve adjustments, in the amount of a $0.2 million increase to revenue and a $1.3 million decrease to revenue, respectively, and during the nine months ending September 30, 2021 and 2020, we recorded an adjustment to rental revenue for bad debt, exclusive of straight-line rent reserve adjustments, in the amount of a $0.5 million decrease to revenue and $4.5 million decrease to revenue, respectively. The three months ended September 30, 2021 included 63 cash basis tenants, resulting in decreases to rental revenue for bad debt and straight-line rent adjustments of $0.02 million and $0.3 million, respectively, and the three months ended September 30, 2020 included 12 cash basis tenants, resulting in decreases to rental revenue for bad debt and straight-line rent adjustments of $0.7 million and $0.1 million, respectively. The nine months ended September 30, 2021 included 63 cash basis tenants, resulting in decreases to rental revenue for bad debt and straight-line rent adjustments of $0.6 million and $0.5 million, respectively, and the nine months ended September 30, 2020 included 84 cash basis tenants, resulting in decreases to rental revenue for bad debt and straight-line rent adjustments of $1.8 million and $1.1 million, respectively. Revenue Recognition. All leases on our properties are classified as operating leases, and the related rental income is recognized on a straight-line basis over the terms of the related leases. Differences between rental income earned and amounts due per the respective lease agreements are capitalized or charged, as applicable, to accrued rents and accounts receivable. Percentage rents are recognized as rental income when the thresholds upon which they are based have been met. Recoveries from tenants for taxes, insurance, and other operating expenses are recognized as revenues in the period the corresponding costs are incurred. We combine lease and nonlease components in lease contracts, which includes combining base rent, recoveries, and percentage rents into a single line item, Rental , within the consolidated statements of operations and comprehensive income (loss). Additionally, we have tenants who pay real estate taxes directly to the taxing authority. We exclude these costs paid directly by the tenant to third parties on our behalf from revenue recognized and the associated property operating expense. Other property income primarily includes amounts recorded in connection with management fees and lease termination fees. Pillarstone OP pays us management fees for property management, leasing and day-to-day advisory and administrative services. Their obligations are satisfied over time. Pillarstone OP is billed monthly and typically pays quarterly. Revenues are governed by the Management Agreements (as defined in Note 6 (Investment in Real Estate Partnership)). Refer to Note 6 (Investment in Real Estate Partnership) for additional information regarding the Management Agreements with Pillarstone OP. Additionally, we recognize lease termination fees in the year that the lease is terminated and collection of the fee is probable. Amounts recorded within other property income are accounted for at the point in time when control of the goods or services transfers to the customer and our performance obligation is satisfied. See our Annual Report on Form 10-K for the year ended December 31, 2020 for further discussion on significant accounting policies. Recent Accounting Pronouncements. In April 2020, the FASB issued guidance on the application of Topic 842, relating to concessions being made by lessors in response to the COVID-19 pandemic. The guidance notes that it would be acceptable for entities to make an election to account for lease concessions relating to the effects of the COVID-19 pandemic consistent with how those concessions would be accounted for under Topic 842 as though enforceable rights and obligations for those concessions existed, even if such enforceable rights and obligations are not explicitly contained in the lease contract. Thus, for concessions relating to the COVID-19 pandemic, an entity would not have to analyze each contract to determine whether enforceable rights and obligations for concessions exist in the contract, and would have the option to apply, or not to apply, the general lease modification guidance in Topic 842 as it stands. We have elected this option to account for lease concessions relating to the effects of the COVID-19 pandemic consistent with how those concessions would be accounted for under Topic 842 as though enforceable rights and obligations for those concessions existed. Therefore, such concessions are not accounted for as a lease modification under Topic 842.

Leases

Leases	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Leases	LEASES As a Lessor. All leases on our properties are classified as noncancelable operating leases, and the related rental income is recognized on a straight-line basis over the terms of the related leases. Differences between rental income earned and amounts due per the respective lease agreements are capitalized or charged, as applicable, to accrued rents and accounts receivable. Percentage rents are recognized as rental income when the thresholds upon which they are based have been met. Recoveries from tenants for taxes, insurance, and other operating expenses are recognized as revenues in the period the corresponding costs are incurred. We combine lease and nonlease components in lease contracts, which includes combining base rent, recoveries, and percentage rents into a single line item, Rental , within the consolidated statements of operations and comprehensive income (loss). A summary of minimum future rents to be received (exclusive of renewals, tenant reimbursements, contingent rents, and collectability adjustments under Topic 842) under noncancelable operating leases in existence as of September 30, 2021 is as follows (in thousands): Years Ended December 31, Minimum Future Rents (1) 2021 (remaining) $ 22,430 2022 85,338 2023 73,467 2024 59,880 2025 44,171 Thereafter 125,750 Total $ 411,036 (1) These amounts do not reflect future rental revenues from the renewal or replacement of existing leases and exclude reimbursements of operating expenses and rental increases that are not fixed. As a Lessee. We have office space, automobile, and office machine leases, which qualify as operating leases, with remaining lease terms of one The following table summarizes the fixed, future minimum rental payments, excluding variable costs, which are discounted by our weighted average incremental borrowing rates to calculate the lease liabilities for our operating leases in which we are the lessee (in thousands): Years Ended December 31, September 30, 2021 2021 (remaining) $ 100 2022 109 2023 63 2024 41 2025 31 Thereafter 1 Total undiscounted rental payments 345 Less imputed interest 22 Total lease liabilities $ 323

Accrued Rents and Accounts Rece

Accrued Rents and Accounts Receivable, Net	9 Months Ended
	Sep. 30, 2021
Receivables [Abstract]
Accrued Rents and Accounts Receivable, Net	ACCRUED RENTS AND ACCOUNTS RECEIVABLE, NET Accrued rents and accounts receivable, net consists of amounts accrued, billed and due from tenants, allowance for doubtful accounts and other receivables as follows (in thousands): September 30, 2021 December 31, 2020 Tenant receivables $ 19,898 $ 22,956 Accrued rents and other recoveries 17,833 16,348 Allowance for doubtful accounts (15,919) (16,426) Other receivables 179 131 Total $ 21,991 $ 23,009

Unamortized Lease Commissions,

Unamortized Lease Commissions, Legal Fees and Loan Costs	9 Months Ended
	Sep. 30, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Unamortized Lease Commissions, Legal Fees and Loan Costs	UNAMORTIZED LEASE COMMISSIONS, LEGAL FEES AND LOAN COSTS Costs which have been deferred consist of the following (in thousands): September 30, 2021 December 31, 2020 Leasing commissions $ 12,686 $ 10,380 Deferred legal cost 365 373 Deferred financing cost 3,898 3,898 Total cost 16,949 14,651 Less: leasing commissions accumulated amortization (5,967) (5,029) Less: deferred legal cost accumulated amortization (239) (216) Less: deferred financing cost accumulated amortization (2,387) (1,720) Total cost, net of accumulated amortization $ 8,356 $ 7,686

Investment in Real Estate Partn

Investment in Real Estate Partnership	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Investment in Real Estate Partnership	INVESTMENT IN REAL ESTATE PARTNERSHIP On December 8, 2016, we, through our Operating Partnership, entered into a Contribution Agreement (the “Contribution Agreement”) with Pillarstone OP and Pillarstone Capital REIT (“Pillarstone REIT”) pursuant to which we contributed all of the equity interests in four of our wholly owned subsidiaries: Whitestone CP Woodland Ph. 2, LLC, a Delaware limited liability company (“CP Woodland”); Whitestone Industrial-Office, LLC, a Texas limited liability company (“Industrial-Office”); Whitestone Offices, LLC, a Texas limited liability company (“Whitestone Offices”); and Whitestone Uptown Tower, LLC, a Delaware limited liability company (“Uptown Tower,” and together with CP Woodland, Industrial-Office and Whitestone Offices, the “Entities”) that own 14 non-core properties that do not fit our Community Centered Property ® strategy (the “Pillarstone Properties”), to Pillarstone OP for aggregate consideration of approximately $84 million, consisting of (1) approximately $18.1 million of Class A units representing limited partnership interests in Pillarstone OP (“Pillarstone OP Units”), issued at a price of $1.331 per Pillarstone OP Unit; and (2) the assumption of approximately $65.9 million of liabilities, consisting of (a) approximately $15.5 million of our liability under the 2018 Facility (as defined in Note 7 (Debt)); (b) an approximately $16.3 million promissory note of Uptown Tower under the Loan Agreement, dated as of September 26, 2013, between Uptown Tower, as borrower, and U.S. Bank, National Association, as successor to Morgan Stanley Mortgage Capital Holdings LLC, as lender; and (c) an approximately $34.1 million promissory note (the “Industrial-Office Promissory Note”) of Industrial-Office issued under the Loan Agreement, dated as of November 26, 2013 (the “Industrial-Office Loan Agreement”), between Industrial-Office, as borrower, and Jackson National Life Insurance Company, as lender (collectively, the “Contribution”). In connection with the Contribution, (1) with respect to each Pillarstone Property (other than Uptown Tower), Whitestone TRS, Inc., a subsidiary of the Company (“Whitestone TRS”), entered into a Management Agreement with the Entity that owns such Pillarstone Property and (2) with respect to Uptown Tower, Whitestone TRS entered into a Management Agreement with Pillarstone OP (collectively, the “Management Agreements”). Pursuant to the Management Agreements with respect to each Pillarstone Property (other than Uptown Tower), Whitestone TRS agreed to provide certain property management, leasing and day-to-day advisory and administrative services to such Pillarstone Property in exchange for (x) a monthly property management fee equal to 5.0% of the monthly revenues of such Pillarstone Property and (y) a monthly asset management fee equal to 0.125% of GAV (as defined in each Management Agreement as, generally, the purchase price of the respective Pillarstone Property based upon the purchase price allocations determined pursuant to the Contribution Agreement, excluding all indebtedness, liabilities or claims of any nature) of such Pillarstone Property. Pursuant to the Management Agreement with respect to Uptown Tower, Whitestone TRS agreed to provide certain property management, leasing and day-to-day advisory and administrative services to Pillarstone OP in exchange for (x) a monthly property management fee equal to 3.0% of the monthly revenues of Uptown Tower and (y) a monthly asset management fee equal to 0.125% of GAV of Uptown Tower. The initial term of each Management Agreement expired on December 31, 2017, after which each Management Agreement became automatically renewable on a month to month basis; provided that each Management Agreement can be terminated by either party thereto upon not less than thirty days’ prior written notice to the other party. None of the Management Agreements had been terminated as of September 30, 2021. In connection with the Contribution, on December 8, 2016, the Operating Partnership entered into a Tax Protection Agreement with Pillarstone REIT and Pillarstone OP pursuant to which Pillarstone OP agreed to indemnify the Operating Partnership for certain tax liabilities resulting from its recognition of income or gain prior to December 8, 2021 if such liabilities result from a transaction involving a direct or indirect taxable disposition of all or a portion of the Pillarstone Properties or if Pillarstone OP fails to maintain and allocate to the Operating Partnership for taxation purposes minimum levels of liabilities as specified in the Tax Protection Agreement, the result of which causes such recognition of income or gain and the Company incurs taxes that must be paid to maintain its REIT status for federal income tax purposes. The table below presents the real estate partnership investment in which the Company holds an ownership interest (in thousands): Company’s Investment as of September 30, 2021 December 31, 2020 Real estate partnership Ownership Interest Pillarstone OP (1) 81.4% $ 34,408 $ 33,979 Total real estate partnership (2) $ 34,408 $ 33,979 (1) The Company manages these real estate partnership investments and, where applicable, earns acquisition fees, leasing commissions, property management fees, and asset management fees. (2) Representing eight property interests and 926,798 square feet of GLA, as of September 30, 2021 and December 31, 2020. The table below presents the Company’s share of net income from its investment in the real estate partnership which is included in equity in earnings of real estate partnership, net on the Company’s consolidated statements of operations and comprehensive income (loss) (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Pillarstone OP $ 151 $ 196 $ 429 $ 752 Summarized financial information for the Company’s investment in real estate partnership is as follows (in thousands): September 30, 2021 December 31, 2020 Assets: Real estate, net $ 48,563 $ 49,113 Other assets 8,442 7,657 Total assets 57,005 56,770 Liabilities and equity: Notes payable 14,988 15,185 Other liabilities 3,349 3,533 Equity 38,668 38,052 Total liabilities and equity 57,005 56,770 Company’s share of equity 31,494 30,992 Cost of investment in excess of the Company’s share of underlying net book value 2,914 2,987 Carrying value of investment in real estate partnership $ 34,408 $ 33,979 Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Revenues $ 2,379 $ 2,371 $ 6,843 $ 7,396 Operating expenses (1,787) (1,713) (5,184) (5,195) Other expenses (351) (391) (1,033) (1,184) Net income $ 241 $ 267 $ 626 $ 1,017 The amortization of the basis difference between the cost of investment and the Company's share of underlying net book value for the three months periods ended September 30, 2021 and 2020 is $45,000 and $27,000, respectively, and for the nine months periods ended September 30, 2021 and 2020 is $81,000. The Company amortized the difference into equity in earnings of real estate partnership on the consolidated statements of operations and comprehensive income (loss). The Company has evaluated its guarantee to Pillarstone OP pursuant to ASC 460, “ Guarantees,” and has determined the guarantee to be a performance guarantee, for which ASC 460 contains initial recognition and measurement requirements, and related disclosure requirements. The Company is obligated in two respects: (i) a noncontingent liability, which represents the Company’s obligation to stand ready to perform under the terms of the guarantee in the event that the specified triggering event(s) occur; and (ii) the contingent liability, which represents the Company’s obligation to make future payments if those triggering events occur. The fair value of our loan guarantee to Pillarstone OP is estimated on a Level 3 basis (as provided by ASC 820), using a probability-weighted discounted cash flow analysis based on a discount rate, discounting the loan balance. The Company recognized a noncontingent liability of $462,000 at the inception of the guarantee at fair value which is recorded on the Company’s consolidated balance sheets, net of accumulated amortization. The Company will amortize the guarantee liability into income over seven years. For the three months ended September 30, 2021 and 2020, the amortization of the guarantee liability was approximately $18,000 and $10,000, respectively, and for the nine months ended September 30, 2021 and 2020, the amortization of the guarantee liability was approximately $28,000 and $29,000, respectively.

Debt

Debt	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Debt	DEBT Certain subsidiaries of Whitestone are the borrowers under various financing arrangements. These subsidiaries are separate legal entities, and their respective assets and credit are not available to satisfy the debt of Whitestone or any of its other subsidiaries. Debt consisted of the following as of the dates indicated (in thousands): Description September 30, 2021 December 31, 2020 Fixed rate notes $100.0 million, 1.73% plus 1.35% to 1.90% Note, due October 30, 2022 (1) $ 100,000 $ 100,000 $165.0 million, 2.24% plus 1.35% to 1.90% Note, due January 31, 2024 (2) 165,000 165,000 $80.0 million, 3.72% Note, due June 1, 2027 80,000 80,000 $19.0 million 4.15% Note, due December 1, 2024 18,442 18,687 $20.2 million 4.28% Note, due June 6, 2023 17,914 18,222 $14.0 million 4.34% Note, due September 11, 2024 13,044 13,236 $14.3 million 4.34% Note, due September 11, 2024 13,834 14,014 $15.1 million 4.99% Note, due January 6, 2024 13,973 14,165 $2.6 million 5.46% Note, due October 1, 2023 2,302 2,339 $50.0 million, 5.09% Note, due March 22, 2029 50,000 50,000 $50.0 million, 5.17% Note, due March 22, 2029 50,000 50,000 $1.7 million 3.25% Note, due December 28, 2021 463 — Floating rate notes Unsecured line of credit, LIBOR plus 1.40% to 1.90%, due January 31, 2023 94,500 119,500 Total notes payable principal 619,472 645,163 Less deferred financing costs, net of accumulated amortization (823) (978) Total notes payable $ 618,649 $ 644,185 (1) Promissory note includes an interest rate swap that fixed the LIBOR portion of Term Loan 3 (as defined below) at 1.73%. (2) Promissory note includes an interest rate swap that fixed the LIBOR portion of the interest rate at an average rate of 2.24% for the duration of the term through January 31, 2024. LIBOR is expected to be discontinued after 2021. A number of our current debt agreements have an interest rate tied to LIBOR. Some of these agreements provide procedures for determining an alternative base rate in the event that LIBOR is discontinued, but not all do so. Regardless, there can be no assurances as to what alternative base rates may be and whether such base rate will be more or less favorable than LIBOR and any other unforeseen impacts of the discontinuation of LIBOR. The Company is monitoring the developments with respect to the phasing out of LIBOR after 2021 and working with its lenders to ensure any transition away from LIBOR will have minimal impact on its financial condition, but can provide no assurances regarding the impact of the discontinuation of LIBOR. On April 30, 2020, the Company entered into a loan in the principal amount of $1,733,510 from U.S. Bank National Association, one of the Company’s existing lenders, pursuant to the Paycheck Protection Program (the “PPP Loan”) of the Coronavirus Aid, Relief, and Economic Security Act of 2020 (the “CARES Act”). The PPP Loan was set to mature on May 6, 2022 (the “Maturity Date”), and accrued interest at 1.00% per annum and could be prepaid in whole or in part without penalty. Principal and interest were payable in 18 monthly installments of $96,864.28, beginning on December 6, 2020, plus a final payment equal to all unpaid principal and accrued interest on the Maturity Date. Pursuant to the CARES Act, the Company applied for and was granted forgiveness for all of the PPP Loan. Forgiveness was determined by the U.S. Small Business Administration based on the use of loan proceeds for payroll costs, mortgage interest, rent or utility costs and the maintenance of employee and compensation levels. The Company intended to and used all proceeds from the PPP Loan to retain employees and maintain payroll and make mortgage payments, lease payments and utility payments to support business continuity throughout the COVID-19 pandemic, which amounts were eligible for forgiveness, subject to the provisions of the CARES Act. Based on the guidance in FASB ASC 405-20, “Liabilities - Extinguishment of Liabilities,” the PPP loan remains a liability until either (1) it is wholly or partially forgiven and we have been legally released, or (2) it is paid off. Since the loan was partially or wholly forgiven and legal release was received, the liability was reduced by the amount forgiven and a gain on extinguishment was recognized. T he Company recognized a $1,734,000 gain for the PPP Loan forgiveness during the year ended December 30, 2020 based on the legal release from the U.S. Small Business Administration. On March 22, 2019, we, through our Operating Partnership, entered into a Note Purchase and Guarantee Agreement (the “Note Agreement”) together with certain subsidiary guarantors as initial guarantor parties thereto (the “Subsidiary Guarantors”) and The Prudential Insurance Company of America and the various other purchasers named therein (collectively, the “Purchasers”) providing for the issuance and sale of $100 million of senior unsecured notes of the Operating Partnership, of which (i) $50 million are designated as 5.09% Series A Senior Notes due March 22, 2029 (the “Series A Notes”) and (ii) $50 million are designated as 5.17% Series B Senior Notes due March 22, 2029 (the “Series B Notes” and, together with the Series A Notes, the “Notes”) pursuant to a private placement that closed on March 22, 2019 (the “Private Placement”). Obligations under the Notes are unconditionally guaranteed by the Company and by the Subsidiary Guarantors. The principal of the Series A Notes will begin to amortize on March 22, 2023 with annual principal payments of approximately $7.1 million. The principal of the Series B Notes will begin to amortize on March 22, 2025 with annual principal payments of $10.0 million. The Notes will pay interest quarterly on the 22nd day of March, June, September and December in each year until maturity. The Operating Partnership may prepay at any time all, or from time to time part of, the Notes, in an amount not less than $1,000,000 in the case of a partial prepayment, at 100% of the principal amount so prepaid, plus a make-whole amount. The make-whole amount is equal to the excess, if any, of the discounted value of the remaining scheduled payments with respect to the Notes being prepaid over the aggregate principal amount of such Notes (as described in the Note Agreement). In addition, in connection with a Change of Control (as defined in the Note Purchase Agreement), the Operating Partnership is required to offer to prepay the Notes at 100% of the principal amount plus accrued and unpaid interest thereon. The Note Agreement contains representations, warranties, covenants, terms and conditions customary for transactions of this type and substantially similar to the Operating Partnership’s existing senior revolving credit facility, including limitations on liens, incurrence of investments, acquisitions, loans and advances and restrictions on dividends and certain other restricted payments. In addition, the Note Agreement contains certain financial covenants substantially similar to the Operating Partnership’s existing senior revolving credit facility, including the following: • maximum total indebtedness to total asset value ratio of 0.60 to 1.00; • maximum secured debt to total asset value ratio of 0.40 to 1.00; • minimum EBITDA (earnings before interest, taxes, depreciation, amortization or extraordinary items) to fixed charges ratio of 1.50 to 1.00; • maximum other recourse debt to total asset value ratio of 0.15 to 1.00; and • maintenance of a minimum tangible net worth (adjusted for accumulated depreciation and amortization) of $372 million plus 75% of the net proceeds from additional equity offerings (as defined therein). In addition, the Note Agreement contains a financial covenant requiring that maximum unsecured debt not exceed the lesser of (i) an amount equal to 60% of the aggregate unencumbered asset value and (ii) the debt service coverage amount (as described in the Note Agreement). That covenant is substantially similar to the borrowing base concept contained in the Operating Partnership’s existing senior revolving credit facility. The Note Agreement also contains default provisions, including defaults for non-payment, breach of representations and warranties, insolvency, non-performance of covenants, cross-defaults with other indebtedness and guarantor defaults. The occurrence of an event of default under the Note Agreement could result in the Purchasers accelerating the payment of all obligations under the Notes. The financial and restrictive covenants and default provisions in the Note Agreement are substantially similar to those contained in the Operating Partnership’s existing credit facility. Net proceeds from the Private Placement were used to refinance existing indebtedness. The Notes have not been and will not be registered under the Securities Act of 1933, as amended (the “Securities Act”), and may not be offered or sold in the United States absent registration or an applicable exemption from the registration requirements of the Securities Act. The Notes were sold in reliance on the exemption from registration provided by Section 4(a)(2) of the Securities Act. On January 31, 2019, we, through our Operating Partnership, entered into an unsecured credit facility (the “2019 Facility”) with the lenders party thereto, Bank of Montreal, as administrative agent (the “Agent”), SunTrust Robinson Humphrey, as syndication agent, and BMO Capital Markets Corp., U.S. Bank National Association, SunTrust Robinson Humphrey and Regions Capital Markets, as co-lead arrangers and joint book runners. The 2019 Facility amended and restated the 2018 Facility (as defined below). The 2019 Facility is comprised of the following three tranches: • $250.0 million unsecured revolving credit facility with a maturity date of January 1, 2023 (the “2019 Revolver”); • $165.0 million unsecured term loan with a maturity date of January 31, 2024 (“Term Loan A”); and • $100.0 million unsecured term loan with a maturity date of October 30, 2022 (“Term Loan B” and together with Term Loan A, the “2019 Term Loans”). Borrowings under the 2019 Facility accrue interest (at the Operating Partnership's option) at a Base Rate or an Adjusted LIBOR plus an applicable margin based upon our then existing leverage. As of September 30, 2021, the interest rate on the 2019 Revolver was 1.73%. The applicable margin for Adjusted LIBOR borrowings ranges from 1.40% to 1.90% for the 2019 Revolver and 1.35% to 1.90% for the 2019 Term Loans. Base Rate means the higher of: (a) the Agent’s prime commercial rate, (b) the sum of (i) the average rate quoted by the Agent by two or more federal funds brokers selected by the Agent for sale to the Agent at face value of federal funds in the secondary market in an amount equal or comparable to the principal amount for which such rate is being determined, plus (ii) 1/2 of 1.00%, and (c) the LIBOR rate for such day plus 1.00%. Adjusted LIBOR means LIBOR divided by one minus the Eurodollar Reserve Percentage. The Eurodollar Reserve Percentage means the maximum reserve percentage at which reserves are imposed by the Board of Governors of the Federal Reserve System on eurocurrency liabilities. Pursuant to the 2019 Facility, in the event of certain circumstances that result in the unavailability of LIBOR, including but not limited to LIBOR no longer being a widely recognized benchmark rate for newly originated dollar loans in the U.S. market, the Operating Partnership and the Agent will establish an alternate interest rate to LIBOR giving due consideration to prevailing market conventions and will amend the 2019 Facility to give effect to such alternate interest rate. The 2019 Facility includes an accordion feature that will allow the Operating Partnership to increase the borrowing capacity by $200.0 million, upon the satisfaction of certain conditions. On March 20, 2020, as a precautionary measure to preserve our financial flexibility in response to potential credit risks posed by the COVID-19 pandemic, the Company drew down approximately $30.0 million under the 2019 Revolver, which we subsequently paid down in the fourth quarter of 2020. As of September 30, 2021, subject to any potential future paydowns or increases in the borrowing base, we have $81.8 million remaining availability under the 2019 Revolver. As of September 30, 2021, $359.5 million was drawn on the 2019 Facility, and $0.5 million was outstanding under a standby letter of credit. The Company used $446.2 million of proceeds from the 2019 Facility to repay amounts outstanding under the 2018 Facility and intends to use the remaining proceeds from the 2019 Facility for general corporate purposes, including property acquisitions, debt repayment, capital expenditures, the expansion, redevelopment and re-tenanting of properties in its portfolio and working capital. The Company, each direct and indirect material subsidiary of the Operating Partnership and any other subsidiary of the Operating Partnership that is a guarantor under any unsecured ratable debt will serve as a guarantor for funds borrowed by the Operating Partnership under the 2019 Facility. The 2019 Facility contains customary terms and conditions, including, without limitation, customary representations and warranties and affirmative and negative covenants including, without limitation, information reporting requirements, limitations on investments, acquisitions, loans and advances, mergers, consolidations and sales, incurrence of liens, dividends and restricted payments. In addition, the 2019 Facility contains certain financial covenants including the following: • maximum total indebtedness to total asset value ratio of 0.60 to 1.00; • maximum secured debt to total asset value ratio of 0.40 to 1.00; • minimum EBITDA (earnings before interest, taxes, depreciation, amortization or extraordinary items) to fixed charges ratio of 1.50 to 1.00; • maximum other recourse debt to total asset value ratio of 0.15 to 1.00; and • maintenance of a minimum tangible net worth (adjusted for accumulated depreciation and amortization) of $372 million plus 75% of the net proceeds from additional equity offerings (as defined therein). We serve as the guarantor for funds borrowed by the Operating Partnership under the 2019 Facility. The 2019 Facility contains customary terms and conditions, including, without limitation, affirmative and negative covenants such as information reporting requirements, maximum secured indebtedness to total asset value, minimum EBITDA (earnings before interest, taxes, depreciation, amortization or extraordinary items) to fixed charges, and maintenance of a minimum net worth. The 2019 Facility also contains customary events of default with customary notice and cure, including, without limitation, nonpayment, breach of covenant, misrepresentation of representations and warranties in a material respect, cross-default to other major indebtedness, change of control, bankruptcy and loss of REIT tax status. On November 7, 2014, we, through our Operating Partnership, entered into an unsecured revolving credit facility (the “2014 Facility”) with the lenders party thereto, with BMO Capital Markets Corp., Wells Fargo Securities, LLC, Merrill Lynch, Pierce, Fenner & Smith Incorporated and U.S. Bank, National Association, as co-lead arrangers and joint book runners, and Bank of Montreal, as administrative agent (the “Agent”). The 2014 Facility amended and restated our previous unsecured revolving credit facility. On October 30, 2015, we, through our Operating Partnership, entered into the First Amendment to the 2014 Facility (the “First Amendment”) with the guarantors party thereto, the lenders party thereto and the Agent. We refer to the 2014 Facility, as amended by the First Amendment, as the “2018 Facility.” Pursuant to the First Amendment, the Company made the following amendments to the 2014 Facility: • extended the maturity date of the $300 million unsecured revolving credit facility under the 2014 Facility (the “2018 Revolver”) to October 30, 2019 from November 7, 2018; • converted $100 million of outstanding borrowings under the Revolver to a new $100 million unsecured term loan under the 2014 Facility (“Term Loan 3”) with a maturity date of October 30, 2022; • extended the maturity date of the first $50 million unsecured term loan under the 2014 Facility (“Term Loan 1”) to October 30, 2020 from February 17, 2017; and • extended the maturity date of the second $50 million unsecured term loan under the 2014 Facility (“Term Loan 2” and together with Term Loan 1 and Term Loan 3, the “2018 Term Loans”) to January 29, 2021 from November 7, 2019. Borrowings under the 2018 Facility accrued interest (at the Operating Partnership's option) at a Base Rate or an Adjusted LIBOR plus an applicable margin based upon our then existing leverage. The applicable margin for Adjusted LIBOR borrowings ranged from 1.40% to 1.95% for the 2018 Revolver and 1.35% to 2.25% for the 2018 Term Loans. Base Rate means the higher of: (a) the Agent’s prime commercial rate, (b) the sum of (i) the average rate quoted by the Agent by two or more federal funds brokers selected by the Agent for sale to the Agent at face value of federal funds in the secondary market in an amount equal or comparable to the principal amount for which such rate is being determined, plus (ii) 1/2 of 1.00%, and (c) the LIBOR rate for such day plus 1.00%. Adjusted LIBOR means LIBOR divided by one minus the Eurodollar Reserve Percentage. The Eurodollar Reserve Percentage means the maximum reserve percentage at which reserves are imposed by the Board of Governors of the Federal Reserve System on eurocurrency liabilities. Proceeds from the 2018 Facility were used for general corporate purposes, including property acquisitions, debt repayment, capital expenditures, the expansion, redevelopment and re-tenanting of properties in our portfolio and working capital. As of September 30, 2021, our $159.5 million in secured debt was collateralized by seven properties with a carrying value of $248.0 million. Our loans contain restrictions that would require the payment of prepayment penalties for the acceleration of outstanding debt and are secured by deeds of trust on certain of our properties and by assignment of the rents and leases associated with those properties. As of September 30, 2021, we were in compliance with all loan covenants. Scheduled maturities of our outstanding debt as of September 30, 2021 were as follows (in thousands): Year Amount Due 2021 (remaining) $ 1,138 2022 101,683 2023 122,363 2024 228,574 2025 17,143 Thereafter 148,571 Total $ 619,472

Derivatives and Hedging Activit

Derivatives and Hedging Activities	9 Months Ended
	Sep. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedging Activities	DERIVATIVES AND HEDGING ACTIVITIES The fair value of our interest rate swaps is as follows (in thousands): September 30, 2021 Balance Sheet Location Estimated Fair Value Accounts payable and accrued expenses $ (9,879) December 31, 2020 Balance Sheet Location Estimated Fair Value Accounts payable and accrued expenses $ (14,663) On January 31, 2019, we, through our Operating Partnership, entered into an interest rate swap of $65 million with Bank of Montreal that fixed the LIBOR portion of Term Loan A under the 2019 Facility at 2.43%. Pursuant to the terms of the agreement governing the interest rate swap, Bank of Montreal assigned $12.9 million of the swap to U.S. Bank, National Association, $11.6 million of the swap to Regions Bank, $15.7 million of the swap to SunTrust Bank, and $5.9 million of the swap to Associated Bank. See Note 7 (Debt) for additional information regarding the 2019 Facility. The swap began on February 7, 2019 and matured on November 9, 2020. We designated the interest rate swap as a cash flow hedge with the effective portion of the changes in fair value recorded in comprehensive income (loss). On January 31, 2019, we, through our Operating Partnership, entered into an interest rate swap of $115 million with Bank of Montreal that fixed the LIBOR portion of Term Loan A under the 2019 Facility at 2.43%. Pursuant to the terms of the agreement governing the interest rate swap, Bank of Montreal assigned $22.7 million of the swap to U.S. Bank, National Association, $20.5 million of the swap to Regions Bank, $27.9 million of the swap to SunTrust Bank, and $10.5 million of the swap to Associated Bank. See Note 7 (Debt) for additional information regarding the 2019 Facility. The swap began on November 9, 2020 and matured on February 8, 2021. We designated the interest rate swap as a cash flow hedge with the effective portion of the changes in fair value recorded in comprehensive income (loss). On January 31, 2019, we, through our Operating Partnership, entered into an interest rate swap of $165 million with Bank of Montreal that fixed the LIBOR portion of Term Loan A under the 2019 Facility at 2.43%. Pursuant to the terms of the agreement governing the interest rate swap, Bank of Montreal assigned $32.6 million of the swap to U.S. Bank, National Association, $29.4 million of the swap to Regions Bank, $40.0 million of the swap to SunTrust Bank, and $15.0 million of the swap to Associated Bank. See Note 7 (Debt) for additional information regarding the 2019 Facility. The swap began on February 8, 2021 and will mature on January 31, 2024. We have designated the interest rate swap as a cash flow hedge with the effective portion of the changes in fair value to be recorded in comprehensive income (loss) and subsequently reclassified into earnings in the period that the hedged transaction affects earnings. The ineffective portion of the change in fair value, if any, will be recognized directly in earnings. The Company does not expect any amount of the existing gains or losses to be reclassified into earnings within the next 12 months. On September 5, 2018, we, through our Operating Partnership, entered into an interest rate swap with Bank of America that fixed the LIBOR portion of the $9.6 million extension loan on the Whitestone Terravita Marketplace property at 2.85%. The swap began on September 25, 2018 and matured on September 24, 2020. We designated the interest rate swap as a cash flow hedge with the effective portion of the changes in fair value recorded in comprehensive income (loss). On November 19, 2015, we, through our Operating Partnership, entered into an interest rate swap with Bank of Montreal that fixed the LIBOR portion of Term Loan 3 under the 2018 Facility at 1.73%. In the fourth quarter of 2015, pursuant to the terms of the agreement governing the interest rate swap, Bank of Montreal assigned $35.0 million of the swap to U.S. Bank, National Association, and $15.0 million of the swap to SunTrust Bank. See Note 7 (Debt) for additional information regarding the 2018 Facility. The swap began on November 30, 2015 and will mature on October 28, 2022. We have designated the interest rate swap as a cash flow hedge with the effective portion of the changes in fair value to be recorded in comprehensive income (loss) and subsequently reclassified into earnings in the period that the hedged transaction affects earnings. The ineffective portion of the change in fair value, if any, will be recognized directly in earnings. The Company does not expect any amount of the existing gains or losses to be reclassified into earnings within the next 12 months. On November 19, 2015, we, through our Operating Partnership, entered into an interest rate swap with Bank of Montreal that fixed the LIBOR portion of Term Loan 1 under the 2018 Facility at 1.75%. In the fourth quarter of 2015, pursuant to the terms of the agreement governing the interest rate swap, Bank of Montreal assigned $3.8 million of the swap to Regions Bank, $6.5 million of the swap to U.S. Bank, National Association, $14.0 million of the swap to Wells Fargo Bank, National Association, $14.0 million of the swap to Bank of America, N.A., and $5.0 million of the swap to SunTrust Bank. See Note 7 (Debt) for additional information regarding the 2018 Facility. The swap began on February 3, 2017 and matured on October 30, 2020. We designated the interest rate swap as a cash flow hedge with the effective portion of the changes in fair value recorded in comprehensive income (loss). On November 19, 2015, we, through our Operating Partnership, entered into an interest rate swap with Bank of Montreal that fixed the LIBOR portion of Term Loan 2 under the 2018 Facility at 1.50%. In the fourth quarter of 2015, pursuant to the terms of the agreement governing the interest rate swap, Bank of Montreal assigned $3.8 million of the swap to Regions Bank, $6.5 million of the swap to U.S. Bank, National Association, $14.0 million of the swap to Wells Fargo Bank, National Association, $14.0 million of the swap to Bank of America, N.A., and $5.0 million of the swap to SunTrust Bank. See Note 7 (Debt) for additional information regarding the 2018 Facility. The swap began on December 7, 2015 and matured on January 29, 2021. We designated the interest rate swap as a cash flow hedge with the effective portion of the changes in fair value recorded in comprehensive income (loss). A summary of our interest rate swap activity is as follows (in thousands): Amount Recognized as Comprehensive Income (Loss) Location of Income (Loss) Recognized in Earnings Amount of Income (Loss) Recognized in Earnings (1) Three Months Ended September 30, 2021 $ 1,273 Interest expense $ (1,401) Three Months Ended September 30, 2020 $ 1,241 Interest expense $ (1,217) Nine Months Ended September 30, 2021 $ 4,783 Interest expense $ (4,057) Nine Months Ended September 30, 2020 $ (10,395) Interest expense $ (2,388) (1) There was no ineffective portion of our interest rate swaps to recognize in earnings for the three and nine months ended September 30, 2021 and 2020.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE Basic earnings per share for our common shareholders is calculated by dividing net income excluding the net income attributable to unvested restricted common shares and the net income attributable to noncontrolling interests, by our weighted average common shares outstanding during the period. Diluted earnings per share is computed by dividing the net income attributable to common shareholders, excluding the net income attributable to unvested restricted common shares and the net income attributable to noncontrolling interests, by the weighted average number of common shares including any dilutive unvested restricted common shares. Certain of our performance-based restricted common shares are considered participating securities that require the use of the two-class method for the computation of basic and diluted earnings per share. During the three months ended September 30, 2021 and 2020, 772,775 and 776,233 OP units, respectively, were excluded from the calculation of diluted earnings per share because their effect would be anti-dilutive, and during the nine months ended September 30, 2021 and 2020, 772,775 and 836,148 OP units, respectively, were excluded from the calculation of diluted earnings per share because their effect would be anti-dilutive. Three Months Ended September 30, Nine Months Ended September 30, (in thousands, except per share data) 2021 2020 2021 2020 Numerator: Income from continuing operations $ 2,946 $ 914 $ 7,772 $ 2,980 Less: Net income attributable to noncontrolling interests (47) (14) (132) (58) Income from continuing operations attributable to Whitestone REIT excluding amounts attributable to unvested restricted shares 2,899 900 7,640 2,922 Income from discontinued operations — — 1,833 — Less: Net income attributable to noncontrolling interests — — (33) — Income from discontinued operations attributable to Whitestone REIT — — 1,800 — Net income attributable to common shareholders excluding amounts attributable to unvested restricted shares $ 2,899 $ 900 $ 9,440 $ 2,922 Denominator: Weighted average number of common shares - basic 46,883 42,346 44,268 42,202 Effect of dilutive securities: Unvested restricted shares 942 1,094 840 838 Weighted average number of common shares - dilutive 47,825 43,440 45,108 43,040 Earnings Per Share: Basic: Income from continuing operations attributable to Whitestone REIT excluding amounts attributable to unvested restricted shares $ 0.06 $ 0.02 $ 0.17 $ 0.07 Income from discontinued operations attributable to Whitestone REIT — — 0.04 — Net income attributable to common shareholders excluding amounts attributable to unvested restricted shares $ 0.06 $ 0.02 $ 0.21 $ 0.07 Diluted: Income from continuing operations attributable to Whitestone REIT excluding amounts attributable to unvested restricted shares $ 0.06 $ 0.02 $ 0.17 $ 0.07 Income from discontinued operations attributable to Whitestone REIT — — 0.04 — Net income attributable to common shareholders excluding amounts attributable to unvested restricted shares $ 0.06 $ 0.02 $ 0.21 $ 0.07

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES With the exception of our taxable REIT subsidiaries, federal income taxes are generally not provided because we intend to and believe we continue to qualify as a REIT under the provisions of the Internal Revenue Code of 1986, as amended (the “Code”), and because we have distributed and intend to continue to distribute all of our taxable income to our shareholders. As a REIT, we must distribute at least 90% of our REIT taxable income to our shareholders and meet certain income sources and investment restriction requirements. In addition, REITs are subject to a number of organizational and operational requirements. If we fail to qualify as a REIT in any taxable year, we will be subject to federal income tax (including any applicable alternative minimum tax) on our taxable income at regular corporate tax rates. We are subject to the Texas Margin Tax, which is computed by applying the applicable tax rate (0.75% for us) to the profit margin, which generally will be determined for us as total revenue less a 30% standard deduction. Although the Texas Margin Tax is not an income tax, FASB ASC 740, “ Income Taxes

Equity

Equity	9 Months Ended
	Sep. 30, 2021
Stockholders' Equity Note [Abstract]
Equity	EQUITY Common Shares Under our declaration of trust, as amended, we have authority to issue up to 400,000,000 common shares of beneficial interest, $0.001 par value per share, and up to 50,000,000 preferred shares of beneficial interest, $0.001 par value per share. Equity Offerings On May 31, 2019, we entered into nine equity distribution agreements for an at-the-market equity distribution program (the “2019 equity distribution agreements”) providing for the issuance and sale of up to an aggregate of $100 million of the Company’s common shares pursuant to our Registration Statement on Form S-3 (File No. 333-225007). Actual sales will depend on a variety of factors determined by us from time to time, including (among others) market conditions, the trading price of our common shares, capital needs and our determinations of the appropriate sources of funding for us, and were made in transactions that will be deemed to be “at-the-market” offerings as defined in Rule 415 under the Securities Act. We have no obligation to sell any of our common shares and can at any time suspend offers under the 2019 equity distribution agreements or terminate the 2019 equity distribution agreements. During the nine months ended September 30, 2021, we sold 6,016,148 common shares under the 2019 equity distribution agreements, with net proceeds to us of approximately $53.3 million. In connection with such sales, we paid compensation of approximately $812,000 to the sales agents. During the three months ended September 30, 2021, we sold 2,991,168 common shares under the 2019 equity distribution agreements, with net proceeds to us of approximately $28.0 million. In connection with such sales, we paid compensation of approximately $426,000 to the sales agents. During the three months ended September 30, 2020, we did not sell shares under the 2019 equity distribution agreements. During the nine months ended September 30, 2020, we sold 170,942 common shares under the 2019 equity distribution agreements, with net proceeds to us of approximately $2.2 million. In connection with such sales, we paid compensation of approximately $34,000 to the sales agents. Operating Partnership Units Substantially all of our business is conducted through our Operating Partnership. We are the sole general partner of the Operating Partnership. As of September 30, 2021, we owned a 98.4% interest in the Operating Partnership. Limited partners in the Operating Partnership holding OP units have the right to redeem their OP units for cash or, at our option, common shares at a ratio of one OP unit for one common share. Distributions to OP unit holders are paid at the same rate per unit as distributions per share to holders of Whitestone common shares. As of September 30, 2021 and December 31, 2020, there were 49,491,529 and 43,043,251 OP units outstanding, respectively. We owned 48,718,754 and 42,270,476 OP units as of September 30, 2021 and December 31, 2020, respectively. The balance of the OP units is owned by third parties, including certain members of our board of trustees. Our weighted average share ownership in the Operating Partnership was approximately 98.4% and 98.2% for the three months ended September 30, 2021 and 2020, respectively, and approximately 98.3% and 98.1% for the nine months ended September 30, 2021 and 2020, respectively. During the three months ended September 30, 2021 and 2020, 0 and 1,331 OP units, respectively, were redeemed for an equal number of c ommon shares, and d uring the nine months ended September 30, 2021 and 2020, 0 and 132,990 OP units, respectively, were redeemed for an equal number of c ommon shares . Distributions The following table summarizes the cash distributions paid or payable to holders of common shares and to holders of noncontrolling OP units during each quarter of 2020 and the nine months ended September 30, 2021 (in thousands, except per share/per OP unit data): Common Shares Noncontrolling OP Unit Holders Total Quarter Paid Distributions Per Common Share Amount Paid Distributions Per OP Unit Amount Paid Amount Paid 2021 Third Quarter $ 0.1075 $ 4,981 $ 0.1075 $ 83 $ 5,064 Second Quarter 0.1075 4,602 0.1075 83 4,685 First Quarter 0.1058 4,480 0.1058 82 4,562 Total $ 0.3208 $ 14,063 $ 0.3208 $ 248 $ 14,311 2020 Fourth Quarter $ 0.1050 $ 4,432 $ 0.1050 $ 81 $ 4,513 Third Quarter 0.1050 4,430 0.1050 81 4,511 Second Quarter 0.1050 4,413 0.1050 91 4,504 First Quarter 0.2850 11,928 0.2850 258 12,186 Total $ 0.6000 $ 25,203 $ 0.6000 $ 511 $ 25,714 The Board will regularly reassess the dividend, particularly as there is more clarity on the duration and severity of the COVID-19 pandemic and as business conditions improve. Shareholders' Rights Plan On May 14, 2020, the Board authorized a dividend of one preferred share purchase right (a “Right”) for each outstanding common share payable on May 26, 2020 (the “Record Date”), to the holders of record of common shares as of 5:00 P.M., New York City time, on the Record Date. In connection with the Rights, the Company and American Stock Transfer & Trust Company, LLC, as rights agent, entered into a Rights Agreement, dated as of May 14, 2020 (the “Rights Agreement”). Each Right entitles the registered holder to purchase from the Company one one-thousandth (a “Unit”) of a Series A Preferred Share, par value $0.001 per share (each a “Preferred Share”), of the Company at a purchase price of $30.00 per Unit, subject to adjustment as described in the Rights Agreement. If a person or group of affiliated or associated persons acquires beneficial ownership of 5% or more of our outstanding common shares (20% or more in the case of a passive institutional investor), subject to certain exceptions described in the Rights Agreement, each Right would entitle its holder (other than the acquiring person or group of affiliated or associated persons) to purchase additional common shares at a substantial discount to the public market price. In addition, under certain circumstances, we may exchange the Rights (other than Rights beneficially owned by the acquiring person or group of affiliated or associated persons), in whole or in part, for common shares on a one-for-one basis. Pursuant to the Rights Agreement, the Rights were scheduled to expire on the earliest of (i) the close of business on May 13, 2021, (ii) the time at which the Rights are redeemed pursuant to the Rights Agreement, (iii) the closing of any merger or other acquisition transaction involving the Company that has been approved by the Board, at which time the Rights are terminated, and (iv) the time at which the Rights are exchanged pursuant to the Rights Agreement. On April 21, 2021, the Company entered into the First Amendment to Rights Agreement (the “First Amendment to Rights Agreement”) with American Stock Transfer and Trust, LLC, as rights agent, solely to extend the expiration date of the Rights under the Rights Agreement from the close of business on May 13, 2021 to the close of business on May 13, 2022, unless earlier exercised, exchanged, amended, redeemed, or terminated, as described above. The Rights are in all respects subject to and governed by the provisions of the Rights Agreement, as amended by the First Amendment to Rights Agreement.

Incentive Share Plan

Incentive Share Plan	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Incentive Share Plan	INCENTIVE SHARE PLAN The Company’s 2008 Long-Term Equity Incentive Ownership Plan (as amended, the “2008 Plan”) expired in July 2018. At the Company’s annual meeting of shareholders on May 11, 2017, our shareholders voted to approve the 2018 Long-Term Equity Incentive Ownership Plan (the “2018 Plan”). The 2018 Plan provides for the issuance of up to 3,433,831 common shares and OP units pursuant to awards under the 2018 Plan. The 2018 Plan became effective on July 30, 2018, which is the day after the 2008 Plan expired. Pursuant to the 2008 Plan, the maximum aggregate number of common shares that were issuable under the 2008 Plan was increased upon each issuance of common shares by the Company so that at any time the maximum number of shares that were issuable under the 2008 Plan equaled 12.5% of the aggregate number of common shares of the Company and OP units issued and outstanding (other than units issued to or held by the Company). The Compensation Committee administered the 2008 Plan and administers the 2018 Plan except, in each case, with respect to awards to non-employee trustees, for which the 2008 Plan was and the 2018 Plan is administered by the board of trustees. The Compensation Committee is authorized to grant share options, including both incentive share options and non-qualified share options, as well as share appreciation rights, either with or without a related option. The Compensation Committee is also authorized to grant restricted common shares, restricted common share units, performance awards and other share-based awards. On September 6, 2017, the Compensation Committee approved the grant of an aggregate of 965,000 performance-based restricted common share units under the 2008 Plan which only vest immediately prior to the consummation of a Change in Control (as defined in the 2008 Plan) that occurs on or before September 30, 2024 (the “CIC Units”) to certain of our employees. Continued employment is required through the vesting date. If a Change in Control does not occur on or before September 30, 2024, the CIC Units shall be immediately forfeited. The Company considers a Change in Control on or before September 30, 2024 to be improbable, and no expense has been recognized for the CIC Units. If a Change in Control occurs, any outstanding CIC Units would be expensed immediately on the date of the Change in Control using the grant date fair value. The grant date fair value for each CIC Unit of $13.05 was determined based on the Company’s closing share price on the grant date. On March 16, 2018, the Compensation Committee approved the grant of an aggregate of 387,499 time-based restricted common share units under the 2008 Plan, which vest annually in three equal installments, and 4,300 performance-based restricted common share units to certain of our employees. On December 1, 2018, the Compensation Committee approved the grant of an aggregate of 229,684 performance-based restricted common share units with market-based vesting conditions (“TSR Units”) under the 2018 Plan to certain of our employees. Vesting is contingent upon achieving Total Shareholder Return relative to the peer group defined in the TSR Unit award agreements over a three On June 30, 2019, the Compensation Committee approved the grant of an aggregate of 405,417 TSR Units and 317,184 time-based restricted common share units under the 2018 Plan to certain of our employees. On September 30, 2019, the Compensation Committee approved the grant of 17,069 time-based restricted common share units under the 2018 Plan to certain of our employees. Vesting of the TSR Units is contingent upon achieving Total Shareholder Return relative to the peer group defined in the TSR Unit award agreements over a three historical period consistent with the performance period of approximately three years. The risk-free interest rate was based on the United States Treasury rate for a term commensurate with the expected life of the grant. The time-based restricted common share units have a grant date fair value of $10.63 and $11.69 and vest annually in three On July 31, 2020, the Compensation Committee approved the grant of an aggregate of 545,000 TSR Units and 530,000 time-based restricted common share units under the 2018 Plan to certain of our employees. Vesting of the TSR Units is contingent upon achieving Total Shareholder Return relative to the peer group defined in the TSR Unit award agreements over a three three On March 17, 2021, the Compensation Committee approved the grant of an aggregate of 2,490 common share units under the 2018 Plan to certain of our employees. The common share units had a grant date fair value of $10.04 each and vested immediately. On June 30, 2021, the Compensation Committee approved the grant of an aggregate of 433,200 TSR Units and 433,200 time-based restricted common share units under the 2018 Plan to certain of our employees. Vesting of the TSR Units is contingent upon achieving Total Shareholder Return relative to the peer group defined in the TSR Unit award agreements over a three three On September 30, 2021, the Compensation Committee approved the grant of an aggregate of 5,500 time-based restricted common share units under the 2018 Plan to certain of our employees. The time-based common share units had a grant date fair value of $9.06 each and vest annually in three equal installments. A summary of the share-based incentive plan activity as of and for the nine months ended September 30, 2021 is as follows: Shares Weighted Average Non-vested at January 1, 2021 2,903,846 $ 9.45 Granted 874,390 5.87 Vested (609,335) 10.35 Forfeited (60,855) 7.25 Non-vested at September 30, 2021 3,108,046 8.31 Available for grant at September 30, 2021 — A summary of our non-vested and vested shares activity for the nine months ended September 30, 2021 and years ended December 31, 2020 and 2019 is presented below: Shares Granted Shares Vested Non-Vested Shares Issued Weighted Average Grant-Date Fair Value Vested Shares Total Vest-Date Fair Value (in thousands) Nine Months Ended September 30, 2021 874,390 $ 5.87 (609,335) $ 6,309 Year Ended December 31, 2020 1,108,014 $ 5.76 (511,621) $ 5,566 Year Ended December 31, 2019 762,630 $ 9.46 (284,964) $ 3,352 Total compensation recognized in earnings for share-based payments was $1,563,000 and $1,645,000 for the three months ended September 30, 2021 and 2020, respectively, and $4,275,000 and $4,167,000 for the nine months ended September 30, 2021 and 2020, respectively. Based on our current financial projections, we expect approximately 100% of the unvested awards, exclusive of 885,000 CIC Units, to vest over the next 33 months. As of September 30, 2021, there was approximately $3.5 million in unrecognized compensation cost related to outstanding non-vested TSR Units, which are expected to vest over a period of 27 months, and approximately $5.7 million in unrecognized compensation cost related to outstanding non-vested time-based shares, which are expected to be recognized over a period of approximately 33 months beginning on July 1, 2021. We expect to record approximately $5.9 million in non-cash share-based compensation expense in 2021 and $7.6 million subsequent to 2021. The unrecognized share-based compensation cost is expected to vest over a weighted average period of 24 months. The dilutive impact of the performance-based shares will be included in the denominator of the earnings per share calculation beginning in the period that the performance conditions are expected to be met. The dilutive impact of the TSR Units is based on the Company’s TSR Peer Group Ranking as of the reporting date and weighted according to the number of days outstanding in the period. The TSR Units issued in 2017 and 2018 vested at 200% and 50% attainment, respectively, based on the TSR Peer Group Ranking, and, as of September 30, 2021, the TSR Peer Group Ranking called for attainment of 0% for the shares issued in 2019, 2020 and 2021. The dilutive impact of the CIC Units is based on the probability of a Change in Control. Because the Company considers a Change in Control on or before September 30, 2024 to be improbable, no CIC Units are included in the Company’s dilutive shares.

Grants to Trustees

Grants to Trustees	9 Months Ended
	Sep. 30, 2021
Grants to Trustees [Abstract]
Grants To Trustees	GRANTS TO TRUSTEESOn December 4, 2020, six independent trustees, including one independent trustee who served on the board until the 2020 annual meeting of shareholders and did not stand for re-election, and one trustee emeritus were granted a total of 29,587 common shares, which vested immediately and are prorated based on date appointed. The 29,587 common shares granted to our trustees had a grant fair value of $8.17 per share. On December 4, 2020, one of our independent trustees elected to receive a total of 3,427 common shares with a grant date fair value of $8.17 in lieu of cash for board fees. The fair value of the shares granted during the year ended December 31, 2020 was determined using quoted prices available on the date of grant.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2021
Segment Reporting [Abstract]
Segment Information	SEGMENT INFORMATIONHistorically, our management has not differentiated results of operations by property type or location and, therefore, does not present segment information.

Real Estate

Real Estate	9 Months Ended
	Sep. 30, 2021
Real Estate [Abstract]
Real Estate	REAL ESTATE Property Acquisitions. On July 8, 2021, we acquired Lakeside Market, a property that meets our Community Centered Property ® strategy, for $53.2 million in cash and net prorations. Lakeside Market, a 163,000 square foot property, was 80.5% leased at the time of purchase and is located in Plano, Texas.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2021
Related Party Transactions [Abstract]
Related Party Transactions	RELATED PARTY TRANSACTIONS The Contribution . Mr. James C. Mastandrea, the Chairman and Chief Executive Officer of the Company, also serves as the Chairman and Chief Executive Officer of Pillarstone REIT and beneficially owns approximately 66.7% of the outstanding equity in Pillarstone REIT (when calculated in accordance with Rule 13d-3(d)(1) under the Exchange Act of 1934, as amended (the “Exchange Act”)). Mr. John J. Dee, the Chief Operating Officer and Corporate Secretary of the Company, also serves as a trustee and the Senior Vice President and Chief Financial Officer of Pillarstone REIT and beneficially owns approximately 20.0% of the outstanding equity in Pillarstone REIT (when calculated in accordance with Rule 13d-3(d)(1) under the Exchange Act). In addition, Mr. Paul T. Lambert, a trustee of the Company, also serves as a trustee of Pillarstone REIT. The Contribution is pursuant to the Company’s strategy of recycling capital by disposing of Non-Core Properties that do not fit the Company’s Community Centered Property® strategy and the terms of the Contribution Agreement, the OP Unit Purchase Agreement, the Tax Protection Agreement and the Contribution were determined through arm’s-length negotiations. The Contribution was unanimously approved and recommended by a special committee of independent trustees of the Company. Pillarstone OP . The Company accounts for its investment in Pillarstone OP under the equity method. During the ordinary course of business, we have transactions with Pillarstone OP that include, but are not limited to, rental income, interest expense, general and administrative costs, commissions, management and asset management fees, and property expenses. The following table presents the revenue and expenses with Pillarstone OP included in our consolidated statements of operations and comprehensive income (loss) for the three and nine months ended September 30, 2021 and 2020 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, Location of Revenue (Expense) 2021 2020 2021 2020 Rent Operating and maintenance $ (225) $ (225) $ (672) $ (701) Property management fee income Management, transaction, and other fees $ 142 $ 144 $ 426 $ 455

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES On December 12, 2017, a property owner that owns a land parcel adjacent to a Whitestone property filed suit against Whitestone Pinnacle of Scottsdale - Phase II, LLC (“Whitestone Pinnacle”), a wholly owned subsidiary of the Operating Partnership, alleging breach of contract and resulting in the delay of the construction of their assisted living facility. The claimant sought approximately $2.3 million in restitution from Whitestone Pinnacle. On June 28, 2021, the parties executed a confidential mutual settlement agreement and release resolving all claims between the parties, and the case has been dismissed. We are subject to various legal proceedings and claims that arise in the ordinary course of business. These matters are generally covered by insurance. While the resolution of these matters cannot be predicted with certainty, management believes the final outcome of such matters will not have a material adverse effect on our financial position, results of operations, cash flows or liquidity.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2021
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Basis of Consolidation	Basis of Consolidation. We are the sole general partner of the Operating Partnership and possess full legal control and authority over the operations of the Operating Partnership. As of September 30, 2021 and December 31, 2020, we owned a majority of the partnership interests in the Operating Partnership. Consequently, the accompanying consolidated financial statements include the accounts of the Operating Partnership. Noncontrolling interest in the accompanying consolidated financial statements represents the share of equity and earnings of the Operating Partnership allocable to holders of partnership interests other than us. Net income or loss is allocated to noncontrolling interests based on the weighted-average percentage ownership of the Operating Partnership during the period. Issuance of additional common shares of beneficial interest in Whitestone (the “common shares”) and units of limited partnership interest in the Operating Partnership that are convertible into cash or, at our option, common shares on a one-for-one basis (the “OP units”) changes the percentage of ownership interests of both the noncontrolling interests and Whitestone.
Equity Method	Equity Method. For the years prior to December 31, 2017, Pillarstone OP was accounted for under the profit-sharing method. In accordance with the Financial Accounting Standards Board’s (“FASB”) guidance applicable to sales of real estate or interests therein, specifically FASB Accounting Standards Codification (“ASC”) 360-20, “ Real Estate Sales, ” Topic 606, “ Revenue from Contracts with Customers ” and ASC 610, “ Other Income–Gains and Losses from the Derecognition of Nonfinancial Assets ,” we adopted Topic 606 and ASC 610 as of January 1, 2018, resulting in the derecognition of the underlying assets and liabilities associated with the Contribution (defined below) as of January 1, 2018 and the recognition of the Company’s investment in Pillarstone OP under the equity method. See Note 6 (Investment in Real Estate Partnership) for additional disclosure on Pillarstone OP. Noncontrolling Interests. Noncontrolling interests are the portion of equity in a subsidiary not attributable to a parent. Accordingly, we have reported noncontrolling interests in equity on the consolidated balance sheets but separate from Whitestone’s equity. On the consolidated statements of operations and comprehensive income (loss), subsidiaries are reported at the consolidated amount, including both the amount attributable to Whitestone and noncontrolling interests. The consolidated statements of changes in equity is included for quarterly financial statements, including beginning balances, activity for the period and ending balances for shareholders’ equity, noncontrolling interests and total equity.
Basis of Accounting	Basis of Accounting. Our financial records are maintained on the accrual basis of accounting whereby revenues are recognized when earned and expenses are recorded when incurred.
Use of Estimates	Use of Estimates. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent liabilities as of the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Significant estimates that we use include the estimated fair values of properties acquired, the estimated useful lives for depreciable and amortizable assets and costs, the grant date fair value of common share units included in share-based compensation expense, the estimated allowance for doubtful accounts, the estimated fair value of interest rate swaps and the estimates supporting our impairment analysis for the carrying values of our real estate assets. Actual results could differ from those estimates. In particular, the COVID-19 pandemic has adversely impacted and is likely to further adversely impact the Company’s business and markets, including the Company’s operations and the operations of its tenants. The full extent to which the pandemic will directly or indirectly impact the Company’s business, results of operations and financial condition, including revenues, expenses, reserves and allowances, fair value measurements, and asset impairment charges, will depend on future developments that are highly uncertain and difficult to predict. These developments include, but are not limited to, the duration and spread of the pandemic, its severity in our markets and elsewhere, the impact on our tenants’ businesses and financial condition, governmental actions to contain the spread of the pandemic and respond to the reduction in global economic activity, and how quickly and to what extent normal economic and operating conditions can resume.
Reclassifications	Reclassifications. We have reclassified certain prior period amounts in the accompanying consolidated financial statements in order to be consistent with the current period presentation. These reclassifications had no effect on net income, total assets, total liabilities or equity.
Restricted Cash	Restricted Cash. We classify all cash pledged as collateral to secure certain obligations and all cash whose use is limited as restricted cash. During 2015, pursuant to the terms of our $15.1 million 4.99% Note, due January 6, 2024 (see Note 7 (Debt)), which is collateralized by our Anthem Marketplace property, we were required by the lenders thereunder to establish a cash management account controlled by the lenders to collect all amounts generated by our Anthem Marketplace property in order to collateralize such promissory note.
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities. We utilize derivative financial instruments, principally interest rate swaps, to manage our exposure to fluctuations in interest rates. We have established policies and procedures for risk assessment, and the approval, reporting and monitoring of derivative financial instruments. We recognize our interest rate swaps as cash flow hedges with the effective portion of the changes in fair value recorded in comprehensive income (loss) and subsequently reclassified into earnings in the period that the hedged transaction affects earnings. Any ineffective portion of a cash flow hedges’ change in fair value is recorded immediately into earnings. Our cash flow hedges are determined using Level 2 inputs under ASC 820, “Fair Value Measurements and Disclosures.” Level 2 inputs represent quoted prices in active markets for similar assets or liabilities; quoted prices in markets that are not active; and model-derived valuations in which significant inputs and significant value drivers are observable. As of September 30, 2021, we consider our cash flow hedges to be highly effective.
Development Properties	Development Properties. Land, buildings and improvements are recorded at cost. Expenditures related to the development of real estate are carried at cost which includes capitalized carrying charges and development costs. Carrying charges (interest, real estate taxes, loan fees, and direct and indirect development costs related to buildings under construction), are capitalized as part of construction in progress. The capitalization of such costs ceases when the property, or any completed portion, becomes available for occupancy.
Share-Based Compensation	Share-Based Compensation.   From time to time, we grant nonvested restricted common share awards or restricted common share unit awards, which may be converted into common shares, to executive officers and employees under our 2018 Long-Term Equity Incentive Ownership Plan (the “2018 Plan”).  Awarded shares and units vest when certain performance conditions are met.  We recognize compensation expense when achievement of the performance conditions is probable based on management’s most recent estimates using the fair value of the shares as of the grant date.
Accrued Rents and Accounts Receivable	Accrued Rents and Accounts Receivable. Included in accrued rents and accounts receivable are base rents, tenant reimbursements and receivables attributable to recording rents on a straight-line basis. We review the collectability of charges under our tenant operating leases on a regular basis, taking into consideration changes in factors such as the tenant’s payment history, the financial condition of the tenant, business conditions in the industry in which the tenant operates and economic conditions in the area where the property is located, including the impact of the COVID-19 pandemic on tenants’ businesses and financial condition. We recognize an adjustment to rental revenue if we deem it probable that the receivable will not be collected. Our review of collectability under our operating leases includes any accrued rental revenues related to the straight-line method of reporting rental revenue.
Revenue Recognition	Revenue Recognition. All leases on our properties are classified as operating leases, and the related rental income is recognized on a straight-line basis over the terms of the related leases. Differences between rental income earned and amounts due per the respective lease agreements are capitalized or charged, as applicable, to accrued rents and accounts receivable. Percentage rents are recognized as rental income when the thresholds upon which they are based have been met. Recoveries from tenants for taxes, insurance, and other operating expenses are recognized as revenues in the period the corresponding costs are incurred. We combine lease and nonlease components in lease contracts, which includes combining base rent, recoveries, and percentage rents into a single line item, Rental , within the consolidated statements of operations and comprehensive income (loss). Additionally, we have tenants who pay real estate taxes directly to the taxing authority. We exclude these costs paid directly by the tenant to third parties on our behalf from revenue recognized and the associated property operating expense. Other property income primarily includes amounts recorded in connection with management fees and lease termination fees. Pillarstone OP pays us management fees for property management, leasing and day-to-day advisory and administrative services. Their obligations are satisfied over time. Pillarstone OP is billed monthly and typically pays quarterly. Revenues are governed by the Management Agreements (as defined in Note 6 (Investment in Real Estate Partnership)). Refer to Note 6 (Investment in Real Estate Partnership) for additional information regarding the Management Agreements with Pillarstone OP. Additionally, we recognize lease termination fees in the year that the lease is terminated and collection of the fee is probable. Amounts recorded within other property income are accounted for at the point in time when control of the goods or services transfers to the customer and our performance obligation is satisfied.
Recent Accounting Pronouncements	Recent Accounting Pronouncements. In April 2020, the FASB issued guidance on the application of Topic 842, relating to concessions being made by lessors in response to the COVID-19 pandemic. The guidance notes that it would be acceptable for entities to make an election to account for lease concessions relating to the effects of the COVID-19 pandemic consistent with how those concessions would be accounted for under Topic 842 as though enforceable rights and obligations for those concessions existed, even if such enforceable rights and obligations are not explicitly contained in the lease contract. Thus, for concessions relating to the COVID-19 pandemic, an entity would not have to analyze each contract to determine whether enforceable rights and obligations for concessions exist in the contract, and would have the option to apply, or not to apply, the general lease modification guidance in Topic 842 as it stands. We have elected this option to account for lease concessions relating to the effects of the COVID-19 pandemic consistent with how those concessions would be accounted for under Topic 842 as though enforceable rights and obligations for those concessions existed. Therefore, such concessions are not accounted for as a lease modification under Topic 842.

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Schedule of Minimum Future Rent Payments	A summary of minimum future rents to be received (exclusive of renewals, tenant reimbursements, contingent rents, and collectability adjustments under Topic 842) under noncancelable operating leases in existence as of September 30, 2021 is as follows (in thousands): Years Ended December 31, Minimum Future Rents (1) 2021 (remaining) $ 22,430 2022 85,338 2023 73,467 2024 59,880 2025 44,171 Thereafter 125,750 Total $ 411,036 (1) These amounts do not reflect future rental revenues from the renewal or replacement of existing leases and exclude reimbursements of operating expenses and rental increases that are not fixed.
Maturities of Operating Lease Liabilities	The following table summarizes the fixed, future minimum rental payments, excluding variable costs, which are discounted by our weighted average incremental borrowing rates to calculate the lease liabilities for our operating leases in which we are the lessee (in thousands): Years Ended December 31, September 30, 2021 2021 (remaining) $ 100 2022 109 2023 63 2024 41 2025 31 Thereafter 1 Total undiscounted rental payments 345 Less imputed interest 22 Total lease liabilities $ 323

Accrued Rents and Accounts Re_2

Accrued Rents and Accounts Receivable, Net (Tables)	9 Months Ended
	Sep. 30, 2021
Receivables [Abstract]
Schedule of Accrued Rent and Accounts Receivable, Net	Accrued rents and accounts receivable, net consists of amounts accrued, billed and due from tenants, allowance for doubtful accounts and other receivables as follows (in thousands): September 30, 2021 December 31, 2020 Tenant receivables $ 19,898 $ 22,956 Accrued rents and other recoveries 17,833 16,348 Allowance for doubtful accounts (15,919) (16,426) Other receivables 179 131 Total $ 21,991 $ 23,009

Unamortized Lease Commissions_2

Unamortized Lease Commissions, Legal Fees and Loan Costs (Tables)	9 Months Ended
	Sep. 30, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Unamortized Lease Commissions and Loan Costs	Costs which have been deferred consist of the following (in thousands): September 30, 2021 December 31, 2020 Leasing commissions $ 12,686 $ 10,380 Deferred legal cost 365 373 Deferred financing cost 3,898 3,898 Total cost 16,949 14,651 Less: leasing commissions accumulated amortization (5,967) (5,029) Less: deferred legal cost accumulated amortization (239) (216) Less: deferred financing cost accumulated amortization (2,387) (1,720) Total cost, net of accumulated amortization $ 8,356 $ 7,686

Investment in Real Estate Par_2

Investment in Real Estate Partnership (Tables)	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Equity Method Investments	The table below presents the real estate partnership investment in which the Company holds an ownership interest (in thousands): Company’s Investment as of September 30, 2021 December 31, 2020 Real estate partnership Ownership Interest Pillarstone OP (1) 81.4% $ 34,408 $ 33,979 Total real estate partnership (2) $ 34,408 $ 33,979 (1) The Company manages these real estate partnership investments and, where applicable, earns acquisition fees, leasing commissions, property management fees, and asset management fees. Summarized financial information for the Company’s investment in real estate partnership is as follows (in thousands): September 30, 2021 December 31, 2020 Assets: Real estate, net $ 48,563 $ 49,113 Other assets 8,442 7,657 Total assets 57,005 56,770 Liabilities and equity: Notes payable 14,988 15,185 Other liabilities 3,349 3,533 Equity 38,668 38,052 Total liabilities and equity 57,005 56,770 Company’s share of equity 31,494 30,992 Cost of investment in excess of the Company’s share of underlying net book value 2,914 2,987 Carrying value of investment in real estate partnership $ 34,408 $ 33,979 Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Revenues $ 2,379 $ 2,371 $ 6,843 $ 7,396 Operating expenses (1,787) (1,713) (5,184) (5,195) Other expenses (351) (391) (1,033) (1,184) Net income $ 241 $ 267 $ 626 $ 1,017
Real Estate Investment Financial Statements, Disclosure	The table below presents the Company’s share of net income from its investment in the real estate partnership which is included in equity in earnings of real estate partnership, net on the Company’s consolidated statements of operations and comprehensive income (loss) (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Pillarstone OP $ 151 $ 196 $ 429 $ 752

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Schedule of Debt	Debt consisted of the following as of the dates indicated (in thousands): Description September 30, 2021 December 31, 2020 Fixed rate notes $100.0 million, 1.73% plus 1.35% to 1.90% Note, due October 30, 2022 (1) $ 100,000 $ 100,000 $165.0 million, 2.24% plus 1.35% to 1.90% Note, due January 31, 2024 (2) 165,000 165,000 $80.0 million, 3.72% Note, due June 1, 2027 80,000 80,000 $19.0 million 4.15% Note, due December 1, 2024 18,442 18,687 $20.2 million 4.28% Note, due June 6, 2023 17,914 18,222 $14.0 million 4.34% Note, due September 11, 2024 13,044 13,236 $14.3 million 4.34% Note, due September 11, 2024 13,834 14,014 $15.1 million 4.99% Note, due January 6, 2024 13,973 14,165 $2.6 million 5.46% Note, due October 1, 2023 2,302 2,339 $50.0 million, 5.09% Note, due March 22, 2029 50,000 50,000 $50.0 million, 5.17% Note, due March 22, 2029 50,000 50,000 $1.7 million 3.25% Note, due December 28, 2021 463 — Floating rate notes Unsecured line of credit, LIBOR plus 1.40% to 1.90%, due January 31, 2023 94,500 119,500 Total notes payable principal 619,472 645,163 Less deferred financing costs, net of accumulated amortization (823) (978) Total notes payable $ 618,649 $ 644,185 (1) Promissory note includes an interest rate swap that fixed the LIBOR portion of Term Loan 3 (as defined below) at 1.73%. (2) Promissory note includes an interest rate swap that fixed the LIBOR portion of the interest rate at an average rate of 2.24% for the duration of the term through January 31, 2024.
Schedule of Maturities of Debt	Scheduled maturities of our outstanding debt as of September 30, 2021 were as follows (in thousands): Year Amount Due 2021 (remaining) $ 1,138 2022 101,683 2023 122,363 2024 228,574 2025 17,143 Thereafter 148,571 Total $ 619,472

Derivatives and Hedging Activ_2

Derivatives and Hedging Activities (Tables)	9 Months Ended
	Sep. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of activity and fair value of interest rate swaps	The fair value of our interest rate swaps is as follows (in thousands): September 30, 2021 Balance Sheet Location Estimated Fair Value Accounts payable and accrued expenses $ (9,879) December 31, 2020 Balance Sheet Location Estimated Fair Value Accounts payable and accrued expenses $ (14,663) A summary of our interest rate swap activity is as follows (in thousands): Amount Recognized as Comprehensive Income (Loss) Location of Income (Loss) Recognized in Earnings Amount of Income (Loss) Recognized in Earnings (1) Three Months Ended September 30, 2021 $ 1,273 Interest expense $ (1,401) Three Months Ended September 30, 2020 $ 1,241 Interest expense $ (1,217) Nine Months Ended September 30, 2021 $ 4,783 Interest expense $ (4,057) Nine Months Ended September 30, 2020 $ (10,395) Interest expense $ (2,388) (1) There was no ineffective portion of our interest rate swaps to recognize in earnings for the three and nine months ended September 30, 2021 and 2020.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Schedule of Earnings Per Share	Three Months Ended September 30, Nine Months Ended September 30, (in thousands, except per share data) 2021 2020 2021 2020 Numerator: Income from continuing operations $ 2,946 $ 914 $ 7,772 $ 2,980 Less: Net income attributable to noncontrolling interests (47) (14) (132) (58) Income from continuing operations attributable to Whitestone REIT excluding amounts attributable to unvested restricted shares 2,899 900 7,640 2,922 Income from discontinued operations — — 1,833 — Less: Net income attributable to noncontrolling interests — — (33) — Income from discontinued operations attributable to Whitestone REIT — — 1,800 — Net income attributable to common shareholders excluding amounts attributable to unvested restricted shares $ 2,899 $ 900 $ 9,440 $ 2,922 Denominator: Weighted average number of common shares - basic 46,883 42,346 44,268 42,202 Effect of dilutive securities: Unvested restricted shares 942 1,094 840 838 Weighted average number of common shares - dilutive 47,825 43,440 45,108 43,040 Earnings Per Share: Basic: Income from continuing operations attributable to Whitestone REIT excluding amounts attributable to unvested restricted shares $ 0.06 $ 0.02 $ 0.17 $ 0.07 Income from discontinued operations attributable to Whitestone REIT — — 0.04 — Net income attributable to common shareholders excluding amounts attributable to unvested restricted shares $ 0.06 $ 0.02 $ 0.21 $ 0.07 Diluted: Income from continuing operations attributable to Whitestone REIT excluding amounts attributable to unvested restricted shares $ 0.06 $ 0.02 $ 0.17 $ 0.07 Income from discontinued operations attributable to Whitestone REIT — — 0.04 — Net income attributable to common shareholders excluding amounts attributable to unvested restricted shares $ 0.06 $ 0.02 $ 0.21 $ 0.07

Equity (Tables)

Equity (Tables)	9 Months Ended
	Sep. 30, 2021
Stockholders' Equity Note [Abstract]
Schedule of Distributions	The following table summarizes the cash distributions paid or payable to holders of common shares and to holders of noncontrolling OP units during each quarter of 2020 and the nine months ended September 30, 2021 (in thousands, except per share/per OP unit data): Common Shares Noncontrolling OP Unit Holders Total Quarter Paid Distributions Per Common Share Amount Paid Distributions Per OP Unit Amount Paid Amount Paid 2021 Third Quarter $ 0.1075 $ 4,981 $ 0.1075 $ 83 $ 5,064 Second Quarter 0.1075 4,602 0.1075 83 4,685 First Quarter 0.1058 4,480 0.1058 82 4,562 Total $ 0.3208 $ 14,063 $ 0.3208 $ 248 $ 14,311 2020 Fourth Quarter $ 0.1050 $ 4,432 $ 0.1050 $ 81 $ 4,513 Third Quarter 0.1050 4,430 0.1050 81 4,511 Second Quarter 0.1050 4,413 0.1050 91 4,504 First Quarter 0.2850 11,928 0.2850 258 12,186 Total $ 0.6000 $ 25,203 $ 0.6000 $ 511 $ 25,714

Incentive Share Plan (Tables)

Incentive Share Plan (Tables)	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Schedule of Share-Based Incentive Plan Activity	summary of the share-based incentive plan activity as of and for the nine months ended September 30, 2021 is as follows: Shares Weighted Average Non-vested at January 1, 2021 2,903,846 $ 9.45 Granted 874,390 5.87 Vested (609,335) 10.35 Forfeited (60,855) 7.25 Non-vested at September 30, 2021 3,108,046 8.31 Available for grant at September 30, 2021 —
Schedule of Nonvested and Vested Shares Activity	A summary of our non-vested and vested shares activity for the nine months ended September 30, 2021 and years ended December 31, 2020 and 2019 is presented below: Shares Granted Shares Vested Non-Vested Shares Issued Weighted Average Grant-Date Fair Value Vested Shares Total Vest-Date Fair Value (in thousands) Nine Months Ended September 30, 2021 874,390 $ 5.87 (609,335) $ 6,309 Year Ended December 31, 2020 1,108,014 $ 5.76 (511,621) $ 5,566 Year Ended December 31, 2019 762,630 $ 9.46 (284,964) $ 3,352

Related Party Transactions (Tab

Related Party Transactions (Tables)	9 Months Ended
	Sep. 30, 2021
Related Party Transactions [Abstract]
Schedule of Related Party Transactions	The following table presents the revenue and expenses with Pillarstone OP included in our consolidated statements of operations and comprehensive income (loss) for the three and nine months ended September 30, 2021 and 2020 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, Location of Revenue (Expense) 2021 2020 2021 2020 Rent Operating and maintenance $ (225) $ (225) $ (672) $ (701) Property management fee income Management, transaction, and other fees $ 142 $ 144 $ 426 $ 455

Interim Financial Statements (D

Interim Financial Statements (Details) $ in Thousands	1 Months Ended	3 Months Ended
	Jul. 31, 2004shares	Sep. 30, 2021USD ($)ft²property	Jul. 08, 2021ft²	Dec. 31, 2020USD ($)ft²property
Real Estate Properties [Line Items]
Reorganization and conversion, number of common shares (in shares) | shares	1.42857
Carrying amount, net | $		$ 981,891		$ 942,714
Lakeside Market
Real Estate Properties [Line Items]
Number of properties acquired		1
Area of real estate property | ft²		200,000	163,000
Carrying amount, net | $		$ 52,900
Wholly Owned Properties
Real Estate Properties [Line Items]
Number of properties		59		58
Retail Site | Wholly Owned Properties | Community Centered Properties™
Real Estate Properties [Line Items]
Number of properties		53
Land | Wholly Owned Properties | Parcels Held for Future Development | Redevelopment, New Acquisitions Portfolio
Real Estate Properties [Line Items]
Number of properties		5
Pillarstone Capital REIT Operating Partnership LP
Real Estate Properties [Line Items]
Ownership interest		81.40%
Pillarstone Capital REIT Operating Partnership LP | Unconsolidated Properties
Real Estate Properties [Line Items]
Number of properties		8		8
Gross leasable area (in square feet) | ft²		926,798		926,798

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Narrative (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2021USD ($)tenantshares	Sep. 30, 2020USD ($)tenant	Sep. 30, 2021USD ($)shares	Sep. 30, 2020USD ($)tenant	Dec. 31, 2020USD ($)	Dec. 31, 2015USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Conversion basis for common shares to OP units (in shares) | shares	1		1
Interest expense capitalized	$ 109,000	$ 122,000	$ 312,000	$ 362,000
Real estate tax capitalized	75,000	71,000	225,000	231,000
Share-based compensation	1,563,000	1,645,000	4,275,000	4,167,000
Allowance for doubtful accounts	(15,919,000)		(15,919,000)		$ (16,426,000)
Bad debt	$ 172,000	$ (1,279,000)	(500,000)	$ (4,451,000)
Number of tenants | tenant	63,000	12,000		84,000
Rental revenue adjustment	$ (20,000)	$ (700,000)	(600,000)	$ (1,800,000)
Straight-line rent reserve adjustment	$ (300,000)	$ (100,000)	$ (500,000)	$ (1,100,000)
Anthem Marketplace Note
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Face amount of debt						$ 15,100,000
Stated interest rate						4.99%

Leases - Minimum Future Rent Pa

Leases - Minimum Future Rent Payments (Details) $ in Thousands	Sep. 30, 2021USD ($)
Leases [Abstract]
2021 (remaining)	$ 22,430
2022	85,338
2023	73,467
2024	59,880
2025	44,171
Thereafter	125,750
Total	$ 411,036

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Lessee, Lease, Description [Line Items]
Operating lease, cost	$ 253	$ 253	$ 778	$ 809
Operating lease, weighted average remaining lease term	2 years 4 months 24 days		2 years 4 months 24 days
Operating lease, weighted average discount rate, percent	4.50%		4.50%
Minimum | Office Space, Automobile, and Office Machine
Lessee, Lease, Description [Line Items]
Lessee, operating lease, remaining lease term	1 year		1 year
Maximum | Office Space, Automobile, and Office Machine
Lessee, Lease, Description [Line Items]
Lessee, operating lease, remaining lease term	3 years		3 years

Leases - Maturities of Operatin

Leases - Maturities of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Operating Lease Liabilities, Payments Due [Abstract]
2021 (remaining)	$ 100
2022	109
2023	63
2024	41
2025	31
Thereafter	1
Total undiscounted rental payments	345
Less imputed interest	22
Total lease liabilities	$ 323	$ 603

Accrued Rents and Accounts Re_3

Accrued Rents and Accounts Receivable, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Receivables [Abstract]
Tenant receivables	$ 19,898	$ 22,956
Accrued rents and other recoveries	17,833	16,348
Allowance for doubtful accounts	(15,919)	(16,426)
Other receivables	179	131
Total	$ 21,991	$ 23,009

Unamortized Lease Commissions_3

Unamortized Lease Commissions, Legal Fees and Loan Costs (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Leasing commissions	$ 12,686	$ 10,380
Deferred legal cost	365	373
Deferred financing cost	3,898	3,898
Total cost	16,949	14,651
Less: leasing commissions accumulated amortization	(5,967)	(5,029)
Less: deferred legal cost accumulated amortization	(239)	(216)
Less: deferred financing cost accumulated amortization	(2,387)	(1,720)
Total cost, net of accumulated amortization	$ 8,356	$ 7,686

Investment in Real Estate Par_3

Investment in Real Estate Partnership - Narrative (Details) $ / shares in Units, $ in Thousands	Dec. 08, 2016USD ($)propertysubsidiary$ / shares	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)
Pillarstone Capital REIT Operating Partnership LP
Variable Interest Entity [Line Items]
Amortization of the basis difference between the cost of investment and the Company's share of underlying net book value		$ 45	$ 27	$ 81	$ 81
Performance Guarantee
Variable Interest Entity [Line Items]
Noncontingent liability		462		$ 462
Guarantee liability, amortization period				7 years
Amortization of guarantee liability		$ 18	$ 10	$ 28	$ 29
Pillarstone Variable Interest Entity
Variable Interest Entity [Line Items]
Number of wholly-owned subsidiaries | subsidiary	4
Number of non-core properties | property	14
Consideration amount	$ 84,000
Consideration, limited partnership interest	$ 18,100
Consideration, limited partnership interest (in dollars per share) | $ / shares	$ 1.331
Liabilities assumed	$ 65,900
Property management fee, percent fee	5.00%
Asset management fee, percent fee	0.125%
Pillarstone Variable Interest Entity | Uptown Tower
Variable Interest Entity [Line Items]
Property management fee, percent fee	3.00%
Asset management fee, percent fee	0.125%
Pillarstone Variable Interest Entity | Line of Credit
Variable Interest Entity [Line Items]
Liabilities assumed	$ 15,500
Pillarstone Variable Interest Entity | Notes Payable | Uptown Tower Promissory Note
Variable Interest Entity [Line Items]
Liabilities assumed	16,300
Pillarstone Variable Interest Entity | Notes Payable | Industrial-Office Promissory Note
Variable Interest Entity [Line Items]
Liabilities assumed	$ 34,100

Investment in Real Estate Par_4

Investment in Real Estate Partnership - Unconsolidated Real Estate Partnership Investments (Details) $ in Thousands	Sep. 30, 2021USD ($)ft²property	Dec. 31, 2020USD ($)ft²property
Schedule of Equity Method Investments [Line Items]
Investment in real estate partnership	$ 34,408	$ 33,979
Pillarstone Capital REIT Operating Partnership LP
Schedule of Equity Method Investments [Line Items]
Ownership interest	81.40%
Investment in real estate partnership		$ 33,979
Pillarstone Capital REIT Operating Partnership LP | Unconsolidated Properties
Schedule of Equity Method Investments [Line Items]
Number of properties | property	8	8
Gross leasable area (in square feet) | ft²	926,798	926,798

Investment in Real Estate Par_5

Investment in Real Estate Partnership - Net Income from Investments in Real Estate Partnerships (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Schedule of Equity Method Investments [Line Items]
Equity in earnings of real estate partnership	$ 151	$ 196	$ 429	$ 752
Pillarstone Capital REIT Operating Partnership LP
Schedule of Equity Method Investments [Line Items]
Equity in earnings of real estate partnership	$ 151	$ 196	$ 429	$ 752

Investment in Real Estate Par_6

Investment in Real Estate Partnership - Summarized Financial Information for Investment in Real Estate Partnership - Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
ASSETS
Total assets	$ 1,071,069			$ 1,045,002
LIABILITIES AND EQUITY
Equity	394,276	$ 366,272	$ 338,372	338,326	$ 336,260	$ 337,031	$ 341,118	$ 353,098
Total liabilities and equity	1,071,069			1,045,002
Carrying value of investment in real estate partnership	34,408			33,979
Pillarstone Capital REIT Operating Partnership LP
LIABILITIES AND EQUITY
Carrying value of investment in real estate partnership				33,979
Equity Method Investment, Nonconsolidated Investee or Group of Investees | Pillarstone Capital REIT Operating Partnership LP
ASSETS
Real estate, net	48,563			49,113
Other assets	8,442			7,657
Total assets	57,005			56,770
LIABILITIES AND EQUITY
Notes payable	14,988			15,185
Other liabilities	3,349			3,533
Equity	38,668			38,052
Total liabilities and equity	57,005			56,770
Company’s share of equity	31,494			30,992
Cost of investment in excess of the Company’s share of underlying net book value	2,914			2,987
Carrying value of investment in real estate partnership	$ 34,408			$ 33,979

Investment in Real Estate Par_7

Investment in Real Estate Partnership - Summarized Financial Information for Investment in Real Estate Partnership - Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Schedule of Equity Method Investments [Line Items]
Revenues	$ 32,444			$ 29,900			$ 92,107	$ 88,081
Net income	2,946	$ 5,218	$ 1,441	914	$ 419	$ 1,647	9,605	2,980
Equity Method Investment, Nonconsolidated Investee or Group of Investees | Pillarstone Capital REIT Operating Partnership LP
Schedule of Equity Method Investments [Line Items]
Revenues	2,379			2,371			6,843	7,396
Operating expenses	(1,787)			(1,713)			(5,184)	(5,195)
Other expenses	(351)			(391)			(1,033)	(1,184)
Net income	$ 241			$ 267			$ 626	$ 1,017

Debt (Schedule of Debt) (Detail

Debt (Schedule of Debt) (Details) - USD ($)	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Total notes payable principal	$ 619,472,000	$ 645,163,000
Less deferred financing costs, net of accumulated amortization	(823,000)	(978,000)
Total notes payable	618,649,000	644,185,000
Fixed rate notes | $100.0 million, 1.73% plus 1.35% to 1.90% Note, due October 2022
Debt Instrument [Line Items]
Total notes payable principal	100,000,000	100,000,000
Face amount of debt	$ 100,000,000
Imputed interest rate	1.73%
Fixed rate notes | $100.0 million, 1.73% plus 1.35% to 1.90% Note, due October 2022 | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	1.35%
Fixed rate notes | $100.0 million, 1.73% plus 1.35% to 1.90% Note, due October 2022 | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	1.90%
Fixed rate notes | $165.0 million, 2.24% plus 1.35% to 1.90% Note, due January 31, 2024
Debt Instrument [Line Items]
Total notes payable principal	$ 165,000,000	165,000,000
Face amount of debt	$ 165,000,000
Imputed interest rate	2.24%
Fixed rate notes | $165.0 million, 2.24% plus 1.35% to 1.90% Note, due January 31, 2024 | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	1.35%
Fixed rate notes | $165.0 million, 2.24% plus 1.35% to 1.90% Note, due January 31, 2024 | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	1.90%
Fixed rate notes | $80.0 million, 3.72% Note, due June 1, 2027
Debt Instrument [Line Items]
Total notes payable principal	$ 80,000,000	80,000,000
Face amount of debt	$ 80,000,000
Stated interest rate	3.72%
Fixed rate notes | $19.0 million 4.15% Note, due December 1, 2024
Debt Instrument [Line Items]
Total notes payable principal	$ 18,442,000	18,687,000
Face amount of debt	$ 19,000,000
Stated interest rate	4.15%
Fixed rate notes | $20.2 million 4.28% Note, due June 6, 2023
Debt Instrument [Line Items]
Total notes payable principal	$ 17,914,000	18,222,000
Face amount of debt	$ 20,200,000
Stated interest rate	4.28%
Fixed rate notes | $14.0 million 4.34% Note, due September 11, 2024
Debt Instrument [Line Items]
Total notes payable principal	$ 13,044,000	13,236,000
Face amount of debt	$ 14,000,000
Stated interest rate	4.34%
Fixed rate notes | $14.3 million 4.34% Note, due September 11, 2024
Debt Instrument [Line Items]
Total notes payable principal	$ 13,834,000	14,014,000
Face amount of debt	$ 14,300,000
Stated interest rate	4.34%
Fixed rate notes | $15.1 million 4.99% Note, due January 6, 2024
Debt Instrument [Line Items]
Total notes payable principal	$ 13,973,000	14,165,000
Face amount of debt	$ 15,100,000
Stated interest rate	4.99%
Fixed rate notes | $2.6 million 5.46% Note, due October 1, 2023
Debt Instrument [Line Items]
Total notes payable principal	$ 2,302,000	2,339,000
Face amount of debt	$ 2,600,000
Stated interest rate	5.46%
Fixed rate notes | $50.0 million, 5.09% Note, due March 22, 2029
Debt Instrument [Line Items]
Total notes payable principal	$ 50,000,000	50,000,000
Face amount of debt	$ 50,000,000
Stated interest rate	5.09%
Fixed rate notes | $50.0 million, 5.17% Note, due March 22, 2029
Debt Instrument [Line Items]
Total notes payable principal	$ 50,000,000	50,000,000
Face amount of debt	$ 50,000,000
Stated interest rate	5.17%
Fixed rate notes | $1.7 million 3.25% Note, due December 28, 2021
Debt Instrument [Line Items]
Total notes payable principal	$ 463,000	0
Face amount of debt	$ 1,700,000
Stated interest rate	3.25%
Floating rate notes | Unsecured line of credit, LIBOR plus 1.40% to 1.90%, due January 31, 2023 | LIBOR Rate
Debt Instrument [Line Items]
Total notes payable principal	$ 94,500,000	$ 119,500,000
Floating rate notes | Unsecured line of credit, LIBOR plus 1.40% to 1.90%, due January 31, 2023 | Minimum | LIBOR Rate
Debt Instrument [Line Items]
Basis spread on variable rate	1.40%
Floating rate notes | Unsecured line of credit, LIBOR plus 1.40% to 1.90%, due January 31, 2023 | Maximum | LIBOR Rate
Debt Instrument [Line Items]
Basis spread on variable rate	1.90%
Interest rate swap | $100.0 million, 1.73% plus 1.35% to 1.90% Note, due October 2022
Debt Instrument [Line Items]
Stated interest rate	1.73%
Interest rate swap | $165.0 million, 2.24% plus 1.35% to 1.90% Note, due January 31, 2024
Debt Instrument [Line Items]
Stated interest rate	2.24%

Debt (Narrative) (Details)

Debt (Narrative) (Details)	Apr. 30, 2020USD ($)	Mar. 22, 2019USD ($)	Jan. 31, 2019USD ($)	Nov. 07, 2014USD ($)	Sep. 30, 2021USD ($)property	Mar. 20, 2020USD ($)
Debt Instrument [Line Items]
Secured debt					$ 159,500,000
Number of collateralized properties (in collateralized properties) | property					7
Carrying value of collateralized properties					$ 248,000,000
U.S. Bank National Association
Debt Instrument [Line Items]
Line of credit outstanding	$ 1,733,510
Interest rate	1.00%
Monthly payments	$ 96,864.28
Gain on loan forgiveness					$ 1,734,000
2019 Facility
Debt Instrument [Line Items]
Credit facility, covenant, total debt to total assets ratio, maximum			0.60
Credit facility, covenant, secured debt to total asset ratio, maximum			0.40
Credit facility, covenant, EBITDA to fixed charges ratio, minimum			1.50
Credit facility, covenant, other recourse debt to total assets ratio, maximum			0.15
Credit facility, interest rate at period end					1.73%
Repayments of long-term debt			$ 446,200,000
Covenant, tangible net worth threshold before percentage of aggregate net proceeds, amount			$ 372,000,000
Covenant, tangible net worth, percentage of aggregate net proceeds, minimum			75.00%
Series A Senior Notes
Debt Instrument [Line Items]
Annual principal payment		$ 7,100,000
Series B Senior Notes
Debt Instrument [Line Items]
Annual principal payment		10,000,000
Senior Notes
Debt Instrument [Line Items]
Face amount of debt		100,000,000
Periodic payment, principal		$ 1,000,000
Credit facility, covenant, total debt to total assets ratio, maximum		0.60
Credit facility, covenant, secured debt to total asset ratio, maximum		0.40
Credit facility, covenant, EBITDA to fixed charges ratio, minimum		1.50
Credit facility, covenant, other recourse debt to total assets ratio, maximum		0.15
Covenant, tangible net worth threshold before percentage of aggregate net proceeds, amount		$ 372,000,000
Covenant, tangible net worth, percentage of aggregate net proceeds, minimum		75.00%
Senior Notes | Series A Senior Notes
Debt Instrument [Line Items]
Face amount of debt		$ 50,000,000
Stated interest rate		5.09%
Senior Notes | Series B Senior Notes
Debt Instrument [Line Items]
Face amount of debt		$ 50,000,000
Stated interest rate		5.17%
Revolving Credit Facility | 2019 Facility
Debt Instrument [Line Items]
Line of credit outstanding					$ 359,500,000	$ 30,000,000
Credit facility, remaining borrowing capacity					81,800,000
Revolving Credit Facility | 2019 Facility | LIBOR Rate
Debt Instrument [Line Items]
Basis spread on variable rate			1.00%
Revolving Credit Facility | 2019 Facility | LIBOR Rate | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate			1.40%
Revolving Credit Facility | 2019 Facility | LIBOR Rate | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate			1.90%
Revolving Credit Facility | 2018 Facility | LIBOR Rate
Debt Instrument [Line Items]
Basis spread on variable rate				1.00%
Revolving Credit Facility | 2018 Facility | LIBOR Rate | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate				1.40%
Revolving Credit Facility | 2018 Facility | LIBOR Rate | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate				1.95%
Revolving Credit Facility | The Revolver
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity				$ 300,000,000
Term Loan | 2019 Facility | LIBOR Rate | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate			1.35%
Term Loan | 2019 Facility | LIBOR Rate | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate			1.90%
Term Loan | 2018 Facility | LIBOR Rate | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate				1.35%
Term Loan | 2018 Facility | LIBOR Rate | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate				2.25%
Term Loan | Term Loan 1
Debt Instrument [Line Items]
Face amount of debt				$ 50,000,000
Term Loan | Term Loan 2
Debt Instrument [Line Items]
Face amount of debt				50,000,000
Term Loan | Term Loan 3
Debt Instrument [Line Items]
Face amount of debt				100,000,000
Credit facility, remaining borrowing capacity				$ 100,000,000
Term Loan | Unsecured Line Of Credit | Term Loan A
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity			$ 165,000,000
Term Loan | Unsecured Line Of Credit | Term Loan B
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity			100,000,000
Revolving Credit Facility | 2019 Facility
Debt Instrument [Line Items]
Credit facility, accordion feature, increase limit			200,000,000
Revolving Credit Facility | Unsecured Line Of Credit | 2019 Revolver
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity			$ 250,000,000
Standby Letters of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit outstanding					$ 500,000

Debt (Schedule of Maturities of

Debt (Schedule of Maturities of Debt) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
2021 (remaining)	$ 1,138
2022	101,683
2023	122,363
2024	228,574
2025	17,143
Thereafter	148,571
Total notes payable principal	$ 619,472	$ 645,163

Derivatives and Hedging Activ_3

Derivatives and Hedging Activities (Details) - USD ($) $ in Thousands

Jan. 31, 2019

Sep. 30, 2021

Jun. 30, 2021

Mar. 31, 2021

Sep. 30, 2020

Jun. 30, 2020

Mar. 31, 2020

Jun. 30, 2016

Dec. 31, 2015

Sep. 30, 2021

Sep. 30, 2020

Dec. 31, 2020

Sep. 05, 2018

Nov. 19, 2015

Derivative [Line Items]

Unrealized gain (loss) on cash flow hedging activities

$ 1,273

$ 1,289

$ 2,221

$ 1,241

$ (684)

$ (10,952)

$ 4,783

$ (10,395)

Term Loan 1

Derivative [Line Items]

Interest rate swap

$ 14,000

U.S. Bank National Association | Term Loan 1

Derivative [Line Items]

Interest rate swap

6,500

U.S. Bank National Association | Term Loan 2

Derivative [Line Items]

Interest rate swap

6,500

U.S. Bank National Association | Term Loan 3

Derivative [Line Items]

Interest rate swap

$ 35,000

Regions Bank | Term Loan 1

Derivative [Line Items]

Interest rate swap

3,800

Regions Bank | Term Loan 2

Derivative [Line Items]

Interest rate swap

3,800

Wells Fargo Bank, National Association | Term Loan 1

Derivative [Line Items]

Interest rate swap

14,000

Wells Fargo Bank, National Association | Term Loan 2

Derivative [Line Items]

Interest rate swap

14,000

Bank of American, N.A. | Term Loan 2

Derivative [Line Items]

Interest rate swap

14,000

SunTrust Bank | Term Loan 1

Derivative [Line Items]

Interest rate swap

5,000

SunTrust Bank | Term Loan 2

Derivative [Line Items]

Interest rate swap

$ 5,000

SunTrust Bank | Term Loan 3

Derivative [Line Items]

Interest rate swap

$ 15,000

Interest rate swap | Interest Expense

Derivative [Line Items]

Unrealized gain (loss) on cash flow hedging activities

1,273

1,241

4,783

(10,395)

Amount of Income (Loss) Recognized in Earnings

(1,401)

$ (1,217)

(4,057)

$ (2,388)

Interest rate swap | Cash Flow Hedging | Term Loan 1

Derivative [Line Items]

Fixed interest rate

1.75%

Interest rate swap | Cash Flow Hedging | Term Loan 2

Derivative [Line Items]

Fixed interest rate

1.50%

Interest rate swap | Cash Flow Hedging | Term Loan 3

Derivative [Line Items]

Fixed interest rate

1.73%

Interest rate swap | Cash Flow Hedging | Extension Loan | Terravita Marketplace

Derivative [Line Items]

Fixed interest rate

2.85%

Extension loan

$ 9,600

Accounts payable and accrued expenses | Interest rate swap

Derivative [Line Items]

Estimated Fair Value

$ (9,879)

$ (9,879)

$ (14,663)

February 7, 2019 | Bank of Montreal | Term Loan A

Derivative [Line Items]

Interest rate swap

$ 65,000

February 7, 2019 | U.S. Bank National Association | Term Loan A

Derivative [Line Items]

Interest rate swap

12,900

February 7, 2019 | Regions Bank | Term Loan A

Derivative [Line Items]

Interest rate swap

11,600

February 7, 2019 | Wells Fargo Bank, National Association | Term Loan A

Derivative [Line Items]

Interest rate swap

5,900

February 7, 2019 | SunTrust Bank | Term Loan A

Derivative [Line Items]

Interest rate swap

$ 15,700

February 7, 2019 | Interest rate swap | Cash Flow Hedging | Term Loan A

Derivative [Line Items]

Fixed interest rate

2.43%

November 9, 2020 | Bank of Montreal | Term Loan A

Derivative [Line Items]

Interest rate swap

$ 115,000

November 9, 2020 | U.S. Bank National Association | Term Loan A

Derivative [Line Items]

Interest rate swap

22,700

November 9, 2020 | Regions Bank | Term Loan A

Derivative [Line Items]

Interest rate swap

20,500

November 9, 2020 | Wells Fargo Bank, National Association | Term Loan A

Derivative [Line Items]

Interest rate swap

10,500

November 9, 2020 | SunTrust Bank | Term Loan A

Derivative [Line Items]

Interest rate swap

$ 27,900

November 9, 2020 | Interest rate swap | Cash Flow Hedging | Term Loan A

Derivative [Line Items]

Fixed interest rate

2.43%

February 8, 2021 | Bank of Montreal | Term Loan A

Derivative [Line Items]

Interest rate swap

$ 165,000

February 8, 2021 | U.S. Bank National Association | Term Loan A

Derivative [Line Items]

Interest rate swap

32,600

February 8, 2021 | Regions Bank | Term Loan A

Derivative [Line Items]

Interest rate swap

29,400

February 8, 2021 | Wells Fargo Bank, National Association | Term Loan A

Derivative [Line Items]

Interest rate swap

15,000

February 8, 2021 | SunTrust Bank | Term Loan A

Derivative [Line Items]

Interest rate swap

$ 40,000

February 8, 2021 | Interest rate swap | Cash Flow Hedging | Term Loan A

Derivative [Line Items]

Fixed interest rate

2.43%

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator:
Net income from continuing operations	$ 2,946	$ 914	$ 7,772	$ 2,980
Less: Net income attributable to noncontrolling interests	(47)	(14)	(132)	(58)
Income from continuing operations attributable to Whitestone REIT excluding amounts attributable to unvested restricted shares	2,899	900	7,640	2,922
Income from discontinued operations	0	0	1,833	0
Less: Net income attributable to noncontrolling interests	0	0	(33)	0
Income from discontinued operations attributable to Whitestone REIT	0	0	1,800	0
Net income attributable to common shareholders excluding amounts attributable to unvested restricted shares	$ 2,899	$ 900	$ 9,440	$ 2,922
Denominator:
Weighted average number of common shares - basic (in shares)	46,883,000	42,346,000	44,268,000	42,202,000
Effect of dilutive securities:
Unvested restricted shares (in shares)	942,000	1,094,000	840,000	838,000
Weighted average number of common shares - dilutive (in shares)	47,825,000	43,440,000	45,108,000	43,040,000
Basic:
Income from continuing operations attributable to Whitestone REIT excluding amounts attributable to unvested restricted shares (in dollars per share)	$ 0.06	$ 0.02	$ 0.17	$ 0.07
Income from discontinued operations attributable to Whitestone REIT (in dollars per share)	0	0	0.04	0
Net income attributable to common shareholders, excluding amounts attributable to unvested restricted shares (in dollars per share)	0.06	0.02	0.21	0.07
Diluted:
Income from continuing operations attributable to Whitestone REIT excluding amounts attributable to unvested restricted shares (in dollars per share)	0.06	0.02	0.17	0.07
Income from discontinued operations attributable to Whitestone REIT (in dollars per share)	0	0	0.04	0
Net income attributable to common shareholders, excluding amounts attributable to unvested restricted shares (in dollars per share)	$ 0.06	$ 0.02	$ 0.21	$ 0.07
OP Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
OP units excluded from diluted earnings per share because their effect would be anti-dilutive (in shares)	772,775	776,233	772,775	836,148

Income Taxes (Details)

Income Taxes (Details) - Texas - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Tax Contingency [Line Items]
Applicable tax rate used to determine state margin tax			0.75%
Standard deduction rate used to determine state margin tax			30.00%
Margin tax provision recognized	$ 99	$ 105	$ 273	$ 285

Equity (Details)

Equity (Details) $ / shares in Units, $ in Thousands	May 14, 2020$ / shares	Sep. 30, 2021USD ($)$ / sharesshares	Jun. 30, 2021USD ($)$ / shares	Mar. 31, 2021USD ($)$ / shares	Dec. 31, 2020USD ($)$ / sharesshares	Sep. 30, 2020USD ($)$ / sharesshares	Jun. 30, 2020USD ($)$ / shares	Mar. 31, 2020USD ($)$ / shares	Sep. 30, 2021USD ($)$ / sharesshares	Sep. 30, 2020USD ($)shares	Dec. 31, 2020USD ($)$ / sharesshares	May 31, 2019USD ($)agreement
Class of Stock [Line Items]
Common shares, authorized (in shares)		400,000,000			400,000,000				400,000,000		400,000,000
Common shares, par value per share (in dollars per share) | $ / shares		$ 0.001			$ 0.001				$ 0.001		$ 0.001
Preferred shares, shares authorized (in shares)		50,000,000			50,000,000				50,000,000		50,000,000
Preferred shares, par value per share (in dollars per share) | $ / shares		$ 0.001			$ 0.001				$ 0.001		$ 0.001
Conversion basis for common shares to OP units (in shares)		1							1
Weighted-average share ownership in operating partnership		98.40%				98.20%
Operating Partnership
Class of Stock [Line Items]
Ownership interest in operating partnership									98.40%
OP Units
Class of Stock [Line Items]
OP units outstanding (in shares)		49,491,529			43,043,251				49,491,529		43,043,251
OP units owned (in shares)		48,718,754			42,270,476				48,718,754		42,270,476
Conversion of stock, shares converted (in shares)		0				1,331
Cash distribution paid (in dollars per share) | $ / shares	$ 30
Ownership interest	20.00%
Preferred Stock | Series A Preferred Stock
Class of Stock [Line Items]
Preferred shares, par value per share (in dollars per share) | $ / shares	$ 0.001
Stock conversion ratio	1
Ownership interest	5.00%
2019 Equity Distribution Agreement
Class of Stock [Line Items]
Number of equity distribution agreements | agreement												9
Equity distribution agreements, authorized amount | $												$ 100,000
Net proceeds | $		$ 28,000							$ 53,300	$ 2,200
Paid compensation | $		$ 426							$ 812	$ 34
2019 Equity Distribution Agreement | Common Stock
Class of Stock [Line Items]
Issuance of common shares, net of offering costs (in shares)		2,991,168							6,016,148	170,942
Cash Distribution
Class of Stock [Line Items]
Cash distribution paid | $		$ 5,064	$ 4,685	$ 4,562	$ 4,513	$ 4,511	$ 4,504	$ 12,186	$ 14,311		$ 25,714
Cash Distribution | Common Stock
Class of Stock [Line Items]
Cash distribution paid (in dollars per share) | $ / shares		$ 0.1075	$ 0.1075	$ 0.1058	$ 0.1050	$ 0.1050	$ 0.1050	$ 0.2850	$ 0.3208		$ 0.6000
Cash distribution paid | $		$ 4,981	$ 4,602	$ 4,480	$ 4,432	$ 4,430	$ 4,413	$ 11,928	$ 14,063		$ 25,203
Cash Distribution | OP Units
Class of Stock [Line Items]
Cash distribution paid (in dollars per share) | $ / shares		$ 0.1075	$ 0.1075	$ 0.1058	$ 0.1050	$ 0.1050	$ 0.1050	$ 0.2850	$ 0.3208		$ 0.6000
Cash distribution paid | $		$ 83	$ 83	$ 82	$ 81	$ 81	$ 91	$ 258	$ 248		$ 511

Incentive Share Plan (Narrative

Incentive Share Plan (Narrative) (Details) $ / shares in Units, $ in Thousands

Jan. 01, 2021shares

Jul. 31, 2020$ / sharesshares

Sep. 30, 2019$ / sharesshares

Jun. 30, 2019$ / sharesshares

Dec. 01, 2018$ / sharesshares

Mar. 16, 2018installmentshares

Sep. 06, 2017$ / sharesshares

Sep. 30, 2021USD ($)

Sep. 30, 2020USD ($)

Jun. 30, 2021$ / sharesshares

Sep. 30, 2021USD ($)shares

Sep. 30, 2020USD ($)

Dec. 31, 2022USD ($)

Dec. 31, 2021USD ($)

Jul. 30, 2018

May 11, 2017shares

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Share-based compensation | $

$ 1,563

$ 1,645

$ 4,275

$ 4,167

Restricted Stock

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Restricted stock granted (in shares)

4,300

Number of equal installments | installment

3

Restricted Stock | Market-Based Vesting (TSR Units)

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting period

27 months

Restricted stock granted to trustees, vested in period (in shares)

208,210

Unrecognized compensation cost | $

3,500

$ 3,500

Restricted Stock | Market-Based Vesting (TSR Units) | Shares Issued 2017

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting percentage

200.00%

Restricted Stock | Market-Based Vesting (TSR Units) | Shared Issued 2018

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting percentage

50.00%

Restricted Stock | Market-Based Vesting (TSR Units) | Shares Issued 2019

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting percentage

0.00%

Restricted Stock | Market-Based Vesting (TSR Units) | Shares issued 2020

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting percentage

0.00%

Restricted Stock | Immediate Vesting (CIC Units)

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Restricted stock granted (in shares)

965,000

885,000

Grant date fair value (in dollars per share) | $ / shares

$ 13.05

Restricted Stock | Maximum | Market-Based Vesting (TSR Units)

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting percentage

50.00%

Time-Based Restricted Units

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Restricted stock granted (in shares)

387,499

Performance Shares

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting period

33 months

Non-Cash Share Based Compensation in 2014 | Subsequent Event | Forecast

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Unrecognized compensation cost | $

$ 7,600

$ 5,900

Common Stock | Market-Based Vesting (TSR Units)

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Stock granted to trustees, increase (decrease) (in shares)

104,105

2008 Long-Term Equity Incentive Ownership Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Percentage of maximum number of shares issued under plan to aggregate shares

12.50%

Shares authorized (in shares)

3,433,831

2008 Long-Term Equity Incentive Ownership Plan | Restricted Common Shares and Restricted Share Units

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting percentage

100.00%

2008 Long-Term Equity Incentive Ownership Plan | Non-Vested Time Based Shares

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Unrecognized compensation cost | $

$ 5,700

$ 5,700

Unrecognized compensation cost, period for recognition

33 months

2008 Long-Term Equity Incentive Ownership Plan | Non-Cash Share Based Compensation in 2014

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Unrecognized compensation cost, period for recognition

24 months

2018 Long-Term Equity Incentive Ownership Plan | Restricted Stock | Market-Based Vesting (TSR Units)

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Restricted stock granted (in shares)

545,000

405,417

229,684

433,200

Performance period

3 years

3 years

3 years

Grant date fair value (in dollars per share) | $ / shares

$ 5.55

$ 8.22

$ 14.89

$ 4.17

Options to be converted to cash

111,465

2018 Long-Term Equity Incentive Ownership Plan | Restricted Stock | Minimum | Market-Based Vesting (TSR Units)

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting percentage

0.00%

0.00%

0.00%

2018 Long-Term Equity Incentive Ownership Plan | Restricted Stock | Maximum | Market-Based Vesting (TSR Units)

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting percentage

200.00%

200.00%

200.00%

2018 Long-Term Equity Incentive Ownership Plan | Time-Based Restricted Units

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Restricted stock granted (in shares)

530,000

17,069

317,184

433,200

Performance period

3 years

3 years

3 years

Grant date fair value (in dollars per share) | $ / shares

$ 5.83

$ 11.69

$ 10.63

$ 7.51

Incentive Share Plan (Schedule

Incentive Share Plan (Schedule of Share-Based Incentive Plan Activity) (Details) - 2008 Long-Term Equity Incentive Ownership Plan - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Shares
Non-vested, beginning balance (in shares)	2,903,846
Granted (in shares)	874,390	1,108,014	762,630
Vested (in shares)	(609,335)	(511,621)	(284,964)
Forfeited (in shares)	(60,855)
Non-vested, ending balance (in shares)	3,108,046	2,903,846
Shares, Available for grant (in shares)	0
Weighted Average Grant Date Fair Value
Non-vested, ending balance (in dollars per share)	$ 8.31	$ 9.45
Granted (in dollars per share)	5.87	$ 5.76	$ 9.46
Vested (in dollars per share)	10.35
Forfeited (in dollars per share)	7.25
Non-vested, beginning balance (in dollars per share)	$ 9.45

Incentive Share Plan (Schedul_2

Incentive Share Plan (Schedule of Nonvested and Vested Shares Activity) (Details) - 2008 Long-Term Equity Incentive Ownership Plan - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Granted, Non-Vested Shares Issued (in shares)	874,390	1,108,014	762,630
Shares Granted, Weighted-Average Grant Date Fair Value (in dollars per share)	$ 5.87	$ 5.76	$ 9.46
Shares Vested (in shares)	(609,335)	(511,621)	(284,964)
Shares Vested, Total Vest-Date Fair Value	$ 6,309	$ 5,566	$ 3,352

Grants to Trustees (Details)

Grants to Trustees (Details)	Dec. 04, 2020trustee$ / sharesshares
Individual Trustee Grant Agreements 1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of independent trustees (in trustees)	6
Number of independent trustees, did not stand for re-election (in trustees)	1
Number of trustee emeritus (in trustees)	1
Individual Trustee Grant Agreements 1 | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock granted to trustees, vested in period (in shares) | shares	29,587
Restricted stock granted to each trustee (in shares) | shares	29,587
Restricted stock granted to trustees, weighted-average grant date fair value (in dollars per share) | $ / shares	$ 8.17
Individual Trustee Grant Agreements 2
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of independent trustees (in trustees)	1
Individual Trustee Grant Agreements 2 | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock granted to each trustee (in shares) | shares	3,427
Restricted stock granted to trustees, weighted-average grant date fair value (in dollars per share) | $ / shares	$ 8.17

Real Estate (Details)

Real Estate (Details) - Lakeside Market ft² in Thousands, $ in Thousands	Jul. 08, 2021USD ($)ft²	Sep. 30, 2021ft²
Real Estate [Line Items]
Payments to acquire productive assets | $	$ 53,200
Area of real estate property | ft²	163	200
Percent of property leased	80.50%

Related Party Transactions - Na

Related Party Transactions - Narrative (Details) - Beneficial Owner	9 Months Ended
	Sep. 30, 2021
James C. Mastandrea
Related Party Transaction [Line Items]
Ownership percentage	66.70%
John J. Dee
Related Party Transaction [Line Items]
Ownership percentage	20.00%

Related Party Transactions - Re

Related Party Transactions - Revenue and Expenses (Details) - Pillarstone OP - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Property operation and maintenance
Related Party Transaction [Line Items]
Rent	$ (225)	$ (225)	$ (672)	$ (701)
Other revenues
Related Party Transaction [Line Items]
Property management fee income	$ 142	$ 144	$ 426	$ 455

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Millions	Dec. 12, 2017USD ($)
Whitestone Pinnacle of Scottsdale - Phase II, LLC | Pending Litigation
Loss Contingencies [Line Items]
Damages sought, value	$ 2.3

Subsequent Events - Narrative (

Subsequent Events - Narrative (Details) - Lakeside Market ft² in Thousands, $ in Thousands	Jul. 08, 2021USD ($)ft²	Sep. 30, 2021ft²
Subsequent Event [Line Items]
Payments to acquire productive assets | $	$ 53,200
Area of real estate property | ft²	163	200
Percent of property leased	80.50%