Kilroy Realty (KRC) 10-K 10 Feb 23 2022 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2022	Feb. 03, 2023	Jun. 30, 2022
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	1-12675
Entity Registrant Name	KILROY REALTY CORPORATION
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	95-4598246
Entity Address, Address Line One	12200 W. Olympic Boulevard
Entity Address, Address Line Two	Suite 200
Entity Address, City or Town	Los Angeles
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	90064
City Area Code	(310)
Local Phone Number	481-8400
Title of 12(b) Security	Common Stock, $.01 par value
Security Exchange Name	NYSE
Trading Symbol	KRC
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 6,078,528,830
Entity Common Stock, Shares Outstanding		117,087,139
Documents Incorporated by Reference	Portions of the Kilroy Realty Corporation’s Proxy Statement with respect to its 2023 Annual Meeting of Stockholders to be filed not later than 120 days after the end of the registrant’s fiscal year are incorporated by reference into Part III of this Form 10-K.
Entity Central Index Key	0001025996
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false
Kilroy Realty L.P.
Entity Information [Line Items]
Current Fiscal Year End Date	--12-31
Entity File Number	000-54005
Entity Registrant Name	KILROY REALTY, L.P.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	95-4612685
Title of 12(g) Security	Common Units Representing Limited Partnership Interests
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Central Index Key	0001493976
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2022
Entity Information [Line Items]
Auditor Name	DELOITTE & TOUCHE LLP
Auditor Firm ID	34
Auditor Location	Los Angeles, California
Kilroy Realty L.P.
Entity Information [Line Items]
Auditor Name	DELOITTE & TOUCHE LLP
Auditor Firm ID	34
Auditor Location	Los Angeles, California

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
REAL ESTATE ASSETS (Notes 2, 3 and 4):
Land and improvements	$ 1,738,242	$ 1,731,982
Buildings and improvements	8,302,081	7,543,585
Undeveloped land and construction in progress	1,691,860	2,017,126
Total real estate assets held for investment	11,732,183	11,292,693
Accumulated depreciation and amortization	(2,218,710)	(2,003,656)
Total real estate assets held for investment, net	9,513,473	9,289,037
CASH AND CASH EQUIVALENTS (Note 22)	347,379	414,077
RESTRICTED CASH (Note 22)	0	13,006
MARKETABLE SECURITIES (Notes 16 and 19)	23,547	27,475
CURRENT RECEIVABLES, NET (Notes 2 and 6)	20,583	14,386
DEFERRED RENT RECEIVABLES, NET (Notes 2 and 6)	452,200	405,665
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Notes 2, 3 and 5)	250,846	234,458
RIGHT OF USE GROUND LEASE ASSETS (Note 18)	126,530	127,302
PREPAID EXPENSES AND OTHER ASSETS, NET (Note 7)	62,429	57,991
TOTAL ASSETS	10,796,987	10,583,397
LIABILITIES:
Secured debt, net (Notes 8, 9 and 19)	242,938	248,367
Unsecured debt, net (Notes 8, 9 and 19)	4,020,058	3,820,383
Accounts payable, accrued expenses and other liabilities (Note 18)	392,360	391,264
Ground lease liabilities (Note 18)	124,994	125,550
Accrued dividends and distributions (Notes 13 and 25)	64,285	61,850
Deferred revenue and acquisition-related intangible liabilities, net (Notes 2, 3, 5 and 10)	195,959	171,151
Rents received in advance and tenant security deposits	81,432	74,962
Total liabilities	5,122,026	4,893,527
COMMITMENTS AND CONTINGENCIES (Note 18)
Stockholders’ Equity (Note 13):
Common stock, $.01 par value, 280,000,000 shares authorized, 116,878,031 and 116,464,169 shares issued and outstanding, respectively	1,169	1,165
Additional paid-in capital	5,170,760	5,155,232
Retained earnings	265,118	283,663
Total stockholders’ equity	5,437,047	5,440,060
Noncontrolling Interests (Notes 2 and 11):
Common units of the Operating Partnership	53,524	53,746
Noncontrolling interests in consolidated property partnerships	184,390	196,064
Total noncontrolling interests	237,914	249,810
Total equity	5,674,961	5,689,870
TOTAL LIABILITIES AND EQUITY	$ 10,796,987	$ 10,583,397

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Common stock, par value (dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	280,000,000	280,000,000
Common stock, shares issued (in shares)	116,878,031	116,464,169
Common stock, shares outstanding (in shares)	116,878,031	116,464,169

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Statement [Abstract]
Revenue, Product and Service [Extensible List]	Service [Member]	Service [Member]	Service [Member]
REVENUES (Note 2):
Rental income (Note 17)	$ 1,086,018	$ 948,994	$ 892,306
Other property income	10,969	6,046	6,091
Total revenues	1,096,987	955,040	898,397
EXPENSES:
Property expenses	202,744	165,702	155,118
Real estate taxes	105,869	93,209	92,218
Ground leases (Note 18)	7,565	7,421	8,891
General and administrative expenses (Note 15)	93,642	92,749	99,264
Leasing costs	4,879	3,249	4,493
Depreciation and amortization (Notes 2 and 5)	357,611	310,043	299,308
Total expenses	772,310	672,373	659,292
OTHER INCOME (EXPENSES) :
Interest and other income, net (Note 19)	1,765	3,916	3,424
Interest expense (Note 9)	(84,278)	(78,555)	(70,772)
Gains on sales of depreciable operating properties (Note 4)	17,329	463,128	35,536
Loss on early extinguishment of debt (Note 9)	0	(12,246)	0
Total other (expenses) income	(65,184)	376,243	(31,812)
NET INCOME	259,493	658,910	207,293
Net income attributable to noncontrolling common units of the Operating Partnership (Notes 2 and 11)	(2,283)	(6,163)	(2,869)
Net income attributable to noncontrolling interests in consolidated property partnerships (Notes 2 and 11)	(24,595)	(24,603)	(17,319)
Total income attributable to noncontrolling interests	(26,878)	(30,766)	(20,188)
Numerator for basic net income available to common stockholders	$ 232,615	$ 628,144	$ 187,105
Net income available to common stockholders per share (dollars per share)	$ 1.98	$ 5.38	$ 1.63
Net income available to common stockholders per share (dollars per share)	$ 1.97	$ 5.36	$ 1.63
Weighted average shares of common stock outstanding – basic (in shares)	116,806,575	116,429,130	113,241,341
Weighted average shares of common stock outstanding – diluted (in shares)	117,220,047	116,948,643	113,719,622

CONSOLIDATED STATEMENTS OF EQUI

CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	Total Stock- holders’ Equity	Common Stock	Additional Paid-in Capital	Retained Earnings (Distributions in Excess of Earnings)	Noncontrolling  Interests
Beginning balance (in shares) at Dec. 31, 2019			106,016,287
Beginning balance at Dec. 31, 2019	$ 4,570,858	$ 4,293,510	$ 1,060	$ 4,350,917	$ (58,467)	$ 277,348
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	207,293	187,105			187,105	20,188
Issuance of common stock (in shares)			8,897,110
Issuance of common stock	721,665	721,665	$ 89	721,576
Issuance of share-based compensation awards	4,441	4,441		4,441
Non-cash amortization of share-based compensation	37,624	37,624		37,624
Settlement of restricted stock units for shares of common stock (in shares)			441,416
Settlement of restricted stock units for shares of common stock	$ 0		$ 4	(4)
Repurchase of common stock and restricted stock units (in shares)	0		(191,699)
Repurchase of common stock and restricted stock units	$ (14,082)	(14,082)	$ (2)	(14,080)
Exchange of common units of the Operating Partnership (in shares)			872,713
Exchange of common units of the Operating Partnership	0	37,640	$ 9	37,631		(37,640)
Distributions to noncontrolling interests in consolidated property partnerships	(15,247)					(15,247)
Adjustment for noncontrolling interest in the Operating Partnership	0	(6,189)		(6,189)		6,189
Dividends declared per share of common stock and common unit	(235,231)	(231,771)			(231,771)	(3,460)
Ending balance (in shares) at Dec. 31, 2020			116,035,827
Ending balance at Dec. 31, 2020	5,277,321	5,029,943	$ 1,160	5,131,916	(103,133)	247,378
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	658,910	628,144			628,144	30,766
Issuance of share-based compensation awards	3,921	3,921		3,921
Non-cash amortization of share-based compensation	40,960	40,960		40,960
Exercise of stock options (in shares)			9,000
Exercise of stock options	383	383		383
Settlement of restricted stock units for shares of common stock (in shares)			785,805
Settlement of restricted stock units for shares of common stock	$ 0		$ 8	(8)
Repurchase of common stock and restricted stock units (in shares)	0		(366,463)
Repurchase of common stock and restricted stock units	$ (21,888)	(21,888)	$ (3)	(21,885)
Contributions from noncontrolling interests in consolidated property partnerships	1,559					1,559
Distributions to noncontrolling interests in consolidated property partnerships	(27,601)					(27,601)
Adjustment for noncontrolling interest in the Operating Partnership	0	(55)		(55)		55
Dividends declared per share of common stock and common unit	$ (243,695)	(241,348)			(241,348)	(2,347)
Ending balance (in shares) at Dec. 31, 2021	116,464,169		116,464,169
Ending balance at Dec. 31, 2021	$ 5,689,870	5,440,060	$ 1,165	5,155,232	283,663	249,810
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	259,493	232,615			232,615	26,878
Issuance of share-based compensation awards	3,607	3,607		3,607
Non-cash amortization of share-based compensation	34,793	34,793		34,793
Settlement of restricted stock units for shares of common stock (in shares)			745,248
Settlement of restricted stock units for shares of common stock	$ 0		$ 7	(7)
Repurchase of common stock and restricted stock units (in shares)	0		(331,386)
Repurchase of common stock and restricted stock units	$ (22,934)	(22,934)	$ (3)	(22,931)
Distributions to noncontrolling interests in consolidated property partnerships	(36,269)					(36,269)
Adjustment for noncontrolling interest in the Operating Partnership	0	66		66		(66)
Dividends declared per share of common stock and common unit	$ (253,599)	(251,160)			(251,160)	(2,439)
Ending balance (in shares) at Dec. 31, 2022	116,878,031		116,878,031
Ending balance at Dec. 31, 2022	$ 5,674,961	$ 5,437,047	$ 1,169	$ 5,170,760	$ 265,118	$ 237,914

CONSOLIDATED STATEMENTS OF EQ_2

CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statement of Stockholders' Equity [Abstract]
Dividends declared per share of common stock and common unit (dollars per share)	$ 2.12	$ 2.04	$ 1.97

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 259,493	$ 658,910	$ 207,293
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of real estate assets and leasing costs	350,665	303,799	290,353
Depreciation of non-real estate furniture, fixtures and equipment	6,946	6,244	8,955
Revenue (recoveries) reversals for doubtful accounts, net (Notes 2 and 17)	(123)	1,433	18,997
Non-cash amortization of share-based compensation awards (Note 15)	28,347	33,800	30,245
Non-cash amortization of deferred financing costs and net debt discounts	3,657	2,831	2,958
Non-cash amortization of net below market rents (Note 5)	(10,476)	(6,904)	(7,603)
Gains on sales of depreciable operating properties (Note 4)	(17,329)	(463,128)	(35,536)
Loss on early extinguishment of debt (Note 9)	0	12,246	0
Non-cash amortization of deferred revenue related to tenant-funded tenant improvements (Note 10)	(19,321)	(17,247)	(17,547)
Straight-line rents	(46,231)	(53,745)	(67,826)
Amortization of right of use ground lease assets	772	1,241	825
Net change in other operating assets	(12,606)	(6,077)	(3,685)
Net change in other operating liabilities	48,441	43,000	28,161
Net cash provided by operating activities	592,235	516,403	455,590
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for acquisitions of development properties and undeveloped land (Note 3)	(40,033)	(586,927)	0
Expenditures for development and redevelopment properties and undeveloped land	(453,774)	(552,837)	(486,565)
Expenditures for operating properties and other capital assets	(92,802)	(120,611)	(129,500)
Expenditures for acquisitions of operating properties (Note 3)	0	(537,429)	0
Net proceeds received from dispositions (Note 4)	33,416	1,048,927	74,937
Decrease (increase) in acquisition-related deposits	0	1,000	(1,000)
Net cash used in investing activities	(553,193)	(747,877)	(542,128)
CASH FLOWS FROM FINANCING ACTIVITIES:
Principal payments and repayments of secured debt (Note 9)	(5,555)	(5,341)	(5,137)
Financing costs (Note 9)	(6,432)	(12,032)	(6,594)
Borrowings on unsecured debt (Note 9)	200,000	0	0
Net proceeds from the issuance of unsecured debt (Note 9)	0	449,807	772,297
Repayments of unsecured debt (Note 9)	0	(312,105)	(150,000)
Borrowings on unsecured revolving credit facility	0	0	190,000
Repayments on unsecured revolving credit facility	0	0	(435,000)
Net proceeds from issuance of common stock	0	0	721,665
Repurchase of common stock and restricted stock units (Note 15)	(22,934)	(21,888)	(14,082)
Distributions to noncontrolling interests in consolidated property partnerships	(36,269)	(27,601)	(15,247)
Dividends and distributions paid to common stockholders and common unitholders	(247,556)	(237,355)	(224,578)
Proceeds from exercise of stock options	0	383	0
Contributions from noncontrolling interests in consolidated property partnerships	0	1,559	0
Net cash (used in) provided by financing activities	(118,746)	(164,573)	833,324
Net (decrease) increase in cash and cash equivalents and restricted cash	(79,704)	(396,047)	746,786
Cash and cash equivalents and restricted cash, beginning of year	427,083	823,130	76,344
Cash and cash equivalents and restricted cash, end of year	$ 347,379	$ 427,083	$ 823,130

CONSOLIDATED BALANCE SHEETS (KI

CONSOLIDATED BALANCE SHEETS (KILROY REALTY, L.P.) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
REAL ESTATE ASSETS (Notes 2, 3 and 4):
Land and improvements	$ 1,738,242	$ 1,731,982
Buildings and improvements	8,302,081	7,543,585
Undeveloped land and construction in progress	1,691,860	2,017,126
Total real estate assets held for investment	11,732,183	11,292,693
Accumulated depreciation and amortization	(2,218,710)	(2,003,656)
Total real estate assets held for investment, net	9,513,473	9,289,037
CASH AND CASH EQUIVALENTS (Note 23)	347,379	414,077
RESTRICTED CASH (Note 23)	0	13,006
MARKETABLE SECURITIES (Notes 16 and 19)	23,547	27,475
CURRENT RECEIVABLES, NET (Notes 2 and 6)	20,583	14,386
DEFERRED RENT RECEIVABLES, NET (Notes 2 and 6)	452,200	405,665
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Notes 2, 3 and 5)	250,846	234,458
RIGHT OF USE GROUND LEASE ASSETS (Note 18)	126,530	127,302
PREPAID EXPENSES AND OTHER ASSETS, NET (Note 7)	62,429	57,991
TOTAL ASSETS	10,796,987	10,583,397
LIABILITIES:
Secured debt	242,938	248,367
Unsecured debt, net (Notes 9 and 19)	4,020,058	3,820,383
Accounts payable, accrued expenses and other liabilities (Note 18)	392,360	391,264
Ground lease liabilities (Note 18)	124,994	125,550
Accrued distributions (Notes 14 and 25)	64,285	61,850
Deferred revenue and acquisition-related intangible liabilities, net (Notes 2, 3, 5 and 10)	195,959	171,151
Rents received in advance and tenant security deposits	81,432	74,962
Total liabilities	5,122,026	4,893,527
COMMITMENTS AND CONTINGENCIES (Note 18)
CAPITAL:
TOTAL LIABILITIES AND EQUITY	10,796,987	10,583,397
Kilroy Realty L.P.
REAL ESTATE ASSETS (Notes 2, 3 and 4):
Land and improvements	1,738,242	1,731,982
Buildings and improvements	8,302,081	7,543,585
Undeveloped land and construction in progress	1,691,860	2,017,126
Total real estate assets held for investment	11,732,183	11,292,693
Accumulated depreciation and amortization	(2,218,710)	(2,003,656)
Total real estate assets held for investment, net	9,513,473	9,289,037
CASH AND CASH EQUIVALENTS (Note 23)	347,379	414,077
RESTRICTED CASH (Note 23)	0	13,006
MARKETABLE SECURITIES (Notes 16 and 19)	23,547	27,475
CURRENT RECEIVABLES, NET (Notes 2 and 6)	20,583	14,386
DEFERRED RENT RECEIVABLES, NET (Notes 2 and 6)	452,200	405,665
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Notes 2, 3 and 5)	250,846	234,458
RIGHT OF USE GROUND LEASE ASSETS (Note 18)	126,530	127,302
PREPAID EXPENSES AND OTHER ASSETS, NET (Note 7)	62,429	57,991
TOTAL ASSETS	10,796,987	10,583,397
LIABILITIES:
Secured debt	242,938	248,367
Unsecured debt, net (Notes 9 and 19)	4,020,058	3,820,383
Accounts payable, accrued expenses and other liabilities (Note 18)	392,360	391,264
Ground lease liabilities (Note 18)	124,994	125,550
Accrued distributions (Notes 14 and 25)	64,285	61,850
Deferred revenue and acquisition-related intangible liabilities, net (Notes 2, 3, 5 and 10)	195,959	171,151
Rents received in advance and tenant security deposits	81,432	74,962
Total liabilities	5,122,026	4,893,527
COMMITMENTS AND CONTINGENCIES (Note 18)
CAPITAL:
Partner’s Capital - Common units, 116,878,031 and 116,464,169 held by the general partner and 1,150,574 and 1,150,574 held by common limited partners issued and outstanding, respectively (Note 14)	5,490,571	5,493,806
Noncontrolling interests in consolidated property partnerships and subsidiaries (Notes 2 and 12)	184,390	196,064
Total capital	5,674,961	5,689,870
TOTAL LIABILITIES AND EQUITY	$ 10,796,987	$ 10,583,397

CONSOLIDATED BALANCE SHEETS (_2

CONSOLIDATED BALANCE SHEETS (KILROY REALTY, L.P.) (Parenthetical) - Common Units - Kilroy Realty L.P. - shares	Dec. 31, 2022	Dec. 31, 2021
General partner, units issued (in shares)	116,878,031	116,464,169
General partner, units outstanding (in shares)	116,878,031	116,464,169
Limited partner, units issued (in shares)	1,150,574	1,150,574
Limited partner, units outstanding (in shares)	1,150,574	1,150,574

CONSOLIDATED STATEMENTS OF OP_2

CONSOLIDATED STATEMENTS OF OPERATIONS (KILROY REALTY, L.P.) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenue, Product and Service [Extensible List]	Service [Member]	Service [Member]	Service [Member]
REVENUES (Note 2):
Rental income (Note 17)	$ 1,086,018	$ 948,994	$ 892,306
Other property income	10,969	6,046	6,091
Total revenues	1,096,987	955,040	898,397
EXPENSES:
Property expenses	202,744	165,702	155,118
Real estate taxes	105,869	93,209	92,218
Ground leases (Note 18)	7,565	7,421	8,891
General and administrative expenses (Note 15)	93,642	92,749	99,264
Leasing costs	4,879	3,249	4,493
Depreciation and amortization (Notes 2 and 5)	357,611	310,043	299,308
Total expenses	772,310	672,373	659,292
OTHER INCOME (EXPENSES):
Interest and other income, net (Note 19)	1,765	3,916	3,424
Interest expense (Note 9)	(84,278)	(78,555)	(70,772)
Gains on sales of depreciable operating properties (Note 4)	17,329	463,128	35,536
Loss on early extinguishment of debt (Note 9)	0	(12,246)	0
Total other (expenses) income	(65,184)	376,243	(31,812)
NET INCOME	259,493	658,910	207,293
Net income attributable to noncontrolling interests in consolidated property partnerships and subsidiaries (Notes 2 and 12)	(26,878)	(30,766)	(20,188)
Numerator for basic net income available to common stockholders	$ 232,615	$ 628,144	$ 187,105
Net income available to common unitholders per unit (dollars per share)	$ 1.98	$ 5.38	$ 1.63
Net income available to common unitholders per unit (dollars per share)	$ 1.97	$ 5.36	$ 1.63
Weighted average common units outstanding - basic (in shares)	116,806,575	116,429,130	113,241,341
Weighted average common units outstanding - diluted (in shares)	117,220,047	116,948,643	113,719,622
Kilroy Realty L.P.
Revenue, Product and Service [Extensible List]	Service [Member]	Service [Member]	Service [Member]
REVENUES (Note 2):
Rental income (Note 17)	$ 1,086,018	$ 948,994	$ 892,306
Other property income	10,969	6,046	6,091
Total revenues	1,096,987	955,040	898,397
EXPENSES:
Property expenses	202,744	165,702	155,118
Real estate taxes	105,869	93,209	92,218
Ground leases (Note 18)	7,565	7,421	8,891
General and administrative expenses (Note 15)	93,642	92,749	99,264
Leasing costs	4,879	3,249	4,493
Depreciation and amortization (Notes 2 and 5)	357,611	310,043	299,308
Total expenses	772,310	672,373	659,292
OTHER INCOME (EXPENSES):
Interest and other income, net (Note 19)	1,765	3,916	3,424
Interest expense (Note 9)	(84,278)	(78,555)	(70,772)
Gains on sales of depreciable operating properties (Note 4)	17,329	463,128	35,536
Loss on early extinguishment of debt (Note 9)	0	(12,246)	0
Total other (expenses) income	(65,184)	376,243	(31,812)
NET INCOME	259,493	658,910	207,293
Net income attributable to noncontrolling interests in consolidated property partnerships and subsidiaries (Notes 2 and 12)	(24,595)	(24,603)	(17,684)
Numerator for basic net income available to common stockholders	$ 234,898	$ 634,307	$ 189,609
Net income available to common unitholders per unit (dollars per share)	$ 1.98	$ 5.38	$ 1.63
Net income available to common unitholders per unit (dollars per share)	$ 1.97	$ 5.36	$ 1.62
Weighted average common units outstanding - basic (in shares)	117,957,149	117,579,704	115,095,506
Weighted average common units outstanding - diluted (in shares)	118,370,621	118,099,217	115,573,787

CONSOLIDATED STATEMENTS OF CAPI

CONSOLIDATED STATEMENTS OF CAPITAL (KILROY REALTY, L.P.) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 259,493	$ 658,910	$ 207,293
Non-cash amortization of share-based compensation	34,793	40,960	37,624
Distributions to noncontrolling interests in consolidated property partnerships	(36,269)	(27,601)	(15,247)
Noncontrolling Interests in Consolidated Property Partnerships and Subsidiaries
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	26,878	30,766	20,188
Distributions to noncontrolling interests in consolidated property partnerships	(36,269)	(27,601)	(15,247)
Kilroy Realty L.P.
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	5,689,870	5,277,321	4,570,858
Net income	259,493	658,910	207,293
Issuance of common units			721,665
Issuance of share-based compensation awards	3,607	3,921	4,441
Non-cash amortization of share-based compensation	34,793	40,960	37,624
Exercise of stock options		383
Repurchase and cancellation of common units and restricted stock units	(22,934)	(21,888)	(14,082)
Contributions from noncontrolling interests in consolidated property partnerships			0
Contributions of noncontrolling interests in consolidated subsidiary		(1,559)
Distributions to noncontrolling interests in consolidated property partnerships	(36,269)	(27,601)	(15,247)
Distributions declared per common unit	(253,599)	(243,695)	(235,231)
Ending balance	$ 5,674,961	$ 5,689,870	$ 5,277,321
Kilroy Realty L.P. | Partners’ Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)	117,614,743	117,186,401	108,039,574
Beginning balance	$ 5,493,806	$ 5,079,818	$ 4,369,758
Net income	234,898	634,307	$ 189,609
Issuance of common units (in shares)			8,897,110
Issuance of common units			$ 721,665
Issuance of share-based compensation awards	3,607	3,921	4,441
Non-cash amortization of share-based compensation	$ 34,793	$ 40,960	$ 37,624
Exercise of stock options (in shares)		9,000
Exercise of stock options		$ 383
Settlement of restricted stock units (in shares)	745,248	785,805	441,416
Repurchase and cancellation of common units and restricted stock units (in shares)	(331,386)	(366,463)	(191,699)
Repurchase and cancellation of common units and restricted stock units	$ (22,934)	$ (21,888)	$ (14,082)
Contributions from noncontrolling interests in consolidated property partnerships			6,034
Distributions declared per common unit	$ (253,599)	$ (243,695)	$ (235,231)
Ending balance (in shares)	118,028,605	117,614,743	117,186,401
Ending balance	$ 5,490,571	$ 5,493,806	$ 5,079,818
Kilroy Realty L.P. | Noncontrolling Interests in Consolidated Property Partnerships and Subsidiaries
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	196,064	197,503	201,100
Net income	24,595	24,603	17,684
Contributions from noncontrolling interests in consolidated property partnerships			(6,034)
Contributions of noncontrolling interests in consolidated subsidiary		(1,559)
Distributions to noncontrolling interests in consolidated property partnerships	(36,269)	(27,601)	(15,247)
Ending balance	$ 184,390	$ 196,064	$ 197,503

CONSOLIDATED STATEMENTS OF CA_2

CONSOLIDATED STATEMENTS OF CAPITAL (KILROY REALTY, L.P.) (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Kilroy Realty L.P.
Distributions declared per common unit (dollars per share)	$ 2.12	$ 2.04	$ 1.97

CONSOLIDATED STATEMENTS OF CA_3

CONSOLIDATED STATEMENTS OF CASH FLOWS (KILROY REALTY, L.P.) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 259,493	$ 658,910	$ 207,293
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of real estate assets and leasing costs	350,665	303,799	290,353
Depreciation of non-real estate furniture, fixtures and equipment	6,946	6,244	8,955
Revenue (recoveries) reversals for doubtful accounts, net (Notes 2 and 17)	(123)	1,433	18,997
Non-cash amortization of share-based compensation awards (Note 15)	28,347	33,800	30,245
Non-cash amortization of deferred financing costs and net debt discounts	3,657	2,831	2,958
Non-cash amortization of net below market rents (Note 5)	(10,476)	(6,904)	(7,603)
Gains on sales of depreciable operating properties (Note 4)	(17,329)	(463,128)	(35,536)
Loss on early extinguishment of debt (Note 9)	0	12,246	0
Non-cash amortization of deferred revenue related to tenant-funded tenant improvements (Note 10)	(19,321)	(17,247)	(17,547)
Straight-line rents	(46,231)	(53,745)	(67,826)
Amortization of right of use ground lease assets	772	1,241	825
Net change in other operating assets	(12,606)	(6,077)	(3,685)
Net change in other operating liabilities	48,441	43,000	28,161
Net cash provided by operating activities	592,235	516,403	455,590
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for acquisitions of development properties and undeveloped land (Note 3)	(40,033)	(586,927)	0
Expenditures for development and redevelopment properties and undeveloped land	(453,774)	(552,837)	(486,565)
Expenditures for operating properties and other capital assets	(92,802)	(120,611)	(129,500)
Expenditures for acquisitions of operating properties (Note 3)	0	(537,429)	0
Net proceeds received from dispositions (Note 4)	33,416	1,048,927	74,937
Decrease (increase) in acquisition-related deposits	0	1,000	(1,000)
Net cash used in investing activities	(553,193)	(747,877)	(542,128)
CASH FLOWS FROM FINANCING ACTIVITIES:
Principal payments and repayments of secured debt (Note 9)	(5,555)	(5,341)	(5,137)
Financing costs (Note 9)	(6,432)	(12,032)	(6,594)
Borrowings on unsecured debt (Note (9)	200,000	0	0
Net proceeds from the issuance of unsecured debt (Note 9)	0	449,807	772,297
Repayments of unsecured debt (Note 9)	0	(312,105)	(150,000)
Borrowings on unsecured revolving credit facility	0	0	190,000
Repayments on unsecured revolving credit facility	0	0	(435,000)
Net proceeds from issuance of common units	0	0	721,665
Repurchase of common stock and restricted stock units (Note 15)	(22,934)	(21,888)	(14,082)
Distributions to noncontrolling interests in consolidated property partnerships	(36,269)	(27,601)	(15,247)
Dividends and distributions paid to common stockholders and common unitholders	(247,556)	(237,355)	(224,578)
Proceeds from exercise of stock options	0	383	0
Contributions from noncontrolling interests in consolidated property partnerships	0	1,559	0
Net cash (used in) provided by financing activities	(118,746)	(164,573)	833,324
Net (decrease) increase in cash and cash equivalents and restricted cash	(79,704)	(396,047)	746,786
Cash and cash equivalents and restricted cash, beginning of year	427,083	823,130	76,344
Cash and cash equivalents and restricted cash, end of year	347,379	427,083	823,130
Kilroy Realty L.P.
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	259,493	658,910	207,293
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of real estate assets and leasing costs	350,665	303,799	290,353
Depreciation of non-real estate furniture, fixtures and equipment	6,946	6,244	8,955
Revenue (recoveries) reversals for doubtful accounts, net (Notes 2 and 17)	(123)	1,433	18,997
Non-cash amortization of share-based compensation awards (Note 15)	28,347	33,800	30,245
Non-cash amortization of deferred financing costs and net debt discounts	3,657	2,831	2,958
Non-cash amortization of net below market rents (Note 5)	(10,476)	(6,904)	(7,603)
Gains on sales of depreciable operating properties (Note 4)	(17,329)	(463,128)	(35,536)
Loss on early extinguishment of debt (Note 9)	0	12,246	0
Non-cash amortization of deferred revenue related to tenant-funded tenant improvements (Note 10)	(19,321)	(17,247)	(17,547)
Straight-line rents	(46,231)	(53,745)	(67,826)
Amortization of right of use ground lease assets	772	1,241	825
Net change in other operating assets	(12,606)	(6,077)	(3,685)
Net change in other operating liabilities	48,441	43,000	28,161
Net cash provided by operating activities	592,235	516,403	455,590
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for acquisitions of development properties and undeveloped land (Note 3)	(40,033)	(586,927)	0
Expenditures for development and redevelopment properties and undeveloped land	(453,774)	(552,837)	(486,565)
Expenditures for operating properties and other capital assets	(92,802)	(120,611)	(129,500)
Expenditures for acquisitions of operating properties (Note 3)	0	(537,429)	0
Net proceeds received from dispositions (Note 4)	33,416	1,048,927	74,937
Decrease (increase) in acquisition-related deposits	0	1,000	(1,000)
Net cash used in investing activities	(553,193)	(747,877)	(542,128)
CASH FLOWS FROM FINANCING ACTIVITIES:
Principal payments and repayments of secured debt (Note 9)	(5,555)	(5,341)	(5,137)
Financing costs (Note 9)	(6,432)	(12,032)	(6,594)
Borrowings on unsecured debt (Note (9)	200,000	0	0
Net proceeds from the issuance of unsecured debt (Note 9)	0	449,807	772,297
Repayments of unsecured debt (Note 9)	0	(312,105)	(150,000)
Borrowings on unsecured revolving credit facility	0	0	190,000
Repayments on unsecured revolving credit facility	0	0	(435,000)
Net proceeds from issuance of common units	0	0	721,665
Repurchase of common stock and restricted stock units (Note 15)	(22,934)	(21,888)	(14,082)
Distributions to noncontrolling interests in consolidated property partnerships	(36,269)	(27,601)	(15,247)
Dividends and distributions paid to common stockholders and common unitholders	(247,556)	(237,355)	(224,578)
Proceeds from exercise of stock options	0	383	0
Contributions from noncontrolling interests in consolidated property partnerships	0	1,559	0
Net cash (used in) provided by financing activities	(118,746)	(164,573)	833,324
Net (decrease) increase in cash and cash equivalents and restricted cash	(79,704)	(396,047)	746,786
Cash and cash equivalents and restricted cash, beginning of year	427,083	823,130	76,344
Cash and cash equivalents and restricted cash, end of year	$ 347,379	$ 427,083	$ 823,130

Organization and Ownership

Organization and Ownership	12 Months Ended
	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Ownership	Organization and Ownership Kilroy Realty Corporation (the “Company”) is a self-administered real estate investment trust (“REIT”) active in premier office, life science and mixed-use submarkets in the United States. We own, develop, acquire and manage real estate assets, consisting primarily of Class A properties in Greater Los Angeles, San Diego County, the San Francisco Bay Area, Greater Seattle and Austin, Texas, which we believe have strategic advantages and strong barriers to entry. Class A real estate encompasses attractive and efficient buildings of high quality that are attractive to tenants, are well-designed and constructed with above-average material, workmanship and finishes and are well-maintained and managed. We qualify as a REIT under the Internal Revenue Code of 1986, as amended (the “Code”). The Company’s common stock is publicly traded on the New York Stock Exchange (“NYSE”) under the ticker symbol “KRC.” We own our interests in all of our real estate assets through Kilroy Realty, L.P. (the “Operating Partnership”). We generally conduct substantially all of our operations through the Operating Partnership. Unless stated otherwise or the context indicates otherwise, the terms “Kilroy Realty Corporation” or the “Company,” “we,” “our,” and “us” refer to Kilroy Realty Corporation and its consolidated subsidiaries and the term “Operating Partnership” refers to Kilroy Realty, L.P. and its consolidated subsidiaries. The descriptions of our business, employees, and properties apply to both the Company and the Operating Partnership. Our stabilized portfolio of operating properties was comprised of the following properties at December 31, 2022: Number of Rentable Number of Percentage Occupied (unaudited) (1) Percentage Leased Stabilized Office Properties (2) 119 16,194,146 406 91.6 % 92.9 % _______________________ (1) Represents economic occupancy. (2) Includes stabilized life science and retail space. Number of Projects Number of Units 2022 Average Occupancy Stabilized Residential Properties 3 1,001 93.5 % Our stabilized portfolio includes all of our properties with the exception of development properties currently committed for construction, under construction, or in the tenant improvement phase, redevelopment properties under construction, undeveloped land and real estate assets held for sale. We define redevelopment properties as those properties for which we expect to spend significant development and construction costs on the existing or acquired buildings pursuant to a formal plan, the intended result of which is a higher economic return on the property. We define properties in the tenant improvement phase as office and life science properties that we are developing or redeveloping where the project has reached cold shell condition and is ready for tenant improvements, which may require additional major base building construction before being placed in service. Projects in the tenant improvement phase are added to our stabilized portfolio once the project reaches the earlier of 95% occupancy or one year from the date of the cessation of major base building construction activities. Costs capitalized to construction in progress for development and redevelopment properties are transferred to land and improvements, buildings and improvements, and deferred leasing costs on our consolidated balance sheets at the historical cost of the property as the projects or phases of projects are placed in service. During the year ended December 31, 2022, we added two development projects and two redevelopment projects to our stabilized portfolio consisting of four buildings totaling 1,114,704 square feet of office and life science space in Seattle, Washington and San Diego, California. We did not have any properties held for sale at December 31, 2022. As of December 31, 2022, the following properties were excluded from our stabilized portfolio: Number of Estimated Rentable Square Feet (1) (unaudited) In-process development projects - tenant improvement 1 734,000 In-process development projects - under construction 2 946,000 In-process redevelopment projects - under construction 2 100,000 ____________________ (1) Estimated rentable square feet upon completion. Our stabilized portfolio also excludes our future development pipeline, which as of December 31, 2022 was comprised of eight future development sites, representing approximately 64 gross acres of undeveloped land. As of December 31, 2022, all of our properties, development projects and redevelopment projects were owned and all of our business was conducted in the state of California with the exception of ten stabilized office properties and one future development project located in the state of Washington and one development project in the tenant improvement phase and one future development project in Austin, Texas. All of our properties, development projects and redevelopment projects are 100% owned, excluding four office properties owned by three consolidated property partnerships. Two of the three consolidated property partnerships, 100 First Street Member, LLC (“100 First LLC”) and 303 Second Street Member, LLC (“303 Second LLC”), each owned one office property in San Francisco, California through subsidiary REITs. As of December 31, 2022, the Company owned a 56% common equity interest in both 100 First LLC and 303 Second LLC. The third consolidated property partnership, Redwood City Partners, LLC (“Redwood LLC”) owned two office properties in Redwood City, California. As of December 31, 2022, the Company owned an approximate 93% common equity interest in Redwood LLC. The remaining interests in all three property partnerships were owned by unrelated third parties. As of December 31, 2022, the Company owned an approximate 99.0% common general partnership interest in the Operating Partnership. The remaining approximate 1.0% common limited partnership interest in the Operating Partnership as of December 31, 2022 was owned by non-affiliated investors and certain of our executive officers and directors. Both the general and limited common partnership interests in the Operating Partnership are denominated in common units. Generally, the number of common units held by the Company is equivalent to the number of outstanding shares of the Company’s common stock, and the rights of all the common units to quarterly distributions and payments in liquidation mirror those of the Company’s common stockholders. The common limited partners have certain redemption rights as provided in the Operating Partnership’s Seventh Amended and Restated Agreement of Limited Partnership, as amended, the “Partnership Agreement”. With the exception of the Operating Partnership and our consolidated property partnerships, all of our subsidiaries are wholly-owned.

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2022
Basis of Presentation and Significant Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	Basis of Presentation and Significant Accounting Policies Basis of Presentation The consolidated financial statements of the Company include the consolidated financial position and results of operations of the Company, the Operating Partnership, 303 Second LLC, 100 First LLC, Redwood LLC and all of our wholly-owned and controlled subsidiaries. The consolidated financial statements of the Operating Partnership include the consolidated financial position and results of operations of the Operating Partnership, 303 Second LLC, 100 First LLC, Redwood LLC and all of our wholly-owned and controlled subsidiaries. All intercompany balances and transactions have been eliminated in the consolidated financial statements. Partially Owned Entities and Variable Interest Entities At December 31, 2022 and 2021, the consolidated financial statements of the Company included two VIEs in addition to the Operating Partnership: 100 First LLC and 303 Second LLC. At December 31, 2022 and 2021, the Company and the Operating Partnership were determined to be the primary beneficiaries of these two VIEs since we had the ability to control the activities that most significantly impact each of the VIEs’ economic performance. As of December 31, 2022, the two VIEs’ total assets, liabilities and noncontrolling interests included on our consolidated balance sheet were approximately $438.7 million (of which $362.7 million related to real estate held for investment), approximately $31.5 million and approximately $179.4 million, respectively. At December 31, 2021, the two VIEs’ total assets, liabilities and noncontrolling interests included on our consolidated balance sheet were approximately $462.3 million (of which $377.9 million related to real estate held for investment on our consolidated balance sheet), approximately $28.1 million and approximately $190.7 million, respectively. Revenues, income and net assets generated by 100 First LLC and 303 Second LLC may only be used to settle their contractual obligations, which primarily consist of operating expenses, capital expenditures and required distributions. Our accounting policy is to consolidate entities in which we have a controlling financial interest and significant decision making control over the entity's operations. In determining whether we have a controlling financial interest in a partially owned entity and the requirement to consolidate the accounts of that entity, we consider factors such as ownership interest, board representation, management representation, size of our investment (including loans), authority to control decisions, and contractual and substantive participating rights of the members. In addition to evaluating control rights, we consolidate entities in which the other members have no substantive kick-out rights to remove the Company as the managing member. Entities in which the equity investors do not have sufficient equity at risk to finance their endeavors without additional financial support or the holders of the equity investment at risk do not have a controlling financial interest are VIEs. We evaluate whether an entity is a VIE and whether we are the primary beneficiary. We are deemed to be the primary beneficiary of a VIE when we have the power to direct the activities of the VIE that most significantly impact the VIEs’ economic performance and the obligation to absorb losses or receive benefits that could potentially be significant to the VIE. If the requirements for consolidation are not met, the Company would account for investments under the equity method of accounting if we have the ability to exercise significant influence over the entity. Equity method investments would be initially recorded at cost and subsequently adjusted for our share of net income or loss and cash contributions and distributions each period. The Company did not have any equity method investments at December 31, 2022 or 2021. Significant Accounting Policies Revenue Recognition Rental revenue for office, life science and retail operating properties is our principal source of revenue. We recognize revenue from base rent (fixed lease payments), additional rent (variable lease payments, which consist of amounts due from tenants for common area maintenance, real estate taxes, and other recoverable costs), parking and other lease-related revenue once all of the following criteria are met: (i) the agreement has been fully executed and delivered, (ii) services have been rendered, (iii) the amount is fixed or determinable and (iv) payment has been received or the collectability of substantially all of the amount due is probable. Minimum annual rental revenues are recognized in rental revenues on a straight-line basis over the non-cancellable term of the related lease. Base Rent The timing of when we commence rental revenue recognition for office, life science and retail properties depends largely on our conclusion as to whether the Company or the tenant is the owner for accounting purposes of tenant improvements at the leased property. When we conclude that the Company is the owner of tenant improvements for accounting purposes, we record the cost to construct the tenant improvements as an asset and commence rental revenue recognition when the tenant takes possession of or controls the finished space, which is generally when tenant improvements being recorded as our assets are substantially complete. In certain instances, when we conclude that the tenant is the owner of certain tenant improvements for accounting purposes, rental revenue recognition begins when the tenant takes possession or controls the physical use of the leased space. The determination of who owns the tenant improvements is made on a lease-by-lease basis and has a significant effect on the timing of commencement of revenue recognition. Further, the Company may deliver leased space in phases, rather than for an entire building or project, resulting in various revenue commencement dates for a particular lease, which involves significant judgment surrounding when the tenant takes possession of or controls each respective phase, building or project. When we conclude that the Company is the owner of tenant improvements for accounting purposes, we record the cost to construct the tenant improvements, including costs paid for or reimbursed by the tenants, as an asset. For these tenant-funded tenant improvements, we record the amount funded by or reimbursed by tenants as deferred revenue, which is amortized and recognized as rental income on a straight-line basis over the term of the related lease. When we conclude that the tenant is the owner of certain tenant improvements for accounting purposes, we record our contribution towards those tenant-owned improvements as a lease incentive, which is included in deferred leasing costs and acquisition-related intangible assets, net on our consolidated balance sheets and amortized as a reduction to rental revenue on a straight-line basis over the term of the related lease. For residential properties, we commence revenue recognition upon lease commencement. Residential rental revenue is recognized on a straight-line basis over the term of the related lease, net of any concessions. When a lease is amended, which may occur from time to time, we determine whether (1) an additional right of use not included in the original lease is being granted as a result of the modification, and (2) there is an increase in the lease payments that is commensurate with the standalone price for the additional right of use. If both of those conditions are met, the amendment is accounted for as a separate lease contract. If either of those conditions are not met, the amendment is accounted for as a lease modification. Most of our lease amendments are accounted for as a modification of our operating leases which will likely require us to reassess both the lease term and fixed lease payments, including considering any prepaid or deferred rent receivables relating to the original lease, as a part of the lease payments for the modified lease. Termination options in some of our leases allow the tenant to terminate the lease, in part or in whole, prior to the end of the lease term under certain circumstances. Termination options require advance notification from the tenant and payment of a termination fee that reimburses us for a portion of the remaining rent under the original lease term and the net book value of lease inception costs such as commissions, tenant improvements and lease incentives. Termination fee income, included in rental income, is recognized on a straight-line basis from the date of notification of early termination through lease expiration when the amount of the fee is determinable and collectability of the fee is probable. This fee income is reduced on a straight-line basis by any deferred rent receivable related to the lease projected at the date of tenant vacancy. Additional Rent - Reimbursements from Tenants Additional rent, consisting of amounts due from tenants for common area maintenance, real estate taxes and other recoverable costs, are recognized in rental income in the period the recoverable costs are incurred. Additional rent where we pay the associated costs directly to third-party vendors and are reimbursed by our tenants are recognized and recorded on a gross basis, with the corresponding expense recognized in property expenses or real estate taxes. Other Property Income Other property income primarily includes amounts recorded in connection with transient daily parking, tenant bankruptcy settlement payments, broken deal income and property damage settlement related payments. Other property income also includes miscellaneous income from tenants, restoration fees and fees for late rental payments. Amounts recorded within other property income fall within the scope of ASC Topic 606 “Revenue from Contracts with Customers” and are recognized as revenue at the point in time when control of the goods or services transfers to the customer and our performance obligation is satisfied. Uncollectible Lease Receivables and Allowances for Tenant and Deferred Rent Receivables We carry our current and deferred rent receivables net of allowances for amounts that may not be collected. These allowances are increased or decreased through rental income, and our determination of the adequacy of the Company’s allowances for tenant receivables includes a binary assessment of whether or not substantially all of the amounts due under a tenant’s lease agreement are probable of collection. Such assessment involves using a methodology that incorporates a specific identification analysis and an aging analysis and considers the current economic and business environment. This determination requires significant judgment and estimates about matters that are uncertain at the time the estimates are made, including the creditworthiness of specific tenants, specific industry trends and conditions, and general economic trends and conditions. For leases that are deemed probable of collection, revenue continues to be recorded on a straight-line basis over the lease term. For leases that are deemed not probable of collection, revenue is recorded as the lesser of (i) the amount which would be recognized on a straight-line basis or (ii) cash that has been received from the tenant, including deferred revenue, with any tenant and deferred rent receivable balances charged as a direct write-off against rental income in the period of the change in the collectability determination. If the collectability determination subsequently changes to being probable of collection for leases for which revenue is recorded based on cash received from the tenant, we resume recognizing revenue, including deferred revenue, on a straight-line basis and recognize incremental revenue related to the reinstatement of cumulative deferred rent receivable and deferred revenue balances, as if revenue had been recorded on a straight-line basis since the inception of the lease. For tenant and deferred rent receivables associated with leases whose rents are deemed probable of collection, we may record an allowance under other authoritative GAAP using a methodology that incorporates a specific identification analysis and an aging analysis and considers the current economic and business environment. This determination requires significant judgment and estimates about matters that are uncertain at the time the estimates are made, including the creditworthiness of specific tenants, specific industry trends and conditions, and general economic trends and conditions. Tenant and deferred rent receivables deemed probable of collection are carried net of allowances for uncollectible accounts, with increases or decreases in the allowances recorded through rental income on our consolidated statements of operations. Current tenant receivables consist primarily of amounts due for contractual lease payments and reimbursements of common area maintenance expenses, property taxes, and other costs recoverable from tenants. With respect to the allowance for uncollectible tenant receivables, the specific identification methodology analysis relies on factors such as the age and nature of the receivables, the payment history and financial condition of the tenant, our assessment of the tenant’s ability to meet its lease obligations, and the status of negotiations of any disputes with the tenant. Deferred rent receivables represent the amount by which the cumulative straight-line rental revenue recorded to date exceeds cash rents billed to date under the lease agreement. With respect to the allowance for deferred rent receivables, given the longer-term nature of these receivables, the specific identification methodology analysis evaluates each of our significant tenants and any tenants on our internal watchlist and relies on factors such as each tenant’s financial condition and its ability to meet its lease obligations. We evaluate our reserve levels quarterly based on changes in the financial condition of tenants and our assessment of the tenant’s ability to meet its lease obligations, overall economic conditions, and the current business environment. Acquisitions Acquisitions of operating properties and development and redevelopment opportunities generally do not meet the definition of a business and are accounted for as asset acquisitions, as substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or a group of similar identifiable assets. For these asset acquisitions, we record the acquired tangible and intangible assets and assumed liabilities based on each asset’s and liability’s relative fair value at the acquisition date of the total purchase price plus any capitalized acquisition costs. We record the acquired tangible and intangible assets and assumed liabilities of acquisitions of operating properties and development and redevelopment opportunities that meet the accounting criteria to be accounted for as business combinations at fair value at the acquisition date. Transaction costs associated with asset acquisitions, including costs incurred during negotiation, are capitalized in addition to the purchase price of the acquisition. The acquired assets and assumed liabilities for an acquisition generally include but are not limited to (i) land and improvements, buildings and improvements, undeveloped land and construction in progress and (ii) identified tangible and intangible assets and liabilities associated with in-place leases, including tenant improvements, leasing costs, value of above-market and below-market operating leases and ground leases, acquired in-place lease values and tenant relationships, if any. Any debt assumed and equity (including common units of the Operating Partnership) issued in connection with a property acquisition is recorded at fair value on the date of acquisition. The fair value of land and improvements is derived from comparable sales of land and improvements within the same submarket and/or region. The fair value of buildings and improvements, tenant improvements and leasing costs considers the value of the property as if it was vacant as well as current replacement costs and other relevant market rate information. The fair value of the above-market or below-market component of an acquired in-place operating lease is based upon the present value (calculated using a market discount rate) of the difference between (i) the contractual rents to be paid pursuant to the lease over its remaining non-cancellable lease term and (ii) our estimate of the rents that would be paid using fair market rental rates and rent escalations at the date of acquisition measured over the remaining non-cancellable term of the lease for above-market operating leases and the initial non-cancellable term plus the term of any below-market fixed rate renewal options, if applicable, for below-market operating leases. Our below-market operating leases generally do not include fixed rate or below-market renewal options. The amounts recorded for above-market operating leases are included in deferred leasing costs and acquisition-related intangible assets, net on the balance sheet and are amortized on a straight-line basis as a reduction of rental income over the remaining term of the applicable leases. The amounts recorded for below-market operating leases are included in deferred revenue and acquisition-related intangible liabilities, net on the balance sheet and are amortized on a straight-line basis as an increase to rental income over the remaining term of the applicable leases plus the term of any below-market fixed rate renewal options, if applicable. The amortization of a below-market ground lease obligation is recorded as an increase to ground lease expense in the consolidated statements of operations for the periods presented. The amortization of an above-market ground lease obligation is recorded as a decrease to ground lease expense in the consolidated statements of operations for the periods presented. The fair value of acquired in-place leases is derived based on our assessment of lost revenue and costs incurred for the period required to lease the “assumed vacant” property to the occupancy level when purchased. The amount recorded for acquired in-place leases is included in deferred leasing costs and acquisition-related intangible assets, net on the balance sheet and amortized as an increase to depreciation and amortization expense over the remaining term of the applicable leases. Fully amortized intangible assets are written off each quarter. Operating Properties Operating properties are generally carried at historical cost less accumulated depreciation. Properties held for sale are reported at the lower of the carrying value or the fair value less estimated cost to sell. The cost of operating properties includes the purchase price or development costs of the properties. Costs incurred for the renovation and betterment of the operating properties are capitalized to our investment in that property. Maintenance and repairs are charged to expense as incurred. When evaluating properties to be held and used for potential impairment, we first evaluate whether there are any indicators of impairment for any of our properties. If any impairment indicators are present for a specific property, we then evaluate the regional market conditions that could reasonably affect the property. If there are negative changes and trends in that regional market, we then perform an undiscounted cash flow analysis and compare the net carrying amount of the property to the property’s estimated undiscounted future cash flow over the anticipated holding period. If the estimated undiscounted future cash flow is less than the net carrying amount of the property, we perform an impairment loss calculation to determine if the fair value of the property is less than the net carrying value of the property. Our impairment loss calculation compares the net carrying amount of the property to the property’s estimated fair value, which may be based on estimated discounted future cash flow calculations or third-party valuations or appraisals. We would recognize an impairment loss if the property's net carrying amount exceeds the property's estimated fair value. If we were to recognize an impairment loss, the estimated fair value of the property becomes its new cost basis. For a depreciable long-lived asset, the new cost basis would be depreciated (amortized) over the remaining useful life of that asset. Cost Capitalization All costs clearly associated with the development, redevelopment and construction of a property are capitalized as project costs, including internal compensation costs. In addition, the following costs are capitalized as project costs during periods in which activities necessary to prepare development and redevelopment properties for their intended use are in progress: pre-construction costs essential to the development of the property, interest, real estate taxes and insurance. • For office, life science and retail development and redevelopment properties that are pre-leased, we cease capitalization when revenue recognition commences, which is upon substantial completion of tenant improvements deemed to be the Company’s asset for accounting purposes. • For office, life science and retail development and redevelopment properties that are not pre-leased, we may not immediately build out the tenant improvements. Therefore, we cease capitalization when revenue recognition commences upon substantial completion of the tenant improvements deemed to be the Company’s asset for accounting purposes, but in any event, no later than one year after the cessation of major base building construction activities. We also cease capitalization on a development or redevelopment property when activities necessary to prepare the property for its intended use have been suspended. • For office, life science and retail development or redevelopment properties with multiple tenants and phased leasing, we cease capitalization and begin depreciation on the portion of the development or redevelopment property for which revenue recognition has commenced. • For residential development properties, we cease capitalization when the property is substantially complete and available for occupancy. Once major base building construction activities have ceased and the development or redevelopment property or phases of the development or redevelopment project is placed in service, which may occur in phases or for an entire building or project, the costs capitalized to construction in progress are transferred to land and improvements, buildings and improvements, and deferred leasing costs on our consolidated balance sheets as the historical cost of the property. Depreciation and Amortization of Buildings and Improvements The costs of buildings and improvements and tenant improvements are depreciated using the straight-line method of accounting over the estimated useful lives set forth in the table below. Depreciation expense for buildings and improvements for the three years ended December 31, 2022, 2021, and 2020 was $287.8 million, $256.3 million, and $244.8 million, respectively. Asset Description Depreciable Lives Buildings and improvements 25 – 40 years Tenant improvements 1 – 20 years (1) ____________________ (1) Tenant improvements are amortized over the shorter of the lease term or the estimated useful life. Real Estate Assets Held for Sale, Dispositions and Discontinued Operations A real estate asset is classified as held for sale when certain criteria are met, including but not limited to the availability of the asset for immediate sale, the existence of an active program to locate a buyer and the probable sale or transfer of the asset within one year. If such criteria are met, we present the applicable assets and liabilities related to the real estate asset, if material, separately on the balance sheet as held for sale and we would cease to record depreciation and amortization expense. Real estate assets held for sale are reported at the lower of their carrying value or their estimated fair value less the estimated costs to sell. As of December 31, 2022 and 2021, we did not have any properties classified as held for sale. Property disposals representing a strategic shift that have (or will have) a major effect on the Company’s operations and financial results, such as a major line of business, a major geographical area or a major equity investment, are required to be presented as discontinued operations. If we were to determine that a property disposition represents a strategic shift, the revenues, expenses and net gain (loss) on dispositions of the property would be recorded in discontinued operations for all periods presented through the date of the applicable disposition. The operations of the properties sold during the years ended December 31, 2022, 2021 and 2020 are presented in continuing operations as they did not represent a strategic shift in the Company’s operations and financial results. The net gains (losses) on dispositions of non-depreciable real estate property, including land, are reported in the consolidated statements of operations as gains (losses) on sale of land within continuing operations in the period the land is sold. The net gains (losses) on dispositions of depreciable real estate property are reported in the consolidated statements of operations as gains (losses) on sales of depreciable operating properties within continuing operations in the period the property is sold. Cash and Cash Equivalents We consider all highly-liquid investments with original maturities of three months or less to be cash equivalents. Restricted Cash Restricted cash consists of cash proceeds from dispositions that are temporarily held at qualified intermediaries for purposes of facilitating potential Section 1031 Exchanges, and cash held in escrow related to acquisition and disposition holdbacks. Restricted cash also includes cash held as collateral to provide credit enhancement for the Operating Partnership’s mortgage debt, including cash reserves for capital expenditures, tenant improvements and property taxes and cash investments with original maturities greater than 3 months. We did not have any cash held at qualified intermediaries at December 31, 2022 and 2021. Marketable Securities / Deferred Compensation Plan Marketable securities reported in our consolidated balance sheets represent the assets held in connection with the Kilroy Realty Corporation 2007 Deferred Compensation Plan (the “Deferred Compensation Plan”) (see Note 16 “Employee Benefit Plans” for additional information). The Deferred Compensation Plan assets are held in a limited rabbi trust and invested in various mutual and money market funds. As a result, the marketable securities are treated as trading securities for financial reporting purposes and are adjusted to fair value at the end of each accounting period. At the time eligible management employees (“Participants”) defer compensation or earn mandatory Company contributions, or if we were to make a discretionary contribution, we record compensation cost and a corresponding deferred compensation plan liability, which is included in accounts payable, accrued expenses, and other liabilities on our consolidated balance sheets. This liability is adjusted to fair value at the end of each accounting period based on the performance of the benchmark funds selected by each Participant, and the impact of adjusting the liability to fair value is recorded as an increase or decrease to compensation cost. The impact of adjusting the deferred compensation plan liability to fair value and the changes in the value of the marketable securities held in connection with the Deferred Compensation Plan generally offset and therefore do not significantly impact net income. Deferred Leasing Costs Costs incurred in connection with successful property leasing are capitalized as deferred leasing costs and classified as investing activities in the statement of cash flows. Deferred leasing costs consist of leasing commissions paid to external third party brokers and lease incentives, and are amortized using the straight-line method of accounting over the lives of the leases which generally range from one Deferred Financing Costs Financing costs related to the origination or assumption of long-term debt are deferred and generally amortized using the straight-line method of accounting, which approximates the effective interest method, over the contractual terms of the applicable financings. Fully amortized deferred financing costs are written off when the corresponding financing is repaid. Debt Discounts and Premiums Original issuance debt discounts and discounts/premiums related to recording debt acquired in connection with operating property acquisitions at fair value are generally amortized and accreted on a straight-line basis, which approximates the effective interest method. Discounts are recorded as additional interest expense from date of issuance or acquisition through the contractual maturity date of the related debt. Premiums are recorded as a reduction to interest expense from the date of issuance or acquisition through the contractual maturity date of the related debt. Noncontrolling Interests - Common Units of the Operating Partnership in the Company's Consolidated Financial Statements Common units of the Operating Partnership within noncontrolling interests in the Company’s consolidated financial statements represent the common limited partnership interests in the Operating Partnership not held by the Company (“noncontrolling common units”). Noncontrolling common units are presented in the equity section of the Company’s consolidated balance sheets and are reported at their proportionate share of the net assets of the Operating Partnership. Noncontrolling interests with redemption provisions that permit the issuer to settle in either cash or shares of common stock must be further evaluated to determine whether equity or temporary equity classification on the balance sheet is appropriate. Since the common units contain such a provision, we evaluated the accounting guidance and determined that the common units qualify for equity presentation in the Company’s consolidated financial statements. Net income attributable to noncontrolling common units is allocated based on their relative ownership percentage of the Operating Partnership during the reported period. The noncontrolling interest ownership percentage is determined by dividing the number of noncontrolling common units by the total number of common units outstanding. The issuance or redemption of additional shares of common stock or common units results in changes to the noncontrolling interest percentage as well as the total net assets of the Company. As a result, all equity transactions result in an allocation between equity and the noncontrolling interest in the Company’s consolidated balance sheets and statements of equity to account for the changes in the noncontrolling interest ownership percentage as well as the change in total net assets of the Company. Noncontrolling Interests in Consolidated Property Partnerships Noncontrolling interests in consolidated property partnerships represent the equity interests held by unrelated third parties in our three consolidated property partnerships (see Note 11 “Noncontrolling Interests on the Company’s Consolidated Financial Statements” and see Note 12 “Noncontrolling Interests on the Operating Partnership’s Consolidated Financial Statements”). Noncontrolling interests in consolidated property partnerships are not redeemable and are presented as permanent equity in the Company's consolidated balance sheets. We account for the noncontrolling interests in consolidated property partnerships using the hypothetical liquidation at book value (“HLBV”) method to attribute the earnings or losses of the consolidated property partnerships between the controlling and noncontrolling interests. Under the HLBV method, the amounts reported as noncontrolling interests in consolidated property partnerships in the consolidated balance sheets represent the amounts the noncontrolling interests would hypothetically receive at each balance sheet reporting date under the liquidation provisions of the governing agreements assuming the net assets of the consolidated property partnerships were liquidated at recorded amounts and distributed between the controlling and noncontrolling interests in accord

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2022
Business Combination and Asset Acquisition [Abstract]
Acquisitions	Acquisitions Operating Property Acquisitions We did not acquire any operating properties during the year ended December 31, 2022. During the year ended December 31, 2021, we acquired the operating property listed below from an unrelated third party. Property Date of Acquisition Number of Buildings Rentable Square Feet (unaudited) Purchase Price (in millions) (1) 2021 Acquisition 2001 West 8th Avenue, Seattle, WA (2) September 17, 2021 1 539,226 $ 490.0 ________________________ (1) Excludes acquisition-related costs. (2) The results of operations for the property acquired during 2021 contributed $9.9 million to revenue and a net loss of $3.1 million for the year ended December 31, 2021 primarily due to the amortization of in-place leases acquired. The related assets, liabilities and results of operations of the acquired property are included in the consolidated financial statements as of the date of acquisition. The following table summarizes the estimated relative fair values of the assets acquired and liabilities assumed at the acquisition date for our 2021 operating property acquisition: Total 2021 Operating Property Acquisition Assets Land and improvements $ 84,033 Buildings and improvements (1) 370,967 Deferred leasing costs and acquisition-related intangible assets (2) 49,882 Total assets acquired $ 504,882 Liabilities Acquisition-related intangible liabilities (3) $ 15,112 Total liabilities assumed $ 15,112 Net assets acquired $ 489,770 ________________________ (1) Represents buildings, building improvements and tenant improvements. (2) Represents in-place leases (approximately $46.5 million with a weighted average amortization period of 2.2 years), leasing commissions (approximately $3.1 million with a weighted average amortization period of 3.1 years) and an above-market lease (approximately $0.3 million with a weighted average amortization period of 8.4 years). (3) Represents below-market leases (approximately $15.1 million with a weighted average amortization period of 2.4 years). In addition to the operating property acquisition listed above, during 2021, we completed the acquisition of the land that was subject to a ground lease underlying our operating property at 601 108th Avenue NE in Bellevue, Washington for $47.0 million. The 2021 acquisitions were funded with proceeds from the operating property disposition completed during the three months ended March 31, 2021 that were temporarily being held by a qualified intermediary, at our discretion, for the purpose of facilitating a Section 1031 Exchange. Development Project Acquisitions The following table summarizes the development sites acquired from unrelated third parties during the years ended December 31, 2022 and 2021: Project Date of Acquisition City/Submarket Purchase Price (in millions) (1) 2022 Acquisitions 10615 Burnet Road, Austin, TX (2) March 9, 2022 Stadium District / Domain $ 40.0 Total 2022 Acquisitions $ 40.0 2021 Acquisitions 2045 Pacific Highway, San Diego, CA (2)(3) June 22, 2021 Little Italy $ 42.0 200 W. 6th Street, Austin, TX (4) June 23, 2021 Austin CBD 580.2 Total 2021 Acquisitions $ 622.2 _______________________ (1) Excludes acquisition-related costs. (2) This property was added to our future development pipeline. (3) In connection with this acquisition, we also recorded $5.2 million of environmental remediation liabilities as of the date of acquisition, which is not included in the purchase price above. (4) This property was added to the tenant improvement phase as it was acquired upon completion of core/shell. In connection with this acquisition, we assumed the underlying ground lease for the property and recorded a right of use ground lease asset and ground lease liability of $46.4 million. We evaluated the ground lease and concluded it met the criteria to be classified as an operating lease. The discount rate used in determining the present value of the minimum future lease payments was 3.97%. Refer to Note 18 “Commitments and Contingencies” for further discussion of the Company’s ground lease obligations. Acquisition Costs

Dispositions

Dispositions	12 Months Ended
	Dec. 31, 2022
Discontinued Operations and Disposal Groups [Abstract]
Dispositions	Dispositions Operating Property Dispositions The following table summarizes the operating properties sold during the years ended December 31, 2022, 2021 and 2020: Location Month of Disposition Number of Buildings Rentable Sales Price (in millions) (1) 2022 Dispositions 3130 Wilshire Boulevard, Santa Monica, CA August 1 96,085 $ 48.0 Total 2022 Dispositions 1 96,085 $ 48.0 2021 Dispositions 1800 Owens Street, San Francisco, CA (The Exchange on 16th) March 1 750,370 $ 1,081.5 13280 & 13290 Evening Creek Drive South, San Diego, CA December 2 102,376 37.0 Total 2021 Dispositions 3 852,746 $ 1,118.5 2020 Dispositions 331 Fairchild Drive, Mountain View, CA December 1 87,147 $ 75.9 Total 2020 Dispositions 1 87,147 $ 75.9 ____________________ (1) Represents gross sales price before broker commissions, closing costs, and purchase price credits.

Deferred Leasing Costs and Acqu

Deferred Leasing Costs and Acquisition-Related Intangible Assets and Liabilities, net	12 Months Ended
	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Deferred Leasing Costs and Acquisition-Related Intangible Assets and Liabilities, net	Deferred Leasing Costs and Acquisition-Related Intangible Assets and Liabilities, net The following table summarizes our deferred leasing costs and acquisition-related intangible assets (acquired value of leasing costs, above-market operating leases, and in-place leases) and intangible liabilities (acquired value of below-market operating leases) as of December 31, 2022 and 2021: December 31, 2022 December 31, 2021 (in thousands) Deferred Leasing Costs and Acquisition-related Intangible Assets, net: Deferred leasing costs $ 301,967 $ 285,247 Accumulated amortization (121,545) (107,329) Deferred leasing costs, net 180,422 177,918 Above-market operating leases 260 260 Accumulated amortization (39) (8) Above-market operating leases, net 221 252 In-place leases 114,435 80,782 Accumulated amortization (44,232) (24,494) In-place leases, net 70,203 56,288 Total deferred leasing costs and acquisition-related intangible assets, net $ 250,846 $ 234,458 Acquisition-related Intangible Liabilities, net: (1) Below-market operating leases $ 52,380 $ 32,953 Accumulated amortization (14,943) (10,700) Below-market operating leases, net 37,437 22,253 Total acquisition-related intangible liabilities, net $ 37,437 $ 22,253 ____________________ (1) Included in deferred revenue and acquisition-related intangible liabilities, net in the consolidated balance sheets. The following table sets forth amortization related to deferred leasing costs and acquisition-related intangibles for the years ended December 31, 2022, 2021 and 2020. Year Ended December 31, 2022 2021 2020 (in thousands) Deferred leasing costs (1) $ 31,059 $ 32,472 $ 33,624 Above-market operating leases (2) 31 8 495 In-place leases (1) 31,647 14,562 11,759 Below-market operating leases (3) (10,508) (6,912) (10,748) Total $ 52,229 $ 40,130 $ 35,130 ____________________ (1) The amortization of deferred leasing costs and in-place leases is recorded to depreciation and amortization expense and the amortization of lease incentives is recorded as a reduction to rental income in the consolidated statements of operations for the periods presented. (2) The amortization of above-market operating leases is recorded as a decrease to rental income in the consolidated statements of operations for the periods presented. (3) The amortization of below-market operating leases is recorded as an increase to rental income in the consolidated statements of operations for the periods presented. The following table sets forth the estimated annual amortization expense related to deferred leasing costs and acquisition-related intangibles as of December 31, 2022 for future periods: Year Ending Deferred Leasing Costs Above-Market Operating Leases (1) In-Place Leases Below-Market Operating Leases (2) (in thousands) 2023 $ 29,783 $ 31 $ 15,469 $ (8,105) 2024 26,158 31 6,742 (3,602) 2025 23,892 31 6,700 (3,506) 2026 20,891 31 6,377 (3,131) 2027 18,073 31 5,105 (2,933) Thereafter 61,625 66 29,810 (16,160) Total $ 180,422 $ 221 $ 70,203 $ (37,437) ____________________ (1) Represents estimated annual amortization related to above-market operating leases. Amounts will be recorded as a decrease to rental income in the consolidated statements of operations. (2) Represents estimated annual amortization related to below-market operating leases. Amounts will be recorded as an increase to rental income in the consolidated statements of operations.

Receivables

Receivables	12 Months Ended
	Dec. 31, 2022
Receivables [Abstract]
Receivables	Receivables Current Receivables, net Current receivables, net is primarily comprised of contractual rents and other lease-related obligations due from tenants. The balance consisted of the following as of December 31, 2022 and 2021: December 31, 2022 December 31, 2021 (in thousands) Current receivables $ 22,816 $ 16,448 Allowance for uncollectible tenant receivables (1) (2,233) (2,062) Current receivables, net $ 20,583 $ 14,386 ____________________ (1) Refer to Note 2 “Basis of Presentation and Significant Accounting Policies” for discussion of our accounting policies related to the allowance for uncollectible tenant receivables for additional information regarding changes in our allowance for uncollectible tenant receivables. Deferred Rent Receivables, net Deferred rent receivables, net consisted of the following as of December 31, 2022 and 2021: December 31, 2022 December 31, 2021 (in thousands) Deferred rent receivables $ 453,165 $ 406,277 Allowance for deferred rent receivables (1) (965) (612) Deferred rent receivables, net $ 452,200 $ 405,665 ____________________

Prepaid Expenses and Other Asse

Prepaid Expenses and Other Assets, Net	12 Months Ended
	Dec. 31, 2022
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid Expenses and Other Assets, Net	Prepaid Expenses and Other Assets, Net Prepaid expenses and other assets, net consisted of the following at December 31, 2022 and 2021: December 31, 2022 December 31, 2021 (in thousands) Furniture, fixtures and other long-lived assets, net $ 41,538 $ 42,760 Prepaid expenses and deferred financing costs, net 11,364 12,564 Other assets 9,527 2,667 Total prepaid expenses and other assets, net $ 62,429 $ 57,991

Secured and Unsecured Debt of t

Secured and Unsecured Debt of the Company	12 Months Ended
	Dec. 31, 2022
Debt Disclosure [Abstract]
Secured and Unsecured Debt of the Company	Secured and Unsecured Debt of the Company In this Note 8, the “Company” refers solely to Kilroy Realty Corporation and not to any of our subsidiaries. The Company itself does not hold any indebtedness. All of our secured and unsecured debt is held directly by the Operating Partnership. The Company generally guarantees all of the Operating Partnership’s unsecured debt obligations including the unsecured revolving credit facility, the unsecured term loan facility and all of the unsecured senior notes. At December 31, 2022 and 2021, the Operating Partnership had $4.0 billion and $3.8 billion, respectively, outstanding in total, including unamortized discounts and deferred financing costs, under these unsecured debt obligations. In addition, although the remaining $0.2 billion of the Operating Partnership’s debt as of December 31, 2022 and 2021, respectively, is secured and non-recourse to the Company, the Company provides limited customary secured debt guarantees for items such as voluntary bankruptcy, fraud, misapplication of payments and environmental liabilities. Debt Covenants and Restrictions

Secured and Unsecured Debt of_2

Secured and Unsecured Debt of the Operating Partnership	12 Months Ended
	Dec. 31, 2022
Debt Instrument [Line Items]
Secured and Unsecured Debt of the Operating Partnership	Secured and Unsecured Debt of the Company In this Note 8, the “Company” refers solely to Kilroy Realty Corporation and not to any of our subsidiaries. The Company itself does not hold any indebtedness. All of our secured and unsecured debt is held directly by the Operating Partnership. The Company generally guarantees all of the Operating Partnership’s unsecured debt obligations including the unsecured revolving credit facility, the unsecured term loan facility and all of the unsecured senior notes. At December 31, 2022 and 2021, the Operating Partnership had $4.0 billion and $3.8 billion, respectively, outstanding in total, including unamortized discounts and deferred financing costs, under these unsecured debt obligations. In addition, although the remaining $0.2 billion of the Operating Partnership’s debt as of December 31, 2022 and 2021, respectively, is secured and non-recourse to the Company, the Company provides limited customary secured debt guarantees for items such as voluntary bankruptcy, fraud, misapplication of payments and environmental liabilities. Debt Covenants and Restrictions
Kilroy Realty L.P.
Debt Instrument [Line Items]
Secured and Unsecured Debt of the Operating Partnership	Secured and Unsecured Debt of the Operating Partnership Secured Debt The following table sets forth the composition of our secured debt as of December 31, 2022 and 2021: Annual Stated Interest Rate (1) GAAP Effective Rate (1)(2) Maturity Date December 31, Type of Debt 2022 2021 (in thousands) Mortgage note payable 3.57% 3.57% December 2026 $ 159,973 $ 163,435 Mortgage note payable (3) 4.48% 4.48% July 2027 83,496 85,588 Total secured debt $ 243,469 $ 249,023 Unamortized deferred financing costs (531) (656) Total secured debt, net $ 242,938 $ 248,367 ____________________ (1) All interest rates presented are fixed-rate interest rates. (2) Represents the effective interest rate including the amortization of initial issuance discounts/premiums excluding the amortization of deferred financing costs. (3) The secured debt and the related properties that secure this debt are held in a special purpose entity and the properties are not available to satisfy the debts and other obligations of the Company or the Operating Partnership. The Operating Partnership’s secured debt was collateralized by operating properties with a combined net book value of approximately $205.0 million as of December 31, 2022. Although our mortgage loans are secured and non-recourse to the Company and the Operating Partnership, the Company provides limited customary secured debt guarantees for items such as voluntary bankruptcy, fraud, misapplication of payments and environmental liabilities. As of December 31, 2022, all of the Operating Partnership’s secured loans contained restrictions that would require the payment of prepayment penalties for the acceleration of outstanding debt. The mortgage notes payable are secured by deeds of trust on certain of our properties and the assignment of certain rents and leases associated with those properties. Unsecured Senior Notes - Registered Offerings In October 2021, the Operating Partnership issued $450.0 million aggregate principal amount of green unsecured senior notes in a registered public offering. The outstanding balance of the unsecured senior notes is included in unsecured debt, net of an initial issuance discount of $0.2 million, on our consolidated balance sheets. The unsecured senior notes, which are scheduled to mature on November 15, 2033, require semi-annual interest payments each May and November based on a stated annual interest rate of 2.650%. The Operating Partnership may redeem the notes at any time prior to August 15, 2033, either in whole or in part, subject to the payment of an early redemption premium prior to a par call option period commencing three months prior to maturity. In October 2021, the Operating Partnership used a portion of the net proceeds from the issuance of the $450.0 million, 2.650% green unsecured senior notes to early redeem, at our option, the $300.0 million aggregate principal amount of our outstanding 3.800% unsecured senior notes that were scheduled to mature on January 15, 2023. In connection with the early redemption, we incurred a $12.2 million loss on early extinguishment of debt comprised of a $12.1 million premium paid to the note holders at the redemption date and a $0.1 million write-off of the unamortized discount and unamortized deferred financing costs. Unsecured Senior Notes The following table summarizes the balance and significant terms of the registered unsecured senior notes issued by the Operating Partnership and outstanding, including the issuances noted above, and including unamortized discounts of $6.4 million and $7.4 million and unamortized deferred financing costs of $19.1 million and $22.2 million as of December 31, 2022 and 2021, respectively: Net Carrying Amount Issuance date Maturity date Stated Effective interest rate (1) 2022 2021 (in thousands) 2.650% Unsecured Senior Notes (2) October 2021 November 2033 2.650% 2.654% $ 450,000 $ 450,000 Unamortized discount and deferred financing costs (3,770) (4,117) Net carrying amount $ 446,230 $ 445,883 2.500% Unsecured Senior Notes (2) August 2020 November 2032 2.500% 2.560% $ 425,000 $ 425,000 Unamortized discount and deferred financing costs (5,268) (5,802) Net carrying amount $ 419,732 $ 419,198 4.270% Unsecured Senior Notes (3) April 2020 January 2031 4.270% 4.270% $ 350,000 $ 350,000 Unamortized discount and deferred financing costs (1,463) (1,644) Net carrying amount $ 348,537 $ 348,356 3.050% Unsecured Senior Notes (4) September 2019 February 2030 3.050% 3.064% $ 500,000 $ 500,000 Unamortized discount and deferred financing costs (4,221) (4,814) Net carrying amount $ 495,779 $ 495,186 4.750% Unsecured Senior Notes (5) November 2018 December 2028 4.750% 4.800% $ 400,000 $ 400,000 Unamortized discount and deferred financing costs (2,963) (3,457) Net carrying amount $ 397,037 $ 396,543 4.350% Unsecured Senior Notes (3) October 2018 October 2026 4.350% 4.350% $ 200,000 $ 200,000 Unamortized discount and deferred financing costs (663) (837) Net carrying amount $ 199,337 $ 199,163 4.300% Unsecured Senior Notes (3) July 2018 July 2026 4.300% 4.300% $ 50,000 $ 50,000 Unamortized discount and deferred financing costs (157) (202) Net carrying amount $ 49,843 $ 49,798 3.450% Unsecured Senior Notes (5) December 2017 December 2024 3.450% 3.470% $ 425,000 $ 425,000 Unamortized discount and deferred financing costs (1,148) (1,734) Net carrying amount $ 423,852 $ 423,266 3.450% Unsecured Senior Notes (6) February 2017 February 2029 3.450% 3.450% $ 75,000 $ 75,000 Unamortized discount and deferred financing costs (262) (304) Net carrying amount $ 74,738 $ 74,696 3.350% Unsecured Senior Notes (6) February 2017 February 2027 3.350% 3.350% $ 175,000 $ 175,000 Unamortized discount and deferred financing costs (478) (594) Net carrying amount $ 174,522 $ 174,406 4.375% Unsecured Senior Notes (7) September 2015 October 2025 4.375% 4.444% $ 400,000 $ 400,000 Unamortized discount and deferred financing costs (1,523) (2,077) Net carrying amount $ 398,477 $ 397,923 4.250% Unsecured Senior Notes (4) July 2014 August 2029 4.250% 4.350% $ 400,000 $ 400,000 Unamortized discount and deferred financing costs (3,503) (4,035) Net carrying amount $ 396,497 $ 395,965 Total Unsecured Senior Notes, Net $ 3,824,581 $ 3,820,383 ____________________ (1) Represents the effective interest rate including the amortization of initial issuance discounts, excluding the amortization of deferred financing costs. (2) Interest on these notes is payable semi-annually in arrears on May 15th and November 15th of each year. (3) Interest on these notes is payable semi-annually in arrears on April 18th and October 18th of each year. (4) Interest on these notes is payable semi-annually in arrears on February 15th and August 15th of each year. (5) Interest on these notes is payable semi-annually in arrears on June 15th and December 15th of each year. (6) Interest on these notes is payable semi-annually in arrears on February 17th and August 17th of each year. (7) Interest on these notes is payable semi-annually in arrears on April 1st and October 1st of each year. Unsecured Revolving Credit Facility and Term Loan Facility In April 2021, the Operating Partnership amended and restated the terms of its unsecured revolving credit facility. The amendment and restatement increased the size of the unsecured revolving credit facility from $750.0 million to $1.1 billion, reduced the borrowing costs, extended the maturity date of the unsecured revolving credit facility to July 2025, with two six-month extension options, and added a sustainability-linked pricing component whereby the interest rate is lowered by 0.01% if certain sustainability performance targets are met. In October 2022, the Operating Partnership amended the terms of its unsecured revolving credit facility to replace the LIBOR-based interest rate option with a secured overnight financing rate administered by the Federal Reserve Bank of New York (“SOFR”) based interest rate option for its borrowings. The following table summarizes the balance and terms of our unsecured revolving credit facility as of December 31, 2022 and 2021: December 31, 2022 December 31, 2021 (in thousands) Outstanding borrowings $ — $ — Remaining borrowing capacity 1,100,000 1,100,000 Total borrowing capacity (1) $ 1,100,000 $ 1,100,000 Interest rate (2) 5.20 % 1.00 % Facility fee-annual rate (3) 0.200% Maturity date July 2025 ____________________ (1) We may elect to borrow, subject to bank approval and obtaining commitments for any additional borrowing capacity, up to an additional $500.0 million under an accordion feature under the terms of the unsecured revolving credit facility. (2) Our unsecured revolving credit facility interest rate was calculated based on the contractual rate of Adjusted SOFR plus 0.900% and LIBOR plus 0.900% as of December 31, 2022 and 2021, respectively. (3) Our facility fee is paid on a quarterly basis and is calculated based on the total borrowing capacity. In addition to the facility fee, we incurred debt origination and legal costs. As of December 31, 2022 and 2021, $5.3 million and $7.3 million of unamortized deferred financing costs, respectively, which are included in prepaid expenses and other assets, net on our consolidated balance sheets, remained to be amortized through the maturity date of our unsecured revolving credit facility. The Operating Partnership intends to borrow under the unsecured revolving credit facility from time to time for general corporate purposes, to finance development and redevelopment expenditures, to fund potential acquisitions and to potentially repay long-term debt and to supplement cash balances given uncertainties and volatility in market conditions. In October 2022, the Operating Partnership entered into a $400.0 million unsecured term loan facility and made an initial draw of $200.0 million. The borrowing rate under the unsecured term loan facility is variable and subject to a ratings-based pricing grid, currently calculated as Adjusted SOFR plus 0.950%. The unsecured term loan facility also has a delayed draw feature and a $100.0 million accordion mechanism, subject to lender commitments. The unsecured term loan facility is scheduled to mature in October 2024 and includes two twelve-month extension options at our option. In January 2023, Operating Partnership amended the terms of the unsecured term loan facility. The following table summarizes the balance and terms of our unsecured term loan facility as of December 31, 2022: December 31, 2022 (in thousands) Outstanding borrowings $ 200,000 Remaining borrowing capacity 200,000 Total borrowing capacity (1) $ 400,000 Interest rate (2) 5.23 % Undrawn facility fee-annual rate (3) 0.200 % Maturity date October 2024 ____________________ (1) We may elect to borrow, subject to bank approval and obtaining commitments for any additional borrowing capacity, up to an additional $100.0 million under an accordion feature under the terms of the unsecured term loan facility. (2) Our unsecured term loan facility interest rate was calculated based on the contractual rate of Adjusted SOFR plus 0.950% as of December 31, 2022. (3) Our undrawn facility fee is paid on a quarterly basis and is calculated based on the remaining borrowing capacity. In addition to the facility fee, we incurred debt origination and legal costs. As of December 31, 2022, $4.5 million of unamortized deferred financing costs remained to be amortized through the maturity date of our unsecured term loan facility. Debt Covenants and Restrictions The unsecured revolving credit facility, unsecured term loan facility, the unsecured senior notes, including the private placement notes, and certain other secured debt arrangements contain covenants and restrictions requiring us to meet certain financial ratios and reporting requirements. Some of the more restrictive financial covenants include a maximum ratio of total debt to total asset value, a minimum fixed-charge coverage ratio, a minimum unsecured debt ratio and a minimum unencumbered asset pool debt service coverage ratio. Noncompliance with one or more of the covenants and restrictions could result in the full principal balance of the associated debt becoming immediately due and payable. We believe we were in compliance with all of our debt covenants as of December 31, 2022 and 2021. Debt Maturities The following table summarizes the stated debt maturities and scheduled amortization payments for all outstanding debt as of December 31, 2022: Year (in thousands) 2023 $ 5,775 2024 (1) 631,006 2025 406,246 2026 401,317 2027 249,125 Thereafter 2,600,000 Total aggregate principal value (2) $ 4,293,469 ________________________ (1) Includes the $200.0 million currently outstanding on the unsecured term loan facility maturing in October 2024, for which the Company has two twelve-month extension options. (2) Includes gross principal balance of outstanding debt before the effect of the following at December 31, 2022: $24.1 million of unamortized deferred financing costs for the unsecured term loan facility, unsecured senior notes and secured debt and $6.4 million of unamortized discounts for the unsecured senior notes. Capitalized Interest and Loan Fees The following table sets forth gross interest expense, including debt discount and deferred financing cost amortization, net of capitalized interest, for the years ended December 31, 2022, 2021 and 2020. The interest expense capitalized was recorded as a cost of development and redevelopment and increased the carrying value of undeveloped land and construction in progress. Year Ended December 31, 2022 2021 2020 (in thousands) Gross interest expense $ 161,761 $ 158,756 $ 150,325 Capitalized interest and deferred financing costs (77,483) (80,201) (79,553) Interest expense $ 84,278 $ 78,555 $ 70,772

Deferred Revenue and Acquisitio

Deferred Revenue and Acquisition-Related Intangible Liabilities, net	12 Months Ended
	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Deferred Revenue and Acquisition-Related Intangible Liabilities, net	Deferred Revenue and Acquisition-Related Intangible Liabilities, net Deferred revenue and acquisition-related intangible liabilities, net consisted of the following at December 31, 2022 and 2021: December 31, 2022 2021 (in thousands) Deferred revenue related to tenant-funded tenant improvements $ 111,453 $ 108,002 Other deferred revenue 47,069 40,896 Acquisition-related intangible liabilities, net (1) 37,437 22,253 Total $ 195,959 $ 171,151 _____________________ (1) See Note 5 “Deferred Leasing Costs and Acquisition-Related Intangible Assets and Liabilities, net” for additional information regarding our acquisition-related intangible liabilities. Deferred Revenue Related to Tenant-funded Tenant Improvements During the years ended December 31, 2022, 2021, and 2020, $19.3 million, $16.5 million and $22.5 million, respectively, of deferred revenue related to tenant-funded tenant improvements was amortized and recognized as rental income. The following is the estimated amortization of deferred revenue related to tenant-funded tenant improvements as of December 31, 2022 for the next five years and thereafter: Year Ending (in thousands) 2023 $ 19,037 2024 16,865 2025 14,061 2026 12,382 2027 10,551 Thereafter 38,557 Total $ 111,453

Noncontrolling Interests on the

Noncontrolling Interests on the Company’s Consolidated Financial Statements	12 Months Ended
	Dec. 31, 2022
Noncontrolling Interest [Abstract]
Noncontrolling Interests on the Company’s Consolidated Financial Statements	Noncontrolling Interests on the Company’s Consolidated Financial Statements Common Units of the Operating Partnership The Company owned an approximate 99.0% common general partnership interest in the Operating Partnership as of December 31, 2022 and 2021. The remaining approximate 1.0% common limited partnership interest as of December 31, 2022 and 2021 was owned by non-affiliated investors and certain of our executive officers and directors in the form of noncontrolling common units. There were 1,150,574 common units outstanding held by these investors, executive officers and directors as of December 31, 2022 and 2021, respectively. The noncontrolling common units may be redeemed by unitholders for cash. Except under certain circumstances, we, at our option, may satisfy the cash redemption obligation with shares of the Company’s common stock on a one-for-one basis. If satisfied in cash, the value for each noncontrolling common unit upon redemption is the amount equal to the average of the closing quoted price per share of the Company’s common stock, par value $.01 per share, as reported on the NYSE for the ten trading days immediately preceding the applicable redemption date. The aggregate value upon redemption of the then-outstanding noncontrolling common units was $44.7 million and $76.2 million as of December 31, 2022 and 2021, respectively. This redemption value does not necessarily represent the amount that would be distributed with respect to each noncontrolling common unit in the event of our termination or liquidation. In the event of our termination or liquidation, it is expected in most cases that each common unit would be entitled to a liquidating distribution equal to the liquidating distribution payable in respect of each share of the Company’s common stock. Noncontrolling Interest in Consolidated Property Partnerships In August 2016, the Operating Partnership entered into agreements with Norges Bank Real Estate Management (“NBREM”) whereby NBREM made contributions, through two REIT subsidiaries, for a 44% common equity interest in two existing companies that owned the Company’s 100 First Street and 303 Second Street office properties located in San Francisco, California. The transactions did not meet the criteria to qualify as sales of real estate because the Company continues to effectively control the properties and therefore continued to account for the 100 First Street and 303 Second Street office properties on a consolidated basis in its financial statements. At formation, the Company accounted for the transactions as equity transactions and recognized noncontrolling interests in its consolidated balance sheets. The noncontrolling interests in 100 First LLC and 303 Second LLC as of December 31, 2022 and 2021 were $179.4 million and $190.7 million, respectively. The remaining amount of noncontrolling interests in consolidated property partnerships represents the third party equity interest in Redwood LLC. This noncontrolling interest was $5.0 million and $5.4 million as of December 31, 2022 and 2021, respectively. Consolidated Property Partnerships In August 2016, the Operating Partnership entered into agreements with NBREM whereby NBREM made contributions, through two REIT subsidiaries, for a 44% common equity interest in two existing companies that owned the Company’s 100 First Street and 303 Second Street office properties located in San Francisco, California. Refer to Note 11 for additional information regarding these consolidated property partnerships.

Noncontrolling Interests on t_2

Noncontrolling Interests on the Operating Partnership’s Consolidated Financial Statements	12 Months Ended
	Dec. 31, 2022
Noncontrolling Interest [Abstract]
Noncontrolling Interests on the Operating Partnership’s Consolidated Financial Statements	Noncontrolling Interests on the Company’s Consolidated Financial Statements Common Units of the Operating Partnership The Company owned an approximate 99.0% common general partnership interest in the Operating Partnership as of December 31, 2022 and 2021. The remaining approximate 1.0% common limited partnership interest as of December 31, 2022 and 2021 was owned by non-affiliated investors and certain of our executive officers and directors in the form of noncontrolling common units. There were 1,150,574 common units outstanding held by these investors, executive officers and directors as of December 31, 2022 and 2021, respectively. The noncontrolling common units may be redeemed by unitholders for cash. Except under certain circumstances, we, at our option, may satisfy the cash redemption obligation with shares of the Company’s common stock on a one-for-one basis. If satisfied in cash, the value for each noncontrolling common unit upon redemption is the amount equal to the average of the closing quoted price per share of the Company’s common stock, par value $.01 per share, as reported on the NYSE for the ten trading days immediately preceding the applicable redemption date. The aggregate value upon redemption of the then-outstanding noncontrolling common units was $44.7 million and $76.2 million as of December 31, 2022 and 2021, respectively. This redemption value does not necessarily represent the amount that would be distributed with respect to each noncontrolling common unit in the event of our termination or liquidation. In the event of our termination or liquidation, it is expected in most cases that each common unit would be entitled to a liquidating distribution equal to the liquidating distribution payable in respect of each share of the Company’s common stock. Noncontrolling Interest in Consolidated Property Partnerships In August 2016, the Operating Partnership entered into agreements with Norges Bank Real Estate Management (“NBREM”) whereby NBREM made contributions, through two REIT subsidiaries, for a 44% common equity interest in two existing companies that owned the Company’s 100 First Street and 303 Second Street office properties located in San Francisco, California. The transactions did not meet the criteria to qualify as sales of real estate because the Company continues to effectively control the properties and therefore continued to account for the 100 First Street and 303 Second Street office properties on a consolidated basis in its financial statements. At formation, the Company accounted for the transactions as equity transactions and recognized noncontrolling interests in its consolidated balance sheets. The noncontrolling interests in 100 First LLC and 303 Second LLC as of December 31, 2022 and 2021 were $179.4 million and $190.7 million, respectively. The remaining amount of noncontrolling interests in consolidated property partnerships represents the third party equity interest in Redwood LLC. This noncontrolling interest was $5.0 million and $5.4 million as of December 31, 2022 and 2021, respectively. Consolidated Property Partnerships In August 2016, the Operating Partnership entered into agreements with NBREM whereby NBREM made contributions, through two REIT subsidiaries, for a 44% common equity interest in two existing companies that owned the Company’s 100 First Street and 303 Second Street office properties located in San Francisco, California. Refer to Note 11 for additional information regarding these consolidated property partnerships.

Stockholders' Equity of the Com

Stockholders' Equity of the Company	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
Stockholders' Equity of the Company	Stockholders’ Equity of the Company Common Stock At-The-Market Stock Offering Program Under the at-the-market stock program, which commenced in June 2018 (the “2018 At-The-Market Program”) and ended during the year ended December 31, 2022, the Company was able to offer and sell shares of our common stock having an aggregate gross sales price of up to $500.0 million from time to time in “at-the-market” offerings. The Company did not complete any sales of common stock under the program during the years ended December 31, 2022, 2021 and 2020. Through the term of the 2018 At-The-Market Program, the Company completed the sale of 3,594,576 shares of common stock. Common Stock Repurchases As of December 31, 2022, 4,935,826 shares remained eligible for repurchase under a share repurchase program approved by the Company’s board of directors in 2016. The Company did not repurchase shares of common stock under this program during the three years ended December 31, 2022, 2021 and 2020. Accrued Dividends and Distributions The following tables summarize accrued dividends and distributions for the noted outstanding shares of common stock and noncontrolling units as of December 31, 2022 and 2021: December 31, 2022 2021 (in thousands) Dividends and Distributions payable to: Common stockholders $ 63,114 $ 60,561 Noncontrolling common unitholders of the Operating Partnership 621 598 RSU holders (1) 550 691 Total accrued dividends and distribution to common stockholders and noncontrolling unitholders $ 64,285 $ 61,850 _____________________ (1) The amount includes the value of the dividend equivalents that will be paid with additional RSUs (see Note 15 “Share-Based and Other Compensation” for additional information). December 31, 2022 2021 Outstanding Shares and Units: Common stock 116,878,031 116,464,169 Noncontrolling common units 1,150,574 1,150,574 RSUs (1) 984,006 1,292,802 _____________________ (1) The amount includes nonvested RSUs. Does not include 1,123,554 and 976,464 market measure-based RSUs because not all the necessary performance conditions have been met as of December 31, 2022 and 2021, respectively. Refer to Note 15 “Share-Based and Other Compensation” for additional information.

Partners' Capital of the Operat

Partners' Capital of the Operating Partnership	12 Months Ended
	Dec. 31, 2022
Partners' Capital [Abstract]
Partners' Capital of the Operating Partnership	Partners’ Capital of the Operating Partnership Common Units At-The-Market Stock Offering Program The Company did not issue any shares of common stock under its at-the-market stock offering program and did not contribute any shares of common stock to the Operating Partnership during the years ended December 31, 2022 and 2021. Common Units Outstanding The following table sets forth the number of common units held by the Company as the general partner and the number of common units held by non-affiliated investors and certain of our executive officers and directors in the form of common limited partner units as well as the ownership interest held on each respective date: December 31, 2022 December 31, 2021 Company owned common units in the Operating Partnership 116,878,031 116,464,169 Company owned general partnership interest 99.0 % 99.0 % Non-affiliated investors and other common units of the Operating Partnership 1,150,574 1,150,574 Ownership interest of limited partnership interests 1.0 % 1.0 % For a further discussion of the redemption features of the common units not owned by the Company as of December 31, 2022 and 2021, refer to Note 11 “Noncontrolling Interests on the Company’s Consolidated Financial Statements.” Accrued Distributions The following tables summarize accrued distributions for the noted common units as of December 31, 2022 and 2021: December 31, 2022 December 31, 2021 (in thousands) Distributions payable to: General partner $ 63,114 $ 60,561 Common limited partners 621 598 RSU holders (1) 550 691 Total accrued distributions to common unitholders $ 64,285 $ 61,850 _____________________ (1) The amount includes the value of the dividend equivalents that will be paid with additional RSUs (see Note 15 “Share-Based and Other Compensation” for additional information). December 31, 2022 December 31, 2021 Outstanding Units: Common units held by the general partner 116,878,031 116,464,169 Common units held by the limited partners 1,150,574 1,150,574 RSUs (1) 984,006 1,292,802 _____________________

Share-Based and Other Compensat

Share-Based and Other Compensation	12 Months Ended
	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Share-Based and Other Compensation	Share-Based and Other Compensation Stockholder Approved Share-Based Incentive Compensation Plan As of December 31, 2022, we maintained one share-based incentive compensation plan, the Kilroy Realty 2006 Incentive Award Plan, as amended (the “2006 Plan”). The Company has a currently effective registration statement registering 10.7 million shares of our common stock for possible issuance under our 2006 Plan. As of December 31, 2022, approximately 1.1 million shares were available for grant under the 2006 Plan. The calculation of shares available for grant is presented after taking into account a reserve for a sufficient number of shares to cover the vesting and payment of 2006 Plan awards that were outstanding on that date, including performance-based vesting awards at (i) levels actually achieved for the performance conditions (as defined below) for which the performance period has been completed and (ii) at maximum levels for the other performance and market conditions (as defined below) for awards still in a performance period. The Executive Compensation Committee of the Company’s Board of Directors (the “Executive Compensation Committee”) may grant the following share-based awards to eligible individuals, as provided under the 2006 Plan: incentive stock options, nonqualified stock options, restricted stock (nonvested shares), stock appreciation rights, performance shares, performance stock units, dividend equivalents, stock payments, deferred stock, restricted stock units (“RSUs”), profit interest units, performance bonus awards, performance-based awards and other incentive awards. For each award granted under our share-based incentive compensation programs, the Operating Partnership simultaneously issues to the Company a number of common units equal to the number of shares of common stock ultimately paid by the Company in respect of such awards. The Executive Compensation Committee generally grants awards to certain officers of the Company under the 2006 Plan annually in January and/or February of RSUs that are subject to market and/or performance-based vesting requirements and RSUs that are subject to time-based vesting requirements. 2022, 2021 and 2020 Annual Performance-Based RSU Grants During each of the three years in the period ended December 31, 2022, the Executive Compensation Committee granted awards to certain officers of the Company under the 2006 Plan that are subject to market and/or performance based vesting requirements (“Performance-Based RSUs”). The Performance-Based RSUs are scheduled to vest at the end of a three year period consisting of calendar years 2022-2024, 2021-2023 and 2020-2022 for the awards granted during the years ended December 31, 2022, 2021, and 2020, respectively. A target number of Performance-Based RSUs were awarded, and the final number of Performance-Based RSUs that vest (which may be more or less than the target number) will be based upon (1) during the first calendar year of the respective awards’ three year performance measurement period, the achievement of pre-set FFO per share goals that applies to 100% of the Performance-Based RSUs awarded (the “FFO Performance Condition”) and (2) a performance measure that applies to 50% of the award based upon a measure of the Company’s average debt to EBITDA ratio for the three year performance period (the “Debt to EBITDA Ratio Performance Condition”) and a market measure that applies to the other 50% of the award based upon the relative ranking of the Company’s total stockholder return for the three year performance period compared to the total stockholder returns of an established comparison group of companies over the same period (the “Market Condition”). The Performance-Based RSUs are also subject to a three year service vesting provision (the “service vesting condition”) and are scheduled to cliff vest on the date the final vesting percentage is determined following the end of the three year performance period under the awards. Compensation expense for the Performance-Based RSU grants are recognized on a straight-line basis over the requisite service period for each participant, which is generally the three year service period, except for one participant whose compensation expense is recognized on an accelerated basis due to clauses that render a portion of the vesting conditions to be non-substantive. The 2022 FFO Performance Condition was achieved at 175% of target for one participant and 150% of target for all other participants. The 2021 FFO Performance Condition was achieved at 175% of target for one participant and 150% of target for all other participants. The number of 2022 and 2021 Performance-Based RSUs ultimately earned could fluctuate from the target number of Performance-Based RSUs granted during 2022 and 2021 based upon the levels of achievement for the Debt to EBITDA Ratio Performance Condition, the Market Condition, and the extent to which the service vesting condition is satisfied. The estimate of the number of Performance-Based RSUs earned is evaluated quarterly during the performance period based on our estimate for each of the performance conditions measured against the applicable goals. The 2020 Performance-Based RSUs completed the performance measurement period and based on the combined results of the 2020 FFO Performance Condition, the Debt to EBITDA Ratio Performance Condition and the Market Condition, the 2020 Performance-Based RSUs achieved at 131% of target for one participant and 121% of target for the other participants. Each Performance-Based RSU represents the right to receive one share of our common stock in the future, subject to, and as modified by, the Company’s level of achievement of the applicable performance and market conditions. The fair values for the awards with market conditions were calculated using a Monte Carlo simulation pricing model based on the assumptions in the table below. The determination of the fair value of the 2022, 2021 and 2020 Performance-Based RSUs takes into consideration the likelihood of achievement of the 2022, 2021 and 2020 Market Condition and the share price on the grant date of the 2022, 2021 and 2020 Performance-Based RSUs, respectively, as discussed above. The following table summarizes the estimated number of RSUs earned for the 2022 and 2021 Performance-Based RSUs and the actual number of RSUs earned for the 2020 Performance-Based RSUs and the assumptions utilized in the Monte Carlo simulation pricing models: 2022 2021 2020 Service vesting period January 28, 2022 - January, 2025 February 18, 2021 - January, 2024 January 31, 2020 - January, 2023 Target RSUs granted 193,111 172,430 154,267 Estimated RSUs earned (1) 304,535 371,518 180,419 Fair Value Assumptions: Valuation date January 28, 2022 February 18, 2021 January 31, 2020 Fair value on valuation date (in millions) $12.7 $10.6 $12.9 Fair value per share on valuation date (2) $67.62 $63.93 $84.54 Expected share price volatility 36.0 % 35.0 % 17.0 % Risk-free interest rate 1.35 % 0.20 % 1.35 % _____________________ (1) Estimated RSUs earned for the 2022 Performance-Based RSUs are based on the actual achievement of the 2022 FFO Performance Condition and assumes the target level of achievement for the 2022 Debt to EBITDA Ratio Performance Condition and the target level of achievement of the 2022 Market Condition. Estimated RSUs earned for the 2021 Performance-Based RSUs are based on the actual achievement of the 2021 FFO Performance Condition and assume target level achievement of the 2021 Market Condition and maximum level of achievement of the 2021 Debt to EBITDA Ratio Performance Condition. The 2020 Performance-Based RSUs earned are based on actual performance of the 2020 Performance Conditions and the 2020 Market Condition. (2) For one participant, the fair value per share on the valuation date for their 2022, 2021, and 2020 Performance-Based RSUs is $70.00, $66.95 and $85.52, respectively. The computation of expected volatility was based on a blend of the historical volatility of our shares of common stock over a period of twice the remaining performance period as of the grant date and implied volatility data based on the observed pricing of six month December 2018 Market-Based RSU Grant In connection with entering into an amended employment agreement (the “Amended Employment Agreement”), on December 27, 2018 the Executive Compensation Committee awarded John Kilroy, the Chairman of the Board of Directors and Chief Executive Officer of the Company and the Operating Partnership, 266,130 RSUs (at the target level of performance) that are subject to market-based vesting requirements, providing an additional retention incentive during the term of the agreement and enticing Mr. Kilroy to delay his retirement. In addition to Mr. Kilroy’s award, the Executive Compensation Committee awarded 80,647 RSUs (at the target level of performance), subject to market-based vesting requirements, to certain members of management. Together, a total of 346,777 target RSUs are referred to as the “December 2018 Market-Based RSUs”. Over the performance period ended December 31, 2022 (consisting of calendar years 2019 through 2022), the December 2018 Market-Based RSUs became eligible to vest at a modification rate of between 0% and 200% based on the Company’s relative total shareholder return (“TSR”) versus a comparative group of companies that comprised what was previously the SNL US REIT Office Index. This 2019-2022 TSR market condition did not achieve the minimum threshold and, as a result, none of the December 2018 Market-Based RSUs were earned as of December 31, 2022 for all participants. The December 2018 Market-Based RSUs were also subject to service vesting requirements through the scheduled vesting dates. Each December 2018 Market-Based RSU represented the right to receive one share of our common stock in the future, subject to, and as modified by, the Company’s level of achievement of the applicable market conditions. The December 27, 2018 grant date fair value of the December 2018 Market-Based RSUs was $23.8 million. The fair value was calculated using a Monte Carlo simulation pricing model based on the assumptions in the table below. For the years ended December 31, 2020, 2019 and 2018, we recorded compensation expense based upon the $68.66 grant date fair value per share. Compensation expense for the December 2018 Market-Based RSUs was recognized using a graded vesting approach, where 75% of the fair value was recognized on a straight-line basis over the three-year initial performance period through the end of 2021, and the remaining 25% of the fair value was recognized on a straight-line basis over the four-year final performance period through the end of 2022. The following table summarizes the assumptions utilized in the Monte Carlo simulation pricing models: December 2018 Market-Based RSU Award Fair Value Assumptions Valuation date December 27, 2018 Fair value per share on valuation date $68.66 Expected share price volatility 23.0% Risk-free interest rate 2.4% The computation of expected volatility was based on a blend of the historical volatility of our shares of common stock over a period of twice the performance period and implied volatility data based on the observed pricing of six month publicly-traded options on shares of our common stock. The risk-free interest rate was based on the yield curve on zero-coupon U.S. Treasury STRIP securities in effect at December 27, 2018. Summary of Performance and Market-Measure Based RSUs A summary of our performance and market-measure based RSU activity from January 1, 2022 through December 31, 2022 is presented below: Nonvested RSUs Vested RSUs Total RSUs Amount Weighted-Average Outstanding at January 1, 2022 976,464 $ 68.75 — 976,464 Granted 310,484 63.05 43,686 354,170 Vested (195,723) 70.52 195,723 — Settled (1) — — (211,478) (211,478) Issuance of dividend equivalents (2) 39,385 55.98 1,775 41,160 Canceled (7,056) 66.06 (1) (7,057) Outstanding as of December 31, 2022 (3) 1,123,554 $ 66.85 29,705 1,153,259 ____________________ (1) Represents vested RSUs that were settled in shares of the Company’s common stock. Total shares settled include 102,945 shares that were tendered in accordance with the terms of the 2006 Plan to satisfy minimum statutory tax withholding requirements related to the RSUs settled. We accept the return of RSUs at the current quoted closing share price of the Company’s common stock to satisfy tax obligations. (2) Represents the issuance of dividend equivalents earned on the underlying RSUs. The dividend equivalents vest based on terms specified under the related RSU award agreement. (3) Outstanding RSUs as of December 31, 2022 represent the actual achievement of the FFO performance conditions and assumes target levels for the market and other performance conditions. The number of restricted stock units ultimately earned is subject to change based upon actual performance over the three-year vesting period. Dividend equivalents earned will vest along with the underlying award and are also subject to changes based on the number of RSUs ultimately earned for each underlying award. A summary of our performance and market-measure based RSU activity for the years ended December 31, 2022, 2021 and 2020 is presented below: RSUs Granted RSUs Vested Years ended December 31, Non-Vested RSUs Granted (1) Weighted-Average Vested RSUs Total Vest-Date Fair Value 2022 310,484 $ 63.05 (241,184) $ 15,200 2021 281,333 $ 57.85 (252,098) $ 14,299 2020 154,267 $ 85.08 (270,054) $ 19,471 ____________________ (1) Non-vested RSUs granted are based on the actual achievement of the FFO performance conditions and assumes target level achievement for the market and other performance conditions. Annual 2022, 2021 and 2020 and December 2018 Time-Based RSU Grants During each of the three years in the period ended December 31, 2022, the Executive Compensation Committee granted awards to certain officers of the Company under the 2006 Plan that are subject to time-based vesting requirements (“Time-Based RSUs”). The annual Time-Based RSUs are scheduled to vest in three equal annual installments over the periods listed below. Additionally, at the time Mr. Kilroy’s Amended Employment Agreement was executed in December 2018, Time-Based RSUs were granted that were scheduled to vest 50% on January 5, 2022 and 50% on January 5, 2023. Compensation expense for the annual 2022, 2021 and 2020 Time-Based RSUs is recognized on a straight-line basis over the requisite service period, which is generally the explicit service period. However, for one participant there is a shorter service period for their 2022 and 2021 Time-Based RSUs due to clauses that render a portion of the vesting conditions to be non-substantive. Each Time-Based RSU represents the right to receive one share of our common stock in the future, subject to continued employment through the applicable vesting date, unless accelerated upon separation of employment, provided certain conditions are met. The total fair value of the Time-Based RSUs is based on the Company’s closing share price on the NYSE on the respective fair valuation dates as detailed in the table below: 2022 Time-Based RSU Grant 2021 Time-Based RSU Grant 2020 Time-Based RSU Grant December 2018 Time-Based RSU Grant Service vesting period January 28, 2022 - January 5, 2025 January & February 2021 - January 5, 2024 January 31, 2020 - January 5, 2023 December 27, 2018 - January 5, 2023 RSUs granted 158,170 160,277 109,359 298,384 Fair value on valuation date (in millions) $ 10.0 $ 9.1 $ 9.0 $ 18.5 Weighted average fair value per share $ 63.05 $ 57.07 $ 82.57 $ 62.00 Date of valuation January 28, 2022 January 29, February 18, 2021 January 31, 2020 December 27, 2018 Summary of Time-Based RSUs A summary of our time-based RSU activity from January 1, 2022 through December 31, 2022 is presented below: Nonvested RSUs Vested RSUs Total RSUs Amount Weighted Average Fair Value Outstanding at January 1, 2022 539,729 $ 64.03 753,073 1,292,802 Granted 177,099 62.58 — 177,099 Vested (270,061) 67.15 270,061 — Settled (1) — — (535,019) (535,019) Issuance of dividend equivalents (2) 15,324 54.15 24,806 40,130 Forfeited (18,724) 62.56 — (18,724) Canceled (3) — — (1,987) (1,987) Outstanding as of December 31, 2022 443,367 $ 61.27 510,934 954,301 ____________________ (1) Represents vested RSUs that were settled in shares of the Company’s common stock. Total shares settled include 231,604 shares that were tendered in accordance with the terms of the 2006 Plan to satisfy minimum statutory tax withholding requirements related to the RSUs settled. We accept the return of RSUs at the current quoted closing share price of the Company’s common stock to satisfy tax obligations. (2) Represents the issuance of dividend equivalents earned on the underlying RSUs. The dividend equivalents vest based on terms specified under the related RSU award agreement. (3) For shares vested but not yet settled, we accept the return of RSUs at the current quoted closing share price of the Company’s common stock to satisfy minimum statutory tax-withholding requirements related to either the settlement or vesting of RSUs in accordance with the terms of the 2006 Plan. A summary of our time-based RSU activity for the years ended December 31, 2022, 2021 and 2020 is presented below: RSUs Granted RSUs Vested Year ended December 31, Non-Vested Weighted-Average Grant Date Vested RSUs Total Vest-Date Fair Value (1) (in thousands) 2022 177,099 $ 62.58 (294,867) $ 19,890 2021 172,181 $ 57.83 (144,838) $ 8,605 2020 120,769 $ 79.74 (208,608) $ 15,066 ____________________ (1) Total fair value of RSUs vested was calculated based on the quoted closing share price of the Company’s common stock on the NYSE on the day of vesting. Excludes the issuance of dividend equivalents earned on the underlying RSUs. The dividend equivalents vest based on terms specified under the related RSU award agreement. Share-Based Compensation Cost Recorded During the Period The total compensation cost for all share-based compensation programs was $34.8 million, $41.0 million and $37.6 million for the years ended December 31, 2022, 2021 and 2020, respectively. Share-based compensation costs for the year ended December 31, 2020 include $4.5 million of accelerated share-based compensation costs related to severance packages, including for the departure of an executive officer. Of the total share-based compensation costs, $6.4 million, $7.2 million and $7.4 million was capitalized as part of real estate assets for the years ended December 31, 2022, 2021 and 2020, respectively. As of December 31, 2022, there was approximately $25.1 million of total unrecognized compensation cost related to nonvested incentive awards granted under share-based compensation arrangements that is expected to be recognized over a weighted-average period of 1.7 years. The remaining compensation cost related to these nonvested incentive awards had been recognized in periods prior to December 31, 2022. The $25.1 million of unrecognized compensation costs does not reflect the future compensation cost related to share-based awards that were granted subsequent to December 31, 2022. Severance Compensation

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2022
Retirement Benefits [Abstract]
Employee Benefit Plans	Employee Benefit Plans 401(k) Plan We have a retirement savings plan designed to qualify under Section 401(k) of the Code (the “401(k) Plan”). Our employees are eligible to participate in the 401(k) Plan on the first day of the month after three months of service. The 401(k) Plan allows eligible employees (“401(k) Participants”) to defer up to 60% of their eligible compensation on a pre-tax basis, subject to certain maximum amounts allowed by the Code. The 401(k) Plan provides for a matching contribution by the Company in an amount equal to 50 cents of each one dollar of participant contributions up to a maximum of 10% of the 401(k) Participant’s annual salary. 401(k) Participants vest immediately in the amounts contributed by us. For each of the years ended December 31, 2022, 2021, and 2020, we contributed $1.6 million, $1.5 million and $1.6 million, respectively, to the 401(k) Plan. Deferred Compensation Plan In 2007, we adopted the Deferred Compensation Plan, under which directors and certain management employees may defer receipt of their compensation, including up to 70% of their salaries and up to 100% of their director fees and bonuses, as applicable. In addition, employee participants will receive mandatory Company contributions to their Deferred Compensation Plan accounts equal to 10% of their gross monthly salaries, without regard to whether such employees elect to defer salary or bonus compensation under the Deferred Compensation Plan. Our Board may, but has no obligation to, approve additional discretionary contributions by the Company to Participant accounts. We hold the Deferred Compensation Plan assets in a limited rabbi trust, which is subject to the claims of our creditors in the event of bankruptcy or insolvency. See Note 19 “Fair Value Measurements and Disclosures” for further discussion of our Deferred Compensation Plan assets as of December 31, 2022 and 2021. Our liability of $23.4 million and $27.4 million under the Deferred Compensation Plan was fully funded as of December 31, 2022 and 2021, respectively.

Rental Income and Future Minimu

Rental Income and Future Minimum Rent	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
Rental Income and Future Minimum Rent	Rental Income and Future Minimum Rent Our rental income is primarily comprised of payments defined under leases and are subject to scheduled fixed increases. Additionally, rental income includes variable payments for tenant reimbursements of property-related expenses and payments based on a percentage of tenant’s sales. The table below sets forth the allocation of rental income between fixed and variable payments and net collectability recoveries or reversals for the years ended December 31, 2022 and 2021: Year Ended December 31, 2022 2021 Fixed lease payments $ 923,257 $ 826,883 Variable lease payments 162,638 123,544 Net collectability recoveries (reversals) (1) 123 (1,433) Total rental income $ 1,086,018 $ 948,994 ____________________ (1) Represents adjustments to rental income related to our assessment of the collectability of amounts due under leases with our tenants, including recognition of deferred rent balances associated with tenants restored from a cash basis of revenue recognition to an accrual basis of revenue recognition and allowances for uncollectible receivables and leases deemed not probable of collection.. We have operating leases with tenants that expire at various dates through 2048 and are subject to scheduled fixed increases. Generally, the leases grant tenants renewal options. Leases also provide for additional rents based on certain operating expenses. Future contractual minimum rent under operating leases, which includes amounts contractually due from leases that are on a cash basis of reporting due to creditworthiness considerations, as of December 31, 2022 for future periods is summarized as follows: Year Ending (in thousands) 2023 $ 809,406 2024 796,645 2025 769,116 2026 716,780 2027 656,100 Thereafter 2,464,166 Total (1) $ 6,212,213 ____________________ (1) Excludes residential leases and leases with a term of one year or less.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies General As of December 31, 2022, we had commitments of approximately $586.6 million, excluding our ground lease commitments, for contracts and executed leases directly related to our operating, development and redevelopment properties. Ground Leases During the year ended December 31, 2021, we acquired the land underlying a historical ground lease (refer to Note 3 “Acquisitions” for further information). The following table summarizes our properties that are held subject to long-term noncancellable ground lease obligations and the respective contractual expiration dates at December 31, 2022: Property Contractual Expiration Date (1) 701, 801 and 837 N. 34th Street, Seattle, WA (2) December 2041 1701 Page Mill Road and 3150 Porter Drive, Palo Alto, CA December 2067 Kilroy Airport Center Phases I, II, and III, Long Beach, CA July 2084 3243 S. La Cienega Boulevard, Los Angeles, CA October 2106 200 W. 6th Street, Austin, TX December 2112 ____________________ (1) Reflects the contractual expiration date prior to the impact of any extension or purchase options held by the Company. (2) The Company has three 10-year and one 45-year extension options for this ground lease, which if exercised would extend the expiration date to December 2116. These extension options are not assumed to be exercised in our calculation of the present value of the future minimum lease payments for this lease. To determine the discount rates used to calculate the present value of the minimum future lease payments for our ground leases, we used a hypothetical curve derived from unsecured corporate borrowing rates over the lease term. The weighted average discount rate used to determine the present value of our minimum lease payments was 4.65%. As of December 31, 2022, the weighted average remaining lease term of our ground leases is 64 years. For the years ended December 31, 2022, 2021 and 2020, variable lease costs totaling $3.6 million, $2.6 million and $3.0 million, respectively, were recorded to ground leases expense on our consolidated statements of operations. The minimum commitment under our ground leases as of December 31, 2022 for future periods is as follows: Year Ending (in thousands) 2023 $ 6,563 2024 6,598 2025 6,634 2026 6,671 2027 6,713 Thereafter 368,281 Total undiscounted cash flows (1)(2)(3)(4)(5)(6) $ 401,460 Present value discount (276,466) Ground lease liabilities $ 124,994 ________________________ (1) Excludes contingent future rent payments based on gross income or adjusted gross income and reflects the minimum ground lease obligations before the impact of ground lease extension options. ( 2) One of our ground lease obligations is subject to a fair market value adjustment every five years; however, the lease includes ground rent subprotection and infrastructure rent credits which currently limit our annual rental obligations to $1.0 million. The contractual obligations for that ground lease included above assumes the lesser of $1.0 million or annual lease rental obligation in effect as of December 31, 2022. (3) One of our ground lease obligations is subject to a fair market value adjustment every five years based on a combination of CPI adjustments and third-party appraisals limited to maximum increases annually. The contractual obligations for that lease included above assume the current annual ground lease obligation in effect at December 31, 2022 for the remainder of the lease term since we cannot predict future adjustments. (4) One of our ground lease obligations includes a component which is based on the percentage of adjusted gross income that exceeds the minimum ground rent. The minimum rent is subject to increases every 10 years by an amount equal to 60% of the average annual percentage rent for the previous three years. The contractual obligations for this lease included above assume the current annual ground lease obligation in effect at December 31, 2022 for the remainder of the lease term since we cannot predict future adjustments. (5) One of our ground lease obligations is subject to fixed 5% ground rent increases every five years, with the next increase occurring on November 1, 2027. (6) One of our ground lease obligations is subject to fixed 2% ground rent increases every year, with ground rent resets occurring every ten years based on CPI. The contractual obligations for that lease included above assume increases for the remaining current ten-year period based on the current annual ground lease obligation in effect at December 31, 2022 and no subsequent changes for the remainder of the lease term since we cannot predict future CPI adjustments. Environmental Matters We follow the policy of evaluating all of our properties, including acquisition, development, redevelopment and existing stabilized portfolio properties, for the presence of hazardous or toxic substances. While there can be no assurance that a material environmental liability does not exist, we are not currently aware of any undisclosed environmental liability with respect to our stabilized portfolio properties that would have a material adverse effect on our financial condition, results of operations and cash flow, or that we believe would require additional disclosure or the recording of a loss contingency. As of December 31, 2022 and 2021, we had accrued environmental remediation liabilities of approximately $80.5 million and $75.2 million, respectively, recorded on our consolidated balance sheets in connection with certain of our in-process and future development projects. The accrued environmental remediation liabilities represent the remaining costs we estimate we will incur prior to and during the development process at various development acquisition sites. These estimates, which we developed with the assistance of third party experts, consist primarily of the removal of contaminated soil, treatment of contaminated groundwater in connection with dewatering efforts, performing environmental closure activities, constructing remedial systems, and other related costs that are necessary when we develop new buildings at these sites. We record estimated environmental remediation obligations for acquired properties at the acquisition date when we are aware of such costs and when such costs are probable of being incurred and can be reasonably estimated. Estimated costs related to development environmental remediation liabilities are recorded as an increase to the cost of the development project. Actual costs are recorded as a decrease to the liability when incurred. These accruals are adjusted as an increase or decrease to the development project costs and as an increase or decrease to the accrued environmental remediation liability if we obtain further information or circumstances change. The environmental remediation obligations recorded at December 31, 2022 and 2021 were not discounted to their present values since the amount and timing of cash payments are not fixed. It is possible that we could incur additional environmental remediation costs in connection with these development projects. However, potential additional environmental costs for these development projects cannot be reasonably estimated at this time and certain changes in estimates could occur as the site conditions, final project timing, design elements, actual soil conditions and other aspects of the projects, which may depend upon municipal and other approvals beyond the control of the Company, are determined. Other than the accrued environmental liabilities discussed above, we are not aware of any unasserted claims and assessments with respect to an environmental liability that we believe would require additional disclosure or the recording of an additional loss contingency. Litigation We and our properties are subject to litigation arising in the ordinary course of business. To our knowledge, neither we nor any of our properties are presently subject to any litigation or threat of litigation which, if determined unfavorably to us, would have a material adverse effect on our cash flow, financial condition, or results of operations. Insurance

Fair Value Measurements and Dis

Fair Value Measurements and Disclosures	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements and Disclosures	Fair Value Measurements and Disclosures Assets and Liabilities Reported at Fair Value The only assets we record at fair value on our consolidated financial statements are the marketable securities related to our Deferred Compensation Plan (see Note 16 “Employee Benefit Plans” for additional information). The following table sets forth the fair value of our marketable securities as of December 31, 2022 and 2021: Fair Value (Level 1) (1) 2022 2021 Description (in thousands) Marketable securities (2) $ 23,547 $ 27,475 ____________________ (1) Based on quoted prices in active markets for identical securities. (2) The marketable securities are held in a limited rabbi trust. Financial Instruments Disclosed at Fair Value The following table sets forth the carrying value and the fair value of our other financial instruments as of December 31, 2022 and 2021: December 31, 2022 2021 Carrying Value Fair Value (1) Carrying Value Fair Value (1) (in thousands) Liabilities Secured debt, net $ 242,938 $ 225,847 $ 248,367 $ 269,687 Unsecured debt, net 4,020,058 3,500,420 3,820,383 4,105,408 _______________ (1) Fair value calculated using Level 2 inputs, which are based on model-derived valuations in which significant inputs and significant value drivers are observable in active markets.

Net Income Available to Common

Net Income Available to Common Stockholders Per Share of the Company	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Net Income Available to Common Stockholders Per Share of the Company	Net Income Available to Common Stockholders Per Share of the Company The following table reconciles the numerator and denominator in computing the Company’s basic and diluted per-share computations for net income available to common stockholders for the years ended December 31, 2022, 2021 and 2020: Year Ended December 31, 2022 2021 2020 (in thousands, except unit and per unit amounts) Numerator: Net income available to common stockholders $ 232,615 $ 628,144 $ 187,105 Allocation to participating securities (1) (1,272) (1,516) (2,229) Numerator for basic and diluted net income available to common stockholders $ 231,343 $ 626,628 $ 184,876 Denominator: Basic weighted average vested shares outstanding 116,806,575 116,429,130 113,241,341 Effect of dilutive securities 413,472 519,513 478,281 Diluted weighted average vested shares and common stock equivalents outstanding 117,220,047 116,948,643 113,719,622 Basic earnings per share: Net income available to common stockholders per share $ 1.98 $ 5.38 $ 1.63 Diluted earnings per share: Net income available to common stockholders per share $ 1.97 $ 5.36 $ 1.63 _____________________ (1) Participating securities include nonvested shares, certain time-based RSUs and vested market measure-based RSUs. Share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are considered participating securities. The impact of potentially dilutive common shares, including stock options and RSUs are considered in our diluted earnings per share calculation for the years ended December 31, 2022, 2021, and 2020. Certain market measure-based RSUs are not included in dilutive securities as of December 31, 2021 and 2020 as not all performance metrics had been met by the end of the applicable reporting periods.

Net Income Available to Commo_2

Net Income Available to Common Unitholders Per Unit of the Operating Partnership	12 Months Ended
	Dec. 31, 2022
Net Income Available To Common Unitholders [Line Items]
Net Income Available to Common Unitholders Per Unit of the Operating Partnership	Net Income Available to Common Stockholders Per Share of the Company The following table reconciles the numerator and denominator in computing the Company’s basic and diluted per-share computations for net income available to common stockholders for the years ended December 31, 2022, 2021 and 2020: Year Ended December 31, 2022 2021 2020 (in thousands, except unit and per unit amounts) Numerator: Net income available to common stockholders $ 232,615 $ 628,144 $ 187,105 Allocation to participating securities (1) (1,272) (1,516) (2,229) Numerator for basic and diluted net income available to common stockholders $ 231,343 $ 626,628 $ 184,876 Denominator: Basic weighted average vested shares outstanding 116,806,575 116,429,130 113,241,341 Effect of dilutive securities 413,472 519,513 478,281 Diluted weighted average vested shares and common stock equivalents outstanding 117,220,047 116,948,643 113,719,622 Basic earnings per share: Net income available to common stockholders per share $ 1.98 $ 5.38 $ 1.63 Diluted earnings per share: Net income available to common stockholders per share $ 1.97 $ 5.36 $ 1.63 _____________________ (1) Participating securities include nonvested shares, certain time-based RSUs and vested market measure-based RSUs. Share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are considered participating securities. The impact of potentially dilutive common shares, including stock options and RSUs are considered in our diluted earnings per share calculation for the years ended December 31, 2022, 2021, and 2020. Certain market measure-based RSUs are not included in dilutive securities as of December 31, 2021 and 2020 as not all performance metrics had been met by the end of the applicable reporting periods.
Kilroy Realty L.P.
Net Income Available To Common Unitholders [Line Items]
Net Income Available to Common Unitholders Per Unit of the Operating Partnership	Net Income Available to Common Unitholders Per Unit of the Operating Partnership The following table reconciles the numerator and denominator in computing the Operating Partnership’s basic and diluted per-unit computations for net income available to common unitholders for the years ended December 31, 2022, 2021 and 2020: Year Ended December 31, 2022 2021 2020 (in thousands, except unit and per unit amounts) Numerator: Net income available to common unitholders $ 234,898 $ 634,307 $ 189,609 Allocation to participating securities (1) (1,272) (1,516) (2,229) Numerator for basic and diluted net income available to common unitholders $ 233,626 $ 632,791 $ 187,380 Denominator: Basic weighted average vested units outstanding 117,957,149 117,579,704 115,095,506 Effect of dilutive securities 413,472 519,513 478,281 Diluted weighted average vested units and common unit equivalents outstanding 118,370,621 118,099,217 115,573,787 Basic earnings per unit: Net income available to common unitholders per unit $ 1.98 $ 5.38 $ 1.63 Diluted earnings per unit: Net income available to common unitholders per unit $ 1.97 $ 5.36 $ 1.62 ____________________ (1) Participating securities include nonvested shares, certain time-based RSUs and vested market measure-based RSUs. Share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are considered participating securities. The impact of potentially dilutive common units, including stock options and RSUs are considered in our diluted earnings per share calculation for the years ended December 31, 2022, 2021 and 2020. Certain market measure-based RSUs are not included in dilutive securities as of December 31, 2021 and 2020 as not all performance metrics had been met by the end of the applicable reporting periods.

Supplemental Cash Flow Informat

Supplemental Cash Flow Information of the Company	12 Months Ended
	Dec. 31, 2022
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information of the Company	Supplemental Cash Flow Information of the Company Supplemental cash flow information as follows (in thousands): Year Ended December 31, 2022 2021 2020 SUPPLEMENTAL CASH FLOWS INFORMATION: Cash paid for interest, net of capitalized interest of $72,973, $75,802, and $75,852 as of December 31, 2022, 2021 and 2020, respectively $ 79,634 $ 77,028 $ 61,741 Cash paid for amounts included in the measurement of ground lease liabilities $ 6,447 $ 6,209 $ 5,744 NON-CASH INVESTING TRANSACTIONS: Accrual for expenditures for operating properties and development and redevelopment properties $ 97,729 $ 119,829 $ 189,161 Tenant improvements funded directly by tenants $ 6,772 $ 20,070 $ 11,592 Assumption of accrued liabilities in connection with acquisitions (Note 3) $ — $ 37,572 $ — Initial measurement of operating right of use ground lease assets (Notes 3 and 18) $ — $ 46,430 $ — Initial measurement of operating ground lease liabilities (Notes 3 and 18) $ — $ 46,430 $ — NON-CASH FINANCING TRANSACTIONS: Accrual of dividends and distributions payable to common stockholders and common $ 64,285 $ 61,850 $ 59,431 Exchange of common units of the Operating Partnership into shares of the Company’s $ — $ — $ 37,640 The following is a reconciliation of our cash and cash equivalents and restricted cash at the beginning and end of the years ended December 31, 2022, 2021 and 2020. Year Ended December 31, 2022 2021 2020 (in thousands) RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH: Cash and cash equivalents at beginning of period $ 414,077 $ 731,991 $ 60,044 Restricted cash at beginning of period 13,006 91,139 16,300 Cash and cash equivalents and restricted cash at beginning of period $ 427,083 $ 823,130 $ 76,344 Cash and cash equivalents at end of period $ 347,379 $ 414,077 $ 731,991 Restricted cash at end of period — 13,006 91,139 Cash and cash equivalents and restricted cash at end of period $ 347,379 $ 427,083 $ 823,130

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information of the Operating Partnership	12 Months Ended
	Dec. 31, 2022
Other Significant Noncash Transactions [Line Items]
Supplemental Cash Flow Information of the Operating Partnership	Supplemental Cash Flow Information of the Company Supplemental cash flow information as follows (in thousands): Year Ended December 31, 2022 2021 2020 SUPPLEMENTAL CASH FLOWS INFORMATION: Cash paid for interest, net of capitalized interest of $72,973, $75,802, and $75,852 as of December 31, 2022, 2021 and 2020, respectively $ 79,634 $ 77,028 $ 61,741 Cash paid for amounts included in the measurement of ground lease liabilities $ 6,447 $ 6,209 $ 5,744 NON-CASH INVESTING TRANSACTIONS: Accrual for expenditures for operating properties and development and redevelopment properties $ 97,729 $ 119,829 $ 189,161 Tenant improvements funded directly by tenants $ 6,772 $ 20,070 $ 11,592 Assumption of accrued liabilities in connection with acquisitions (Note 3) $ — $ 37,572 $ — Initial measurement of operating right of use ground lease assets (Notes 3 and 18) $ — $ 46,430 $ — Initial measurement of operating ground lease liabilities (Notes 3 and 18) $ — $ 46,430 $ — NON-CASH FINANCING TRANSACTIONS: Accrual of dividends and distributions payable to common stockholders and common $ 64,285 $ 61,850 $ 59,431 Exchange of common units of the Operating Partnership into shares of the Company’s $ — $ — $ 37,640 The following is a reconciliation of our cash and cash equivalents and restricted cash at the beginning and end of the years ended December 31, 2022, 2021 and 2020. Year Ended December 31, 2022 2021 2020 (in thousands) RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH: Cash and cash equivalents at beginning of period $ 414,077 $ 731,991 $ 60,044 Restricted cash at beginning of period 13,006 91,139 16,300 Cash and cash equivalents and restricted cash at beginning of period $ 427,083 $ 823,130 $ 76,344 Cash and cash equivalents at end of period $ 347,379 $ 414,077 $ 731,991 Restricted cash at end of period — 13,006 91,139 Cash and cash equivalents and restricted cash at end of period $ 347,379 $ 427,083 $ 823,130
Kilroy Realty L.P.
Other Significant Noncash Transactions [Line Items]
Supplemental Cash Flow Information of the Operating Partnership	Supplemental Cash Flow Information of the Operating Partnership: Supplemental cash flow information as follows (in thousands): Year Ended December 31, 2022 2021 2020 SUPPLEMENTAL CASH FLOWS INFORMATION: Cash paid for interest, net of capitalized interest of $72,973, $75,802, and $75,852 as of December 31, 2022, 2021 and 2020, respectively $ 79,634 $ 77,028 $ 61,741 Cash paid for amounts included in the measurement of ground lease liabilities $ 6,447 $ 6,209 $ 5,744 NON-CASH INVESTING TRANSACTIONS: Accrual for expenditures for operating properties and development and redevelopment properties $ 97,729 $ 119,829 $ 189,161 Tenant improvements funded directly by tenants $ 6,772 $ 20,070 $ 11,592 Assumption of accrued liabilities in connection with acquisitions (Note 3) $ — $ 37,572 $ — Initial measurement of operating right of use ground lease assets (Notes 3 and 18) $ — $ 46,430 $ — Initial measurement of operating ground lease liabilities (Notes 3 and 18) $ — $ 46,430 $ — NON-CASH FINANCING TRANSACTIONS: Accrual of distributions payable to common unitholders (Notes 14 and 25) $ 64,285 $ 61,850 $ 59,431 The following is a reconciliation of our cash and cash equivalents and restricted cash at the beginning and end of the years ended December 31, 2022, 2021 and 2020. Year Ended December 31, 2022 2021 2020 (in thousands) RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH: Cash and cash equivalents at beginning of period $ 414,077 $ 731,991 $ 60,044 Restricted cash at beginning of period 13,006 91,139 16,300 Cash and cash equivalents and restricted cash at beginning of period $ 427,083 $ 823,130 $ 76,344 Cash and cash equivalents at end of period $ 347,379 $ 414,077 $ 731,991 Restricted cash at end of period — 13,006 91,139 Cash and cash equivalents and restricted cash at end of period $ 347,379 $ 427,083 $ 823,130

Tax Treatment of Distributions

Tax Treatment of Distributions	12 Months Ended
	Dec. 31, 2022
Tax Treatment of Distributions [Abstract]
Tax Treatment of Distributions	Tax Treatment of Distributions The following table reconciles the dividends declared per share of common stock to the dividends paid per share of common stock during the years ended December 31, 2022, 2021 and 2020 as follows: Year Ended December 31, Dividends 2022 2021 2020 Dividends declared per share of common stock $ 2.120 $ 2.040 $ 1.970 Less: Dividends declared in the current year and paid in the following year (0.540) (0.520) (0.500) Add: Dividends declared in the prior year and paid in the current year 0.520 0.500 0.485 Dividends paid per share of common stock $ 2.100 $ 2.020 $ 1.955 The unaudited income tax treatment for the dividends to common stockholders reportable for the years ended December 31, 2022, 2021 and 2020 as identified in the table above was as follows: Year Ended December 31, Shares of Common Stock 2022 2021 2020 Ordinary income (1) $ 1.865 88.80 % $ 1.338 66.22 % $ 1.474 75.40 % Qualified dividend 0.001 0.02 % 0.003 0.15 % 0.002 0.12 % Return of capital 0.230 10.99 % 0.551 27.30 % 0.162 8.30 % Capital gains (2) 0.004 0.19 % 0.075 3.72 % 0.275 14.05 % Unrecaptured section 1250 gains — — % 0.053 2.61 % 0.042 2.13 % $ 2.100 100.00 % $ 2.020 100.00 % $ 1.955 100.00 % ____________________ (1) The Tax Cuts and Jobs Act enacted on December 22, 2017 generally allows a deduction for noncorporate taxpayers equal to 20% of ordinary dividends distributed by a REIT (excluding capital gain dividends and qualified dividend income). The amount of dividend eligible for this deduction is referred to as the Section 199A Dividend. For the year ended December 31, 2022, the Section 199A Dividend is equal to the total ordinary income dividend. (2) Capital gains are comprised entirely of 20% rate gains.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2022
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On January 11, 2023, $64.3 million of dividends were paid to common stockholders, common unitholders and RSU holders of record on December 30, 2022. On January 27, 2023, the Operating Partnership amended the unsecured term loan facility agreement to (i) exercise the accordion feature under the term loan agreement to provide for borrowings of up to $500.0 million and (ii) increase the capacity under the accordion feature to provide additional term loan commitments up to an aggregate amount of $650.0 million. On February 6, 2023, the Executive Compensation Committee granted 218,951 Time-Based RSUs and 300,007 Performance-Based RSUs to key employees under the 2006 Plan. The compensation cost related to the RSUs is expected to be recognized over a period of three years.

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2022
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts	SCHEDULE II – VALUATION AND QUALIFYING ACCOUNTS Years ended December 31, 2022, 2021 and 2020 (in thousands) Balance at Charged to Costs and Expenses (1) Deductions (2) Balance Allowance for Uncollectible Tenant Receivables for the year ended 2022 – Allowance for uncollectible tenant receivables $ 2,062 $ 1,447 $ (1,276) $ 2,233 2021 – Allowance for uncollectible tenant receivables 1,799 1,532 (1,269) 2,062 2020 – Allowance for uncollectible tenant receivables 1,171 1,977 (1,349) 1,799 Allowance for Deferred Rent Receivables for the year ended 2022 – Allowance for deferred rent $ 612 $ 864 $ (511) $ 965 2021 – Allowance for deferred rent 804 320 (512) 612 2020 – Allowance for deferred rent 1,552 832 (1,580) 804 ____________________ (1) Amounts do not reflect leases deemed not probable of collection for which we reversed the associated revenue under Topic 842. In addition, for the year ended December 31, 2020, $1.7 million was charged to costs and expenses for a valuation allowance for a note receivable. (2) For the years ended December 31, 2021 and 2020, includes reversals of allowance for doubtful accounts for tenants with an allowance at January 1, 2021 and 2020, respectively, that were subsequently deemed not probable of collection and transitioned to a cash basis of reporting.

Schedule III - Real Estate and

Schedule III - Real Estate and Accumulated Depreciation	12 Months Ended
	Dec. 31, 2022
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Abstract]
Schedule III - Real Estate and Accumulated Depreciation	SCHEDULE III – REAL ESTATE AND ACCUMULATED DEPRECIATION December 31, 2022 Initial Cost Gross Amounts at Which Property Location Encumb- Land and Improve- Buildings Costs Land and Improve- Buildings Total Accumulated Depreci- ation Life (1) Date of Acquisition (A)/ Construction (C) (2) Rentable Square Feet (3) (unaudited) ($ in thousands) Office Properties: 3101 - 3243 S. La Cienega Blvd., Culver City, CA $ 150,718 $ 31,033 $ 911 $ 150,718 $ 31,944 $ 182,662 $ 15,782 35 2019 A 154,165 2240 E. Imperial Highway, El Segundo, CA 1,044 11,763 29,799 1,048 41,558 42,606 30,664 35 1983 C 122,870 2250 E. Imperial Highway, El Segundo, CA 2,579 29,062 36,425 2,547 65,519 68,066 60,241 35 1983 C 298,728 2260 E. Imperial Highway, El Segundo, CA 2,518 28,370 36,887 2,547 65,228 67,775 23,022 35 1983 C 298,728 909 N. Pacific Coast Highway, El Segundo, CA 3,577 34,042 54,886 3,565 88,940 92,505 51,400 35 2005 C 244,880 999 N. Pacific Coast Highway, El Segundo, CA 1,407 34,326 18,361 1,407 52,687 54,094 31,642 35 2003 C 138,389 1350 Ivar Ave., Los Angeles, CA 1,575 — 14,253 1,575 14,253 15,828 877 35 2020 C 16,448 1355 Vine St., Los Angeles, CA 17,588 — 120,967 17,588 120,967 138,555 7,602 35 2020 C 183,129 1375 Vine St., Los Angeles, CA 15,578 — 103,084 15,578 103,084 118,662 6,488 35 2020 C 159,236 1395 Vine St., Los Angeles, CA 278 — 3,283 278 3,283 3,561 201 35 2020 C 2,575 1500 N. El Centro Ave., Los Angeles, CA (4) 9,235 21 59,160 9,235 59,181 68,416 15,995 35 2016 C 113,447 1525 N. Gower St., Los Angeles, CA (4) 1,318 3 9,742 1,318 9,745 11,063 2,220 35 2016 C 9,610 1575 N. Gower St., Los Angeles, CA (4) 22,153 51 119,602 22,153 119,653 141,806 22,890 35 2016 C 264,430 6115 W. Sunset Blvd., Los Angeles, CA (4) 1,313 3 17,392 2,455 16,253 18,708 4,133 35 2015 C 26,238 6121 W. Sunset Blvd., Los Angeles, CA (4) 11,120 4,256 44,031 8,703 50,704 59,407 11,849 35 2015 C 93,418 6255 W. Sunset Blvd., Los Angeles, CA 18,111 60,320 52,399 18,111 112,719 130,830 53,140 35 2012 A 331,888 3750 Kilroy Airport Way, Long Beach, CA — 1,941 13,732 — 15,673 15,673 12,103 35 1989 C 10,718 3760 Kilroy Airport Way, Long Beach, CA — 17,467 21,186 — 38,653 38,653 30,843 35 1989 C 166,761 3780 Kilroy Airport Way, Long Beach, CA — 22,319 37,277 — 59,596 59,596 45,988 35 1989 C 221,452 3800 Kilroy Airport Way, Long Beach, CA — 19,408 24,334 — 43,742 43,742 29,745 35 2000 C 192,476 3840 Kilroy Airport Way, Long Beach, CA — 13,586 16,768 — 30,354 30,354 18,101 35 1999 C 138,441 3880 Kilroy Airport Way, Long Beach, CA — 9,704 12,115 — 21,819 21,819 6,615 35 1997 A 96,923 3900 Kilroy Airport Way, Long Beach, CA — 12,615 17,130 — 29,745 29,745 21,034 35 1997 A 130,935 8560 W. Sunset Blvd., West Hollywood, CA 9,720 50,956 5,881 9,720 56,837 66,557 12,496 35 2016 A 76,558 8570 W. Sunset Blvd., West Hollywood, CA 31,693 27,974 7,110 31,693 35,084 66,777 7,154 35 2016 A 49,276 8580 W. Sunset Blvd., West Hollywood, CA 10,013 3,695 1,856 10,013 5,551 15,564 952 35 2016 A 6,875 8590 W. Sunset Blvd., West Hollywood, CA 39,954 27,884 5,608 39,954 33,492 73,446 7,213 35 2016 A 56,750 12100 W. Olympic Blvd., Los Angeles, CA $159,973 (5) 352 45,611 25,334 9,633 61,664 71,297 34,464 35 2003 C 155,679 12200 W. Olympic Blvd., Los Angeles, CA (5) 4,329 35,488 26,399 3,977 62,239 66,216 47,437 35 2000 C 154,544 12233 W. Olympic Blvd., Los Angeles, CA 22,100 53,170 6,398 22,100 59,568 81,668 20,181 35 2012 A 156,746 12312 W. Olympic Blvd., Los Angeles, CA (5) 3,325 12,202 12,671 3,399 24,799 28,198 18,006 35 1997 A 76,644 2100/2110 Colorado Ave., Santa Monica, CA 5,474 26,087 15,937 5,476 42,022 47,498 30,599 35 1997 A 104,853 501 Santa Monica Blvd., Santa Monica, CA 4,547 12,044 18,723 4,551 30,763 35,314 22,436 35 1998 A 78,509 12225 El Camino Real, Del Mar, CA 1,700 9,633 4,409 1,673 14,069 15,742 10,451 35 1998 A 58,401 KILROY REALTY CORPORATION AND KILROY REALTY, L.P. SCHEDULE III – REAL ESTATE AND ACCUMULATED DEPRECIATION – (Continued) December 31, 2022 Initial Cost Gross Amounts at Which Property Location Encumb- Land and Improve- Buildings Costs Land and Improve- Buildings Total Accumulated Depreci- ation Life (1) Date of Acquisition (A)/ Construction (C) (2) Rentable Square Feet (3) (unaudited) ($ in thousands) 12235 El Camino Real, Del Mar, CA 1,507 8,543 9,974 1,540 18,484 20,024 12,892 35 1998 A 53,751 12340 El Camino Real, Del Mar, CA (6) 4,201 — 35,553 4,201 35,553 39,754 3,375 35 2022 C 109,307 12390 El Camino Real, Del Mar, CA 3,453 11,981 11,618 3,453 23,599 27,052 13,100 35 2000 C 73,238 12770 El Camino Real, Del Mar, CA 9,360 — 35,006 9,360 35,006 44,366 6,990 35 2015 C 75,035 12780 El Camino Real, Del Mar, CA 18,398 54,954 24,127 18,398 79,081 97,479 25,319 35 2013 A 140,591 12790 El Camino Real, Del Mar, CA 10,252 21,236 17,133 10,252 38,369 48,621 10,204 35 2013 A 87,944 12830 El Camino Real, Del Mar, CA 28,645 — 112,741 28,645 112,741 141,386 8,764 35 2021 C 196,444 12860 El Camino Real, Del Mar, CA 11,326 — 51,662 11,326 51,662 62,988 4,229 35 2021 C 92,042 12348 High Bluff Dr., Del Mar, CA 1,629 3,096 8,496 1,629 11,592 13,221 8,071 35 1999 C 39,193 12400 High Bluff Dr., Del Mar, CA (7) 15,167 — 46,755 15,167 46,755 61,922 9,856 35 2022 C 216,518 3579 Valley Centre Dr., Del Mar, CA 2,167 6,897 11,319 2,858 17,525 20,383 11,461 35 1999 C 54,960 3611 Valley Centre Dr., Del Mar, CA 4,184 19,352 29,293 5,259 47,570 52,829 31,308 35 2000 C 132,425 3661 Valley Centre Dr., Del Mar, CA 4,038 21,144 20,567 4,725 41,024 45,749 27,697 35 2001 C 131,662 3721 Valley Centre Dr., Del Mar, CA 4,297 18,967 16,203 4,254 35,213 39,467 22,563 35 2003 C 115,193 3811 Valley Centre Dr., Del Mar, CA 3,452 16,152 21,883 4,457 37,030 41,487 25,813 35 2000 C 118,912 3745 Paseo Place, Del Mar, CA (Retail) 24,358 — 73,942 24,358 73,942 98,300 8,857 35 2019 C 95,871 13480 Evening Creek Dr. North, San Diego, CA 7,997 — 57,000 7,997 57,000 64,997 25,377 35 2008 C 143,401 13500 Evening Creek Dr. North, San Diego, CA 7,581 35,903 24,926 7,580 60,830 68,410 30,838 35 2004 A 143,749 13520 Evening Creek Dr. North, San Diego, CA 7,581 35,903 24,767 7,580 60,671 68,251 33,028 35 2004 A 146,701 2100 Kettner Blvd., San Diego, CA 19,861 — 97,396 19,861 97,396 117,257 918 35 2022 C 204,682 2305 Historic Decatur Rd., San Diego, CA 5,240 22,220 9,757 5,240 31,977 37,217 15,472 35 2010 A 107,456 4690 Executive Dr., San Diego, CA (8) — — 6,264 — 6,264 6,264 77 35 1999 A — 9455 Towne Centre Dr., San Diego, CA 6,081 — 80,076 6,081 80,076 86,157 4,913 35 2021 C 160,444 4100 Bohannon Dr., Menlo Park, CA 4,835 15,526 1,583 4,860 17,084 21,944 6,104 35 2012 A 47,379 4200 Bohannon Dr., Menlo Park, CA 4,798 15,406 6,967 4,662 22,509 27,171 8,428 35 2012 A 45,451 4300 Bohannon Dr., Menlo Park, CA 6,527 20,958 8,611 6,470 29,626 36,096 10,389 35 2012 A 63,079 4400 Bohannon Dr., Menlo Park, CA (9) — — 3,002 — 3,002 3,002 2,057 35 2012 A — 4500 Bohannon Dr., Menlo Park, CA 6,527 20,957 4,479 6,470 25,493 31,963 9,519 35 2012 A 63,078 4600 Bohannon Dr., Menlo Park, CA 4,798 15,406 4,531 4,939 19,796 24,735 7,975 35 2012 A 48,147 4700 Bohannon Dr., Menlo Park, CA 6,527 20,958 1,572 6,470 22,587 29,057 8,432 35 2012 A 63,078 1290 - 1300 Terra Bella Ave., Mountain View, CA 28,730 27,555 12,305 28,730 39,860 68,590 7,462 35 2016 A 114,175 680 E. Middlefield Rd., Mountain View, CA 34,755 — 56,759 34,755 56,759 91,514 15,612 35 2014 C 171,676 690 E. Middlefield Rd., Mountain View, CA 34,605 — 56,515 34,605 56,515 91,120 15,546 35 2014 C 171,215 KILROY REALTY CORPORATION AND KILROY REALTY, L.P. SCHEDULE III – REAL ESTATE AND ACCUMULATED DEPRECIATION – (Continued) December 31, 2022 Initial Cost Gross Amounts at Which Property Location Encumb- Land and Improve- Buildings Costs Land and Improve- Buildings Total Accumulated Depreci- ation Life (1) Date of Acquisition (A)/ Construction (C) (2) Rentable Square Feet (3) (unaudited) ($ in thousands) 1701 Page Mill Rd., Palo Alto, CA — 99,522 108 — 99,630 99,630 18,011 35 2016 A 128,688 3150 Porter Dr., Palo Alto, CA — 21,715 6,327 — 28,042 28,042 4,961 35 2016 A 36,886 900 Jefferson Ave., Redwood City, CA (10) 16,668 — 109,626 18,063 108,231 126,294 27,378 35 2015 C 228,505 900 Middlefield Rd., Redwood City, CA (10) 7,959 — 50,293 8,626 49,626 58,252 12,241 35 2015 C 118,764 100 Hooper St., San Francisco, CA 78,564 — 196,708 85,510 189,762 275,272 23,632 35 2018 C 417,914 100 First St., San Francisco, CA (11) 49,150 131,238 78,071 49,150 209,309 258,459 95,413 35 2010 A 480,457 303 Second St., San Francisco, CA (12) 63,550 154,153 109,843 63,550 263,996 327,546 122,578 35 2010 A 784,658 201 Third St., San Francisco, CA 19,260 84,018 77,793 19,260 161,811 181,071 84,332 35 2011 A 346,538 360 Third St., San Francisco, CA — 88,235 126,260 28,504 185,991 214,495 67,999 35 2011 A 429,796 250 Brannan St., San Francisco, CA 7,630 22,770 10,752 7,630 33,522 41,152 14,079 35 2011 A 100,850 301 Brannan St., San Francisco, CA 5,910 22,450 16,647 5,910 39,097 45,007 14,016 35 2011 A 82,834 333 Brannan St., San Francisco, CA 18,645 — 80,640 18,645 80,640 99,285 16,195 35 2016 C 185,602 345 Brannan St., San Francisco, CA 29,405 113,179 1,135 29,403 114,316 143,719 13,548 35 2018 A 110,050 350 Mission St., San Francisco, CA 52,815 — 212,731 52,815 212,731 265,546 44,523 35 2016 C 455,340 345 Oyster Point Blvd., South San Francisco, CA 13,745 18,575 — 13,745 18,575 32,320 2,835 35 2018 A 40,410 347 Oyster Point Blvd., South San Francisco, CA 14,071 18,289 44 14,071 18,333 32,404 2,803 35 2018 A 39,780 349 Oyster Point Blvd., South San Francisco, CA 23,112 22,601 324 23,112 22,925 46,037 4,741 35 2018 A 65,340 350 Oyster Point Blvd., South San Francisco, CA 23,719 — 178,544 23,719 178,544 202,263 6,529 35 2021 C 234,892 352 Oyster Point Blvd., South San Francisco, CA 23,449 — 166,919 23,449 166,919 190,368 5,965 35 2021 C 232,215 354 Oyster Point Blvd., South San Francisco, CA 19,538 — 142,080 19,538 142,080 161,618 5,995 35 2021 C 193,472 505 Mathilda Ave., Sunnyvale, CA 37,843 1,163 50,450 37,943 51,513 89,456 12,147 35 2014 C 212,322 555 Mathilda Ave., Sunnyvale, CA 37,843 1,163 50,447 37,943 51,510 89,453 12,146 35 2014 C 212,322 599 Mathilda Ave., Sunnyvale, CA 13,538 12,559 71 13,538 12,630 26,168 5,386 35 2012 A 76,031 605 Mathilda Ave., Sunnyvale, CA 29,014 891 77,281 29,090 78,096 107,186 27,048 35 2014 C 162,785 601 108th Ave., Bellevue, WA — 214,095 88,313 42,680 259,728 302,408 108,785 35 2011 A 490,738 10900 NE 4th St., Bellevue, WA 25,080 150,877 51,424 25,080 202,301 227,381 80,659 35 2012 A 428,557 2001 W. 8th Ave., Seattle, WA 84,076 371,154 309 84,076 371,463 455,539 17,757 35 2021 A 539,226 701 N. 34th St., Seattle, WA — 48,027 9,063 — 57,090 57,090 22,769 35 2012 A 141,860 801 N. 34th St., Seattle, WA — 58,537 22,448 — 80,985 80,985 26,673 35 2012 A 173,615 837 N. 34th St., Seattle, WA — 37,404 6,563 — 43,967 43,967 16,307 35 2012 A 112,487 320 Westlake Ave. North, Seattle, WA 83,496 (13) 14,710 82,018 14,823 14,710 96,841 111,551 30,346 35 2013 A 184,644 321 Terry Ave. North, Seattle, WA (13) 10,430 60,003 10,717 10,430 70,720 81,150 23,174 35 2013 A 135,755 401 Terry Ave. North, Seattle, WA 22,500 77,046 31 22,500 77,077 99,577 22,544 35 2014 A 174,530 333 Dexter Ave. North, Seattle, WA 42,854 — 327,999 42,854 327,999 370,853 17,074 35 2022 C 618,766 200 W. 6th St., Austin, TX (14) — — 611,622 — 611,622 611,622 4,622 35 — C — KILROY REALTY CORPORATION AND KILROY REALTY, L.P. SCHEDULE III – REAL ESTATE AND ACCUMULATED DEPRECIATION – (Continued) December 31, 2022 Initial Cost Gross Amounts at Which Property Location Encumb- Land and Improve- Buildings Costs Land and Improve- Buildings Total Accumulated Depreci- ation Life (1) Date of Acquisition (A)/ Construction (C) (2) Rentable Square Feet (3) (unaudited) ($ in thousands) Residential Properties: 1550 N. El Centro Ave., Los Angeles, CA (4) 16,970 39 136,782 16,970 136,821 153,791 25,942 35 2016 C — 6390 De Longpre Ave., Hollywood, CA 12,112 — 163,539 12,112 163,539 175,651 8,132 35 2021 C — 3200 Paseo Village Way, Del Mar, CA 106,419 — 270,120 106,419 270,120 376,539 22,815 35 2020 C — TOTAL OPERATING PROPERTIES 243,469 1,646,775 2,959,869 5,433,679 1,738,242 8,302,081 10,040,323 2,218,710 16,194,146 Undeveloped land and construction in progress — 918,291 — 773,569 918,291 773,569 1,691,860 — — TOTAL ALL PROPERTIES $ 243,469 (15) $ 2,565,066 $ 2,959,869 $ 6,207,248 $ 2,656,533 $ 9,075,650 $ 11,732,183 $ 2,218,710 16,194,146 ____________________ (1) The initial costs of buildings and improvements are depreciated over 35 years using a straight-line method of accounting; improvements capitalized subsequent to acquisition or development are depreciated over the shorter of the lease term or useful life, generally ranging from one (2) Represents our date of construction or acquisition, or of our predecessor, the Kilroy Group. (3) Represents the square footage of our stabilized portfolio. (4) These properties include the allocated costs of a shared parking structure for a complex comprised of five office buildings and one residential tower. (5) These properties secure a $160.0 million mortgage note. (6) This property was taken out of the stabilized portfolio in the fourth quarter of 2021 for redevelopment. We completed construction and added the property back to the stabilized portfolio in the third quarter of 2022. (7) This property was taken out of the stabilized portfolio in the first quarter of 2022 for redevelopment. We completed construction and added the property back to the stabilized portfolio in the third quarter of 2022. (8) This property was taken out of the stabilized portfolio in the first quarter of 2022 for redevelopment in phases. (9) This property was taken out of the stabilized portfolio in the fourth quarter of 2022 for redevelopment. (10) These properties are owned by Redwood City Partners LLC, a consolidated property partnership. (11) This property is owned by 100 First Street Member LLC, a consolidated property partnership. (12) This property is owned by 303 Second Street Member LLC, a consolidated property partnership. (13) These properties secure a $83.5 million mortgage note. (14) This property is currently in the tenant improvement phase of our in-process development projects and not yet in the stabilized portfolio. The estimated rentable square feet for this property is 734,000 rentable square feet. (15) Represents gross aggregate principal amount before the effect of the deferred financing costs of $0.5 million as of December 31, 2022. As of December 31, 2022, the aggregate gross cost of property included above for federal income tax purposes approximated $9.6 billion. The following table reconciles the historical cost of total real estate held for investment from January 1, 2020 to December 31, 2022: Year Ended December 31, 2022 2021 2020 (in thousands) Total real estate held for investment, beginning of year $ 11,292,693 $ 10,190,046 $ 9,628,773 Additions during period: Acquisitions 40,033 1,131,248 — Improvements, etc. 439,759 547,468 645,170 Total additions during period 479,792 1,678,716 645,170 Deductions during period: Cost of real estate sold (32,855) (572,985) (44,070) Other (7,447) (3,084) (39,827) Total deductions during period (40,302) (576,069) (83,897) Total real estate held for investment, end of year $ 11,732,183 $ 11,292,693 $ 10,190,046 The following table reconciles the accumulated depreciation from January 1, 2020 to December 31, 2022: Year Ended December 31, 2022 2021 2020 (in thousands) Accumulated depreciation, beginning of year $ 2,003,656 $ 1,798,646 $ 1,561,361 Additions during period: Depreciation of real estate 287,799 256,304 244,815 Total additions during period 287,799 256,304 244,815 Deductions during period: Write-offs due to sale (19,114) (38,156) (6,401) Other (53,631) (13,138) (1,129) Total deductions during period (72,745) (51,294) (7,530) Accumulated depreciation, end of year $ 2,218,710 $ 2,003,656 $ 1,798,646

Basis of Presentation and Sig_2

Basis of Presentation and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2022
Basis of Presentation and Significant Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements of the Company include the consolidated financial position and results of operations of the Company, the Operating Partnership, 303 Second LLC, 100 First LLC, Redwood LLC and all of our wholly-owned and controlled subsidiaries. The consolidated financial statements of the Operating Partnership include the consolidated financial position and results of operations of the Operating Partnership, 303 Second LLC, 100 First LLC, Redwood LLC and all of our wholly-owned and controlled subsidiaries. All intercompany balances and transactions have been eliminated in the consolidated financial statements.
Partially Owned Entities and Variable Interest Entities	Our accounting policy is to consolidate entities in which we have a controlling financial interest and significant decision making control over the entity's operations. In determining whether we have a controlling financial interest in a partially owned entity and the requirement to consolidate the accounts of that entity, we consider factors such as ownership interest, board representation, management representation, size of our investment (including loans), authority to control decisions, and contractual and substantive participating rights of the members. In addition to evaluating control rights, we consolidate entities in which the other members have no substantive kick-out rights to remove the Company as the managing member. Entities in which the equity investors do not have sufficient equity at risk to finance their endeavors without additional financial support or the holders of the equity investment at risk do not have a controlling financial interest are VIEs. We evaluate whether an entity is a VIE and whether we are the primary beneficiary. We are deemed to be the primary beneficiary of a VIE when we have the power to direct the activities of the VIE that most significantly impact the VIEs’ economic performance and the obligation to absorb losses or receive benefits that could potentially be significant to the VIE.
Revenue Recognition, Base Rent, Additional Rent - Reimbursements from Tenants, Other Property Income, Uncollectible Lease Receivables and Allowance for Tenant and Deferred Rent Receivables	Revenue Recognition Rental revenue for office, life science and retail operating properties is our principal source of revenue. We recognize revenue from base rent (fixed lease payments), additional rent (variable lease payments, which consist of amounts due from tenants for common area maintenance, real estate taxes, and other recoverable costs), parking and other lease-related revenue once all of the following criteria are met: (i) the agreement has been fully executed and delivered, (ii) services have been rendered, (iii) the amount is fixed or determinable and (iv) payment has been received or the collectability of substantially all of the amount due is probable. Minimum annual rental revenues are recognized in rental revenues on a straight-line basis over the non-cancellable term of the related lease. Base Rent The timing of when we commence rental revenue recognition for office, life science and retail properties depends largely on our conclusion as to whether the Company or the tenant is the owner for accounting purposes of tenant improvements at the leased property. When we conclude that the Company is the owner of tenant improvements for accounting purposes, we record the cost to construct the tenant improvements as an asset and commence rental revenue recognition when the tenant takes possession of or controls the finished space, which is generally when tenant improvements being recorded as our assets are substantially complete. In certain instances, when we conclude that the tenant is the owner of certain tenant improvements for accounting purposes, rental revenue recognition begins when the tenant takes possession or controls the physical use of the leased space. The determination of who owns the tenant improvements is made on a lease-by-lease basis and has a significant effect on the timing of commencement of revenue recognition. Further, the Company may deliver leased space in phases, rather than for an entire building or project, resulting in various revenue commencement dates for a particular lease, which involves significant judgment surrounding when the tenant takes possession of or controls each respective phase, building or project. When we conclude that the Company is the owner of tenant improvements for accounting purposes, we record the cost to construct the tenant improvements, including costs paid for or reimbursed by the tenants, as an asset. For these tenant-funded tenant improvements, we record the amount funded by or reimbursed by tenants as deferred revenue, which is amortized and recognized as rental income on a straight-line basis over the term of the related lease. When we conclude that the tenant is the owner of certain tenant improvements for accounting purposes, we record our contribution towards those tenant-owned improvements as a lease incentive, which is included in deferred leasing costs and acquisition-related intangible assets, net on our consolidated balance sheets and amortized as a reduction to rental revenue on a straight-line basis over the term of the related lease. For residential properties, we commence revenue recognition upon lease commencement. Residential rental revenue is recognized on a straight-line basis over the term of the related lease, net of any concessions. When a lease is amended, which may occur from time to time, we determine whether (1) an additional right of use not included in the original lease is being granted as a result of the modification, and (2) there is an increase in the lease payments that is commensurate with the standalone price for the additional right of use. If both of those conditions are met, the amendment is accounted for as a separate lease contract. If either of those conditions are not met, the amendment is accounted for as a lease modification. Most of our lease amendments are accounted for as a modification of our operating leases which will likely require us to reassess both the lease term and fixed lease payments, including considering any prepaid or deferred rent receivables relating to the original lease, as a part of the lease payments for the modified lease. Termination options in some of our leases allow the tenant to terminate the lease, in part or in whole, prior to the end of the lease term under certain circumstances. Termination options require advance notification from the tenant and payment of a termination fee that reimburses us for a portion of the remaining rent under the original lease term and the net book value of lease inception costs such as commissions, tenant improvements and lease incentives. Termination fee income, included in rental income, is recognized on a straight-line basis from the date of notification of early termination through lease expiration when the amount of the fee is determinable and collectability of the fee is probable. This fee income is reduced on a straight-line basis by any deferred rent receivable related to the lease projected at the date of tenant vacancy. Additional Rent - Reimbursements from Tenants Additional rent, consisting of amounts due from tenants for common area maintenance, real estate taxes and other recoverable costs, are recognized in rental income in the period the recoverable costs are incurred. Additional rent where we pay the associated costs directly to third-party vendors and are reimbursed by our tenants are recognized and recorded on a gross basis, with the corresponding expense recognized in property expenses or real estate taxes. Other Property Income Other property income primarily includes amounts recorded in connection with transient daily parking, tenant bankruptcy settlement payments, broken deal income and property damage settlement related payments. Other property income also includes miscellaneous income from tenants, restoration fees and fees for late rental payments. Amounts recorded within other property income fall within the scope of ASC Topic 606 “Revenue from Contracts with Customers” and are recognized as revenue at the point in time when control of the goods or services transfers to the customer and our performance obligation is satisfied. Uncollectible Lease Receivables and Allowances for Tenant and Deferred Rent Receivables We carry our current and deferred rent receivables net of allowances for amounts that may not be collected. These allowances are increased or decreased through rental income, and our determination of the adequacy of the Company’s allowances for tenant receivables includes a binary assessment of whether or not substantially all of the amounts due under a tenant’s lease agreement are probable of collection. Such assessment involves using a methodology that incorporates a specific identification analysis and an aging analysis and considers the current economic and business environment. This determination requires significant judgment and estimates about matters that are uncertain at the time the estimates are made, including the creditworthiness of specific tenants, specific industry trends and conditions, and general economic trends and conditions. For leases that are deemed probable of collection, revenue continues to be recorded on a straight-line basis over the lease term. For leases that are deemed not probable of collection, revenue is recorded as the lesser of (i) the amount which would be recognized on a straight-line basis or (ii) cash that has been received from the tenant, including deferred revenue, with any tenant and deferred rent receivable balances charged as a direct write-off against rental income in the period of the change in the collectability determination. If the collectability determination subsequently changes to being probable of collection for leases for which revenue is recorded based on cash received from the tenant, we resume recognizing revenue, including deferred revenue, on a straight-line basis and recognize incremental revenue related to the reinstatement of cumulative deferred rent receivable and deferred revenue balances, as if revenue had been recorded on a straight-line basis since the inception of the lease. For tenant and deferred rent receivables associated with leases whose rents are deemed probable of collection, we may record an allowance under other authoritative GAAP using a methodology that incorporates a specific identification analysis and an aging analysis and considers the current economic and business environment. This determination requires significant judgment and estimates about matters that are uncertain at the time the estimates are made, including the creditworthiness of specific tenants, specific industry trends and conditions, and general economic trends and conditions. Tenant and deferred rent receivables deemed probable of collection are carried net of allowances for uncollectible accounts, with increases or decreases in the allowances recorded through rental income on our consolidated statements of operations. Current tenant receivables consist primarily of amounts due for contractual lease payments and reimbursements of common area maintenance expenses, property taxes, and other costs recoverable from tenants. With respect to the allowance for uncollectible tenant receivables, the specific identification methodology analysis relies on factors such as the age and nature of the receivables, the payment history and financial condition of the tenant, our assessment of the tenant’s ability to meet its lease obligations, and the status of negotiations of any disputes with the tenant. Deferred rent receivables represent the amount by which the cumulative straight-line rental revenue recorded to date exceeds cash rents billed to date under the lease agreement. With respect to the allowance for deferred rent receivables, given the longer-term nature of these receivables, the specific identification methodology analysis evaluates each of our significant tenants and any tenants on our internal watchlist and relies on factors such as each tenant’s financial condition and its ability to meet its lease obligations. We evaluate our reserve levels quarterly based on changes in the financial condition of tenants and our assessment of the tenant’s ability to meet its lease obligations, overall economic conditions, and the current business environment.
Acquisitions	Acquisitions Acquisitions of operating properties and development and redevelopment opportunities generally do not meet the definition of a business and are accounted for as asset acquisitions, as substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or a group of similar identifiable assets. For these asset acquisitions, we record the acquired tangible and intangible assets and assumed liabilities based on each asset’s and liability’s relative fair value at the acquisition date of the total purchase price plus any capitalized acquisition costs. We record the acquired tangible and intangible assets and assumed liabilities of acquisitions of operating properties and development and redevelopment opportunities that meet the accounting criteria to be accounted for as business combinations at fair value at the acquisition date. Transaction costs associated with asset acquisitions, including costs incurred during negotiation, are capitalized in addition to the purchase price of the acquisition. The acquired assets and assumed liabilities for an acquisition generally include but are not limited to (i) land and improvements, buildings and improvements, undeveloped land and construction in progress and (ii) identified tangible and intangible assets and liabilities associated with in-place leases, including tenant improvements, leasing costs, value of above-market and below-market operating leases and ground leases, acquired in-place lease values and tenant relationships, if any. Any debt assumed and equity (including common units of the Operating Partnership) issued in connection with a property acquisition is recorded at fair value on the date of acquisition. The fair value of land and improvements is derived from comparable sales of land and improvements within the same submarket and/or region. The fair value of buildings and improvements, tenant improvements and leasing costs considers the value of the property as if it was vacant as well as current replacement costs and other relevant market rate information. The fair value of the above-market or below-market component of an acquired in-place operating lease is based upon the present value (calculated using a market discount rate) of the difference between (i) the contractual rents to be paid pursuant to the lease over its remaining non-cancellable lease term and (ii) our estimate of the rents that would be paid using fair market rental rates and rent escalations at the date of acquisition measured over the remaining non-cancellable term of the lease for above-market operating leases and the initial non-cancellable term plus the term of any below-market fixed rate renewal options, if applicable, for below-market operating leases. Our below-market operating leases generally do not include fixed rate or below-market renewal options. The amounts recorded for above-market operating leases are included in deferred leasing costs and acquisition-related intangible assets, net on the balance sheet and are amortized on a straight-line basis as a reduction of rental income over the remaining term of the applicable leases. The amounts recorded for below-market operating leases are included in deferred revenue and acquisition-related intangible liabilities, net on the balance sheet and are amortized on a straight-line basis as an increase to rental income over the remaining term of the applicable leases plus the term of any below-market fixed rate renewal options, if applicable. The amortization of a below-market ground lease obligation is recorded as an increase to ground lease expense in the consolidated statements of operations for the periods presented. The amortization of an above-market ground lease obligation is recorded as a decrease to ground lease expense in the consolidated statements of operations for the periods presented. The fair value of acquired in-place leases is derived based on our assessment of lost revenue and costs incurred for the period required to lease the “assumed vacant” property to the occupancy level when purchased. The amount recorded for acquired in-place leases is included in deferred leasing costs and acquisition-related intangible assets,
Operating Properties, Cost Capitalization, Depreciation and Amortization of Buildings and Improvements	Operating Properties Operating properties are generally carried at historical cost less accumulated depreciation. Properties held for sale are reported at the lower of the carrying value or the fair value less estimated cost to sell. The cost of operating properties includes the purchase price or development costs of the properties. Costs incurred for the renovation and betterment of the operating properties are capitalized to our investment in that property. Maintenance and repairs are charged to expense as incurred. When evaluating properties to be held and used for potential impairment, we first evaluate whether there are any indicators of impairment for any of our properties. If any impairment indicators are present for a specific property, we then evaluate the regional market conditions that could reasonably affect the property. If there are negative changes and trends in that regional market, we then perform an undiscounted cash flow analysis and compare the net carrying amount of the property to the property’s estimated undiscounted future cash flow over the anticipated holding period. If the estimated undiscounted future cash flow is less than the net carrying amount of the property, we perform an impairment loss calculation to determine if the fair value of the property is less than the net carrying value of the property. Our impairment loss calculation compares the net carrying amount of the property to the property’s estimated fair value, which may be based on estimated discounted future cash flow calculations or third-party valuations or appraisals. We would recognize an impairment loss if the property's net carrying amount exceeds the property's estimated fair value. If we were to recognize an impairment loss, the estimated fair value of the property becomes its new cost basis. For a depreciable long-lived asset, the new cost basis would be depreciated (amortized) over the remaining useful life of that asset. Cost Capitalization All costs clearly associated with the development, redevelopment and construction of a property are capitalized as project costs, including internal compensation costs. In addition, the following costs are capitalized as project costs during periods in which activities necessary to prepare development and redevelopment properties for their intended use are in progress: pre-construction costs essential to the development of the property, interest, real estate taxes and insurance. • For office, life science and retail development and redevelopment properties that are pre-leased, we cease capitalization when revenue recognition commences, which is upon substantial completion of tenant improvements deemed to be the Company’s asset for accounting purposes. • For office, life science and retail development and redevelopment properties that are not pre-leased, we may not immediately build out the tenant improvements. Therefore, we cease capitalization when revenue recognition commences upon substantial completion of the tenant improvements deemed to be the Company’s asset for accounting purposes, but in any event, no later than one year after the cessation of major base building construction activities. We also cease capitalization on a development or redevelopment property when activities necessary to prepare the property for its intended use have been suspended. • For office, life science and retail development or redevelopment properties with multiple tenants and phased leasing, we cease capitalization and begin depreciation on the portion of the development or redevelopment property for which revenue recognition has commenced. • For residential development properties, we cease capitalization when the property is substantially complete and available for occupancy. Once major base building construction activities have ceased and the development or redevelopment property or phases of the development or redevelopment project is placed in service, which may occur in phases or for an entire building or project, the costs capitalized to construction in progress are transferred to land and improvements, buildings and improvements, and deferred leasing costs on our consolidated balance sheets as the historical cost of the property. Depreciation and Amortization of Buildings and Improvements
Real Estate Assets Held for Sale, Dispositions and Discontinued Operations	Real Estate Assets Held for Sale, Dispositions and Discontinued Operations A real estate asset is classified as held for sale when certain criteria are met, including but not limited to the availability of the asset for immediate sale, the existence of an active program to locate a buyer and the probable sale or transfer of the asset within one year. If such criteria are met, we present the applicable assets and liabilities related to the real estate asset, if material, separately on the balance sheet as held for sale and we would cease to record depreciation and amortization expense. Real estate assets held for sale are reported at the lower of their carrying value or their estimated fair value less the estimated costs to sell. As of December 31, 2022 and 2021, we did not have any properties classified as held for sale. Property disposals representing a strategic shift that have (or will have) a major effect on the Company’s operations and financial results, such as a major line of business, a major geographical area or a major equity investment, are required to be presented as discontinued operations. If we were to determine that a property disposition represents a strategic shift, the revenues, expenses and net gain (loss) on dispositions of the property would be recorded in discontinued operations for all periods presented through the date of the applicable disposition. The operations of the properties sold during the years ended December 31, 2022, 2021 and 2020 are presented in continuing operations as they did not represent a strategic shift in the Company’s operations and financial results. The net gains (losses) on dispositions of non-depreciable real estate property, including land, are reported in the consolidated statements of operations as gains (losses) on sale of land within continuing operations in the period the land is sold. The net gains (losses) on dispositions of depreciable real estate property are reported in the consolidated statements of operations as gains (losses) on sales of depreciable operating properties within continuing operations in the period the property is sold.
Cash and Cash Equivalents	Cash and Cash Equivalents We consider all highly-liquid investments with original maturities of three months or less to be cash equivalents.
Restricted Cash	Restricted CashRestricted cash consists of cash proceeds from dispositions that are temporarily held at qualified intermediaries for purposes of facilitating potential Section 1031 Exchanges, and cash held in escrow related to acquisition and disposition holdbacks. Restricted cash also includes cash held as collateral to provide credit enhancement for the Operating Partnership’s mortgage debt, including cash reserves for capital expenditures, tenant improvements and property taxes and cash investments with original maturities greater than 3 months.
Marketable Securities	Marketable securities reported in our consolidated balance sheets represent the assets held in connection with the Kilroy Realty Corporation 2007 Deferred Compensation Plan (the “Deferred Compensation Plan”) (see Note 16 “Employee Benefit Plans” for additional information). The Deferred Compensation Plan assets are held in a limited rabbi trust and invested in various mutual and money market funds. As a result, the marketable securities are treated as trading securities for financial reporting purposes and are adjusted to fair value at the end of each accounting period.
Deferred Compensation Plan	At the time eligible management employees (“Participants”) defer compensation or earn mandatory Company contributions, or if we were to make a discretionary contribution, we record compensation cost and a corresponding deferred compensation plan liability, which is included in accounts payable, accrued expenses, and other liabilities on our consolidated balance sheets. This liability is adjusted to fair value at the end of each accounting period based on the performance of the benchmark funds selected by each Participant, and the impact of adjusting the liability to fair value is recorded as an increase or decrease to compensation cost. The impact of adjusting the deferred compensation plan liability to fair value and the changes in the value of the marketable securities held in connection with the Deferred Compensation Plan generally offset and therefore do not significantly impact net income.
Deferred Leasing Costs	Deferred Leasing Costs Costs incurred in connection with successful property leasing are capitalized as deferred leasing costs and classified as investing activities in the statement of cash flows. Deferred leasing costs consist of leasing commissions paid to external third party brokers and lease incentives, and are amortized using the straight-line method of accounting over the lives of the leases which generally range from one
Deferred Financing Costs and Debt Discounts and Premiums	Deferred Financing Costs Financing costs related to the origination or assumption of long-term debt are deferred and generally amortized using the straight-line method of accounting, which approximates the effective interest method, over the contractual terms of the applicable financings. Fully amortized deferred financing costs are written off when the corresponding financing is repaid. Debt Discounts and Premiums
Noncontrolling Interests and Common Partnership Interests	Noncontrolling Interests - Common Units of the Operating Partnership in the Company's Consolidated Financial Statements Common units of the Operating Partnership within noncontrolling interests in the Company’s consolidated financial statements represent the common limited partnership interests in the Operating Partnership not held by the Company (“noncontrolling common units”). Noncontrolling common units are presented in the equity section of the Company’s consolidated balance sheets and are reported at their proportionate share of the net assets of the Operating Partnership. Noncontrolling interests with redemption provisions that permit the issuer to settle in either cash or shares of common stock must be further evaluated to determine whether equity or temporary equity classification on the balance sheet is appropriate. Since the common units contain such a provision, we evaluated the accounting guidance and determined that the common units qualify for equity presentation in the Company’s consolidated financial statements. Net income attributable to noncontrolling common units is allocated based on their relative ownership percentage of the Operating Partnership during the reported period. The noncontrolling interest ownership percentage is determined by dividing the number of noncontrolling common units by the total number of common units outstanding. The issuance or redemption of additional shares of common stock or common units results in changes to the noncontrolling interest percentage as well as the total net assets of the Company. As a result, all equity transactions result in an allocation between equity and the noncontrolling interest in the Company’s consolidated balance sheets and statements of equity to account for the changes in the noncontrolling interest ownership percentage as well as the change in total net assets of the Company. Noncontrolling Interests in Consolidated Property Partnerships Noncontrolling interests in consolidated property partnerships represent the equity interests held by unrelated third parties in our three consolidated property partnerships (see Note 11 “Noncontrolling Interests on the Company’s Consolidated Financial Statements” and see Note 12 “Noncontrolling Interests on the Operating Partnership’s Consolidated Financial Statements”). Noncontrolling interests in consolidated property partnerships are not redeemable and are presented as permanent equity in the Company's consolidated balance sheets. We account for the noncontrolling interests in consolidated property partnerships using the hypothetical liquidation at book value (“HLBV”) method to attribute the earnings or losses of the consolidated property partnerships between the controlling and noncontrolling interests. Under the HLBV method, the amounts reported as noncontrolling interests in consolidated property partnerships in the consolidated balance sheets represent the amounts the noncontrolling interests would hypothetically receive at each balance sheet reporting date under the liquidation provisions of the governing agreements assuming the net assets of the consolidated property partnerships were liquidated at recorded amounts and distributed between the controlling and noncontrolling interests in accordance with the governing documents. The net income attributable to noncontrolling interests in consolidated property partnerships in the consolidated statements of operations is associated with the increase or decrease in the noncontrolling interest holders’ contractual claims on the respective entities’ balance sheets assuming a hypothetical liquidation at the end of that reporting period when compared with their claims on the respective entities’ balance sheets assuming a hypothetical liquidation at the beginning of that reporting period, after removing any contributions or distributions. Common Partnership Interests on the Operating Partnership’s Consolidated Balance Sheets The common units held by the Company and the noncontrolling common units held by the common limited partners are both presented in the permanent equity section of the Operating Partnership’s consolidated balance sheets in partners’ capital. The redemption rights of the noncontrolling common units permit us to settle the redemption obligation in either cash or shares of the Company’s common stock at our option (see Note 11 “Noncontrolling Interests on the Company’s Consolidated Financial Statements” for additional information). Noncontrolling Interests on the Operating Partnership’s Consolidated Financial Statements
Equity Offerings	Equity Offerings Underwriting commissions and offering costs incurred in connection with common equity offerings and our at-the-market stock offering program (see Note 13 “Stockholders’ Equity of the Company”) are reflected as a reduction of additional paid-in capital. Issuance costs incurred in connection with preferred equity offerings are reflected as a reduction of the carrying value of the preferred equity.
Share-based Incentive Compensation Accounting	Share-based Incentive Compensation Accounting Compensation cost for all share-based awards, including options, requires measurement at estimated fair value on the grant date. Compensation cost is recognized on a straight-line basis over the service vesting period, which represents the requisite service period. The grant date fair value of market measure-based share-based compensation plans are calculated using a Monte Carlo simulation pricing model. Equity awards settled in cash are valued at the fair value of our common stock on the period end date through the settlement date. Equity awards settled in cash are remeasured at each reporting period and are recognized as a liability in the consolidated balance sheet during the vesting period until settlement. Forfeitures of all share-based awards are recognized when they occur. For share-based awards in which the performance period precedes the grant date, we recognize compensation cost over the requisite service period, which includes both the performance and service vesting periods, using the accelerated attribution expense method. The requisite service period begins on the date the Executive Compensation Committee authorizes the award and adopts any relevant performance measures. For share-based awards with performance-based measures, the total estimated compensation cost is based on our most recent estimate of the probable achievement of the pre-established specific corporate performance measures. These estimates are based on actual results and our latest internal forecasts for each performance measure. For share-based awards with market measures, the total estimated compensation cost is based on the fair value of the award at the grant date. For share-based awards with performance-based measures and market measures, the total estimated compensation cost is based on the fair value per share at the grant date multiplied by our most recent estimate of the number of shares to be earned based on actual results and the probable achievement of the pre-established corporate performance measures based on our latest internal forecasts. In accordance with the provisions of our share-based incentive compensation plan, we accept the return of shares of Company common stock, at the current quoted market price, from employees to satisfy minimum statutory tax-withholding requirements related to shares that vested during the period.
Basic and Diluted Net Income Available to Common Stockholders (Unitholders) per Share (Unit)	Basic and Diluted Net Income Available to Common Stockholders per Share Basic net income available to common stockholders per share is computed by dividing net income available to common stockholders, after preferred distributions and the allocation of income to participating securities, by the weighted-average number of shares of common stock outstanding for the period. Diluted net income available to common stockholders per share is computed by dividing net income available for common stockholders, after preferred distributions and the allocation of income to participating securities, by the sum of the weighted-average number of shares of common stock outstanding for the period plus the assumed exercise of all dilutive securities. The impact of the outstanding common units is considered in the calculation of diluted net income available to common stockholders per share. The common units are not reflected in the diluted net income available to common stockholders per share calculation because the exchange of common units into common stock is on a one for one basis, and the common units are allocated net income on a per share basis equal to the common stock (see Note 21 “Net Income Available to Common Stockholders Per Share of the Company”). Accordingly, any exchange would not have any effect on diluted net income (loss) available to common stockholders per share. Nonvested share-based payment awards (including nonvested restricted stock units (“RSUs”), vested market-measure RSUs and vested dividend equivalents issued to holders of RSUs) containing nonforfeitable rights to dividends or dividend equivalents are accounted for as participating securities and included in the computation of basic and diluted net income available to common stockholders per share pursuant to the two-class method. The dilutive effect of shares issuable under executed forward equity sale agreements, if any, and stock options are reflected in the weighted average diluted outstanding shares calculation by application of the treasury stock method. The dilutive effect of the outstanding nonvested shares of common stock (“nonvested shares”) and RSUs that have not yet been granted but are contingently issuable under the share-based compensation programs is reflected in the weighted average diluted shares calculation by application of the treasury stock method at the beginning of the quarterly period in which all necessary conditions have been satisfied. Basic and Diluted Net Income Available to Common Unitholders per Unit Basic net income available to common unitholders per unit is computed by dividing net income available to common unitholders, after preferred distributions and the allocation of income to participating securities, by the weighted-average number of vested common units outstanding for the period. Diluted net income available to common unitholders per unit is computed by dividing net income available to common unitholders, after preferred distributions and the allocation of income to participating securities, by the sum of the weighted-average number of common units outstanding for the period plus the assumed exercise of all dilutive securities.
Fair Value Measurements	Fair Value Measurements The fair values of our financial assets and liabilities are disclosed in Note 19, “Fair Value Measurements and Disclosures,” to our consolidated financial statements. The only financial assets recorded at fair value on a recurring basis in our consolidated financial statements are our marketable securities. We elected not to apply the fair value option for any of our eligible financial instruments or other items. We determine the estimated fair value of financial assets and liabilities utilizing a hierarchy of valuation techniques based on whether the inputs to a fair value measurement are considered to be observable or unobservable in a marketplace. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect our market assumptions. This hierarchy requires the use of observable market data when available. The following is the fair value hierarchy: • Level 1 – quoted prices for identical instruments in active markets; • Level 2 – quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active and model-derived valuations in which significant inputs and significant value drivers are observable in active markets; and • Level 3 – fair value measurements derived from valuation techniques in which one or more significant inputs or significant value drivers are unobservable. We determine the fair value for the marketable securities using quoted prices in active markets for identical assets. Our other financial instruments, which are only disclosed at fair value, are comprised of secured debt, unsecured senior notes, unsecured line of credit and unsecured term loan facility. We generally determine the fair value of our secured debt, unsecured debt, unsecured term loan facility and unsecured line of credit by performing discounted cash flow analyses using an appropriate market discount rate. We calculate the market rate by obtaining period-end treasury rates for maturities that correspond to the maturities of our fixed-rate debt and then adding an appropriate credit spread based on information obtained from third-party financial institutions. These credit spreads take into account factors, including but not limited to, our credit profile, the tenure of the debt, amortization period, whether the debt is secured or unsecured, and the loan-to-value ratio of the debt to the collateral. These calculations are significantly affected by the assumptions used, including the discount rate, credit spreads and estimates of future cash flow. Prior to amending the terms of our unsecured line of credit in October 2022, we calculated the market rate by obtaining the period-end LIBOR and then adding an appropriate credit spread based on our credit ratings and the amended terms of our unsecured line of credit agreement. Subsequent to amending the terms of our unsecured line of credit in October 2022, we calculate the market rate by obtaining Adjusted SOFR and then adding an appropriate credit spread based on our credit ratings and the amended terms of our unsecured line of credit agreement. We determine the fair value of each of our publicly traded unsecured senior notes based on their quoted trading price at the end of the reporting period, if such prices are available. Carrying amounts of our cash and cash equivalents, restricted cash and accounts payable approximate fair value due to their short-term maturities.
Income Taxes	Income Taxes We have elected to be taxed as a REIT under Sections 856 through 860 of the Code. To qualify as a REIT, we must distribute annually at least 90% of our adjusted taxable income, as defined in the Code, to our stockholders and satisfy certain other organizational and operating requirements. We generally will not be subject to federal income taxes if we distribute 100% of our taxable income for each year to our stockholders. If we fail to qualify as a REIT in any taxable year, we will be subject to federal income taxes on our taxable income at regular corporate rates and we may not be able to qualify as a REIT for four subsequent taxable years. Even if we qualify for taxation as a REIT, we may be subject to certain state and local taxes on our income and property and to federal income taxes and excise taxes on our undistributed taxable income. We believe that we have met all of the REIT distribution and technical requirements for the years ended December 31, 2022, 2021 and 2020, and we were not subject to any federal income taxes (see Note 24 “Tax Treatment of Distributions” for additional information). We intend to continue to adhere to these requirements and maintain the Company’s REIT status. Accordingly, no provision for income taxes has been made in the accompanying financial statements. In addition, any taxable income from our taxable REIT subsidiaries are subject to federal, state, and local income taxes. For the years ended December 31, 2022, 2021 and 2020 the taxable REIT subsidiaries had de minimis taxable income.
Uncertain Tax Positions	Uncertain Tax Positions We include favorable tax positions in the calculation of tax liabilities if it is more likely than not that our adopted tax position will prevail if challenged by tax authorities.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reported periods. Actual results could differ from those estimates.
Segments	SegmentsWe currently operate in one operating segment, our office and life science properties segment.
Concentration of Credit Risk	Concentration of Credit RiskAll of our properties and development and redevelopment projects are owned and all of our business is currently conducted in the state of California with the exception of the ownership and operation of ten stabilized office properties and one future development project located in the state of Washington and one development project in the tenant improvement phase and one future development project located in Austin, Texas. The ability of tenants to honor the terms of their leases is dependent upon the economic, regulatory, and social factors affecting the communities in which our tenants operate.

Organization and Ownership (Tab

Organization and Ownership (Tables)	12 Months Ended
	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Real Estate Properties	Our stabilized portfolio of operating properties was comprised of the following properties at December 31, 2022: Number of Rentable Number of Percentage Occupied (unaudited) (1) Percentage Leased Stabilized Office Properties (2) 119 16,194,146 406 91.6 % 92.9 % _______________________ (1) Represents economic occupancy. (2) Includes stabilized life science and retail space. Number of Projects Number of Units 2022 Average Occupancy Stabilized Residential Properties 3 1,001 93.5 % Number of Estimated Rentable Square Feet (1) (unaudited) In-process development projects - tenant improvement 1 734,000 In-process development projects - under construction 2 946,000 In-process redevelopment projects - under construction 2 100,000 ____________________ (1) Estimated rentable square feet upon completion.

Basis of Presentation and Sig_3

Basis of Presentation and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2022
Basis of Presentation and Significant Accounting Policies [Abstract]
Schedule of Buildings, Improvements, and Tenant Improvements Depreciation	The costs of buildings and improvements and tenant improvements are depreciated using the straight-line method of accounting over the estimated useful lives set forth in the table below. Depreciation expense for buildings and improvements for the three years ended December 31, 2022, 2021, and 2020 was $287.8 million, $256.3 million, and $244.8 million, respectively. Asset Description Depreciable Lives Buildings and improvements 25 – 40 years Tenant improvements 1 – 20 years (1) ____________________

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2022
Business Combination and Asset Acquisition [Abstract]
Schedule of Acquisitions	We did not acquire any operating properties during the year ended December 31, 2022. During the year ended December 31, 2021, we acquired the operating property listed below from an unrelated third party. Property Date of Acquisition Number of Buildings Rentable Square Feet (unaudited) Purchase Price (in millions) (1) 2021 Acquisition 2001 West 8th Avenue, Seattle, WA (2) September 17, 2021 1 539,226 $ 490.0 ________________________ (1) Excludes acquisition-related costs. (2) The results of operations for the property acquired during 2021 contributed $9.9 million to revenue and a net loss of $3.1 million for the year ended December 31, 2021 primarily due to the amortization of in-place leases acquired. The following table summarizes the development sites acquired from unrelated third parties during the years ended December 31, 2022 and 2021: Project Date of Acquisition City/Submarket Purchase Price (in millions) (1) 2022 Acquisitions 10615 Burnet Road, Austin, TX (2) March 9, 2022 Stadium District / Domain $ 40.0 Total 2022 Acquisitions $ 40.0 2021 Acquisitions 2045 Pacific Highway, San Diego, CA (2)(3) June 22, 2021 Little Italy $ 42.0 200 W. 6th Street, Austin, TX (4) June 23, 2021 Austin CBD 580.2 Total 2021 Acquisitions $ 622.2 _______________________ (1) Excludes acquisition-related costs. (2) This property was added to our future development pipeline. (3) In connection with this acquisition, we also recorded $5.2 million of environmental remediation liabilities as of the date of acquisition, which is not included in the purchase price above. (4) This property was added to the tenant improvement phase as it was acquired upon completion of core/shell. In connection with this acquisition, we assumed the underlying ground lease for the property and recorded a right of use ground lease asset and ground lease liability of $46.4 million. We evaluated the ground lease and concluded it met the criteria to be classified as an operating lease. The discount rate used in determining the present value of the minimum future lease payments was 3.97%. Refer to Note 18 “Commitments and Contingencies” for further discussion of the Company’s ground lease obligations.
Schedule of Estimated Fair Values of the Assets Acquired and Liabilities Assumed	The related assets, liabilities and results of operations of the acquired property are included in the consolidated financial statements as of the date of acquisition. The following table summarizes the estimated relative fair values of the assets acquired and liabilities assumed at the acquisition date for our 2021 operating property acquisition: Total 2021 Operating Property Acquisition Assets Land and improvements $ 84,033 Buildings and improvements (1) 370,967 Deferred leasing costs and acquisition-related intangible assets (2) 49,882 Total assets acquired $ 504,882 Liabilities Acquisition-related intangible liabilities (3) $ 15,112 Total liabilities assumed $ 15,112 Net assets acquired $ 489,770 ________________________ (1) Represents buildings, building improvements and tenant improvements. (2) Represents in-place leases (approximately $46.5 million with a weighted average amortization period of 2.2 years), leasing commissions (approximately $3.1 million with a weighted average amortization period of 3.1 years) and an above-market lease (approximately $0.3 million with a weighted average amortization period of 8.4 years). (3) Represents below-market leases (approximately $15.1 million with a weighted average amortization period of 2.4 years).

Dispositions (Tables)

Dispositions (Tables)	12 Months Ended
	Dec. 31, 2022
Discontinued Operations and Disposal Groups [Abstract]
Schedule Operating Properties and Land Dispositions	The following table summarizes the operating properties sold during the years ended December 31, 2022, 2021 and 2020: Location Month of Disposition Number of Buildings Rentable Sales Price (in millions) (1) 2022 Dispositions 3130 Wilshire Boulevard, Santa Monica, CA August 1 96,085 $ 48.0 Total 2022 Dispositions 1 96,085 $ 48.0 2021 Dispositions 1800 Owens Street, San Francisco, CA (The Exchange on 16th) March 1 750,370 $ 1,081.5 13280 & 13290 Evening Creek Drive South, San Diego, CA December 2 102,376 37.0 Total 2021 Dispositions 3 852,746 $ 1,118.5 2020 Dispositions 331 Fairchild Drive, Mountain View, CA December 1 87,147 $ 75.9 Total 2020 Dispositions 1 87,147 $ 75.9 ____________________ (1) Represents gross sales price before broker commissions, closing costs, and purchase price credits.

Deferred Leasing Costs and Ac_2

Deferred Leasing Costs and Acquisition-Related Intangible Assets and Liabilities, net (Tables)	12 Months Ended
	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Identified Deferred Leasing Costs and Acquisition-Related Intangible Assets	The following table summarizes our deferred leasing costs and acquisition-related intangible assets (acquired value of leasing costs, above-market operating leases, and in-place leases) and intangible liabilities (acquired value of below-market operating leases) as of December 31, 2022 and 2021: December 31, 2022 December 31, 2021 (in thousands) Deferred Leasing Costs and Acquisition-related Intangible Assets, net: Deferred leasing costs $ 301,967 $ 285,247 Accumulated amortization (121,545) (107,329) Deferred leasing costs, net 180,422 177,918 Above-market operating leases 260 260 Accumulated amortization (39) (8) Above-market operating leases, net 221 252 In-place leases 114,435 80,782 Accumulated amortization (44,232) (24,494) In-place leases, net 70,203 56,288 Total deferred leasing costs and acquisition-related intangible assets, net $ 250,846 $ 234,458 Acquisition-related Intangible Liabilities, net: (1) Below-market operating leases $ 52,380 $ 32,953 Accumulated amortization (14,943) (10,700) Below-market operating leases, net 37,437 22,253 Total acquisition-related intangible liabilities, net $ 37,437 $ 22,253 ____________________
Schedule of Amortization for the Period Related to Deferred Leasing Costs and Acquisition-Related Intangibles	The following table sets forth amortization related to deferred leasing costs and acquisition-related intangibles for the years ended December 31, 2022, 2021 and 2020. Year Ended December 31, 2022 2021 2020 (in thousands) Deferred leasing costs (1) $ 31,059 $ 32,472 $ 33,624 Above-market operating leases (2) 31 8 495 In-place leases (1) 31,647 14,562 11,759 Below-market operating leases (3) (10,508) (6,912) (10,748) Total $ 52,229 $ 40,130 $ 35,130 ____________________ (1) The amortization of deferred leasing costs and in-place leases is recorded to depreciation and amortization expense and the amortization of lease incentives is recorded as a reduction to rental income in the consolidated statements of operations for the periods presented. (2) The amortization of above-market operating leases is recorded as a decrease to rental income in the consolidated statements of operations for the periods presented.
Schedule of Estimated Annual Amortization Related to Deferred Leasing Costs and Acquisition-Related Intangibles	The following table sets forth the estimated annual amortization expense related to deferred leasing costs and acquisition-related intangibles as of December 31, 2022 for future periods: Year Ending Deferred Leasing Costs Above-Market Operating Leases (1) In-Place Leases Below-Market Operating Leases (2) (in thousands) 2023 $ 29,783 $ 31 $ 15,469 $ (8,105) 2024 26,158 31 6,742 (3,602) 2025 23,892 31 6,700 (3,506) 2026 20,891 31 6,377 (3,131) 2027 18,073 31 5,105 (2,933) Thereafter 61,625 66 29,810 (16,160) Total $ 180,422 $ 221 $ 70,203 $ (37,437) ____________________ (1) Represents estimated annual amortization related to above-market operating leases. Amounts will be recorded as a decrease to rental income in the consolidated statements of operations. (2) Represents estimated annual amortization related to below-market operating leases. Amounts will be recorded as an increase to rental income in the consolidated statements of operations.

Receivables (Tables)

Receivables (Tables)	12 Months Ended
	Dec. 31, 2022
Receivables [Abstract]
Schedule of Current Receivables, Net	Current receivables, net is primarily comprised of contractual rents and other lease-related obligations due from tenants. The balance consisted of the following as of December 31, 2022 and 2021: December 31, 2022 December 31, 2021 (in thousands) Current receivables $ 22,816 $ 16,448 Allowance for uncollectible tenant receivables (1) (2,233) (2,062) Current receivables, net $ 20,583 $ 14,386 ____________________
Schedule of Deferred Rent Receivables, Net	Deferred rent receivables, net consisted of the following as of December 31, 2022 and 2021: December 31, 2022 December 31, 2021 (in thousands) Deferred rent receivables $ 453,165 $ 406,277 Allowance for deferred rent receivables (1) (965) (612) Deferred rent receivables, net $ 452,200 $ 405,665 ____________________

Prepaid Expenses and Other As_2

Prepaid Expenses and Other Assets, Net (Tables)	12 Months Ended
	Dec. 31, 2022
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Prepaid Expenses and Other Assets, Net	Prepaid expenses and other assets, net consisted of the following at December 31, 2022 and 2021: December 31, 2022 December 31, 2021 (in thousands) Furniture, fixtures and other long-lived assets, net $ 41,538 $ 42,760 Prepaid expenses and deferred financing costs, net 11,364 12,564 Other assets 9,527 2,667 Total prepaid expenses and other assets, net $ 62,429 $ 57,991

Secured and Unsecured Debt of_3

Secured and Unsecured Debt of the Operating Partnership (Tables) - Kilroy Realty L.P.	12 Months Ended
	Dec. 31, 2022
Debt Instrument [Line Items]
Schedule of Unsecured Revolving Credit and Term Loan Facility	The following table summarizes the balance and terms of our unsecured revolving credit facility as of December 31, 2022 and 2021: December 31, 2022 December 31, 2021 (in thousands) Outstanding borrowings $ — $ — Remaining borrowing capacity 1,100,000 1,100,000 Total borrowing capacity (1) $ 1,100,000 $ 1,100,000 Interest rate (2) 5.20 % 1.00 % Facility fee-annual rate (3) 0.200% Maturity date July 2025 ____________________ (1) We may elect to borrow, subject to bank approval and obtaining commitments for any additional borrowing capacity, up to an additional $500.0 million under an accordion feature under the terms of the unsecured revolving credit facility. (2) Our unsecured revolving credit facility interest rate was calculated based on the contractual rate of Adjusted SOFR plus 0.900% and LIBOR plus 0.900% as of December 31, 2022 and 2021, respectively. The following table summarizes the balance and terms of our unsecured term loan facility as of December 31, 2022: December 31, 2022 (in thousands) Outstanding borrowings $ 200,000 Remaining borrowing capacity 200,000 Total borrowing capacity (1) $ 400,000 Interest rate (2) 5.23 % Undrawn facility fee-annual rate (3) 0.200 % Maturity date October 2024 ____________________ (1) We may elect to borrow, subject to bank approval and obtaining commitments for any additional borrowing capacity, up to an additional $100.0 million under an accordion feature under the terms of the unsecured term loan facility. (2) Our unsecured term loan facility interest rate was calculated based on the contractual rate of Adjusted SOFR plus 0.950% as of December 31, 2022. (3) Our undrawn facility fee is paid on a quarterly basis and is calculated based on the remaining borrowing capacity. In addition to the facility fee, we incurred debt origination and legal costs. As of December 31, 2022, $4.5 million of unamortized deferred financing costs remained to be amortized through the maturity date of our unsecured term loan facility.
Schedule of Debt Maturities	The following table summarizes the stated debt maturities and scheduled amortization payments for all outstanding debt as of December 31, 2022: Year (in thousands) 2023 $ 5,775 2024 (1) 631,006 2025 406,246 2026 401,317 2027 249,125 Thereafter 2,600,000 Total aggregate principal value (2) $ 4,293,469 ________________________ (1) Includes the $200.0 million currently outstanding on the unsecured term loan facility maturing in October 2024, for which the Company has two twelve-month extension options. (2) Includes gross principal balance of outstanding debt before the effect of the following at December 31, 2022: $24.1 million of unamortized deferred financing costs for the unsecured term loan facility, unsecured senior notes and secured debt and $6.4 million of unamortized discounts for the unsecured senior notes.
Schedule of Capitalized Interest and Loan Fees	The following table sets forth gross interest expense, including debt discount and deferred financing cost amortization, net of capitalized interest, for the years ended December 31, 2022, 2021 and 2020. The interest expense capitalized was recorded as a cost of development and redevelopment and increased the carrying value of undeveloped land and construction in progress. Year Ended December 31, 2022 2021 2020 (in thousands) Gross interest expense $ 161,761 $ 158,756 $ 150,325 Capitalized interest and deferred financing costs (77,483) (80,201) (79,553) Interest expense $ 84,278 $ 78,555 $ 70,772
Secured debt
Debt Instrument [Line Items]
Schedule of Debt Balance and Significant Terms	The following table sets forth the composition of our secured debt as of December 31, 2022 and 2021: Annual Stated Interest Rate (1) GAAP Effective Rate (1)(2) Maturity Date December 31, Type of Debt 2022 2021 (in thousands) Mortgage note payable 3.57% 3.57% December 2026 $ 159,973 $ 163,435 Mortgage note payable (3) 4.48% 4.48% July 2027 83,496 85,588 Total secured debt $ 243,469 $ 249,023 Unamortized deferred financing costs (531) (656) Total secured debt, net $ 242,938 $ 248,367 ____________________ (1) All interest rates presented are fixed-rate interest rates. (2) Represents the effective interest rate including the amortization of initial issuance discounts/premiums excluding the amortization of deferred financing costs.
Unsecured senior notes
Debt Instrument [Line Items]
Schedule of Debt Balance and Significant Terms	The following table summarizes the balance and significant terms of the registered unsecured senior notes issued by the Operating Partnership and outstanding, including the issuances noted above, and including unamortized discounts of $6.4 million and $7.4 million and unamortized deferred financing costs of $19.1 million and $22.2 million as of December 31, 2022 and 2021, respectively: Net Carrying Amount Issuance date Maturity date Stated Effective interest rate (1) 2022 2021 (in thousands) 2.650% Unsecured Senior Notes (2) October 2021 November 2033 2.650% 2.654% $ 450,000 $ 450,000 Unamortized discount and deferred financing costs (3,770) (4,117) Net carrying amount $ 446,230 $ 445,883 2.500% Unsecured Senior Notes (2) August 2020 November 2032 2.500% 2.560% $ 425,000 $ 425,000 Unamortized discount and deferred financing costs (5,268) (5,802) Net carrying amount $ 419,732 $ 419,198 4.270% Unsecured Senior Notes (3) April 2020 January 2031 4.270% 4.270% $ 350,000 $ 350,000 Unamortized discount and deferred financing costs (1,463) (1,644) Net carrying amount $ 348,537 $ 348,356 3.050% Unsecured Senior Notes (4) September 2019 February 2030 3.050% 3.064% $ 500,000 $ 500,000 Unamortized discount and deferred financing costs (4,221) (4,814) Net carrying amount $ 495,779 $ 495,186 4.750% Unsecured Senior Notes (5) November 2018 December 2028 4.750% 4.800% $ 400,000 $ 400,000 Unamortized discount and deferred financing costs (2,963) (3,457) Net carrying amount $ 397,037 $ 396,543 4.350% Unsecured Senior Notes (3) October 2018 October 2026 4.350% 4.350% $ 200,000 $ 200,000 Unamortized discount and deferred financing costs (663) (837) Net carrying amount $ 199,337 $ 199,163 4.300% Unsecured Senior Notes (3) July 2018 July 2026 4.300% 4.300% $ 50,000 $ 50,000 Unamortized discount and deferred financing costs (157) (202) Net carrying amount $ 49,843 $ 49,798 3.450% Unsecured Senior Notes (5) December 2017 December 2024 3.450% 3.470% $ 425,000 $ 425,000 Unamortized discount and deferred financing costs (1,148) (1,734) Net carrying amount $ 423,852 $ 423,266 3.450% Unsecured Senior Notes (6) February 2017 February 2029 3.450% 3.450% $ 75,000 $ 75,000 Unamortized discount and deferred financing costs (262) (304) Net carrying amount $ 74,738 $ 74,696 3.350% Unsecured Senior Notes (6) February 2017 February 2027 3.350% 3.350% $ 175,000 $ 175,000 Unamortized discount and deferred financing costs (478) (594) Net carrying amount $ 174,522 $ 174,406 4.375% Unsecured Senior Notes (7) September 2015 October 2025 4.375% 4.444% $ 400,000 $ 400,000 Unamortized discount and deferred financing costs (1,523) (2,077) Net carrying amount $ 398,477 $ 397,923 4.250% Unsecured Senior Notes (4) July 2014 August 2029 4.250% 4.350% $ 400,000 $ 400,000 Unamortized discount and deferred financing costs (3,503) (4,035) Net carrying amount $ 396,497 $ 395,965 Total Unsecured Senior Notes, Net $ 3,824,581 $ 3,820,383 ____________________ (1) Represents the effective interest rate including the amortization of initial issuance discounts, excluding the amortization of deferred financing costs. (2) Interest on these notes is payable semi-annually in arrears on May 15th and November 15th of each year. (3) Interest on these notes is payable semi-annually in arrears on April 18th and October 18th of each year. (4) Interest on these notes is payable semi-annually in arrears on February 15th and August 15th of each year. (5) Interest on these notes is payable semi-annually in arrears on June 15th and December 15th of each year. (6) Interest on these notes is payable semi-annually in arrears on February 17th and August 17th of each year. (7) Interest on these notes is payable semi-annually in arrears on April 1st and October 1st of each year.

Deferred Revenue and Acquisit_2

Deferred Revenue and Acquisition-Related Intangible Liabilities, net (Tables)	12 Months Ended
	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Schedule of Deferred Revenue and Acquisition-Related Liabilities	Deferred revenue and acquisition-related intangible liabilities, net consisted of the following at December 31, 2022 and 2021: December 31, 2022 2021 (in thousands) Deferred revenue related to tenant-funded tenant improvements $ 111,453 $ 108,002 Other deferred revenue 47,069 40,896 Acquisition-related intangible liabilities, net (1) 37,437 22,253 Total $ 195,959 $ 171,151 _____________________ (1) See Note 5 “Deferred Leasing Costs and Acquisition-Related Intangible Assets and Liabilities, net” for additional information regarding our acquisition-related intangible liabilities.
Schedule of Estimated Amortization of Deferred Revenue Related to Tenant-Funded Improvements	The following is the estimated amortization of deferred revenue related to tenant-funded tenant improvements as of December 31, 2022 for the next five years and thereafter: Year Ending (in thousands) 2023 $ 19,037 2024 16,865 2025 14,061 2026 12,382 2027 10,551 Thereafter 38,557 Total $ 111,453

Stockholders' Equity of the C_2

Stockholders' Equity of the Company (Tables)	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
Schedule of Accrued Dividends and Distributions	The following tables summarize accrued dividends and distributions for the noted outstanding shares of common stock and noncontrolling units as of December 31, 2022 and 2021: December 31, 2022 2021 (in thousands) Dividends and Distributions payable to: Common stockholders $ 63,114 $ 60,561 Noncontrolling common unitholders of the Operating Partnership 621 598 RSU holders (1) 550 691 Total accrued dividends and distribution to common stockholders and noncontrolling unitholders $ 64,285 $ 61,850 _____________________ (1) The amount includes the value of the dividend equivalents that will be paid with additional RSUs (see Note 15 “Share-Based and Other Compensation” for additional information).
Schedule of Outstanding Shares of Common Stock, Preferred Stock and Noncontrolling Units	December 31, 2022 2021 Outstanding Shares and Units: Common stock 116,878,031 116,464,169 Noncontrolling common units 1,150,574 1,150,574 RSUs (1) 984,006 1,292,802 _____________________ (1) The amount includes nonvested RSUs. Does not include 1,123,554 and 976,464 market measure-based RSUs because not all the necessary performance conditions have been met as of December 31, 2022 and 2021, respectively. Refer to Note 15 “Share-Based and Other Compensation” for additional information.

Partners' Capital of the Oper_2

Partners' Capital of the Operating Partnership (Tables)	12 Months Ended
	Dec. 31, 2022
Class of Stock [Line Items]
Schedule of Accrued Dividends and Distributions	The following tables summarize accrued dividends and distributions for the noted outstanding shares of common stock and noncontrolling units as of December 31, 2022 and 2021: December 31, 2022 2021 (in thousands) Dividends and Distributions payable to: Common stockholders $ 63,114 $ 60,561 Noncontrolling common unitholders of the Operating Partnership 621 598 RSU holders (1) 550 691 Total accrued dividends and distribution to common stockholders and noncontrolling unitholders $ 64,285 $ 61,850 _____________________ (1) The amount includes the value of the dividend equivalents that will be paid with additional RSUs (see Note 15 “Share-Based and Other Compensation” for additional information).
Schedule of Outstanding Shares of Common Stock, Preferred Stock and Noncontrolling Units	December 31, 2022 2021 Outstanding Shares and Units: Common stock 116,878,031 116,464,169 Noncontrolling common units 1,150,574 1,150,574 RSUs (1) 984,006 1,292,802 _____________________ (1) The amount includes nonvested RSUs. Does not include 1,123,554 and 976,464 market measure-based RSUs because not all the necessary performance conditions have been met as of December 31, 2022 and 2021, respectively. Refer to Note 15 “Share-Based and Other Compensation” for additional information.
Kilroy Realty L.P.
Class of Stock [Line Items]
Schedule of Redeemable Noncontrolling Interest	The following table sets forth the number of common units held by the Company as the general partner and the number of common units held by non-affiliated investors and certain of our executive officers and directors in the form of common limited partner units as well as the ownership interest held on each respective date: December 31, 2022 December 31, 2021 Company owned common units in the Operating Partnership 116,878,031 116,464,169 Company owned general partnership interest 99.0 % 99.0 % Non-affiliated investors and other common units of the Operating Partnership 1,150,574 1,150,574 Ownership interest of limited partnership interests 1.0 % 1.0 %
Schedule of Accrued Dividends and Distributions	The following tables summarize accrued distributions for the noted common units as of December 31, 2022 and 2021: December 31, 2022 December 31, 2021 (in thousands) Distributions payable to: General partner $ 63,114 $ 60,561 Common limited partners 621 598 RSU holders (1) 550 691 Total accrued distributions to common unitholders $ 64,285 $ 61,850 _____________________ (1) The amount includes the value of the dividend equivalents that will be paid with additional RSUs (see Note 15 “Share-Based and Other Compensation” for additional information).
Schedule of Outstanding Shares of Common Stock, Preferred Stock and Noncontrolling Units	December 31, 2022 December 31, 2021 Outstanding Units: Common units held by the general partner 116,878,031 116,464,169 Common units held by the limited partners 1,150,574 1,150,574 RSUs (1) 984,006 1,292,802 _____________________

Share-Based and Other Compens_2

Share-Based and Other Compensation (Tables)	12 Months Ended
	Dec. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Restricted Stock Units Valuation Assumptions	The total fair value of the Time-Based RSUs is based on the Company’s closing share price on the NYSE on the respective fair valuation dates as detailed in the table below: 2022 Time-Based RSU Grant 2021 Time-Based RSU Grant 2020 Time-Based RSU Grant December 2018 Time-Based RSU Grant Service vesting period January 28, 2022 - January 5, 2025 January & February 2021 - January 5, 2024 January 31, 2020 - January 5, 2023 December 27, 2018 - January 5, 2023 RSUs granted 158,170 160,277 109,359 298,384 Fair value on valuation date (in millions) $ 10.0 $ 9.1 $ 9.0 $ 18.5 Weighted average fair value per share $ 63.05 $ 57.07 $ 82.57 $ 62.00 Date of valuation January 28, 2022 January 29, February 18, 2021 January 31, 2020 December 27, 2018
2022, 2021 and 2020 Performance-Based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Restricted Stock Units Valuation Assumptions	The following table summarizes the estimated number of RSUs earned for the 2022 and 2021 Performance-Based RSUs and the actual number of RSUs earned for the 2020 Performance-Based RSUs and the assumptions utilized in the Monte Carlo simulation pricing models: 2022 2021 2020 Service vesting period January 28, 2022 - January, 2025 February 18, 2021 - January, 2024 January 31, 2020 - January, 2023 Target RSUs granted 193,111 172,430 154,267 Estimated RSUs earned (1) 304,535 371,518 180,419 Fair Value Assumptions: Valuation date January 28, 2022 February 18, 2021 January 31, 2020 Fair value on valuation date (in millions) $12.7 $10.6 $12.9 Fair value per share on valuation date (2) $67.62 $63.93 $84.54 Expected share price volatility 36.0 % 35.0 % 17.0 % Risk-free interest rate 1.35 % 0.20 % 1.35 % _____________________ (1) Estimated RSUs earned for the 2022 Performance-Based RSUs are based on the actual achievement of the 2022 FFO Performance Condition and assumes the target level of achievement for the 2022 Debt to EBITDA Ratio Performance Condition and the target level of achievement of the 2022 Market Condition. Estimated RSUs earned for the 2021 Performance-Based RSUs are based on the actual achievement of the 2021 FFO Performance Condition and assume target level achievement of the 2021 Market Condition and maximum level of achievement of the 2021 Debt to EBITDA Ratio Performance Condition. The 2020 Performance-Based RSUs earned are based on actual performance of the 2020 Performance Conditions and the 2020 Market Condition. (2) For one participant, the fair value per share on the valuation date for their 2022, 2021, and 2020 Performance-Based RSUs is $70.00, $66.95 and $85.52, respectively.
December 2018 Market-Based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Restricted Stock Units Valuation Assumptions	The following table summarizes the assumptions utilized in the Monte Carlo simulation pricing models: December 2018 Market-Based RSU Award Fair Value Assumptions Valuation date December 27, 2018 Fair value per share on valuation date $68.66 Expected share price volatility 23.0% Risk-free interest rate 2.4%
Market measure-based Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of Restricted Stock Units Award Activity	A summary of our performance and market-measure based RSU activity from January 1, 2022 through December 31, 2022 is presented below: Nonvested RSUs Vested RSUs Total RSUs Amount Weighted-Average Outstanding at January 1, 2022 976,464 $ 68.75 — 976,464 Granted 310,484 63.05 43,686 354,170 Vested (195,723) 70.52 195,723 — Settled (1) — — (211,478) (211,478) Issuance of dividend equivalents (2) 39,385 55.98 1,775 41,160 Canceled (7,056) 66.06 (1) (7,057) Outstanding as of December 31, 2022 (3) 1,123,554 $ 66.85 29,705 1,153,259 ____________________ (1) Represents vested RSUs that were settled in shares of the Company’s common stock. Total shares settled include 102,945 shares that were tendered in accordance with the terms of the 2006 Plan to satisfy minimum statutory tax withholding requirements related to the RSUs settled. We accept the return of RSUs at the current quoted closing share price of the Company’s common stock to satisfy tax obligations. (2) Represents the issuance of dividend equivalents earned on the underlying RSUs. The dividend equivalents vest based on terms specified under the related RSU award agreement. (3) Outstanding RSUs as of December 31, 2022 represent the actual achievement of the FFO performance conditions and assumes target levels for the market and other performance conditions. The number of restricted stock units ultimately earned is subject to change based upon actual performance over the three-year vesting period. Dividend equivalents earned will vest along with the underlying award and are also subject to changes based on the number of RSUs ultimately earned for each underlying award. A summary of our performance and market-measure based RSU activity for the years ended December 31, 2022, 2021 and 2020 is presented below: RSUs Granted RSUs Vested Years ended December 31, Non-Vested RSUs Granted (1) Weighted-Average Vested RSUs Total Vest-Date Fair Value 2022 310,484 $ 63.05 (241,184) $ 15,200 2021 281,333 $ 57.85 (252,098) $ 14,299 2020 154,267 $ 85.08 (270,054) $ 19,471 ____________________
RSUs granted
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of Restricted Stock Units Award Activity	A summary of our time-based RSU activity from January 1, 2022 through December 31, 2022 is presented below: Nonvested RSUs Vested RSUs Total RSUs Amount Weighted Average Fair Value Outstanding at January 1, 2022 539,729 $ 64.03 753,073 1,292,802 Granted 177,099 62.58 — 177,099 Vested (270,061) 67.15 270,061 — Settled (1) — — (535,019) (535,019) Issuance of dividend equivalents (2) 15,324 54.15 24,806 40,130 Forfeited (18,724) 62.56 — (18,724) Canceled (3) — — (1,987) (1,987) Outstanding as of December 31, 2022 443,367 $ 61.27 510,934 954,301 ____________________ (1) Represents vested RSUs that were settled in shares of the Company’s common stock. Total shares settled include 231,604 shares that were tendered in accordance with the terms of the 2006 Plan to satisfy minimum statutory tax withholding requirements related to the RSUs settled. We accept the return of RSUs at the current quoted closing share price of the Company’s common stock to satisfy tax obligations. (2) Represents the issuance of dividend equivalents earned on the underlying RSUs. The dividend equivalents vest based on terms specified under the related RSU award agreement. (3) For shares vested but not yet settled, we accept the return of RSUs at the current quoted closing share price of the Company’s common stock to satisfy minimum statutory tax-withholding requirements related to either the settlement or vesting of RSUs in accordance with the terms of the 2006 Plan. A summary of our time-based RSU activity for the years ended December 31, 2022, 2021 and 2020 is presented below: RSUs Granted RSUs Vested Year ended December 31, Non-Vested Weighted-Average Grant Date Vested RSUs Total Vest-Date Fair Value (1) (in thousands) 2022 177,099 $ 62.58 (294,867) $ 19,890 2021 172,181 $ 57.83 (144,838) $ 8,605 2020 120,769 $ 79.74 (208,608) $ 15,066 ____________________

Rental Income and Future Mini_2

Rental Income and Future Minimum Rent (Tables)	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
Schedule of Rental Income	The table below sets forth the allocation of rental income between fixed and variable payments and net collectability recoveries or reversals for the years ended December 31, 2022 and 2021: Year Ended December 31, 2022 2021 Fixed lease payments $ 923,257 $ 826,883 Variable lease payments 162,638 123,544 Net collectability recoveries (reversals) (1) 123 (1,433) Total rental income $ 1,086,018 $ 948,994 ____________________
Future Contractual Minimum Rent Under Operating Lease	Future contractual minimum rent under operating leases, which includes amounts contractually due from leases that are on a cash basis of reporting due to creditworthiness considerations, as of December 31, 2022 for future periods is summarized as follows: Year Ending (in thousands) 2023 $ 809,406 2024 796,645 2025 769,116 2026 716,780 2027 656,100 Thereafter 2,464,166 Total (1) $ 6,212,213 ____________________ (1) Excludes residential leases and leases with a term of one year or less.

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Schedule of Contractual Expiration Dates for Ground Leases	The following table summarizes our properties that are held subject to long-term noncancellable ground lease obligations and the respective contractual expiration dates at December 31, 2022: Property Contractual Expiration Date (1) 701, 801 and 837 N. 34th Street, Seattle, WA (2) December 2041 1701 Page Mill Road and 3150 Porter Drive, Palo Alto, CA December 2067 Kilroy Airport Center Phases I, II, and III, Long Beach, CA July 2084 3243 S. La Cienega Boulevard, Los Angeles, CA October 2106 200 W. 6th Street, Austin, TX December 2112 ____________________ (1) Reflects the contractual expiration date prior to the impact of any extension or purchase options held by the Company. (2) The Company has three 10-year and one 45-year extension options for this ground lease, which if exercised would extend the expiration date to December 2116. These extension options are not assumed to be exercised in our calculation of the present value of the future minimum lease payments for this lease.
Schedule of Minimum Commitment Under Ground Leases	The minimum commitment under our ground leases as of December 31, 2022 for future periods is as follows: Year Ending (in thousands) 2023 $ 6,563 2024 6,598 2025 6,634 2026 6,671 2027 6,713 Thereafter 368,281 Total undiscounted cash flows (1)(2)(3)(4)(5)(6) $ 401,460 Present value discount (276,466) Ground lease liabilities $ 124,994 ________________________ (1) Excludes contingent future rent payments based on gross income or adjusted gross income and reflects the minimum ground lease obligations before the impact of ground lease extension options. ( 2) One of our ground lease obligations is subject to a fair market value adjustment every five years; however, the lease includes ground rent subprotection and infrastructure rent credits which currently limit our annual rental obligations to $1.0 million. The contractual obligations for that ground lease included above assumes the lesser of $1.0 million or annual lease rental obligation in effect as of December 31, 2022. (3) One of our ground lease obligations is subject to a fair market value adjustment every five years based on a combination of CPI adjustments and third-party appraisals limited to maximum increases annually. The contractual obligations for that lease included above assume the current annual ground lease obligation in effect at December 31, 2022 for the remainder of the lease term since we cannot predict future adjustments. (4) One of our ground lease obligations includes a component which is based on the percentage of adjusted gross income that exceeds the minimum ground rent. The minimum rent is subject to increases every 10 years by an amount equal to 60% of the average annual percentage rent for the previous three years. The contractual obligations for this lease included above assume the current annual ground lease obligation in effect at December 31, 2022 for the remainder of the lease term since we cannot predict future adjustments. (5) One of our ground lease obligations is subject to fixed 5% ground rent increases every five years, with the next increase occurring on November 1, 2027.

Fair Value Measurements and D_2

Fair Value Measurements and Disclosures (Tables)	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value of the Company's Marketable Securities	The following table sets forth the fair value of our marketable securities as of December 31, 2022 and 2021: Fair Value (Level 1) (1) 2022 2021 Description (in thousands) Marketable securities (2) $ 23,547 $ 27,475 ____________________ (1) Based on quoted prices in active markets for identical securities. (2) The marketable securities are held in a limited rabbi trust.
Carrying Value and Fair Value of Other Financial Instruments	The following table sets forth the carrying value and the fair value of our other financial instruments as of December 31, 2022 and 2021: December 31, 2022 2021 Carrying Value Fair Value (1) Carrying Value Fair Value (1) (in thousands) Liabilities Secured debt, net $ 242,938 $ 225,847 $ 248,367 $ 269,687 Unsecured debt, net 4,020,058 3,500,420 3,820,383 4,105,408 _______________ (1) Fair value calculated using Level 2 inputs, which are based on model-derived valuations in which significant inputs and significant value drivers are observable in active markets.

Net Income Available to Commo_3

Net Income Available to Common Stockholders Per Share of the Company (Tables)	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Net income Available to Common Stockholders	The following table reconciles the numerator and denominator in computing the Company’s basic and diluted per-share computations for net income available to common stockholders for the years ended December 31, 2022, 2021 and 2020: Year Ended December 31, 2022 2021 2020 (in thousands, except unit and per unit amounts) Numerator: Net income available to common stockholders $ 232,615 $ 628,144 $ 187,105 Allocation to participating securities (1) (1,272) (1,516) (2,229) Numerator for basic and diluted net income available to common stockholders $ 231,343 $ 626,628 $ 184,876 Denominator: Basic weighted average vested shares outstanding 116,806,575 116,429,130 113,241,341 Effect of dilutive securities 413,472 519,513 478,281 Diluted weighted average vested shares and common stock equivalents outstanding 117,220,047 116,948,643 113,719,622 Basic earnings per share: Net income available to common stockholders per share $ 1.98 $ 5.38 $ 1.63 Diluted earnings per share: Net income available to common stockholders per share $ 1.97 $ 5.36 $ 1.63 _____________________ (1) Participating securities include nonvested shares, certain time-based RSUs and vested market measure-based RSUs.

Net Income Available to Commo_4

Net Income Available to Common Unitholders Per Unit of the Operating Partnership (Tables)	12 Months Ended
	Dec. 31, 2022
Net Income Available To Common Unitholders [Line Items]
Net income Available to Common Unitholders	The following table reconciles the numerator and denominator in computing the Company’s basic and diluted per-share computations for net income available to common stockholders for the years ended December 31, 2022, 2021 and 2020: Year Ended December 31, 2022 2021 2020 (in thousands, except unit and per unit amounts) Numerator: Net income available to common stockholders $ 232,615 $ 628,144 $ 187,105 Allocation to participating securities (1) (1,272) (1,516) (2,229) Numerator for basic and diluted net income available to common stockholders $ 231,343 $ 626,628 $ 184,876 Denominator: Basic weighted average vested shares outstanding 116,806,575 116,429,130 113,241,341 Effect of dilutive securities 413,472 519,513 478,281 Diluted weighted average vested shares and common stock equivalents outstanding 117,220,047 116,948,643 113,719,622 Basic earnings per share: Net income available to common stockholders per share $ 1.98 $ 5.38 $ 1.63 Diluted earnings per share: Net income available to common stockholders per share $ 1.97 $ 5.36 $ 1.63 _____________________ (1) Participating securities include nonvested shares, certain time-based RSUs and vested market measure-based RSUs.
Kilroy Realty L.P.
Net Income Available To Common Unitholders [Line Items]
Net income Available to Common Unitholders	The following table reconciles the numerator and denominator in computing the Operating Partnership’s basic and diluted per-unit computations for net income available to common unitholders for the years ended December 31, 2022, 2021 and 2020: Year Ended December 31, 2022 2021 2020 (in thousands, except unit and per unit amounts) Numerator: Net income available to common unitholders $ 234,898 $ 634,307 $ 189,609 Allocation to participating securities (1) (1,272) (1,516) (2,229) Numerator for basic and diluted net income available to common unitholders $ 233,626 $ 632,791 $ 187,380 Denominator: Basic weighted average vested units outstanding 117,957,149 117,579,704 115,095,506 Effect of dilutive securities 413,472 519,513 478,281 Diluted weighted average vested units and common unit equivalents outstanding 118,370,621 118,099,217 115,573,787 Basic earnings per unit: Net income available to common unitholders per unit $ 1.98 $ 5.38 $ 1.63 Diluted earnings per unit: Net income available to common unitholders per unit $ 1.97 $ 5.36 $ 1.62 ____________________ (1) Participating securities include nonvested shares, certain time-based RSUs and vested market measure-based RSUs.

Supplemental Cash Flow Inform_3

Supplemental Cash Flow Information of the Company (Tables)	12 Months Ended
	Dec. 31, 2022
Supplemental Cash Flow Elements [Abstract]
Schedule of Supplemental Cash Flows	Supplemental cash flow information as follows (in thousands): Year Ended December 31, 2022 2021 2020 SUPPLEMENTAL CASH FLOWS INFORMATION: Cash paid for interest, net of capitalized interest of $72,973, $75,802, and $75,852 as of December 31, 2022, 2021 and 2020, respectively $ 79,634 $ 77,028 $ 61,741 Cash paid for amounts included in the measurement of ground lease liabilities $ 6,447 $ 6,209 $ 5,744 NON-CASH INVESTING TRANSACTIONS: Accrual for expenditures for operating properties and development and redevelopment properties $ 97,729 $ 119,829 $ 189,161 Tenant improvements funded directly by tenants $ 6,772 $ 20,070 $ 11,592 Assumption of accrued liabilities in connection with acquisitions (Note 3) $ — $ 37,572 $ — Initial measurement of operating right of use ground lease assets (Notes 3 and 18) $ — $ 46,430 $ — Initial measurement of operating ground lease liabilities (Notes 3 and 18) $ — $ 46,430 $ — NON-CASH FINANCING TRANSACTIONS: Accrual of dividends and distributions payable to common stockholders and common $ 64,285 $ 61,850 $ 59,431 Exchange of common units of the Operating Partnership into shares of the Company’s $ — $ — $ 37,640
Reconciliation of Cash and Cash Equivalents and Restricted Cash	The following is a reconciliation of our cash and cash equivalents and restricted cash at the beginning and end of the years ended December 31, 2022, 2021 and 2020. Year Ended December 31, 2022 2021 2020 (in thousands) RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH: Cash and cash equivalents at beginning of period $ 414,077 $ 731,991 $ 60,044 Restricted cash at beginning of period 13,006 91,139 16,300 Cash and cash equivalents and restricted cash at beginning of period $ 427,083 $ 823,130 $ 76,344 Cash and cash equivalents at end of period $ 347,379 $ 414,077 $ 731,991 Restricted cash at end of period — 13,006 91,139 Cash and cash equivalents and restricted cash at end of period $ 347,379 $ 427,083 $ 823,130
Reconciliation of Cash and Cash Equivalents and Restricted Cash	The following is a reconciliation of our cash and cash equivalents and restricted cash at the beginning and end of the years ended December 31, 2022, 2021 and 2020. Year Ended December 31, 2022 2021 2020 (in thousands) RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH: Cash and cash equivalents at beginning of period $ 414,077 $ 731,991 $ 60,044 Restricted cash at beginning of period 13,006 91,139 16,300 Cash and cash equivalents and restricted cash at beginning of period $ 427,083 $ 823,130 $ 76,344 Cash and cash equivalents at end of period $ 347,379 $ 414,077 $ 731,991 Restricted cash at end of period — 13,006 91,139 Cash and cash equivalents and restricted cash at end of period $ 347,379 $ 427,083 $ 823,130

Supplemental Cash Flow Inform_4

Supplemental Cash Flow Information of the Operating Partnership (Tables)	12 Months Ended
	Dec. 31, 2022
Other Significant Noncash Transactions [Line Items]
Schedule of Supplemental Cash Flows	Supplemental cash flow information as follows (in thousands): Year Ended December 31, 2022 2021 2020 SUPPLEMENTAL CASH FLOWS INFORMATION: Cash paid for interest, net of capitalized interest of $72,973, $75,802, and $75,852 as of December 31, 2022, 2021 and 2020, respectively $ 79,634 $ 77,028 $ 61,741 Cash paid for amounts included in the measurement of ground lease liabilities $ 6,447 $ 6,209 $ 5,744 NON-CASH INVESTING TRANSACTIONS: Accrual for expenditures for operating properties and development and redevelopment properties $ 97,729 $ 119,829 $ 189,161 Tenant improvements funded directly by tenants $ 6,772 $ 20,070 $ 11,592 Assumption of accrued liabilities in connection with acquisitions (Note 3) $ — $ 37,572 $ — Initial measurement of operating right of use ground lease assets (Notes 3 and 18) $ — $ 46,430 $ — Initial measurement of operating ground lease liabilities (Notes 3 and 18) $ — $ 46,430 $ — NON-CASH FINANCING TRANSACTIONS: Accrual of dividends and distributions payable to common stockholders and common $ 64,285 $ 61,850 $ 59,431 Exchange of common units of the Operating Partnership into shares of the Company’s $ — $ — $ 37,640
Reconciliation of Cash and Cash Equivalents and Restricted Cash	The following is a reconciliation of our cash and cash equivalents and restricted cash at the beginning and end of the years ended December 31, 2022, 2021 and 2020. Year Ended December 31, 2022 2021 2020 (in thousands) RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH: Cash and cash equivalents at beginning of period $ 414,077 $ 731,991 $ 60,044 Restricted cash at beginning of period 13,006 91,139 16,300 Cash and cash equivalents and restricted cash at beginning of period $ 427,083 $ 823,130 $ 76,344 Cash and cash equivalents at end of period $ 347,379 $ 414,077 $ 731,991 Restricted cash at end of period — 13,006 91,139 Cash and cash equivalents and restricted cash at end of period $ 347,379 $ 427,083 $ 823,130
Reconciliation of Cash and Cash Equivalents and Restricted Cash	The following is a reconciliation of our cash and cash equivalents and restricted cash at the beginning and end of the years ended December 31, 2022, 2021 and 2020. Year Ended December 31, 2022 2021 2020 (in thousands) RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH: Cash and cash equivalents at beginning of period $ 414,077 $ 731,991 $ 60,044 Restricted cash at beginning of period 13,006 91,139 16,300 Cash and cash equivalents and restricted cash at beginning of period $ 427,083 $ 823,130 $ 76,344 Cash and cash equivalents at end of period $ 347,379 $ 414,077 $ 731,991 Restricted cash at end of period — 13,006 91,139 Cash and cash equivalents and restricted cash at end of period $ 347,379 $ 427,083 $ 823,130
Kilroy Realty L.P.
Other Significant Noncash Transactions [Line Items]
Schedule of Supplemental Cash Flows	Supplemental cash flow information as follows (in thousands): Year Ended December 31, 2022 2021 2020 SUPPLEMENTAL CASH FLOWS INFORMATION: Cash paid for interest, net of capitalized interest of $72,973, $75,802, and $75,852 as of December 31, 2022, 2021 and 2020, respectively $ 79,634 $ 77,028 $ 61,741 Cash paid for amounts included in the measurement of ground lease liabilities $ 6,447 $ 6,209 $ 5,744 NON-CASH INVESTING TRANSACTIONS: Accrual for expenditures for operating properties and development and redevelopment properties $ 97,729 $ 119,829 $ 189,161 Tenant improvements funded directly by tenants $ 6,772 $ 20,070 $ 11,592 Assumption of accrued liabilities in connection with acquisitions (Note 3) $ — $ 37,572 $ — Initial measurement of operating right of use ground lease assets (Notes 3 and 18) $ — $ 46,430 $ — Initial measurement of operating ground lease liabilities (Notes 3 and 18) $ — $ 46,430 $ — NON-CASH FINANCING TRANSACTIONS: Accrual of distributions payable to common unitholders (Notes 14 and 25) $ 64,285 $ 61,850 $ 59,431
Reconciliation of Cash and Cash Equivalents and Restricted Cash	The following is a reconciliation of our cash and cash equivalents and restricted cash at the beginning and end of the years ended December 31, 2022, 2021 and 2020. Year Ended December 31, 2022 2021 2020 (in thousands) RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH: Cash and cash equivalents at beginning of period $ 414,077 $ 731,991 $ 60,044 Restricted cash at beginning of period 13,006 91,139 16,300 Cash and cash equivalents and restricted cash at beginning of period $ 427,083 $ 823,130 $ 76,344 Cash and cash equivalents at end of period $ 347,379 $ 414,077 $ 731,991 Restricted cash at end of period — 13,006 91,139 Cash and cash equivalents and restricted cash at end of period $ 347,379 $ 427,083 $ 823,130
Reconciliation of Cash and Cash Equivalents and Restricted Cash	The following is a reconciliation of our cash and cash equivalents and restricted cash at the beginning and end of the years ended December 31, 2022, 2021 and 2020. Year Ended December 31, 2022 2021 2020 (in thousands) RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH: Cash and cash equivalents at beginning of period $ 414,077 $ 731,991 $ 60,044 Restricted cash at beginning of period 13,006 91,139 16,300 Cash and cash equivalents and restricted cash at beginning of period $ 427,083 $ 823,130 $ 76,344 Cash and cash equivalents at end of period $ 347,379 $ 414,077 $ 731,991 Restricted cash at end of period — 13,006 91,139 Cash and cash equivalents and restricted cash at end of period $ 347,379 $ 427,083 $ 823,130

Tax Treatment of Distributions

Tax Treatment of Distributions (Tables)	12 Months Ended
	Dec. 31, 2022
Class of Stock [Line Items]
Schedule of Reconciliation of Dividends Declared to Dividends Paid	The following table reconciles the dividends declared per share of common stock to the dividends paid per share of common stock during the years ended December 31, 2022, 2021 and 2020 as follows: Year Ended December 31, Dividends 2022 2021 2020 Dividends declared per share of common stock $ 2.120 $ 2.040 $ 1.970 Less: Dividends declared in the current year and paid in the following year (0.540) (0.520) (0.500) Add: Dividends declared in the prior year and paid in the current year 0.520 0.500 0.485 Dividends paid per share of common stock $ 2.100 $ 2.020 $ 1.955
Common Stock
Class of Stock [Line Items]
Schedule of Reconciliation of Dividends Declared to Dividends Paid	The unaudited income tax treatment for the dividends to common stockholders reportable for the years ended December 31, 2022, 2021 and 2020 as identified in the table above was as follows: Year Ended December 31, Shares of Common Stock 2022 2021 2020 Ordinary income (1) $ 1.865 88.80 % $ 1.338 66.22 % $ 1.474 75.40 % Qualified dividend 0.001 0.02 % 0.003 0.15 % 0.002 0.12 % Return of capital 0.230 10.99 % 0.551 27.30 % 0.162 8.30 % Capital gains (2) 0.004 0.19 % 0.075 3.72 % 0.275 14.05 % Unrecaptured section 1250 gains — — % 0.053 2.61 % 0.042 2.13 % $ 2.100 100.00 % $ 2.020 100.00 % $ 1.955 100.00 % ____________________ (1) The Tax Cuts and Jobs Act enacted on December 22, 2017 generally allows a deduction for noncorporate taxpayers equal to 20% of ordinary dividends distributed by a REIT (excluding capital gain dividends and qualified dividend income). The amount of dividend eligible for this deduction is referred to as the Section 199A Dividend. For the year ended December 31, 2022, the Section 199A Dividend is equal to the total ordinary income dividend. (2) Capital gains are comprised entirely of 20% rate gains.

Organization and Ownership - Op

Organization and Ownership - Operating Properties (Details)	12 Months Ended
	Dec. 31, 2022 ft² project property building tenant
Real Estate Properties [Line Items]
Rentable Square Feet (unaudited)	16,194,146
Stabilized Office Properties
Real Estate Properties [Line Items]
Number of Buildings | building	119
Rentable Square Feet (unaudited)	16,194,146
Number of Tenants | tenant	406
Percentage Occupied (unaudited)	91.60%
Percentage Leased (unaudited)	92.90%
Stabilized Residential Properties
Real Estate Properties [Line Items]
Number of Projects | property	3
Number of Units | property	1,001
2022 Average Occupancy (unaudited)	93.50%
In-process development projects - tenant improvement
Real Estate Properties [Line Items]
Rentable Square Feet (unaudited)	734,000
Number of Projects | property	1
In-process development projects - under construction
Real Estate Properties [Line Items]
Rentable Square Feet (unaudited)	946,000
Number of Projects | project	2
In-process redevelopment projects - under construction
Real Estate Properties [Line Items]
Rentable Square Feet (unaudited)	100,000
Number of Projects | project	2

Organization and Ownership - Na

Organization and Ownership - Narrative (Details)	12 Months Ended
	Dec. 31, 2022 ft² a property developmentProject building development_site redevelopmentProject property_partnership	Dec. 31, 2021
Real Estate Properties [Line Items]
Lease-up properties occupancy percentage	95%
Lease-up properties occupancy duration	1 year
Rentable square feet | ft²	16,194,146
100 First LLC and 303 Second LLC
Real Estate Properties [Line Items]
Company owned general partnership interest	56%
Redwood LLC
Real Estate Properties [Line Items]
Company owned general partnership interest	93%
Operating Partnership
Real Estate Properties [Line Items]
Ownership interest (percent)	99%	99%
Operating Partnership | Noncontrolling common units
Real Estate Properties [Line Items]
Ownership interest (percent)	1%	1%
San Francisco, California
Real Estate Properties [Line Items]
Number of properties | building	1
Redwood City, California | Redwood LLC
Real Estate Properties [Line Items]
Number of properties | property	2
Stabilized Development Projects | Seattle, Washington and San Diego, CA
Real Estate Properties [Line Items]
Number of development projects added during the period | developmentProject	2
Stabilized Redevelopment Projects | San Diego, CA
Real Estate Properties [Line Items]
Number of buildings added for redevelopment during the period | redevelopmentProject	2
Stabilized Office and Life Science Space | Seattle, Washington and San Diego, CA
Real Estate Properties [Line Items]
Number of buildings | building	4
Rentable square feet | ft²	1,114,704
Development sites
Real Estate Properties [Line Items]
Number of future development sites	8
Future Development Site
Real Estate Properties [Line Items]
Area of undeveloped land | a	64
Stabilized Office Properties
Real Estate Properties [Line Items]
Number of buildings | building	119
Rentable square feet | ft²	16,194,146
Stabilized Office Properties | Washington
Real Estate Properties [Line Items]
Number of properties | property	10
Future development project | Washington
Real Estate Properties [Line Items]
Number of properties	1
Future development project | Texas
Real Estate Properties [Line Items]
Number of properties	1
Development project in the tenant improvement phase | Texas
Real Estate Properties [Line Items]
Number of properties	1
Properties and development projects
Real Estate Properties [Line Items]
Property ownership percentage	100%
Office Properties Owned by Consolidated Property Partnerships
Real Estate Properties [Line Items]
Number of properties | property	4
Consolidated property partnerships
Real Estate Properties [Line Items]
Number of property partnerships | property_partnership	3
Consolidated Property Partnerships Owning Office Properties Through REITs | 100 First LLC and 303 Second LLC
Real Estate Properties [Line Items]
Number of property partnerships | property_partnership	2

Basis of Presentation and Sig_4

Basis of Presentation and Significant Accounting Policies - Narrative (Details)	12 Months Ended
	Dec. 31, 2022 USD ($) property property_partnership development_site investment variableInterestEntity segment	Dec. 31, 2021 USD ($) property investment variableInterestEntity	Dec. 31, 2020 USD ($)
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Assets	$ 10,796,987,000	$ 10,583,397,000
Liabilities	5,122,026,000	4,893,527,000
Noncontrolling interest in consolidated subsidiary	$ 184,390,000	$ 196,064,000
Number of equity method investments | investment	0	0
Number of properties classified as held for sale | property	0	0
Number of consolidated property partnerships | property_partnership	3
Conversion ratio	1
Income tax provision	$ 0	$ 0	$ 0
Number of operating segments | segment	1
Lease Agreements | Minimum
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Finite-lived intangible asset, useful life	1 year
Lease Agreements | Maximum
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Finite-lived intangible asset, useful life	20 years
Disposal group, disposed of by sale
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Restricted cash	$ 0	0
Building and building improvements
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Depreciation of real estate	$ 287,800,000	$ 256,300,000	$ 244,800,000
Building and building improvements | Minimum
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Property depreciable lives	25 years
Building and building improvements | Maximum
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Property depreciable lives	40 years
Leasehold improvements | Minimum
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Property depreciable lives	1 year
Leasehold improvements | Maximum
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Property depreciable lives	20 years
Stabilized Office Properties | Washington
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of buildings | property	10
Future development project | Washington
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of buildings | development_site	1
Future development project | Texas
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of buildings | development_site	1
Development project in the tenant improvement phase | Texas
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of buildings | development_site	1
Variable Interest Entity, Primary Beneficiary
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of VIEs | variableInterestEntity	2	2
Assets	$ 438,700,000	$ 462,300,000
Liabilities	31,500,000	28,100,000
Variable Interest Entity, Primary Beneficiary | 100 First LLC and 303 Second LLC
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncontrolling interest in consolidated subsidiary	179,400,000	190,700,000
Variable Interest Entity, Primary Beneficiary | Real estate investment
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Assets	$ 362,700,000	$ 377,900,000

Acquisitions - Operating Proper

Acquisitions - Operating Property and Development Project Acquisitions (Details) $ in Thousands					12 Months Ended
	Mar. 09, 2022 USD ($)	Sep. 17, 2021 USD ($) ft² property	Jun. 23, 2021 USD ($)	Jun. 22, 2021 USD ($)	Dec. 31, 2022 USD ($) ft² property	Dec. 31, 2021 USD ($)
Schedule of Asset Acquisitions, by Acquisition [Line Items]
Number of buildings acquired | property					0
Rentable square feet (unaudited) | ft²					16,194,146
Ground lease right-of-use-asset					$ 126,530	$ 127,302
Development properties
Schedule of Asset Acquisitions, by Acquisition [Line Items]
Purchase price					$ 40,000	622,200
2001 West 8th Avenue, Seattle, WA
Schedule of Asset Acquisitions, by Acquisition [Line Items]
Number of buildings acquired | property		1
Rentable square feet (unaudited) | ft²		539,226
Purchase price		$ 490,000
Revenue contributed from acquired properties						9,900
Net income (loss) contributed from acquired properties						$ (3,100)
10615 Burnet Road, Austin, TX | Development properties
Schedule of Asset Acquisitions, by Acquisition [Line Items]
Purchase price	$ 40,000
2045 Pacific Highway, San Diego, CA | Development properties
Schedule of Asset Acquisitions, by Acquisition [Line Items]
Purchase price				$ 42,000
Accrued environmental remediation liabilities				$ 5,200
200 W. 6th Street, Austin, TX
Schedule of Asset Acquisitions, by Acquisition [Line Items]
Rentable square feet (unaudited) | ft²					0
200 W. 6th Street, Austin, TX | Development properties
Schedule of Asset Acquisitions, by Acquisition [Line Items]
Purchase price			$ 580,200
Ground lease liabilities			46,400
Ground lease right-of-use-asset			$ 46,400
Discount rate			3.97%

Acquisitions - Assets Acquired

Acquisitions - Assets Acquired and Liabilities Assumed (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($)
Assets
Land and improvements	$ 84,033
Buildings and improvements	370,967
Deferred leasing costs and acquisition-related intangible assets	49,882
Total assets acquired	504,882
Liabilities
Acquisition-related intangible liabilities	15,112
Total liabilities assumed	15,112
Net assets acquired	489,770
Below-market leases acquired	$ 15,100
Weighted average amortization period of below-market leases	2 years 4 months 24 days
In-Place Leases
Assets
Deferred leasing costs and acquisition-related intangible assets	$ 46,500
Liabilities
Weighted average amortization period of above-market leases (in years)	2 years 2 months 12 days
Leasing Commissions
Assets
Deferred leasing costs and acquisition-related intangible assets	$ 3,100
Liabilities
Weighted average amortization period of above-market leases (in years)	3 years 1 month 6 days
Above Market Leases
Assets
Deferred leasing costs and acquisition-related intangible assets	$ 300
Liabilities
Weighted average amortization period of above-market leases (in years)	8 years 4 months 24 days

Acquisitions - Narrative (Detai

Acquisitions - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jul. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Schedule of Asset Acquisitions, by Acquisition [Line Items]
Payments to acquire land parcel		$ 40,033	$ 586,927	$ 0
Acquisition costs, capitalized		$ 200	$ 1,300	$ 300
601 108th Avenue NE, Bellevue, WA
Schedule of Asset Acquisitions, by Acquisition [Line Items]
Payments to acquire land parcel	$ 47,000

Dispositions - Operating Proper

Dispositions - Operating Property Dispositions (Details) $ in Thousands	1 Months Ended				12 Months Ended
	Aug. 31, 2022 USD ($) ft² property	Dec. 31, 2021 USD ($) ft² property	Mar. 31, 2021 USD ($) ft² property	Dec. 31, 2020 USD ($) ft² property	Dec. 31, 2022 USD ($) ft² property	Dec. 31, 2021 USD ($) ft² property	Dec. 31, 2020 USD ($) ft² property
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Rentable square feet | ft²					16,194,146
Gains on sales of operating properties | $					$ 17,329	$ 463,128	$ 35,536
Disposal group, disposed of by sale | 2022 Dispositions
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of buildings | property					1
Rentable square feet | ft²					96,085
Sales price | $					$ 48,000
Disposal group, disposed of by sale | 3130 Wilshire Boulevard, Santa Monica, CA
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of buildings | property	1
Rentable square feet | ft²	96,085
Sales price | $	$ 48,000
Disposal group, disposed of by sale | 2021 Dispositions
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of buildings | property		3				3
Rentable square feet | ft²		852,746				852,746
Sales price | $						$ 1,118,500
Disposal group, disposed of by sale | 1800 Owens Street, San Francisco, CA (The Exchange on 16th)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of buildings | property			1
Rentable square feet | ft²			750,370
Sales price | $			$ 1,081,500
Disposal group, disposed of by sale | 13280 & 13290 Evening Creek Drive South, San Diego, CA
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of buildings | property		2				2
Rentable square feet | ft²		102,376				102,376
Sales price | $		$ 37,000
Disposal group, disposed of by sale | 2020 Dispositions
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of buildings | property				1			1
Rentable square feet | ft²				87,147			87,147
Sales price | $							$ 75,900
Disposal group, disposed of by sale | 331 Fairchild Drive, Mountain View, CA
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of buildings | property				1			1
Rentable square feet | ft²				87,147			87,147
Sales price | $				$ 75,900

Deferred Leasing Costs and Ac_3

Deferred Leasing Costs and Acquisition-Related Intangible Assets and Liabilities, net - Deferred Leasing Costs and Acquisition-related Intangible Assets and Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred Leasing Costs and Acquisition-related Intangible Assets, net:
Total deferred leasing costs and acquisition-related intangible assets, net	$ 250,846	$ 234,458
Acquisition-related Intangible Liabilities, net:
Total acquisition-related intangible liabilities, net	37,437	22,253
Deferred Leasing Costs
Deferred Leasing Costs and Acquisition-related Intangible Assets, net:
Finite-lived intangible assets, gross	301,967	285,247
Accumulated amortization	(121,545)	(107,329)
Finite-lived intangible assets	180,422	177,918
Above-market operating leases
Deferred Leasing Costs and Acquisition-related Intangible Assets, net:
Finite-lived intangible assets, gross	260	260
Accumulated amortization	(39)	(8)
Finite-lived intangible assets	221	252
In-Place Leases
Deferred Leasing Costs and Acquisition-related Intangible Assets, net:
Finite-lived intangible assets, gross	114,435	80,782
Accumulated amortization	(44,232)	(24,494)
Finite-lived intangible assets	70,203	56,288
Below-market operating leases
Acquisition-related Intangible Liabilities, net:
Acquisition-related intangible liabilities, gross	52,380	32,953
Accumulated amortization	(14,943)	(10,700)
Acquisition-related intangible liabilities, net	$ 37,437	$ 22,253

Deferred Leasing Costs and Ac_4

Deferred Leasing Costs and Acquisition-Related Intangible Assets and Liabilities, net - Amortization of Deferred Leasing Costs and Acquisition-related Intangibles (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Amortization for the period related to deferred leasing costs and acquisition-related intangibles
Amortization for the period related to deferred leasing costs and acquisition-related intangibles	$ 52,229	$ 40,130	$ 35,130
Deferred Leasing Costs
Amortization for the period related to deferred leasing costs and acquisition-related intangibles
Amortization for the period related to deferred leasing costs and acquisition-related intangibles	31,059	32,472	33,624
Estimated annual amortization related to acquisition-related intangible assets
Finite-lived intangible assets, 2023	29,783
Finite-lived intangible assets, 2024	26,158
Finite-lived intangible assets, 2025	23,892
Finite-lived intangible assets, 2026	20,891
Finite-lived intangible assets, 2027	18,073
Finite-lived intangible assets, thereafter	61,625
Finite-lived intangible assets	180,422	177,918
Above-market operating leases
Amortization for the period related to deferred leasing costs and acquisition-related intangibles
Amortization for the period related to deferred leasing costs and acquisition-related intangibles	31	8	495
Estimated annual amortization related to acquisition-related intangible assets
Finite-lived intangible assets, 2023	31
Finite-lived intangible assets, 2024	31
Finite-lived intangible assets, 2025	31
Finite-lived intangible assets, 2026	31
Finite-lived intangible assets, 2027	31
Finite-lived intangible assets, thereafter	66
Finite-lived intangible assets	221	252
In-Place Leases
Amortization for the period related to deferred leasing costs and acquisition-related intangibles
Amortization for the period related to deferred leasing costs and acquisition-related intangibles	31,647	14,562	11,759
Estimated annual amortization related to acquisition-related intangible assets
Finite-lived intangible assets, 2023	15,469
Finite-lived intangible assets, 2024	6,742
Finite-lived intangible assets, 2025	6,700
Finite-lived intangible assets, 2026	6,377
Finite-lived intangible assets, 2027	5,105
Finite-lived intangible assets, thereafter	29,810
Finite-lived intangible assets	70,203	56,288
Below-market operating leases
Amortization for the period related to deferred leasing costs and acquisition-related intangibles
Amortization of intangible liabilities	(10,508)	(6,912)	$ (10,748)
Estimated annual amortization related to acquisition-related intangible liabilities
Acquisition-related intangible liabilities, 2023	(8,105)
Acquisition-related intangible liabilities, 2024	(3,602)
Acquisition-related intangible liabilities, 2025	(3,506)
Acquisition-related intangible liabilities, 2026	(3,131)
Acquisition-related intangible liabilities, 2027	(2,933)
Acquisition-related intangible liabilities, thereafter	(16,160)
Acquisition-related intangible liabilities	$ (37,437)	$ (22,253)

Receivables - Current Receivabl

Receivables - Current Receivables and Deferred Rent Receivables (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current Receivables, net
Current receivables	$ 22,816	$ 16,448
Allowance for uncollectible tenant receivables	(2,233)	(2,062)
Current receivables, net	20,583	14,386
Deferred Rent Receivables, net
Deferred rent receivables	453,165	406,277
Allowance for deferred rent receivables	(965)	(612)
Deferred rent receivables, net	$ 452,200	$ 405,665

Prepaid Expenses and Other As_3

Prepaid Expenses and Other Assets, Net - Schedule of Prepaid Expenses and Other Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Furniture, fixtures and other long-lived assets, net	$ 41,538	$ 42,760
Prepaid expenses and deferred financing costs, net	11,364	12,564
Other assets	9,527	2,667
Total prepaid expenses and other assets, net	$ 62,429	$ 57,991

Secured and Unsecured Debt of_4

Secured and Unsecured Debt of the Company (Details) $ in Thousands	Dec. 31, 2022 USD ($) debt_covenant	Dec. 31, 2021 USD ($)
Debt Instrument [Line Items]
Secured debt	$ 242,938	$ 248,367
Number of debt covenants impacting payment of dividends during event of default | debt_covenant	1
Unsecured debt
Debt Instrument [Line Items]
Long-term debt	$ 4,000,000	$ 3,800,000

Secured and Unsecured Debt of_5

Secured and Unsecured Debt of the Operating Partnership - Secured Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Secured Debt
Secured debt	$ 242,938	$ 248,367
Kilroy Realty L.P.
Secured Debt
Long-term debt, gross	4,293,469
Secured debt	242,938	248,367
Kilroy Realty L.P. | 3.57% Mortgage Payable due December 2026
Secured Debt
Long-term debt, gross	160,000
Kilroy Realty L.P. | Secured debt
Secured Debt
Secured debt	243,469	249,023
Unamortized deferred financing costs	(531)	(656)
Total secured debt, net	242,938	248,367
Net book value of properties pledged as collateral for secured debt	$ 205,000
Kilroy Realty L.P. | Secured debt | 3.57% Mortgage Payable due December 2026
Secured Debt
Stated interest rate	3.57%
Effective interest rate	3.57%
Long-term debt, gross	$ 159,973	163,435
Kilroy Realty L.P. | Secured debt | 4.48% Mortgage Payable due July 2027
Secured Debt
Stated interest rate	4.48%
Effective interest rate	4.48%
Long-term debt, gross	$ 83,496	$ 85,588

Secured and Unsecured Debt of_6

Secured and Unsecured Debt of the Operating Partnership - Unsecured Senior Notes - Registered Offerings and Private Placement (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Oct. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Loss on early extinguishment of debt	$ (12,200)	$ 0	$ 12,246	$ 0
2.650% Unsecured Senior Notes
Debt Instrument [Line Items]
Long-term debt, gross	450,000	$ 450,000	450,000
Unamortized discount (premium), net	$ (200)
Stated interest rate	2.65%	2.65%
Debt redemption, par call option period	3 months
Kilroy Realty L.P.
Debt Instrument [Line Items]
Long-term debt, gross		$ 4,293,469
Loss on early extinguishment of debt		0	12,246	$ 0
Kilroy Realty L.P. | Unsecured debt | 2.500% Unsecured Senior Notes
Debt Instrument [Line Items]
Long-term debt, gross		$ 425,000	$ 425,000
Stated interest rate		2.50%
Kilroy Realty L.P. | Unsecured debt | 3.800% Unsecured Senior Notes
Debt Instrument [Line Items]
Stated interest rate	3.80%
Debt redemption, principal amount	$ 300,000
Premium paid to the note holders at the redemption date	12,100
Write-off of unamortized discount and unamortized deferred financing costs	$ 100

Secured and Unsecured Debt of_7

Secured and Unsecured Debt of the Operating Partnership - Unsecured Senior Notes (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Oct. 31, 2021
Debt Instrument [Line Items]
Unsecured debt, net	$ 4,020,058	$ 3,820,383
2.650% Unsecured Senior Notes
Debt Instrument [Line Items]
Unamortized discount (premium), net			$ (200)
Stated coupon rate	2.65%		2.65%
Effective interest rate	2.654%
Long-term debt, gross	$ 450,000	450,000	$ 450,000
Unamortized discount and deferred financing costs	(3,770)	(4,117)
Unsecured debt, net	446,230	445,883
Unsecured debt | Unsecured Senior Notes
Debt Instrument [Line Items]
Unamortized discount (premium), net	(6,400)	(7,400)
Unamortized debt issuance expense	19,100	22,200
Kilroy Realty L.P.
Debt Instrument [Line Items]
Long-term debt, gross	4,293,469
Unsecured debt, net	4,020,058	3,820,383
Kilroy Realty L.P. | Unsecured debt
Debt Instrument [Line Items]
Unsecured debt, net	$ 3,824,581	3,820,383
Kilroy Realty L.P. | Unsecured debt | 2.500% Unsecured Senior Notes
Debt Instrument [Line Items]
Stated coupon rate	2.50%
Effective interest rate	2.56%
Long-term debt, gross	$ 425,000	425,000
Unamortized discount and deferred financing costs	(5,268)	(5,802)
Unsecured debt, net	$ 419,732	419,198
Kilroy Realty L.P. | Unsecured debt | 4.270% Unsecured Senior Notes
Debt Instrument [Line Items]
Stated coupon rate	4.27%
Effective interest rate	4.27%
Long-term debt, gross	$ 350,000	350,000
Unamortized discount and deferred financing costs	(1,463)	(1,644)
Unsecured debt, net	$ 348,537	348,356
Kilroy Realty L.P. | Unsecured debt | 3.050% Unsecured Senior Notes
Debt Instrument [Line Items]
Stated coupon rate	3.05%
Effective interest rate	3.064%
Long-term debt, gross	$ 500,000	500,000
Unamortized discount and deferred financing costs	(4,221)	(4,814)
Unsecured debt, net	$ 495,779	495,186
Kilroy Realty L.P. | Unsecured debt | 4.750% Unsecured Senior Notes
Debt Instrument [Line Items]
Stated coupon rate	4.75%
Effective interest rate	4.80%
Long-term debt, gross	$ 400,000	400,000
Unamortized discount and deferred financing costs	(2,963)	(3,457)
Unsecured debt, net	$ 397,037	396,543
Kilroy Realty L.P. | Unsecured debt | 4.350% Unsecured Senior Notes
Debt Instrument [Line Items]
Stated coupon rate	4.35%
Effective interest rate	4.35%
Long-term debt, gross	$ 200,000	200,000
Unamortized discount and deferred financing costs	(663)	(837)
Unsecured debt, net	$ 199,337	199,163
Kilroy Realty L.P. | Unsecured debt | 4.300% Unsecured Senior Notes
Debt Instrument [Line Items]
Stated coupon rate	4.30%
Effective interest rate	4.30%
Long-term debt, gross	$ 50,000	50,000
Unamortized discount and deferred financing costs	(157)	(202)
Unsecured debt, net	$ 49,843	49,798
Kilroy Realty L.P. | Unsecured debt | 3.450% Unsecured Senior Notes
Debt Instrument [Line Items]
Stated coupon rate	3.45%
Effective interest rate	3.47%
Long-term debt, gross	$ 425,000	425,000
Unamortized discount and deferred financing costs	(1,148)	(1,734)
Unsecured debt, net	$ 423,852	423,266
Kilroy Realty L.P. | Unsecured debt | 3.450% Unsecured Senior Notes
Debt Instrument [Line Items]
Stated coupon rate	3.45%
Effective interest rate	3.45%
Long-term debt, gross	$ 75,000	75,000
Unamortized discount and deferred financing costs	(262)	(304)
Unsecured debt, net	$ 74,738	74,696
Kilroy Realty L.P. | Unsecured debt | 3.350% Unsecured Senior Notes
Debt Instrument [Line Items]
Stated coupon rate	3.35%
Effective interest rate	3.35%
Long-term debt, gross	$ 175,000	175,000
Unamortized discount and deferred financing costs	(478)	(594)
Unsecured debt, net	$ 174,522	174,406
Kilroy Realty L.P. | Unsecured debt | 4.375% Unsecured Senior Notes
Debt Instrument [Line Items]
Stated coupon rate	4.375%
Effective interest rate	4.444%
Long-term debt, gross	$ 400,000	400,000
Unamortized discount and deferred financing costs	(1,523)	(2,077)
Unsecured debt, net	$ 398,477	397,923
Kilroy Realty L.P. | Unsecured debt | 4.250% Unsecured Senior Notes
Debt Instrument [Line Items]
Stated coupon rate	4.25%
Effective interest rate	4.35%
Long-term debt, gross	$ 400,000	400,000
Unamortized discount and deferred financing costs	(3,503)	(4,035)
Unsecured debt, net	$ 396,497	$ 395,965

Secured and Unsecured Debt of_8

Secured and Unsecured Debt of the Operating Partnership - Unsecured Revolving Credit Facility and Term Loan Facility (Details)	1 Months Ended		12 Months Ended
	Oct. 31, 2022 USD ($) extension_option	Apr. 29, 2021 USD ($) extension_option	Dec. 31, 2022 USD ($) extension_option	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Debt Instrument [Line Items]
Proceeds from the issuance of unsecured debt			$ 0	$ 449,807,000	$ 772,297,000
Kilroy Realty L.P.
Debt Instrument [Line Items]
Proceeds from the issuance of unsecured debt			0	449,807,000	772,297,000
Revolving credit facility | Kilroy Realty L.P.
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 1,100,000,000	1,100,000,000	1,100,000,000	$ 750,000,000
Number of extension options | extension_option		2
Extension period (in months)		6 months
Percentage of debt instrument, interest rate reduction if sustainability performance targets met		0.01%
Contingent additional borrowings			$ 500,000,000	$ 500,000,000
Revolving credit facility | Kilroy Realty L.P. | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Variable rate (percent)			0.90%
Unsecured debt | Unsecured Term Loan Facility
Debt Instrument [Line Items]
Number of extension options | extension_option	2
Extension period (in months)	12 months
Principal amount of debt	$ 400,000,000
Proceeds from the issuance of unsecured debt	200,000,000
Unsecured debt | Kilroy Realty L.P. | Unsecured Term Loan Facility
Debt Instrument [Line Items]
Number of extension options | extension_option			2
Extension period (in months)			12 months
Line of credit | Kilroy Realty L.P. | Unsecured Term Loan Facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity			$ 400,000,000
Contingent additional borrowings	$ 100,000,000
Line of credit | Kilroy Realty L.P. | Unsecured Term Loan Facility | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Variable rate (percent)			0.95%

Secured and Unsecured Debt of_9

Secured and Unsecured Debt of the Operating Partnership - Unsecured Senior Notes, Unsecured Revolving Credit Facility and Term Loan Facility (Details) - Kilroy Realty L.P. - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Oct. 31, 2022	Apr. 29, 2021	Dec. 31, 2020
Revolving credit facility
Terms of the Credit Facility
Outstanding borrowings	$ 0	$ 0
Remaining borrowing capacity	1,100,000,000	1,100,000,000
Total borrowing capacity	$ 1,100,000,000	$ 1,100,000,000		$ 1,100,000,000	$ 750,000,000
Interest rate	5.20%	1%
Facility fee-annual rate (percent)	0.20%	0.20%
Contingent additional borrowings	$ 500,000,000	$ 500,000,000
Unamortized debt issuance expense	$ 5,300,000	$ 7,300,000
Revolving credit facility | London Interbank Offered Rate (LIBOR)
Terms of the Credit Facility
Basis spread on SOFR and LIBOR		0.90%
Revolving credit facility | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Terms of the Credit Facility
Basis spread on SOFR and LIBOR	0.90%
Term loan facility | $400.0 million term loan facility
Terms of the Credit Facility
Outstanding borrowings	$ 200,000,000
Remaining borrowing capacity	200,000,000
Total borrowing capacity	$ 400,000,000
Interest rate	5.23%
Undrawn facility fee-annual rate	0.20%
Contingent additional borrowings			$ 100,000,000
Unamortized debt issuance expense	$ 4,500,000
Term loan facility | $400.0 million term loan facility | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Terms of the Credit Facility
Basis spread on SOFR and LIBOR	0.95%

Secured and Unsecured Debt o_10

Secured and Unsecured Debt of the Operating Partnership - Debt Covenants and Restrictions (Details)	Dec. 31, 2022 debt_covenant
Debt Disclosure [Abstract]
Number of noncompliant debt covenants that could require immediate repayment of full principal balance of associated debt	1

Secured and Unsecured Debt o_11

Secured and Unsecured Debt of the Operating Partnership - Debt Maturities (Details) $ in Thousands	1 Months Ended	12 Months Ended
	Oct. 31, 2022 extension_option	Dec. 31, 2022 USD ($) extension_option debt_covenant	Dec. 31, 2021 USD ($)
Stated debt maturities and scheduled amortization payments, excluding debt discounts
Number of noncompliant debt covenants that could require immediate repayment of full principal balance of associated debt | debt_covenant		1
Unsecured debt
Stated debt maturities and scheduled amortization payments, excluding debt discounts
Long-term debt		$ 4,000,000	$ 3,800,000
Unsecured Term Loan Facility | Unsecured debt
Stated debt maturities and scheduled amortization payments, excluding debt discounts
Number of extension options | extension_option	2
Extension period (in months)	12 months
Kilroy Realty L.P.
Stated debt maturities and scheduled amortization payments, excluding debt discounts
2023		5,775
2024		631,006
2025		406,246
2026		401,317
2027		249,125
Thereafter		2,600,000
Total aggregate principal value		4,293,469
Kilroy Realty L.P. | Unsecured Term Loan Facility, Unsecured Senior Notes and Secured Debt
Stated debt maturities and scheduled amortization payments, excluding debt discounts
Unamortized debt issuance expense		(24,100)
Kilroy Realty L.P. | Unsecured senior notes
Stated debt maturities and scheduled amortization payments, excluding debt discounts
Debt issuance discount		(6,400)
Kilroy Realty L.P. | Unsecured Term Loan Facility | Unsecured debt
Stated debt maturities and scheduled amortization payments, excluding debt discounts
Long-term debt		$ 200,000
Number of extension options | extension_option		2
Extension period (in months)		12 months

Secured and Unsecured Debt o_12

Secured and Unsecured Debt of the Operating Partnership - Capitalized Interest and Loan Fees (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Capitalized Interest and Loan Fees [Line Items]
Interest expense	$ 84,278	$ 78,555	$ 70,772
Kilroy Realty L.P.
Capitalized Interest and Loan Fees [Line Items]
Gross interest expense	161,761	158,756	150,325
Capitalized interest and deferred financing costs	(77,483)	(80,201)	(79,553)
Interest expense	$ 84,278	$ 78,555	$ 70,772

Deferred Revenue and Acquisit_3

Deferred Revenue and Acquisition-Related Intangible Liabilities, net - Deferred Revenue and Acquisition-Related Intangible Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Revenue from Contract with Customer [Abstract]
Deferred revenue related to tenant-funded tenant improvements	$ 111,453	$ 108,002
Other deferred revenue	47,069	40,896
Acquisition-related intangible liabilities, net	37,437	22,253
Deferred revenue and acquisition-related intangible liabilities, net	$ 195,959	$ 171,151

Deferred Revenue and Acquisit_4

Deferred Revenue and Acquisition-Related Intangible Liabilities, net - Estimated Amortization of Deferred Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Deferred Revenue, Future Amortization Recognized By Year [Abstract]
Total	$ 111,453	$ 108,002
Tenant funded tenant improvements
Disaggregation of Revenue [Line Items]
Deferred revenues amortized and recognized as rental income	19,300	$ 16,500	$ 22,500
Deferred Revenue, Future Amortization Recognized By Year [Abstract]
2023	19,037
2024	16,865
2025	14,061
2026	12,382
2027	10,551
Thereafter	38,557
Total	$ 111,453

Noncontrolling Interests on t_3

Noncontrolling Interests on the Company’s Consolidated Financial Statements (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) trading_day $ / shares shares	Dec. 31, 2021 USD ($) trading_day $ / shares shares	Aug. 30, 2016 rEITSubsidiary company
Noncontrolling Interest [Line Items]
Conversion ratio	1
Common stock, par value (dollars per share) | $ / shares	$ 0.01	$ 0.01
Number of trading days | trading_day	10	10
Aggregate value upon redemption of outstanding noncontrolling common units	$ 44,700	$ 76,200
Noncontrolling interest in consolidated subsidiary	$ 184,390	$ 196,064
Noncontrolling common units | Noncontrolling common unitholders of the Operating Partnership
Noncontrolling Interest [Line Items]
Common units outstanding held by common limited partners (in shares) | shares	1,150,574	1,150,574
Kilroy Realty L.P. | Noncontrolling common unitholders of the Operating Partnership
Noncontrolling Interest [Line Items]
Conversion ratio	1
Kilroy Realty L.P. | Noncontrolling common unitholders of the Operating Partnership
Noncontrolling Interest [Line Items]
Common units outstanding held by common limited partners (in shares) | shares	1,150,574	1,150,574
Operating Partnership
Noncontrolling Interest [Line Items]
Ownership interest (percent)	99%	99%
Operating Partnership | Noncontrolling common units
Noncontrolling Interest [Line Items]
Ownership interest (percent)	1%	1%
Norges Bank Real Estate Management (NBREM) | Consolidated property partnerships
Noncontrolling Interest [Line Items]
Contributions, number of REIT subsidiaries | rEITSubsidiary			2
Ownership interest of limited partnership interests			44%
Ownership interest, number of existing companies | company			2
100 First LLC and 303 Second LLC | Variable Interest Entity, Primary Beneficiary
Noncontrolling Interest [Line Items]
Noncontrolling interest in consolidated subsidiary	$ 179,400	$ 190,700
Redwood LLC
Noncontrolling Interest [Line Items]
Noncontrolling interest in consolidated subsidiary	$ 5,000	$ 5,400

Noncontrolling Interests on t_4

Noncontrolling Interests on the Operating Partnership’s Consolidated Financial Statements (Details) - Consolidated property partnerships - Norges Bank Real Estate Management (NBREM)	Aug. 30, 2016 rEITSubsidiary company
Noncontrolling Interest [Line Items]
Contributions, number of REIT subsidiaries | rEITSubsidiary	2
Ownership interest of limited partnership interests	44%
Ownership interest, number of existing companies | company	2

Stockholders' Equity of the C_3

Stockholders' Equity of the Company - Narrative (Details) - USD ($)	1 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Net proceeds from issuance of common units		$ 0	$ 0	$ 721,665,000
Sale of stock, shares issued (in shares)		116,878,031	116,464,169
Stock repurchase program, number of shares authorized to be repurchased (in shares)		4,935,826
Stock repurchased during period (in shares)		0	0	0
2018 At-The-Market Program
Class of Stock [Line Items]
Common stock, aggregate gross sales price	$ 500,000,000
2018 At-The-Market Program | Forward Equity Offering | Common Stock
Class of Stock [Line Items]
Net proceeds from issuance of common units		$ 0	$ 0	$ 0
Sale of stock, shares issued (in shares)		3,594,576

Stockholders' Equity of the C_4

Stockholders' Equity of the Company - At-The-Market Offering and Derivatives and Distributions (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Dividends and Distributions payable to:
Accrued distributions (Notes 14 and 25)	$ 64,285	$ 61,850
Outstanding Shares and Units:
Common stock (in shares)	116,878,031	116,464,169
Restricted Stock Units (RSUs)
Outstanding Shares and Units:
RSUs (in shares)	984,006	1,292,802
Kilroy Realty L.P.
Dividends and Distributions payable to:
Accrued distributions (Notes 14 and 25)	$ 64,285	$ 61,850
Kilroy Realty L.P. | Restricted Stock Units (RSUs)
Dividends and Distributions payable to:
Accrued distributions (Notes 14 and 25)	$ 550	$ 691
Kilroy Realty L.P. | Market measure-based Restricted Stock Units (RSUs)
Outstanding Shares and Units:
Number of RSUs outstanding (in shares)	1,123,554	976,464
Kilroy Realty L.P. | Common Units
Outstanding Shares and Units:
Non-affiliated investors and other common units of the Operating Partnership (in shares)	1,150,574	1,150,574
Noncontrolling common units | Common Units
Outstanding Shares and Units:
Non-affiliated investors and other common units of the Operating Partnership (in shares)	1,150,574	1,150,574
Common stockholders and noncontrolling unitholders
Dividends and Distributions payable to:
Accrued distributions (Notes 14 and 25)	$ 64,285	$ 61,850
Common Stock
Dividends and Distributions payable to:
Accrued distributions (Notes 14 and 25)	$ 63,114	$ 60,561
Outstanding Shares and Units:
Common stock (in shares)	116,878,031	116,464,169
Common Units
Dividends and Distributions payable to:
Accrued distributions (Notes 14 and 25)	$ 621	$ 598

Partners' Capital of the Oper_3

Partners' Capital of the Operating Partnership - At-The-Market Stock Offering, Common Units and Accrued Distributions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Accrued distributions
Accrued distributions (Notes 14 and 25)	$ 64,285	$ 61,850
Operating Partnership
General Partners' Capital Account
Ownership interest (percent)	99%	99%
Kilroy Realty L.P.
Accrued distributions
Accrued distributions (Notes 14 and 25)	$ 64,285	$ 61,850
Kilroy Realty L.P. | Restricted Stock Units (RSUs)
Accrued distributions
Accrued distributions (Notes 14 and 25)	$ 550	$ 691
RSUs (in shares)	984,006	1,292,802
Kilroy Realty L.P. | Market measure-based Restricted Stock Units (RSUs)
Accrued distributions
Number of RSUs outstanding (in shares)	1,123,554	976,464
Kilroy Realty L.P. | Partners’ Capital
Accrued distributions
Accrued distributions (Notes 14 and 25)	$ 64,285	$ 61,850
Kilroy Realty L.P. | Partners capital general partner
Accrued distributions
Accrued distributions (Notes 14 and 25)	63,114	60,561
Kilroy Realty L.P. | Partners capital limited partner
Accrued distributions
Accrued distributions (Notes 14 and 25)	$ 621	$ 598
Non-Affiliated Investors | Operating Partnership
General Partners' Capital Account
Ownership interest (percent)	1%	1%
Noncontrolling common unitholders of the Operating Partnership | Kilroy Realty L.P.
General Partners' Capital Account
Company owned common units in the Operating Partnership (in shares)	116,878,031	116,464,169
Non-affiliated investors and other common units of the Operating Partnership (in shares)	1,150,574	1,150,574
Noncontrolling common unitholders of the Operating Partnership | Non-Affiliated Investors
General Partners' Capital Account
Non-affiliated investors and other common units of the Operating Partnership (in shares)	1,150,574	1,150,574

Share-Based and Other Compens_3

Share-Based and Other Compensation - Stockholder Approved Share-Based Incentive Compensation Plan (Details) shares in Millions	Dec. 31, 2022 compensation_plan shares
Share-Based Payment Arrangement [Abstract]
Number of share-based incentive compensation plans | compensation_plan	1
Effective registration shares (in shares)	10.7
Number of shares available for grant (in shares)	1.1

Share-Based and Other Compens_4

Share-Based and Other Compensation - Annual Performance-Based RSU Grants (Details) $ / shares in Units, $ in Millions				1 Months Ended	12 Months Ended
	Jan. 28, 2022 USD ($) $ / shares shares	Feb. 18, 2021 USD ($) $ / shares shares	Jan. 31, 2020 USD ($) $ / shares shares	Jan. 31, 2022 participant	Dec. 31, 2022 participant $ / shares	Dec. 31, 2021 $ / shares	Dec. 31, 2020 $ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term of publicly-traded options on shares of Company stock					6 months
Performance-Based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				3 years	3 years	3 years	3 years
Vesting, achievement of pre-set FFO per share goals, percentage of RSUs					100%
Vesting, average debt to EBIDTA ratio, percentage of RSUs					50%
Vesting, market measure, percentage of RSUs					50%
Number of participants with compensation expense recognized on a rolling twelve-month basis | participant				1
Number of shares issuable per RSU					1
2022 Performance-Based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of participants with compensation expense recognized on a rolling twelve-month basis | participant					1
Performance-based RSUs achievement target, participant one, percent					175%
Performance-based RSUs achievement target, all other participants, percent					150%
Fair value on valuation date | $	$ 12.7
Fair value per share on valuation date (dollars per share) | $ / shares	$ 67.62
Expected share price volatility	36%
Risk-free interest rate	1.35%
2022 Performance-Based RSUs | One Participant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value per share on valuation date (dollars per share) | $ / shares					$ 70
2022 Performance-Based RSUs | Executive officer share-based compensation programs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target RSUs granted (in shares) | shares	193,111
2022 Performance-Based RSUs | Market measure-based RSU estimate of probable
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Estimated RSUs earned (in shares) | shares	304,535
2021 Performance-Based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of participants with compensation expense recognized on a rolling twelve-month basis | participant					1
Performance-based RSUs achievement target, participant one, percent					175%
Performance-based RSUs achievement target, all other participants, percent					150%
Fair value on valuation date | $		$ 10.6
Fair value per share on valuation date (dollars per share) | $ / shares		$ 63.93
Expected share price volatility		35%
Risk-free interest rate		0.20%
2021 Performance-Based RSUs | One Participant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value per share on valuation date (dollars per share) | $ / shares						$ 66.95
2021 Performance-Based RSUs | Executive officer share-based compensation programs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target RSUs granted (in shares) | shares		172,430
2021 Performance-Based RSUs | Market measure-based RSU estimate of probable
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Estimated RSUs earned (in shares) | shares		371,518
2020 Performance Based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of participants with compensation expense recognized on a rolling twelve-month basis | participant					1
Performance-based RSUs achievement target, participant one, percent					131%
Performance-based RSUs achievement target, all other participants, percent					121%
Fair value on valuation date | $			$ 12.9
Fair value per share on valuation date (dollars per share) | $ / shares			$ 84.54
Expected share price volatility			17%
Risk-free interest rate			1.35%
2020 Performance Based RSUs | One Participant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value per share on valuation date (dollars per share) | $ / shares							$ 85.52
2020 Performance Based RSUs | Executive officer share-based compensation programs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target RSUs granted (in shares) | shares			154,267
2020 Performance Based RSUs | Market measure-based RSU estimate of probable
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Estimated RSUs earned (in shares) | shares			180,419

Share-Based and Other Compens_5

Share-Based and Other Compensation - December 2018 Market-Based RSU Grant (Details) $ / shares in Units, $ in Millions		12 Months Ended				48 Months Ended
	Dec. 27, 2018 USD ($) $ / shares shares	Dec. 31, 2021	Dec. 31, 2020 $ / shares	Dec. 31, 2019 $ / shares	Dec. 31, 2018 $ / shares	Dec. 31, 2022
December 2018 Market-Based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants in period (in shares)	346,777
Number of shares issuable per RSU	1
Fair value RSUs granted | $	$ 23.8
Fair value per share on valuation date (dollars per share) | $ / shares	$ 68.66		$ 68.66	$ 68.66	$ 68.66
Vesting criteria, one (percent)					75%
Vesting criteria, period one		3 years
Vesting criteria, period two		4 years
Vesting criteria, two (percent)					25%
Expected share price volatility	23%
Risk-free interest rate	2.40%
December 2018 Market-Based RSUs | Chairman And Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants in period (in shares)	266,130
December 2018 Market-Based RSUs | Management
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants in period (in shares)	80,647
December 2018 Market-Based RSUs, TSR | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target percent						0%
December 2018 Market-Based RSUs, TSR | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target percent						200%

Share-Based and Other Compens_6

Share-Based and Other Compensation - Summary of Performance and Market-Measure Based RSUs (Details) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Market measure-based Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Vested (in shares)	241,184	252,098	270,054
Weighted-Average Fair Value Per Share
Outstanding beginning balance (dollars per share)	$ 68.75
Granted (dollars per share)	63.05
Vested (dollars per share)	70.52
Issuance of dividend equivalents (dollars per share)	55.98
Canceled (dollars per share)	66.06
Outstanding ending balance (dollars per share)	$ 66.85	$ 68.75
Nonvested Restricted Stock Units RSU | Market measure-based Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of RSUs outstanding, beginning balance (in shares)	976,464
Granted (in shares)	310,484	281,333	154,267
Vested (in shares)	195,723
Issuance of dividend equivalents (in shares)	39,385
Canceled (in shares)	(7,056)
Number of RSUs outstanding, ending balance (in shares)	1,123,554	976,464
Weighted-Average Fair Value Per Share
Granted (dollars per share)	$ 63.05	$ 57.85	$ 85.08
Vested Restricted Stock Units RSU | Market measure-based Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Vested RSUs, beginning balance (in shares)	0
Granted (in shares)	43,686
Vested (in shares)	195,723
Settled (in shares)	(211,478)
Issuance of dividend equivalents (in shares)	1,775
Canceled (in shares)	(1)
Vested RSUs, ending balance (in shares)	29,705	0
Restricted Stock Units (RSUs)
Weighted-Average Fair Value Per Share
Vesting period	3 years
Restricted Stock Units (RSUs) | Market measure-based Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Total RSUs, beginning balance (in shares)	976,464
Granted (in shares)	354,170
Vested (in shares)	0
Settled (in shares)	(211,478)
Issuance of dividend equivalents (in shares)	41,160
Canceled (in shares)	(7,057)
Total RSUs, ending balance (in shares)	1,153,259	976,464
Restricted Stock Units (RSUs) | Market measure-based Restricted Stock Units (RSUs) | Kilroy Realty 2006 Incentive Award Plan
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Settled (in shares)	(102,945)

Share-Based and Other Compens_7

Share-Based and Other Compensation - Market-Measure Based RSUs (Details) - Market measure-based Restricted Stock Units (RSUs) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value per share on valuation date (dollars per share)	$ 63.05
Vested (in shares)	(241,184)	(252,098)	(270,054)
Nonvested Restricted Stock Units RSU
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	310,484	281,333	154,267
Fair value per share on valuation date (dollars per share)	$ 63.05	$ 57.85	$ 85.08
Vested (in shares)	(195,723)
Vested RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	43,686
Vested (in shares)	(195,723)
Total Fair Value at Vest Date	$ 15,200	$ 14,299	$ 19,471

Share-Based and Other Compens_8

Share-Based and Other Compensation - Annual Time-Based RSU Grants (Details) $ / shares in Units, $ in Millions				2 Months Ended	12 Months Ended
	Jan. 28, 2022 USD ($) $ / shares shares	Jan. 31, 2020 USD ($) $ / shares shares	Dec. 27, 2018 USD ($) $ / shares shares	Feb. 28, 2021 USD ($) $ / shares shares	Dec. 31, 2022 participant installment shares	Dec. 31, 2018
Time-Based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of installments | installment					3
Vesting criteria, one (percent)						50%
Vesting criteria, two (percent)						50%
Right to receive number of shares (in shares) | shares					1
2021 Time-Based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of participants with compensation expense recognized on a rolling twelve-month basis | participant					1
2022 Time-Based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of participants with compensation expense recognized on a rolling twelve-month basis | participant					1
RSUs granted | Executive officer share-based compensation programs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares) | shares	158,170	109,359	298,384	160,277
Fair value on valuation date | $	$ 10	$ 9	$ 18.5	$ 9.1
Weighted average fair value per share | $ / shares	$ 63.05	$ 82.57	$ 62	$ 57.07

Share-Based and Other Compens_9

Share-Based and Other Compensation - Summary of Time-Based RSUs (Details) - RSUs granted - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Vested (in shares)	(294,867)	(144,838)	(208,608)
Nonvested Restricted Stock Units RSU
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of RSUs outstanding, beginning balance (in shares)	539,729
Granted (in shares)	177,099	172,181	120,769
Vested (in shares)	(270,061)
Issuance of dividend equivalents (in shares)	15,324
Forfeited (in shares)	(18,724)
Number of RSUs outstanding, ending balance (in shares)	443,367	539,729
Weighted Average Fair Value Per Share
Outstanding beginning balance (dollars per share)	$ 64.03
Granted (dollars per share)	62.58	$ 57.83	$ 79.74
Vested (dollars per share)	67.15
Issuance of dividend equivalents (dollars per share)	54.15
Forfeited (dollars per share)	62.56
Outstanding ending balance (dollars per share)	$ 61.27	$ 64.03
Vested RSUs
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Vested RSUs, beginning balance (in shares)	753,073
Granted (in shares)	0
Vested (in shares)	(270,061)
Settled (in shares)	(535,019)
Issuance of dividend equivalents (in shares)	24,806
Forfeited (in shares)	0
Canceled (in shares)	(1,987)
Vested RSUs, ending balance (in shares)	510,934	753,073
Vested RSUs | Kilroy Realty 2006 Incentive Award Plan
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Settled (in shares)	(231,604)
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Total RSUs, beginning balance (in shares)	1,292,802
Granted (in shares)	177,099
Vested (in shares)	0
Settled (in shares)	(535,019)
Issuance of dividend equivalents (in shares)	40,130
Forfeited (in shares)	(18,724)
Canceled (in shares)	(1,987)
Total RSUs, ending balance (in shares)	954,301	1,292,802

Share-Based and Other Compen_10

Share-Based and Other Compensation - Time-Based RSUs (Details) - RSUs granted - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested (in shares)	(294,867)	(144,838)	(208,608)
Nonvested Restricted Stock Units RSU
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	177,099	172,181	120,769
Fair value per share on valuation date (dollars per share)	$ 62.58	$ 57.83	$ 79.74
Vested (in shares)	(270,061)
Vested Restricted Stock Units RSU
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	0
Vested (in shares)	(270,061)
Total Fair Value at Vest Date	$ 19,890	$ 8,605	$ 15,066

Share-Based and Other Compen_11

Share-Based and Other Compensation - Share-Based Compensation Cost Recorded During the Period and Other Compensation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 34.8	$ 41	$ 37.6
Share-based compensation expense capitalized	6.4	$ 7.2	7.4
Share-based compensation not yet recognized	$ 25.1
Share-based compensation not yet recognized period of recognition	1 year 8 months 12 days
Chief Executive Officer | General and Administrative Expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Severance costs			14.1
Severance
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense			$ 4.5

Employee Benefit Plans (Details

Employee Benefit Plans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Retirement Benefits [Abstract]
Eligibility period for 401K savings plan, period	3 months
401(k) plan, maximum participant deferral percent	60%
401(k) plan, employer match per dollar of participant contribution	$ 0.50
401(k) plan, maximum employer match percentage	10%
401(k) plan, contributions made	$ 1,600,000	$ 1,500,000	$ 1,600,000
Deferred Compensation, maximum participant deferral percent	70%
Deferred Compensation, maximum director fees and bonuses that may be deferred (percent)	100%
Deferred Compensation, mandatory Company contributions as percentage of gross monthly salary (percent)	10%
Deferred Compensation, liability under plan	$ 23,400,000	$ 27,400,000

Rental Income and Future Mini_3

Rental Income and Future Minimum Rent - Allocation of Rental Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
Fixed lease payments	$ 923,257	$ 826,883
Variable lease payments	162,638	123,544
Net collectability recoveries (reversals)	123	(1,433)
Total rental income	$ 1,086,018	$ 948,994	$ 892,306

Rental Income and Future Mini_4

Rental Income and Future Minimum Rent - Future Contractual Minimum Rent (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Future contractual minimum rent under operating lease
2023	$ 809,406
2024	796,645
2025	769,116
2026	716,780
2027	656,100
Thereafter	2,464,166
Total	$ 6,212,213

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($) ground_lease	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Long-term Purchase Commitment [Line Items]
Commitments for contracts and executed leases, operating and redevelopment and development properties	$ 586.6
Weighted average discount rate	4.65%
Weighted average remaining lease term	64 years
Variable lease, cost	$ 3.6	$ 2.6	$ 3
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration]	consolidated balance sheet
Environmental matters
Long-term Purchase Commitment [Line Items]
Accrued environmental remediation liabilities	$ 80.5	$ 75.2
Ten year ground lease extension option
Long-term Purchase Commitment [Line Items]
Number of extension options | ground_lease	3
Ground lease extension option term	10 years
Forty-five year ground lease extension option
Long-term Purchase Commitment [Line Items]
Number of extension options | ground_lease	1
Ground lease extension option term	45 years

Commitments and Contingencies_2

Commitments and Contingencies - Minimum Commitment Under Ground Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Minimum commitment under our ground leases
2023	$ 6,563
2024	6,598
2025	6,634
2026	6,671
2027	6,713
Thereafter	368,281
Total undiscounted cash flows	401,460
Present value discount	(276,466)
Ground lease liabilities	$ 124,994	$ 125,550
Period after which ground lease rentals are adjusted based on fair market value and the Consumer Price Index	5 years
Annual ground lease rental obligations limit	$ 1,000
Duration of ground lease increase	10 years
Average annual percentage rent for previous ten years (percent)	60%
Previous period included in average annual rent percentage for ten-year increases	3 years
Ground lease fixed ground rent increase, percent	5%
Percentage rent increase every year	2%
Ground lease reset period	10 years
Remaining ground lease obligation period	10 years

Fair Value Measurements and D_3

Fair Value Measurements and Disclosures - Assets and Liabilities Reported at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Fair value, measurements, recurring | Fair Value (Level 1)
Assets and Liabilities Reported at Fair Value
Marketable securities	$ 23,547	$ 27,475

Fair Value Measurements and D_4

Fair Value Measurements and Disclosures - Financial Instruments Disclosed at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Carrying Value | Secured debt, net
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of debt, net	$ 242,938	$ 248,367
Carrying Value | Unsecured debt, net
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of debt, net	4,020,058	3,820,383
Fair value | Secured debt, net | Fair value (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of debt, net	225,847	269,687
Fair value | Unsecured debt, net | Fair value (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of debt, net	$ 3,500,420	$ 4,105,408

Net Income Available to Commo_5

Net Income Available to Common Stockholders Per Share of the Company - Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Numerator:
Net income available to common stockholders	$ 232,615	$ 628,144	$ 187,105
Allocation to participating securities	(1,272)	(1,516)	(2,229)
Numerator for basic net income available to common stockholders	$ 231,343	$ 626,628	$ 184,876
Denominator:
Basic weighted average vested shares/units outstanding (in shares)	116,806,575	116,429,130	113,241,341
Effect of dilutive securities (in shares)	413,472	519,513	478,281
Diluted weighted average vested shares and common stock/ unit equivalents outstanding (in shares)	117,220,047	116,948,643	113,719,622
Basic earnings per share:
Net income available to common stockholders per share (dollars per share)	$ 1.98	$ 5.38	$ 1.63
Diluted earnings per share:
Net income available to common stockholders per share (dollars per share)	$ 1.97	$ 5.36	$ 1.63

Net Income Available to Commo_6

Net Income Available to Common Unitholders Per Unit of the Operating Partnership - Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Numerator:
Net income available to common unitholders	$ 232,615	$ 628,144	$ 187,105
Allocation to participating securities	(1,272)	(1,516)	(2,229)
Numerator for basic net income available to common unitholders	$ 231,343	$ 626,628	$ 184,876
Denominator:
Basic weighted average vested shares/units outstanding (in shares)	116,806,575	116,429,130	113,241,341
Effect of dilutive securities (in shares)	413,472	519,513	478,281
Diluted weighted average vested shares and common stock/ unit equivalents outstanding (in shares)	117,220,047	116,948,643	113,719,622
Basic earnings per unit:
Net income available to common unitholders per unit (dollars per share)	$ 1.98	$ 5.38	$ 1.63
Diluted earnings per unit:
Net income available to common unitholders per unit (dollars per share)	$ 1.97	$ 5.36	$ 1.63
Kilroy Realty L.P.
Numerator:
Net income available to common unitholders	$ 234,898	$ 634,307	$ 189,609
Allocation to participating securities	(1,272)	(1,516)	(2,229)
Numerator for basic net income available to common unitholders	$ 233,626	$ 632,791	$ 187,380
Denominator:
Basic weighted average vested shares/units outstanding (in shares)	117,957,149	117,579,704	115,095,506
Effect of dilutive securities (in shares)	413,472	519,513	478,281
Diluted weighted average vested shares and common stock/ unit equivalents outstanding (in shares)	118,370,621	118,099,217	115,573,787
Basic earnings per unit:
Net income available to common unitholders per unit (dollars per share)	$ 1.98	$ 5.38	$ 1.63
Diluted earnings per unit:
Net income available to common unitholders per unit (dollars per share)	$ 1.97	$ 5.36	$ 1.62

Supplemental Cash Flow Inform_5

Supplemental Cash Flow Information of the Company - Supplemental Cash Flow (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
SUPPLEMENTAL CASH FLOWS INFORMATION:
Capitalized interest	$ 72,973	$ 75,802	$ 75,852
Cash paid for interest, net of capitalized interest of $72,973, $75,802, and $75,852 as of December 31, 2022, 2021 and 2020, respectively	79,634	77,028	61,741
Cash paid for amounts included in the measurement of ground lease liabilities	6,447	6,209	5,744
NON-CASH INVESTING TRANSACTIONS:
Accrual for expenditures for operating properties and development and redevelopment properties	97,729	119,829	189,161
Tenant improvements funded directly by tenants	6,772	20,070	11,592
Assumption of accrued liabilities in connection with acquisitions (Note 3)	0	37,572	0
Initial measurement of operating right of use ground lease assets (Notes 3 and 18)	0	46,430	0
Initial measurement of operating ground lease liabilities (Notes 3 and 18)	0	46,430	0
NON-CASH FINANCING TRANSACTIONS:
Accrual of dividends and distributions payable to common stockholders and common unitholders (Notes 13 and 25)	64,285	61,850	59,431
Exchange of common units of the Operating Partnership into shares of the Company’s common stock	$ 0	$ 0	$ 37,640

Supplemental Cash Flow Inform_6

Supplemental Cash Flow Information of the Company - Cash and Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH:
Cash and cash equivalents	$ 347,379	$ 414,077	$ 731,991	$ 60,044
Restricted cash	0	13,006	91,139	16,300
Cash and cash equivalents and restricted cash	$ 347,379	$ 427,083	$ 823,130	$ 76,344

Supplemental Cash Flow Inform_7

Supplemental Cash Flow Information of the Operating Partnership - Supplemental Cash Flow (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
SUPPLEMENTAL CASH FLOWS INFORMATION:
Capitalized interest	$ 72,973	$ 75,802	$ 75,852
Cash paid for interest, net of capitalized interest of $72,973, $75,802, and $75,852 as of December 31, 2022, 2021 and 2020, respectively	79,634	77,028	61,741
Cash paid for amounts included in the measurement of ground lease liabilities	6,447	6,209	5,744
NON-CASH INVESTING TRANSACTIONS:
Accrual for expenditures for operating properties and development and redevelopment properties	97,729	119,829	189,161
Tenant improvements funded directly by tenants	6,772	20,070	11,592
Assumption of accrued liabilities in connection with acquisitions (Note 3)	0	37,572	0
Initial measurement of operating right of use ground lease assets (Notes 3 and 18)	0	46,430	0
Initial measurement of operating ground lease liabilities (Notes 3 and 18)	0	46,430	0
NON-CASH FINANCING TRANSACTIONS:
Accrual of distributions payable to common unitholders (Notes 14 and 25)	64,285	61,850	59,431
Kilroy Realty L.P.
SUPPLEMENTAL CASH FLOWS INFORMATION:
Capitalized interest	72,973	75,802	75,852
Cash paid for interest, net of capitalized interest of $72,973, $75,802, and $75,852 as of December 31, 2022, 2021 and 2020, respectively	79,634	77,028	61,741
Cash paid for amounts included in the measurement of ground lease liabilities	6,447	6,209	5,744
NON-CASH INVESTING TRANSACTIONS:
Accrual for expenditures for operating properties and development and redevelopment properties	97,729	119,829	189,161
Tenant improvements funded directly by tenants	6,772	20,070	11,592
Assumption of accrued liabilities in connection with acquisitions (Note 3)	0	37,572	0
Initial measurement of operating right of use ground lease assets (Notes 3 and 18)	0	46,430	0
Initial measurement of operating ground lease liabilities (Notes 3 and 18)	0	46,430	0
NON-CASH FINANCING TRANSACTIONS:
Accrual of distributions payable to common unitholders (Notes 14 and 25)	$ 64,285	$ 61,850	$ 59,431

Supplemental Cash Flow Inform_8

Supplemental Cash Flow Information of the Operating Partnership - Cash and Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH:
Cash and cash equivalents	$ 347,379	$ 414,077	$ 731,991	$ 60,044
Restricted cash	0	13,006	91,139	16,300
Cash and cash equivalents and restricted cash	347,379	427,083	823,130	76,344
Kilroy Realty L.P.
RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH:
Cash and cash equivalents	347,379	414,077	731,991	60,044
Restricted cash	0	13,006	91,139	16,300
Cash and cash equivalents and restricted cash	$ 347,379	$ 427,083	$ 823,130	$ 76,344

Tax Treatment of Distribution_2

Tax Treatment of Distributions - Dividends (Details) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Dividends declared per share of common stock (dollars per share)	$ 2.12	$ 2.04	$ 1.97
Common Stock
Class of Stock [Line Items]
Dividends declared per share of common stock (dollars per share)	2.120	2.040	1.970
Less: Dividends declared in the current year and paid in the following year (dollars per share)	(0.540)	(0.520)	(0.500)
Add: Dividends declared in the prior year and paid in the current year (dollars per share)	0.520	0.500	0.485
Dividends paid per share of common stock (dollars per share)	$ 2.100	$ 2.020	$ 1.955

Tax Treatment of Distribution_3

Tax Treatment of Distributions - Dividends Tax Treatment (Details) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Treatment of Dividends Paid [Line Items]
Capital gains, federal statutory tax rate	20%
Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per share of common stock (dollars per share)	$ 2.100	$ 2.020	$ 1.955
Ordinary income | Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per share of common stock (dollars per share)	$ 1.865	$ 1.338	$ 1.474
Dividends paid per share of common stock, percentage	88.80%	66.22%	75.40%
Qualified dividend | Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per share of common stock (dollars per share)	$ 0.001	$ 0.003	$ 0.002
Dividends paid per share of common stock, percentage	0.02%	0.15%	0.12%
Return of capital | Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per share of common stock (dollars per share)	$ 0.230	$ 0.551	$ 0.162
Dividends paid per share of common stock, percentage	10.99%	27.30%	8.30%
Capital gains | Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per share of common stock (dollars per share)	$ 0.004	$ 0.075	$ 0.275
Dividends paid per share of common stock, percentage	0.19%	3.72%	14.05%
Unrecaptured section 1250 gains | Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per share of common stock (dollars per share)	$ 0	$ 0.053	$ 0.042
Dividends paid per share of common stock, percentage	0%	2.61%	2.13%
Tax treatment | Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per share of common stock (dollars per share)	$ 2.100	$ 2.020	$ 1.955
Dividends paid per share of common stock, percentage	100%	100%	100%

Subsequent Events (Details)

Subsequent Events (Details) - USD ($)	Feb. 06, 2023	Jan. 11, 2023	Jan. 27, 2023	Dec. 31, 2022
Subsequent Event [Line Items]
Number of shares available for grant (in shares)				1,100,000
Subsequent event
Subsequent Event [Line Items]
Payments of dividends		$ 64,300,000
Subsequent event | Kilroy Realty 2006 Incentive Award Plan | Market measure-based Restricted Stock Units (RSUs) | Key Employees
Subsequent Event [Line Items]
Recognition period	3 years
Subsequent event | Kilroy Realty 2006 Incentive Award Plan | Time-Based Restricted Stock Units (RSUs) | Key Employees
Subsequent Event [Line Items]
Number of shares available for grant (in shares)	218,951
Subsequent event | Kilroy Realty 2006 Incentive Award Plan | Performance-Based Restricted Stock Units (RSUs) | Key Employees
Subsequent Event [Line Items]
Number of shares available for grant (in shares)	300,007
Subsequent event | Term Loan
Subsequent Event [Line Items]
Line of credit facility, maximum borrowing capacity			$ 500,000,000
Line of credit facility, additional borrowing capacity			$ 650,000,000

Schedule II - Valuation and Q_2

Schedule II - Valuation and Qualifying Accounts - Allowances (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Notes receivable, valuation allowance			$ 1,700
Uncollectible tenant receivables
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 2,062	$ 1,799	1,171
Charged to Costs and Expenses	1,447	1,532	1,977
Deductions	(1,276)	(1,269)	(1,349)
Balance at End of Period	2,233	2,062	1,799
Allowance for deferred rent
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	612	804	1,552
Charged to Costs and Expenses	864	320	832
Deductions	(511)	(512)	(1,580)
Balance at End of Period	$ 965	$ 612	$ 804

Schedule III - Real Estate an_2

Schedule III - Real Estate and Accumulated Depreciation - Schedule of Real Estate and Accumulated Depreciation (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) ft²	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, encumbrances	$ 243,469
Initial cost, land and improvements	2,565,066
Initial cost, buildings and Improvements	2,959,869
Costs Capitalized Subsequent  to Acquisition/ Improvement	6,207,248
Land and improvements, gross	2,656,533
Buildings and improvements, gross	9,075,650
Land and improvements and buildings and improvements, gross	11,732,183
Accumulated Depreciation	$ 2,218,710	$ 2,003,656	$ 1,798,646	$ 1,561,361
Rentable square feet | ft²	16,194,146
3101 - 3243 S. La Cienega Blvd., Culver City, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 150,718
Initial cost, buildings and Improvements	31,033
Costs Capitalized Subsequent  to Acquisition/ Improvement	911
Land and improvements, gross	150,718
Buildings and improvements, gross	31,944
Land and improvements and buildings and improvements, gross	182,662
Accumulated Depreciation	$ 15,782
Depreciation life	35 years
Rentable square feet | ft²	154,165
2240 E. Imperial Highway, El Segundo, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 1,044
Initial cost, buildings and Improvements	11,763
Costs Capitalized Subsequent  to Acquisition/ Improvement	29,799
Land and improvements, gross	1,048
Buildings and improvements, gross	41,558
Land and improvements and buildings and improvements, gross	42,606
Accumulated Depreciation	$ 30,664
Depreciation life	35 years
Rentable square feet | ft²	122,870
2250 E. Imperial Highway, El Segundo, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 2,579
Initial cost, buildings and Improvements	29,062
Costs Capitalized Subsequent  to Acquisition/ Improvement	36,425
Land and improvements, gross	2,547
Buildings and improvements, gross	65,519
Land and improvements and buildings and improvements, gross	68,066
Accumulated Depreciation	$ 60,241
Depreciation life	35 years
Rentable square feet | ft²	298,728
2260 E. Imperial Highway, El Segundo, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 2,518
Initial cost, buildings and Improvements	28,370
Costs Capitalized Subsequent  to Acquisition/ Improvement	36,887
Land and improvements, gross	2,547
Buildings and improvements, gross	65,228
Land and improvements and buildings and improvements, gross	67,775
Accumulated Depreciation	$ 23,022
Depreciation life	35 years
Rentable square feet | ft²	298,728
909 N. Pacific Coast Highway, El Segundo, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 3,577
Initial cost, buildings and Improvements	34,042
Costs Capitalized Subsequent  to Acquisition/ Improvement	54,886
Land and improvements, gross	3,565
Buildings and improvements, gross	88,940
Land and improvements and buildings and improvements, gross	92,505
Accumulated Depreciation	$ 51,400
Depreciation life	35 years
Rentable square feet | ft²	244,880
999 N. Pacific Coast Highway, El Segundo, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 1,407
Initial cost, buildings and Improvements	34,326
Costs Capitalized Subsequent  to Acquisition/ Improvement	18,361
Land and improvements, gross	1,407
Buildings and improvements, gross	52,687
Land and improvements and buildings and improvements, gross	54,094
Accumulated Depreciation	$ 31,642
Depreciation life	35 years
Rentable square feet | ft²	138,389
1350 Ivar Ave., Los Angeles, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 1,575
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	14,253
Land and improvements, gross	1,575
Buildings and improvements, gross	14,253
Land and improvements and buildings and improvements, gross	15,828
Accumulated Depreciation	$ 877
Depreciation life	35 years
Rentable square feet | ft²	16,448
1355 Vine St., Los Angeles, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 17,588
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	120,967
Land and improvements, gross	17,588
Buildings and improvements, gross	120,967
Land and improvements and buildings and improvements, gross	138,555
Accumulated Depreciation	$ 7,602
Depreciation life	35 years
Rentable square feet | ft²	183,129
1375 Vine St., Los Angeles, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 15,578
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	103,084
Land and improvements, gross	15,578
Buildings and improvements, gross	103,084
Land and improvements and buildings and improvements, gross	118,662
Accumulated Depreciation	$ 6,488
Depreciation life	35 years
Rentable square feet | ft²	159,236
1395 Vine St., Los Angeles, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 278
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	3,283
Land and improvements, gross	278
Buildings and improvements, gross	3,283
Land and improvements and buildings and improvements, gross	3,561
Accumulated Depreciation	$ 201
Depreciation life	35 years
Rentable square feet | ft²	2,575
1500 N. El Centro Ave., Los Angeles, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 9,235
Initial cost, buildings and Improvements	21
Costs Capitalized Subsequent  to Acquisition/ Improvement	59,160
Land and improvements, gross	9,235
Buildings and improvements, gross	59,181
Land and improvements and buildings and improvements, gross	68,416
Accumulated Depreciation	$ 15,995
Depreciation life	35 years
Rentable square feet | ft²	113,447
1525 N. Gower St., Los Angeles, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 1,318
Initial cost, buildings and Improvements	3
Costs Capitalized Subsequent  to Acquisition/ Improvement	9,742
Land and improvements, gross	1,318
Buildings and improvements, gross	9,745
Land and improvements and buildings and improvements, gross	11,063
Accumulated Depreciation	$ 2,220
Depreciation life	35 years
Rentable square feet | ft²	9,610
1575 N. Gower St., Los Angeles, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 22,153
Initial cost, buildings and Improvements	51
Costs Capitalized Subsequent  to Acquisition/ Improvement	119,602
Land and improvements, gross	22,153
Buildings and improvements, gross	119,653
Land and improvements and buildings and improvements, gross	141,806
Accumulated Depreciation	$ 22,890
Depreciation life	35 years
Rentable square feet | ft²	264,430
6115 W. Sunset Blvd., Los Angeles, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 1,313
Initial cost, buildings and Improvements	3
Costs Capitalized Subsequent  to Acquisition/ Improvement	17,392
Land and improvements, gross	2,455
Buildings and improvements, gross	16,253
Land and improvements and buildings and improvements, gross	18,708
Accumulated Depreciation	$ 4,133
Depreciation life	35 years
Rentable square feet | ft²	26,238
6121 W. Sunset Blvd., Los Angeles, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 11,120
Initial cost, buildings and Improvements	4,256
Costs Capitalized Subsequent  to Acquisition/ Improvement	44,031
Land and improvements, gross	8,703
Buildings and improvements, gross	50,704
Land and improvements and buildings and improvements, gross	59,407
Accumulated Depreciation	$ 11,849
Depreciation life	35 years
Rentable square feet | ft²	93,418
6255 W. Sunset Blvd., Los Angeles, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 18,111
Initial cost, buildings and Improvements	60,320
Costs Capitalized Subsequent  to Acquisition/ Improvement	52,399
Land and improvements, gross	18,111
Buildings and improvements, gross	112,719
Land and improvements and buildings and improvements, gross	130,830
Accumulated Depreciation	$ 53,140
Depreciation life	35 years
Rentable square feet | ft²	331,888
3750 Kilroy Airport Way, Long Beach, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 0
Initial cost, buildings and Improvements	1,941
Costs Capitalized Subsequent  to Acquisition/ Improvement	13,732
Land and improvements, gross	0
Buildings and improvements, gross	15,673
Land and improvements and buildings and improvements, gross	15,673
Accumulated Depreciation	$ 12,103
Depreciation life	35 years
Rentable square feet | ft²	10,718
3760 Kilroy Airport Way, Long Beach, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 0
Initial cost, buildings and Improvements	17,467
Costs Capitalized Subsequent  to Acquisition/ Improvement	21,186
Land and improvements, gross	0
Buildings and improvements, gross	38,653
Land and improvements and buildings and improvements, gross	38,653
Accumulated Depreciation	$ 30,843
Depreciation life	35 years
Rentable square feet | ft²	166,761
3780 Kilroy Airport Way, Long Beach, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 0
Initial cost, buildings and Improvements	22,319
Costs Capitalized Subsequent  to Acquisition/ Improvement	37,277
Land and improvements, gross	0
Buildings and improvements, gross	59,596
Land and improvements and buildings and improvements, gross	59,596
Accumulated Depreciation	$ 45,988
Depreciation life	35 years
Rentable square feet | ft²	221,452
3800 Kilroy Airport Way, Long Beach, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 0
Initial cost, buildings and Improvements	19,408
Costs Capitalized Subsequent  to Acquisition/ Improvement	24,334
Land and improvements, gross	0
Buildings and improvements, gross	43,742
Land and improvements and buildings and improvements, gross	43,742
Accumulated Depreciation	$ 29,745
Depreciation life	35 years
Rentable square feet | ft²	192,476
3840 Kilroy Airport Way, Long Beach, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 0
Initial cost, buildings and Improvements	13,586
Costs Capitalized Subsequent  to Acquisition/ Improvement	16,768
Land and improvements, gross	0
Buildings and improvements, gross	30,354
Land and improvements and buildings and improvements, gross	30,354
Accumulated Depreciation	$ 18,101
Depreciation life	35 years
Rentable square feet | ft²	138,441
3880 Kilroy Airport Way, Long Beach, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 0
Initial cost, buildings and Improvements	9,704
Costs Capitalized Subsequent  to Acquisition/ Improvement	12,115
Land and improvements, gross	0
Buildings and improvements, gross	21,819
Land and improvements and buildings and improvements, gross	21,819
Accumulated Depreciation	$ 6,615
Depreciation life	35 years
Rentable square feet | ft²	96,923
3900 Kilroy Airport Way, Long Beach, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 0
Initial cost, buildings and Improvements	12,615
Costs Capitalized Subsequent  to Acquisition/ Improvement	17,130
Land and improvements, gross	0
Buildings and improvements, gross	29,745
Land and improvements and buildings and improvements, gross	29,745
Accumulated Depreciation	$ 21,034
Depreciation life	35 years
Rentable square feet | ft²	130,935
8560 W. Sunset Blvd., West Hollywood, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 9,720
Initial cost, buildings and Improvements	50,956
Costs Capitalized Subsequent  to Acquisition/ Improvement	5,881
Land and improvements, gross	9,720
Buildings and improvements, gross	56,837
Land and improvements and buildings and improvements, gross	66,557
Accumulated Depreciation	$ 12,496
Depreciation life	35 years
Rentable square feet | ft²	76,558
8570 W. Sunset Blvd., West Hollywood, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 31,693
Initial cost, buildings and Improvements	27,974
Costs Capitalized Subsequent  to Acquisition/ Improvement	7,110
Land and improvements, gross	31,693
Buildings and improvements, gross	35,084
Land and improvements and buildings and improvements, gross	66,777
Accumulated Depreciation	$ 7,154
Depreciation life	35 years
Rentable square feet | ft²	49,276
8580 W. Sunset Blvd., West Hollywood, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 10,013
Initial cost, buildings and Improvements	3,695
Costs Capitalized Subsequent  to Acquisition/ Improvement	1,856
Land and improvements, gross	10,013
Buildings and improvements, gross	5,551
Land and improvements and buildings and improvements, gross	15,564
Accumulated Depreciation	$ 952
Depreciation life	35 years
Rentable square feet | ft²	6,875
8590 W. Sunset Blvd., West Hollywood, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 39,954
Initial cost, buildings and Improvements	27,884
Costs Capitalized Subsequent  to Acquisition/ Improvement	5,608
Land and improvements, gross	39,954
Buildings and improvements, gross	33,492
Land and improvements and buildings and improvements, gross	73,446
Accumulated Depreciation	$ 7,213
Depreciation life	35 years
Rentable square feet | ft²	56,750
12100 W. Olympic Blvd., Los Angeles, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 352
Initial cost, buildings and Improvements	45,611
Costs Capitalized Subsequent  to Acquisition/ Improvement	25,334
Land and improvements, gross	9,633
Buildings and improvements, gross	61,664
Land and improvements and buildings and improvements, gross	71,297
Accumulated Depreciation	$ 34,464
Depreciation life	35 years
Rentable square feet | ft²	155,679
12200 W. Olympic Blvd., Los Angeles, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 4,329
Initial cost, buildings and Improvements	35,488
Costs Capitalized Subsequent  to Acquisition/ Improvement	26,399
Land and improvements, gross	3,977
Buildings and improvements, gross	62,239
Land and improvements and buildings and improvements, gross	66,216
Accumulated Depreciation	$ 47,437
Depreciation life	35 years
Rentable square feet | ft²	154,544
12233 W. Olympic Blvd., Los Angeles, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 22,100
Initial cost, buildings and Improvements	53,170
Costs Capitalized Subsequent  to Acquisition/ Improvement	6,398
Land and improvements, gross	22,100
Buildings and improvements, gross	59,568
Land and improvements and buildings and improvements, gross	81,668
Accumulated Depreciation	$ 20,181
Depreciation life	35 years
Rentable square feet | ft²	156,746
12312 W. Olympic Blvd., Los Angeles, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 3,325
Initial cost, buildings and Improvements	12,202
Costs Capitalized Subsequent  to Acquisition/ Improvement	12,671
Land and improvements, gross	3,399
Buildings and improvements, gross	24,799
Land and improvements and buildings and improvements, gross	28,198
Accumulated Depreciation	$ 18,006
Depreciation life	35 years
Rentable square feet | ft²	76,644
2100/2110 Colorado Ave., Santa Monica, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 5,474
Initial cost, buildings and Improvements	26,087
Costs Capitalized Subsequent  to Acquisition/ Improvement	15,937
Land and improvements, gross	5,476
Buildings and improvements, gross	42,022
Land and improvements and buildings and improvements, gross	47,498
Accumulated Depreciation	$ 30,599
Depreciation life	35 years
Rentable square feet | ft²	104,853
501 Santa Monica Blvd., Santa Monica, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 4,547
Initial cost, buildings and Improvements	12,044
Costs Capitalized Subsequent  to Acquisition/ Improvement	18,723
Land and improvements, gross	4,551
Buildings and improvements, gross	30,763
Land and improvements and buildings and improvements, gross	35,314
Accumulated Depreciation	$ 22,436
Depreciation life	35 years
Rentable square feet | ft²	78,509
12225 El Camino Real, Del Mar, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 1,700
Initial cost, buildings and Improvements	9,633
Costs Capitalized Subsequent  to Acquisition/ Improvement	4,409
Land and improvements, gross	1,673
Buildings and improvements, gross	14,069
Land and improvements and buildings and improvements, gross	15,742
Accumulated Depreciation	$ 10,451
Depreciation life	35 years
Rentable square feet | ft²	58,401
12235 El Camino Real, Del Mar, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 1,507
Initial cost, buildings and Improvements	8,543
Costs Capitalized Subsequent  to Acquisition/ Improvement	9,974
Land and improvements, gross	1,540
Buildings and improvements, gross	18,484
Land and improvements and buildings and improvements, gross	20,024
Accumulated Depreciation	$ 12,892
Depreciation life	35 years
Rentable square feet | ft²	53,751
12340 El Camino Real, Del Mar, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 4,201
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	35,553
Land and improvements, gross	4,201
Buildings and improvements, gross	35,553
Land and improvements and buildings and improvements, gross	39,754
Accumulated Depreciation	$ 3,375
Depreciation life	35 years
Rentable square feet | ft²	109,307
12390 El Camino Real, Del Mar, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 3,453
Initial cost, buildings and Improvements	11,981
Costs Capitalized Subsequent  to Acquisition/ Improvement	11,618
Land and improvements, gross	3,453
Buildings and improvements, gross	23,599
Land and improvements and buildings and improvements, gross	27,052
Accumulated Depreciation	$ 13,100
Depreciation life	35 years
Rentable square feet | ft²	73,238
12770 El Camino Real, Del Mar, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 9,360
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	35,006
Land and improvements, gross	9,360
Buildings and improvements, gross	35,006
Land and improvements and buildings and improvements, gross	44,366
Accumulated Depreciation	$ 6,990
Depreciation life	35 years
Rentable square feet | ft²	75,035
12780 El Camino Real, Del Mar, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 18,398
Initial cost, buildings and Improvements	54,954
Costs Capitalized Subsequent  to Acquisition/ Improvement	24,127
Land and improvements, gross	18,398
Buildings and improvements, gross	79,081
Land and improvements and buildings and improvements, gross	97,479
Accumulated Depreciation	$ 25,319
Depreciation life	35 years
Rentable square feet | ft²	140,591
12790 El Camino Real, Del Mar, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 10,252
Initial cost, buildings and Improvements	21,236
Costs Capitalized Subsequent  to Acquisition/ Improvement	17,133
Land and improvements, gross	10,252
Buildings and improvements, gross	38,369
Land and improvements and buildings and improvements, gross	48,621
Accumulated Depreciation	$ 10,204
Depreciation life	35 years
Rentable square feet | ft²	87,944
12830 El Camino Real, Del Mar, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 28,645
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	112,741
Land and improvements, gross	28,645
Buildings and improvements, gross	112,741
Land and improvements and buildings and improvements, gross	141,386
Accumulated Depreciation	$ 8,764
Depreciation life	35 years
Rentable square feet | ft²	196,444
12860 El Camino Real, Del Mar, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 11,326
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	51,662
Land and improvements, gross	11,326
Buildings and improvements, gross	51,662
Land and improvements and buildings and improvements, gross	62,988
Accumulated Depreciation	$ 4,229
Depreciation life	35 years
Rentable square feet | ft²	92,042
12348 High Bluff Dr., Del Mar, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 1,629
Initial cost, buildings and Improvements	3,096
Costs Capitalized Subsequent  to Acquisition/ Improvement	8,496
Land and improvements, gross	1,629
Buildings and improvements, gross	11,592
Land and improvements and buildings and improvements, gross	13,221
Accumulated Depreciation	$ 8,071
Depreciation life	35 years
Rentable square feet | ft²	39,193
12400 High Bluff Dr., Del Mar, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 15,167
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	46,755
Land and improvements, gross	15,167
Buildings and improvements, gross	46,755
Land and improvements and buildings and improvements, gross	61,922
Accumulated Depreciation	$ 9,856
Depreciation life	35 years
Rentable square feet | ft²	216,518
3579 Valley Centre Dr., Del Mar, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 2,167
Initial cost, buildings and Improvements	6,897
Costs Capitalized Subsequent  to Acquisition/ Improvement	11,319
Land and improvements, gross	2,858
Buildings and improvements, gross	17,525
Land and improvements and buildings and improvements, gross	20,383
Accumulated Depreciation	$ 11,461
Depreciation life	35 years
Rentable square feet | ft²	54,960
3611 Valley Centre Dr., Del Mar, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 4,184
Initial cost, buildings and Improvements	19,352
Costs Capitalized Subsequent  to Acquisition/ Improvement	29,293
Land and improvements, gross	5,259
Buildings and improvements, gross	47,570
Land and improvements and buildings and improvements, gross	52,829
Accumulated Depreciation	$ 31,308
Depreciation life	35 years
Rentable square feet | ft²	132,425
3661 Valley Centre Dr., Del Mar, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 4,038
Initial cost, buildings and Improvements	21,144
Costs Capitalized Subsequent  to Acquisition/ Improvement	20,567
Land and improvements, gross	4,725
Buildings and improvements, gross	41,024
Land and improvements and buildings and improvements, gross	45,749
Accumulated Depreciation	$ 27,697
Depreciation life	35 years
Rentable square feet | ft²	131,662
3721 Valley Centre Dr., Del Mar, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 4,297
Initial cost, buildings and Improvements	18,967
Costs Capitalized Subsequent  to Acquisition/ Improvement	16,203
Land and improvements, gross	4,254
Buildings and improvements, gross	35,213
Land and improvements and buildings and improvements, gross	39,467
Accumulated Depreciation	$ 22,563
Depreciation life	35 years
Rentable square feet | ft²	115,193
3811 Valley Centre Dr., Del Mar, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 3,452
Initial cost, buildings and Improvements	16,152
Costs Capitalized Subsequent  to Acquisition/ Improvement	21,883
Land and improvements, gross	4,457
Buildings and improvements, gross	37,030
Land and improvements and buildings and improvements, gross	41,487
Accumulated Depreciation	$ 25,813
Depreciation life	35 years
Rentable square feet | ft²	118,912
3745 Paseo Place, Del Mar, CA (Retail)
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 24,358
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	73,942
Land and improvements, gross	24,358
Buildings and improvements, gross	73,942
Land and improvements and buildings and improvements, gross	98,300
Accumulated Depreciation	$ 8,857
Depreciation life	35 years
Rentable square feet | ft²	95,871
13480 Evening Creek Dr. North, San Diego, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 7,997
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	57,000
Land and improvements, gross	7,997
Buildings and improvements, gross	57,000
Land and improvements and buildings and improvements, gross	64,997
Accumulated Depreciation	$ 25,377
Depreciation life	35 years
Rentable square feet | ft²	143,401
13500 Evening Creek Dr. North, San Diego, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 7,581
Initial cost, buildings and Improvements	35,903
Costs Capitalized Subsequent  to Acquisition/ Improvement	24,926
Land and improvements, gross	7,580
Buildings and improvements, gross	60,830
Land and improvements and buildings and improvements, gross	68,410
Accumulated Depreciation	$ 30,838
Depreciation life	35 years
Rentable square feet | ft²	143,749
13520 Evening Creek Dr. North, San Diego, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 7,581
Initial cost, buildings and Improvements	35,903
Costs Capitalized Subsequent  to Acquisition/ Improvement	24,767
Land and improvements, gross	7,580
Buildings and improvements, gross	60,671
Land and improvements and buildings and improvements, gross	68,251
Accumulated Depreciation	$ 33,028
Depreciation life	35 years
Rentable square feet | ft²	146,701
2100 Kettner Blvd., San Diego, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 19,861
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	97,396
Land and improvements, gross	19,861
Buildings and improvements, gross	97,396
Land and improvements and buildings and improvements, gross	117,257
Accumulated Depreciation	$ 918
Depreciation life	35 years
Rentable square feet | ft²	204,682
2305 Historic Decatur Rd., San Diego, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 5,240
Initial cost, buildings and Improvements	22,220
Costs Capitalized Subsequent  to Acquisition/ Improvement	9,757
Land and improvements, gross	5,240
Buildings and improvements, gross	31,977
Land and improvements and buildings and improvements, gross	37,217
Accumulated Depreciation	$ 15,472
Depreciation life	35 years
Rentable square feet | ft²	107,456
4690 Executive Dr., San Diego, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 0
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	6,264
Land and improvements, gross	0
Buildings and improvements, gross	6,264
Land and improvements and buildings and improvements, gross	6,264
Accumulated Depreciation	$ 77
Depreciation life	35 years
Rentable square feet | ft²	0
9455 Towne Centre Dr., San Diego, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 6,081
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	80,076
Land and improvements, gross	6,081
Buildings and improvements, gross	80,076
Land and improvements and buildings and improvements, gross	86,157
Accumulated Depreciation	$ 4,913
Depreciation life	35 years
Rentable square feet | ft²	160,444
4100 Bohannon Dr., Menlo Park, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 4,835
Initial cost, buildings and Improvements	15,526
Costs Capitalized Subsequent  to Acquisition/ Improvement	1,583
Land and improvements, gross	4,860
Buildings and improvements, gross	17,084
Land and improvements and buildings and improvements, gross	21,944
Accumulated Depreciation	$ 6,104
Depreciation life	35 years
Rentable square feet | ft²	47,379
4200 Bohannon Dr., Menlo Park, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 4,798
Initial cost, buildings and Improvements	15,406
Costs Capitalized Subsequent  to Acquisition/ Improvement	6,967
Land and improvements, gross	4,662
Buildings and improvements, gross	22,509
Land and improvements and buildings and improvements, gross	27,171
Accumulated Depreciation	$ 8,428
Depreciation life	35 years
Rentable square feet | ft²	45,451
4300 Bohannon Dr., Menlo Park, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 6,527
Initial cost, buildings and Improvements	20,958
Costs Capitalized Subsequent  to Acquisition/ Improvement	8,611
Land and improvements, gross	6,470
Buildings and improvements, gross	29,626
Land and improvements and buildings and improvements, gross	36,096
Accumulated Depreciation	$ 10,389
Depreciation life	35 years
Rentable square feet | ft²	63,079
4400 Bohannon Dr., Menlo Park, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 0
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	3,002
Land and improvements, gross	0
Buildings and improvements, gross	3,002
Land and improvements and buildings and improvements, gross	3,002
Accumulated Depreciation	$ 2,057
Depreciation life	35 years
Rentable square feet | ft²	0
4500 Bohannon Dr., Menlo Park, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 6,527
Initial cost, buildings and Improvements	20,957
Costs Capitalized Subsequent  to Acquisition/ Improvement	4,479
Land and improvements, gross	6,470
Buildings and improvements, gross	25,493
Land and improvements and buildings and improvements, gross	31,963
Accumulated Depreciation	$ 9,519
Depreciation life	35 years
Rentable square feet | ft²	63,078
4600 Bohannon Dr., Menlo Park, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 4,798
Initial cost, buildings and Improvements	15,406
Costs Capitalized Subsequent  to Acquisition/ Improvement	4,531
Land and improvements, gross	4,939
Buildings and improvements, gross	19,796
Land and improvements and buildings and improvements, gross	24,735
Accumulated Depreciation	$ 7,975
Depreciation life	35 years
Rentable square feet | ft²	48,147
4700 Bohannon Dr., Menlo Park, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 6,527
Initial cost, buildings and Improvements	20,958
Costs Capitalized Subsequent  to Acquisition/ Improvement	1,572
Land and improvements, gross	6,470
Buildings and improvements, gross	22,587
Land and improvements and buildings and improvements, gross	29,057
Accumulated Depreciation	$ 8,432
Depreciation life	35 years
Rentable square feet | ft²	63,078
1290 - 1300 Terra Bella Ave., Mountain View, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 28,730
Initial cost, buildings and Improvements	27,555
Costs Capitalized Subsequent  to Acquisition/ Improvement	12,305
Land and improvements, gross	28,730
Buildings and improvements, gross	39,860
Land and improvements and buildings and improvements, gross	68,590
Accumulated Depreciation	$ 7,462
Depreciation life	35 years
Rentable square feet | ft²	114,175
680 E. Middlefield Rd., Mountain View, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 34,755
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	56,759
Land and improvements, gross	34,755
Buildings and improvements, gross	56,759
Land and improvements and buildings and improvements, gross	91,514
Accumulated Depreciation	$ 15,612
Depreciation life	35 years
Rentable square feet | ft²	171,676
690 E. Middlefield Rd., Mountain View, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 34,605
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	56,515
Land and improvements, gross	34,605
Buildings and improvements, gross	56,515
Land and improvements and buildings and improvements, gross	91,120
Accumulated Depreciation	$ 15,546
Depreciation life	35 years
Rentable square feet | ft²	171,215
1701 Page Mill Rd., Palo Alto, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 0
Initial cost, buildings and Improvements	99,522
Costs Capitalized Subsequent  to Acquisition/ Improvement	108
Land and improvements, gross	0
Buildings and improvements, gross	99,630
Land and improvements and buildings and improvements, gross	99,630
Accumulated Depreciation	$ 18,011
Depreciation life	35 years
Rentable square feet | ft²	128,688
3150 Porter Dr., Palo Alto, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 0
Initial cost, buildings and Improvements	21,715
Costs Capitalized Subsequent  to Acquisition/ Improvement	6,327
Land and improvements, gross	0
Buildings and improvements, gross	28,042
Land and improvements and buildings and improvements, gross	28,042
Accumulated Depreciation	$ 4,961
Depreciation life	35 years
Rentable square feet | ft²	36,886
900 Jefferson Ave., Redwood City, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 16,668
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	109,626
Land and improvements, gross	18,063
Buildings and improvements, gross	108,231
Land and improvements and buildings and improvements, gross	126,294
Accumulated Depreciation	$ 27,378
Depreciation life	35 years
Rentable square feet | ft²	228,505
900 Middlefield Rd., Redwood City, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 7,959
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	50,293
Land and improvements, gross	8,626
Buildings and improvements, gross	49,626
Land and improvements and buildings and improvements, gross	58,252
Accumulated Depreciation	$ 12,241
Depreciation life	35 years
Rentable square feet | ft²	118,764
100 Hooper St., San Francisco, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 78,564
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	196,708
Land and improvements, gross	85,510
Buildings and improvements, gross	189,762
Land and improvements and buildings and improvements, gross	275,272
Accumulated Depreciation	$ 23,632
Depreciation life	35 years
Rentable square feet | ft²	417,914
100 First St., San Francisco, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 49,150
Initial cost, buildings and Improvements	131,238
Costs Capitalized Subsequent  to Acquisition/ Improvement	78,071
Land and improvements, gross	49,150
Buildings and improvements, gross	209,309
Land and improvements and buildings and improvements, gross	258,459
Accumulated Depreciation	$ 95,413
Depreciation life	35 years
Rentable square feet | ft²	480,457
303 Second St., San Francisco, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 63,550
Initial cost, buildings and Improvements	154,153
Costs Capitalized Subsequent  to Acquisition/ Improvement	109,843
Land and improvements, gross	63,550
Buildings and improvements, gross	263,996
Land and improvements and buildings and improvements, gross	327,546
Accumulated Depreciation	$ 122,578
Depreciation life	35 years
Rentable square feet | ft²	784,658
201 Third St., San Francisco, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 19,260
Initial cost, buildings and Improvements	84,018
Costs Capitalized Subsequent  to Acquisition/ Improvement	77,793
Land and improvements, gross	19,260
Buildings and improvements, gross	161,811
Land and improvements and buildings and improvements, gross	181,071
Accumulated Depreciation	$ 84,332
Depreciation life	35 years
Rentable square feet | ft²	346,538
360 Third St., San Francisco, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 0
Initial cost, buildings and Improvements	88,235
Costs Capitalized Subsequent  to Acquisition/ Improvement	126,260
Land and improvements, gross	28,504
Buildings and improvements, gross	185,991
Land and improvements and buildings and improvements, gross	214,495
Accumulated Depreciation	$ 67,999
Depreciation life	35 years
Rentable square feet | ft²	429,796
250 Brannan St., San Francisco, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 7,630
Initial cost, buildings and Improvements	22,770
Costs Capitalized Subsequent  to Acquisition/ Improvement	10,752
Land and improvements, gross	7,630
Buildings and improvements, gross	33,522
Land and improvements and buildings and improvements, gross	41,152
Accumulated Depreciation	$ 14,079
Depreciation life	35 years
Rentable square feet | ft²	100,850
301 Brannan St., San Francisco, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 5,910
Initial cost, buildings and Improvements	22,450
Costs Capitalized Subsequent  to Acquisition/ Improvement	16,647
Land and improvements, gross	5,910
Buildings and improvements, gross	39,097
Land and improvements and buildings and improvements, gross	45,007
Accumulated Depreciation	$ 14,016
Depreciation life	35 years
Rentable square feet | ft²	82,834
333 Brannan St., San Francisco, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 18,645
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	80,640
Land and improvements, gross	18,645
Buildings and improvements, gross	80,640
Land and improvements and buildings and improvements, gross	99,285
Accumulated Depreciation	$ 16,195
Depreciation life	35 years
Rentable square feet | ft²	185,602
345 Brannan St., San Francisco, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 29,405
Initial cost, buildings and Improvements	113,179
Costs Capitalized Subsequent  to Acquisition/ Improvement	1,135
Land and improvements, gross	29,403
Buildings and improvements, gross	114,316
Land and improvements and buildings and improvements, gross	143,719
Accumulated Depreciation	$ 13,548
Depreciation life	35 years
Rentable square feet | ft²	110,050
350 Mission St., San Francisco, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 52,815
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	212,731
Land and improvements, gross	52,815
Buildings and improvements, gross	212,731
Land and improvements and buildings and improvements, gross	265,546
Accumulated Depreciation	$ 44,523
Depreciation life	35 years
Rentable square feet | ft²	455,340
345 Oyster Point Blvd., South San Francisco, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 13,745
Initial cost, buildings and Improvements	18,575
Costs Capitalized Subsequent  to Acquisition/ Improvement	0
Land and improvements, gross	13,745
Buildings and improvements, gross	18,575
Land and improvements and buildings and improvements, gross	32,320
Accumulated Depreciation	$ 2,835
Depreciation life	35 years
Rentable square feet | ft²	40,410
347 Oyster Point Blvd., South San Francisco, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 14,071
Initial cost, buildings and Improvements	18,289
Costs Capitalized Subsequent  to Acquisition/ Improvement	44
Land and improvements, gross	14,071
Buildings and improvements, gross	18,333
Land and improvements and buildings and improvements, gross	32,404
Accumulated Depreciation	$ 2,803
Depreciation life	35 years
Rentable square feet | ft²	39,780
349 Oyster Point Blvd., South San Francisco, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 23,112
Initial cost, buildings and Improvements	22,601
Costs Capitalized Subsequent  to Acquisition/ Improvement	324
Land and improvements, gross	23,112
Buildings and improvements, gross	22,925
Land and improvements and buildings and improvements, gross	46,037
Accumulated Depreciation	$ 4,741
Depreciation life	35 years
Rentable square feet | ft²	65,340
350 Oyster Point Blvd., South San Francisco, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 23,719
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	178,544
Land and improvements, gross	23,719
Buildings and improvements, gross	178,544
Land and improvements and buildings and improvements, gross	202,263
Accumulated Depreciation	$ 6,529
Depreciation life	35 years
Rentable square feet | ft²	234,892
352 Oyster Point Blvd., South San Francisco, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 23,449
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	166,919
Land and improvements, gross	23,449
Buildings and improvements, gross	166,919
Land and improvements and buildings and improvements, gross	190,368
Accumulated Depreciation	$ 5,965
Depreciation life	35 years
Rentable square feet | ft²	232,215
354 Oyster Point Blvd., South San Francisco, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 19,538
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	142,080
Land and improvements, gross	19,538
Buildings and improvements, gross	142,080
Land and improvements and buildings and improvements, gross	161,618
Accumulated Depreciation	$ 5,995
Depreciation life	35 years
Rentable square feet | ft²	193,472
505 Mathilda Ave., Sunnyvale, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 37,843
Initial cost, buildings and Improvements	1,163
Costs Capitalized Subsequent  to Acquisition/ Improvement	50,450
Land and improvements, gross	37,943
Buildings and improvements, gross	51,513
Land and improvements and buildings and improvements, gross	89,456
Accumulated Depreciation	$ 12,147
Depreciation life	35 years
Rentable square feet | ft²	212,322
555 Mathilda Ave., Sunnyvale, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 37,843
Initial cost, buildings and Improvements	1,163
Costs Capitalized Subsequent  to Acquisition/ Improvement	50,447
Land and improvements, gross	37,943
Buildings and improvements, gross	51,510
Land and improvements and buildings and improvements, gross	89,453
Accumulated Depreciation	$ 12,146
Depreciation life	35 years
Rentable square feet | ft²	212,322
599 Mathilda Ave., Sunnyvale, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 13,538
Initial cost, buildings and Improvements	12,559
Costs Capitalized Subsequent  to Acquisition/ Improvement	71
Land and improvements, gross	13,538
Buildings and improvements, gross	12,630
Land and improvements and buildings and improvements, gross	26,168
Accumulated Depreciation	$ 5,386
Depreciation life	35 years
Rentable square feet | ft²	76,031
605 Mathilda Ave., Sunnyvale, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 29,014
Initial cost, buildings and Improvements	891
Costs Capitalized Subsequent  to Acquisition/ Improvement	77,281
Land and improvements, gross	29,090
Buildings and improvements, gross	78,096
Land and improvements and buildings and improvements, gross	107,186
Accumulated Depreciation	$ 27,048
Depreciation life	35 years
Rentable square feet | ft²	162,785
601 108th Ave., Bellevue, WA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 0
Initial cost, buildings and Improvements	214,095
Costs Capitalized Subsequent  to Acquisition/ Improvement	88,313
Land and improvements, gross	42,680
Buildings and improvements, gross	259,728
Land and improvements and buildings and improvements, gross	302,408
Accumulated Depreciation	$ 108,785
Depreciation life	35 years
Rentable square feet | ft²	490,738
10900 NE 4th St., Bellevue, WA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 25,080
Initial cost, buildings and Improvements	150,877
Costs Capitalized Subsequent  to Acquisition/ Improvement	51,424
Land and improvements, gross	25,080
Buildings and improvements, gross	202,301
Land and improvements and buildings and improvements, gross	227,381
Accumulated Depreciation	$ 80,659
Depreciation life	35 years
Rentable square feet | ft²	428,557
2001 W. 8th Ave., Seattle, WA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 84,076
Initial cost, buildings and Improvements	371,154
Costs Capitalized Subsequent  to Acquisition/ Improvement	309
Land and improvements, gross	84,076
Buildings and improvements, gross	371,463
Land and improvements and buildings and improvements, gross	455,539
Accumulated Depreciation	$ 17,757
Depreciation life	35 years
Rentable square feet | ft²	539,226
701 N. 34th St., Seattle, WA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 0
Initial cost, buildings and Improvements	48,027
Costs Capitalized Subsequent  to Acquisition/ Improvement	9,063
Land and improvements, gross	0
Buildings and improvements, gross	57,090
Land and improvements and buildings and improvements, gross	57,090
Accumulated Depreciation	$ 22,769
Depreciation life	35 years
Rentable square feet | ft²	141,860
801 N. 34th St., Seattle, WA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 0
Initial cost, buildings and Improvements	58,537
Costs Capitalized Subsequent  to Acquisition/ Improvement	22,448
Land and improvements, gross	0
Buildings and improvements, gross	80,985
Land and improvements and buildings and improvements, gross	80,985
Accumulated Depreciation	$ 26,673
Depreciation life	35 years
Rentable square feet | ft²	173,615
837 N. 34th St., Seattle, WA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 0
Initial cost, buildings and Improvements	37,404
Costs Capitalized Subsequent  to Acquisition/ Improvement	6,563
Land and improvements, gross	0
Buildings and improvements, gross	43,967
Land and improvements and buildings and improvements, gross	43,967
Accumulated Depreciation	$ 16,307
Depreciation life	35 years
Rentable square feet | ft²	112,487
320 Westlake Ave. North, Seattle, WA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 14,710
Initial cost, buildings and Improvements	82,018
Costs Capitalized Subsequent  to Acquisition/ Improvement	14,823
Land and improvements, gross	14,710
Buildings and improvements, gross	96,841
Land and improvements and buildings and improvements, gross	111,551
Accumulated Depreciation	$ 30,346
Depreciation life	35 years
Rentable square feet | ft²	184,644
321 Terry Ave. North, Seattle, WA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 10,430
Initial cost, buildings and Improvements	60,003
Costs Capitalized Subsequent  to Acquisition/ Improvement	10,717
Land and improvements, gross	10,430
Buildings and improvements, gross	70,720
Land and improvements and buildings and improvements, gross	81,150
Accumulated Depreciation	$ 23,174
Depreciation life	35 years
Rentable square feet | ft²	135,755
401 Terry Ave. North, Seattle, WA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 22,500
Initial cost, buildings and Improvements	77,046
Costs Capitalized Subsequent  to Acquisition/ Improvement	31
Land and improvements, gross	22,500
Buildings and improvements, gross	77,077
Land and improvements and buildings and improvements, gross	99,577
Accumulated Depreciation	$ 22,544
Depreciation life	35 years
Rentable square feet | ft²	174,530
333 Dexter Ave. North, Seattle, WA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 42,854
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	327,999
Land and improvements, gross	42,854
Buildings and improvements, gross	327,999
Land and improvements and buildings and improvements, gross	370,853
Accumulated Depreciation	$ 17,074
Depreciation life	35 years
Rentable square feet | ft²	618,766
200 W. 6th St., Austin, TX
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 0
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	611,622
Land and improvements, gross	0
Buildings and improvements, gross	611,622
Land and improvements and buildings and improvements, gross	611,622
Accumulated Depreciation	$ 4,622
Depreciation life	35 years
Rentable square feet | ft²	0
1550 N. El Centro Avenue, Los Angeles, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 16,970
Initial cost, buildings and Improvements	39
Costs Capitalized Subsequent  to Acquisition/ Improvement	136,782
Land and improvements, gross	16,970
Buildings and improvements, gross	136,821
Land and improvements and buildings and improvements, gross	153,791
Accumulated Depreciation	$ 25,942
Depreciation life	35 years
Rentable square feet | ft²	0
6390 De Longpre Ave., Hollywood, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 12,112
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	163,539
Land and improvements, gross	12,112
Buildings and improvements, gross	163,539
Land and improvements and buildings and improvements, gross	175,651
Accumulated Depreciation	$ 8,132
Depreciation life	35 years
Rentable square feet | ft²	0
3200 Paseo Village Way, Del Mar, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 106,419
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	270,120
Land and improvements, gross	106,419
Buildings and improvements, gross	270,120
Land and improvements and buildings and improvements, gross	376,539
Accumulated Depreciation	$ 22,815
Depreciation life	35 years
Rentable square feet | ft²	0
Office Building | 12100, 12200 and 12312 W. Olympic Blvd., Los Angeles, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, encumbrances	$ 159,973
Office Building | 320 Westlake Ave. North, WA and 321 Terry Avenue North, Lake Union, WA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, encumbrances	83,496
Operating Properties
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, encumbrances	243,469
Initial cost, land and improvements	1,646,775
Initial cost, buildings and Improvements	2,959,869
Costs Capitalized Subsequent  to Acquisition/ Improvement	5,433,679
Land and improvements, gross	1,738,242
Buildings and improvements, gross	8,302,081
Land and improvements and buildings and improvements, gross	10,040,323
Accumulated Depreciation	$ 2,218,710
Rentable square feet | ft²	16,194,146
Undeveloped land and construction in progress
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, encumbrances	$ 0
Initial cost, land and improvements	918,291
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	773,569
Land and improvements, gross	918,291
Buildings and improvements, gross	773,569
Land and improvements and buildings and improvements, gross	1,691,860
Accumulated Depreciation	$ 0
Rentable square feet | ft²	0

Schedule III - Real Estate an_3

Schedule III - Real Estate and Accumulated Depreciation - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) ft² property	Dec. 31, 2021 USD ($)
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, encumbrances	$ 243,469
Rentable square feet (unaudited) | ft²	16,194,146
Investment in real estate, federal Income tax basis	$ 9,600,000
In Process Research and Development
Real Estate and Accumulated Depreciation [Line Items]
Rentable square feet (unaudited) | ft²	734,000
Kilroy Realty L.P.
Real Estate and Accumulated Depreciation [Line Items]
Long-term debt, gross	$ 4,293,469
Kilroy Realty L.P. | Secured debt
Real Estate and Accumulated Depreciation [Line Items]
Unamortized debt issuance expense	(531)	$ (656)
3.57% Mortgage Payable due December 2026 | Kilroy Realty L.P.
Real Estate and Accumulated Depreciation [Line Items]
Long-term debt, gross	160,000
3.57% Mortgage Payable due December 2026 | Kilroy Realty L.P. | Secured debt
Real Estate and Accumulated Depreciation [Line Items]
Long-term debt, gross	159,973	163,435
4.48% Mortgage Payable due July 2027 | Kilroy Realty L.P. | Secured debt
Real Estate and Accumulated Depreciation [Line Items]
Long-term debt, gross	83,496	$ 85,588
Office Building
Real Estate and Accumulated Depreciation [Line Items]
Unamortized debt issuance expense	$ (500)
Office Building | Sunset Blvd., Gower St. and El Centro Ave. Properties in Los Angeles
Real Estate and Accumulated Depreciation [Line Items]
Number of buildings | property	5
Residential Tower | Sunset Blvd., Gower St. and El Centro Ave. Properties in Los Angeles
Real Estate and Accumulated Depreciation [Line Items]
Number of buildings | property	1
Building
Real Estate and Accumulated Depreciation [Line Items]
Depreciation life	35 years
Tenant Improvements | Minimum
Real Estate and Accumulated Depreciation [Line Items]
Property depreciable lives	1 year
Tenant Improvements | Maximum
Real Estate and Accumulated Depreciation [Line Items]
Property depreciable lives	20 years

Schedule III - Real Estate an_4

Schedule III - Real Estate and Accumulated Depreciation - Historical Cost Real Estate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate [Roll Forward]
Total real estate held for investment, beginning of year	$ 11,292,693	$ 10,190,046	$ 9,628,773
Acquisitions	40,033	1,131,248	0
Improvements, etc.	439,759	547,468	645,170
Total additions during period	479,792	1,678,716	645,170
Cost of real estate sold	(32,855)	(572,985)	(44,070)
Other	(7,447)	(3,084)	(39,827)
Total deductions during period	(40,302)	(576,069)	(83,897)
Total real estate held for investment, end of year	$ 11,732,183	$ 11,292,693	$ 10,190,046

Schedule III - Real Estate an_5

Schedule III - Real Estate and Accumulated Depreciation - Accumulated Depreciation Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation [Roll Forward]
Accumulated depreciation, beginning of year	$ 2,003,656	$ 1,798,646	$ 1,561,361
Depreciation of real estate	287,799	256,304	244,815
Total additions during period	287,799	256,304	244,815
Write-offs due to sale	(19,114)	(38,156)	(6,401)
Other	(53,631)	(13,138)	(1,129)
Total deductions during period	(72,745)	(51,294)	(7,530)
Accumulated depreciation, end of year	$ 2,218,710	$ 2,003,656	$ 1,798,646