Kilroy Realty (KRC) 10-K 9 Feb 24 2023 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2023	Feb. 02, 2024	Jun. 30, 2023
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2023
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
Document Financial Statement Error Correction	false
Entity Shell Company	false
Entity Public Float			$ 3,505,253,788
Entity Common Stock, Shares Outstanding		117,326,410
Documents Incorporated by Reference	Portions of the Kilroy Realty Corporation’s Proxy Statement with respect to its 2024 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	2023
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
Document Financial Statement Error Correction	false
Entity Shell Company	false
Entity Central Index Key	0001493976
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Amendment Flag	false

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2023
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, 2023	Dec. 31, 2022
REAL ESTATE ASSETS (Notes 2, 3 and 4):
Land and improvements	$ 1,743,170	$ 1,738,242
Buildings and improvements	8,463,674	8,302,081
Undeveloped land and construction in progress	2,034,804	1,691,860
Total real estate assets held for investment	12,241,648	11,732,183
Accumulated depreciation and amortization	(2,518,304)	(2,218,710)
Total real estate assets held for investment, net	9,723,344	9,513,473
CASH AND CASH EQUIVALENTS (Note 23)	510,163	347,379
MARKETABLE SECURITIES (Notes 5, 17 and 20)	284,670	23,547
CURRENT RECEIVABLES, NET (Notes 2 and 6)	13,609	20,583
DEFERRED RENT RECEIVABLES, NET (Notes 2 and 6)	460,979	452,200
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Notes 2, 3 and 7)	229,705	250,846
RIGHT OF USE GROUND LEASE ASSETS (Note 19)	125,506	126,530
PREPAID EXPENSES AND OTHER ASSETS, NET (Note 8)	53,069	62,429
TOTAL ASSETS	11,401,045	10,796,987
LIABILITIES:
Secured debt, net (Notes 9, 10 and 20)	603,225	242,938
Unsecured debt, net (Notes 9, 10 and 20)	4,325,153	4,020,058
Accounts payable, accrued expenses and other liabilities (Note 19)	371,179	392,360
Ground lease liabilities (Note 19)	124,353	124,994
Accrued dividends and distributions (Notes 14 and 26)	64,440	64,285
Deferred revenue and acquisition-related intangible liabilities, net (Notes 2, 3, 7 and 11)	173,638	195,959
Rents received in advance and tenant security deposits	79,364	81,432
Total liabilities	5,741,352	5,122,026
COMMITMENTS AND CONTINGENCIES (Note 19)
Stockholders’ Equity (Note 14):
Common stock, $.01 par value, 280,000,000 shares authorized, 117,239,558 and 116,878,031 shares issued and outstanding, respectively	1,173	1,169
Additional paid-in capital	5,205,839	5,170,760
Retained earnings	221,149	265,118
Total stockholders’ equity	5,428,161	5,437,047
Noncontrolling Interests (Notes 2 and 12):
Common units of the Operating Partnership	53,275	53,524
Noncontrolling interests in consolidated property partnerships	178,257	184,390
Total noncontrolling interests	231,532	237,914
Total equity	5,659,693	5,674,961
TOTAL LIABILITIES AND EQUITY	$ 11,401,045	$ 10,796,987

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Common stock, par value ( in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	280,000,000	280,000,000
Common stock, shares issued (in shares)	117,239,558	116,878,031
Common stock, shares outstanding (in shares)	117,239,558	116,878,031

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Revenue, Product and Service [Extensible List]	Service [Member]	Service [Member]	Service [Member]
REVENUES (Note 2):
Rental income (Note 18)	$ 1,117,737	$ 1,086,018	$ 948,994
Other property income	11,957	10,969	6,046
Total revenues	1,129,694	1,096,987	955,040
EXPENSES:
Property expenses	228,964	202,744	165,702
Real estate taxes	105,868	105,869	93,209
Ground leases (Note 19)	9,732	7,565	7,421
General and administrative expenses (Note 16)	93,434	93,642	92,749
Leasing costs	6,506	4,879	3,249
Depreciation and amortization (Notes 2 and 7)	355,278	357,611	310,043
Total expenses	799,782	772,310	672,373
OTHER INCOME (EXPENSES) :
Interest and other income, net (Note 20)	22,592	1,765	3,916
Interest expense (Note 10)	(114,216)	(84,278)	(78,555)
Gains on sales of depreciable operating properties (Note 4)	0	17,329	463,128
Loss on early extinguishment of debt (Note 10)	0	0	(12,246)
Total other (expenses) income	(91,624)	(65,184)	376,243
NET INCOME	238,288	259,493	658,910
Net income attributable to noncontrolling common units of the Operating Partnership (Notes 2 and 12)	(2,083)	(2,283)	(6,163)
Net income attributable to noncontrolling interests in consolidated property partnerships (Notes 2 and 12)	(23,964)	(24,595)	(24,603)
Total income attributable to noncontrolling interests	(26,047)	(26,878)	(30,766)
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	$ 212,241	$ 232,615	$ 628,144
Net income available to common stockholders per share - basic ( in dollars per share)	$ 1.80	$ 1.98	$ 5.38
Net income available to common stockholders per share - diluted (in dollars per share)	$ 1.80	$ 1.97	$ 5.36
Weighted average common units outstanding - basic (in shares)	117,160,173	116,806,575	116,429,130
Weighted average shares of common stock outstanding – diluted (in shares)	117,506,255	117,220,047	116,948,643

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, 2020			116,035,827
Beginning 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	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)
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)
Contributions from noncontrolling interests in consolidated property partnerships	1,559					1,559
Ending balance (in shares) at Dec. 31, 2021			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	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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	238,288	212,241			212,241	26,047
Issuance of share-based compensation awards	3,110	3,110		3,110
Non-cash amortization of share-based compensation	43,721	43,721		43,721
Settlement of restricted stock units for shares of common stock (in shares)			664,600
Settlement of restricted stock units for shares of common stock	$ 0	0	$ 7	(7)
Repurchase of common stock and restricted stock units (in shares)	0		(303,073)
Repurchase of common stock and restricted stock units	$ (11,595)	(11,595)	$ (3)	(11,592)
Distributions to noncontrolling interests in consolidated property partnerships	(30,097)					(30,097)
Adjustment for noncontrolling interest in the Operating Partnership	0	(153)		(153)		153
Dividends declared per share of common stock and common unit	$ (258,695)	(256,210)			(256,210)	(2,485)
Ending balance (in shares) at Dec. 31, 2023	117,239,558		117,239,558
Ending balance at Dec. 31, 2023	$ 5,659,693	$ 5,428,161	$ 1,173	$ 5,205,839	$ 221,149	$ 231,532

CONSOLIDATED STATEMENTS OF EQ_2

CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Stockholders' Equity [Abstract]
Dividends declared per share of common stock and common unit ( in dollars per share)	$ 2.16	$ 2.12	$ 2.04

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 238,288	$ 259,493	$ 658,910
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of real estate assets and leasing costs	348,064	350,665	303,799
Depreciation of non-real estate furniture, fixtures and equipment	7,214	6,946	6,244
Revenue reversals (recoveries) for doubtful accounts, net (Notes 2 and 18)	11,553	(123)	1,433
Non-cash amortization of share-based compensation awards (Note 16)	36,858	28,347	33,800
Non-cash amortization of deferred financing costs and net debt discounts	5,200	3,657	2,831
Non-cash amortization of net below market rents (Note 7)	(6,648)	(10,476)	(6,904)
Gains on sales of depreciable operating properties (Note 4)	0	(17,329)	(463,128)
Loss on early extinguishment of debt (Note 10)	0	0	12,246
Non-cash amortization of deferred revenue related to tenant-funded tenant improvements (Note 11)	(19,181)	(19,321)	(17,247)
Straight-line rents	(19,262)	(46,231)	(53,745)
Amortization of right of use ground lease assets	1,024	772	1,241
Net change in other operating assets	2,322	(12,606)	(6,077)
Net change in other operating liabilities	(2,843)	48,441	43,000
Net cash provided by operating activities	602,589	592,235	516,403
CASH FLOWS FROM INVESTING ACTIVITIES:
Investments in certificates of deposit (Note 5)	(256,581)	0	0
Expenditures for development and redevelopment properties and undeveloped land	(446,426)	(453,774)	(552,837)
Expenditures for operating properties and other capital assets	(97,393)	(92,802)	(120,611)
Expenditures for acquisitions of development properties and undeveloped land (Note 3)	0	(40,033)	(586,927)
Net proceeds received from dispositions (Note 4)	0	33,416	1,048,927
Expenditures for acquisitions of operating properties	0	0	(537,429)
Decrease in acquisition-related deposits	0	0	1,000
Net cash used in investing activities	(800,400)	(553,193)	(747,877)
CASH FLOWS FROM FINANCING ACTIVITIES:
Principal payments and repayments of secured debt (Note 10)	(5,775)	(5,555)	(5,341)
Borrowings on unsecured debt (Note 10)	320,000	200,000	0
Proceeds from the issuance of secured debt (Note 10)	375,000	0	0
Repurchases of unsecured debt (Note 10)	(20,584)	0	0
Net proceeds from the issuance of unsecured debt (Note 10)	0	0	449,807
Repayments of unsecured debt (Note 10)	0	0	(312,105)
Financing costs (Note 10)	(10,924)	(6,432)	(12,032)
Proceeds from exercise of stock options	0	0	383
Repurchase of common stock and restricted stock units (Note 16)	(11,595)	(22,934)	(21,888)
Distributions to noncontrolling interests in consolidated property partnerships	(30,097)	(36,269)	(27,601)
Dividends and distributions paid to common stockholders and common unitholders	(255,430)	(247,556)	(237,355)
Contributions from noncontrolling interests in consolidated property partnerships	0	0	1,559
Net cash provided by (used in) financing activities	360,595	(118,746)	(164,573)
Net increase (decrease) in cash and cash equivalents and restricted cash	162,784	(79,704)	(396,047)
Cash and cash equivalents and restricted cash, beginning of year	347,379	427,083	823,130
Cash and cash equivalents and restricted cash, end of year	$ 510,163	$ 347,379	$ 427,083

CONSOLIDATED BALANCE SHEETS (KI

CONSOLIDATED BALANCE SHEETS (KILROY REALTY, L.P.) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
REAL ESTATE ASSETS (Notes 2, 3 and 4):
Land and improvements	$ 1,743,170	$ 1,738,242
Buildings and improvements	8,463,674	8,302,081
Undeveloped land and construction in progress	2,034,804	1,691,860
Total real estate assets held for investment	12,241,648	11,732,183
Accumulated depreciation and amortization	(2,518,304)	(2,218,710)
Total real estate assets held for investment, net	9,723,344	9,513,473
CASH AND CASH EQUIVALENTS (Note 24)	510,163	347,379
MARKETABLE SECURITIES (Notes 5, 17 and 20)	284,670	23,547
CURRENT RECEIVABLES, NET (Notes 2 and 6)	13,609	20,583
DEFERRED RENT RECEIVABLES, NET (Notes 2 and 6)	460,979	452,200
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Notes 2, 3 and 7)	229,705	250,846
RIGHT OF USE GROUND LEASE ASSETS (Note 19)	125,506	126,530
PREPAID EXPENSES AND OTHER ASSETS, NET (Note 8)	53,069	62,429
TOTAL ASSETS	11,401,045	10,796,987
LIABILITIES:
Secured debt, net (Notes 10 and 20)	603,225	242,938
Unsecured debt, net (Notes 10 and 20)	4,325,153	4,020,058
Accounts payable, accrued expenses and other liabilities (Note 19)	371,179	392,360
Ground lease liabilities (Note 19)	124,353	124,994
Accrued distributions (Notes 15 and 26)	64,440	64,285
Deferred revenue and acquisition-related intangible liabilities, net (Notes 2, 3, 7 and 11)	173,638	195,959
Rents received in advance and tenant security deposits	79,364	81,432
Total liabilities	5,741,352	5,122,026
COMMITMENTS AND CONTINGENCIES (Note 19)
CAPITAL:
TOTAL LIABILITIES AND EQUITY	11,401,045	10,796,987
Kilroy Realty L.P.
REAL ESTATE ASSETS (Notes 2, 3 and 4):
Land and improvements	1,743,170	1,738,242
Buildings and improvements	8,463,674	8,302,081
Undeveloped land and construction in progress	2,034,804	1,691,860
Total real estate assets held for investment	12,241,648	11,732,183
Accumulated depreciation and amortization	(2,518,304)	(2,218,710)
Total real estate assets held for investment, net	9,723,344	9,513,473
CASH AND CASH EQUIVALENTS (Note 24)	510,163	347,379
MARKETABLE SECURITIES (Notes 5, 17 and 20)	284,670	23,547
CURRENT RECEIVABLES, NET (Notes 2 and 6)	13,609	20,583
DEFERRED RENT RECEIVABLES, NET (Notes 2 and 6)	460,979	452,200
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Notes 2, 3 and 7)	229,705	250,846
RIGHT OF USE GROUND LEASE ASSETS (Note 19)	125,506	126,530
PREPAID EXPENSES AND OTHER ASSETS, NET (Note 8)	53,069	62,429
TOTAL ASSETS	11,401,045	10,796,987
LIABILITIES:
Secured debt, net (Notes 10 and 20)	603,225	242,938
Unsecured debt, net (Notes 10 and 20)	4,325,153	4,020,058
Accounts payable, accrued expenses and other liabilities (Note 19)	371,179	392,360
Ground lease liabilities (Note 19)	124,353	124,994
Accrued distributions (Notes 15 and 26)	64,440	64,285
Deferred revenue and acquisition-related intangible liabilities, net (Notes 2, 3, 7 and 11)	173,638	195,959
Rents received in advance and tenant security deposits	79,364	81,432
Total liabilities	5,741,352	5,122,026
COMMITMENTS AND CONTINGENCIES (Note 19)
CAPITAL:
Partner’s Capital - Common units, 117,239,558 and 116,878,031 held by the general partner and 1,150,574 and 1,150,574 held by common limited partners issued and outstanding, respectively (Note 15)	5,481,436	5,490,571
Noncontrolling interests in consolidated property partnerships and subsidiaries (Notes 2 and 13)	178,257	184,390
Total capital	5,659,693	5,674,961
TOTAL LIABILITIES AND EQUITY	$ 11,401,045	$ 10,796,987

CONSOLIDATED BALANCE SHEETS (_2

CONSOLIDATED BALANCE SHEETS (KILROY REALTY, L.P.) (Parenthetical) - Common Units - Kilroy Realty L.P. - shares	Dec. 31, 2023	Dec. 31, 2022
General partner, units issued (in shares)	117,239,558	116,878,031
General partner, units outstanding (in shares)	117,239,558	116,878,031
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, 2023	Dec. 31, 2022	Dec. 31, 2021
Revenue, Product and Service [Extensible List]	Service [Member]	Service [Member]	Service [Member]
REVENUES (Note 2):
Rental income (Note 18)	$ 1,117,737	$ 1,086,018	$ 948,994
Other property income	11,957	10,969	6,046
Total revenues	1,129,694	1,096,987	955,040
EXPENSES:
Property expenses	228,964	202,744	165,702
Real estate taxes	105,868	105,869	93,209
Ground leases (Note 19)	9,732	7,565	7,421
General and administrative expenses (Note 16)	93,434	93,642	92,749
Leasing costs	6,506	4,879	3,249
Depreciation and amortization (Notes 2 and 7)	355,278	357,611	310,043
Total expenses	799,782	772,310	672,373
OTHER INCOME (EXPENSES):
Interest and other income, net (Note 20)	22,592	1,765	3,916
Interest expense (Note 10)	(114,216)	(84,278)	(78,555)
Gains on sales of depreciable operating properties (Note 4)	0	17,329	463,128
Loss on early extinguishment of debt (Note 10)	0	0	(12,246)
Total other (expenses) income	(91,624)	(65,184)	376,243
NET INCOME	238,288	259,493	658,910
Net income attributable to noncontrolling interests in consolidated property partnerships and subsidiaries (Notes 2 and 13)	(26,047)	(26,878)	(30,766)
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS (UNITHOLDERS)	$ 212,241	$ 232,615	$ 628,144
Net income available to common stockholders per share - basic ( in dollars per share)	$ 1.80	$ 1.98	$ 5.38
Net income available to common stockholders per share - diluted (in dollars per share)	$ 1.80	$ 1.97	$ 5.36
Weighted average common units outstanding - basic (in shares)	117,160,173	116,806,575	116,429,130
Weighted average common units outstanding - diluted (in shares)	117,506,255	117,220,047	116,948,643
Kilroy Realty L.P.
Revenue, Product and Service [Extensible List]	Service [Member]	Service [Member]	Service [Member]
REVENUES (Note 2):
Rental income (Note 18)	$ 1,117,737	$ 1,086,018	$ 948,994
Other property income	11,957	10,969	6,046
Total revenues	1,129,694	1,096,987	955,040
EXPENSES:
Property expenses	228,964	202,744	165,702
Real estate taxes	105,868	105,869	93,209
Ground leases (Note 19)	9,732	7,565	7,421
General and administrative expenses (Note 16)	93,434	93,642	92,749
Leasing costs	6,506	4,879	3,249
Depreciation and amortization (Notes 2 and 7)	355,278	357,611	310,043
Total expenses	799,782	772,310	672,373
OTHER INCOME (EXPENSES):
Interest and other income, net (Note 20)	22,592	1,765	3,916
Interest expense (Note 10)	(114,216)	(84,278)	(78,555)
Gains on sales of depreciable operating properties (Note 4)	0	17,329	463,128
Loss on early extinguishment of debt (Note 10)	0	0	(12,246)
Total other (expenses) income	(91,624)	(65,184)	376,243
NET INCOME	238,288	259,493	658,910
Net income attributable to noncontrolling interests in consolidated property partnerships and subsidiaries (Notes 2 and 13)	(23,964)	(24,595)	(24,603)
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS (UNITHOLDERS)	$ 214,324	$ 234,898	$ 634,307
Net income available to common stockholders per share - basic ( in dollars per share)	$ 1.80	$ 1.98	$ 5.38
Net income available to common stockholders per share - diluted (in dollars per share)	$ 1.80	$ 1.97	$ 5.36
Weighted average common units outstanding - basic (in shares)	118,310,747	117,957,149	117,579,704
Weighted average common units outstanding - diluted (in shares)	118,656,829	118,370,621	118,099,217

CONSOLIDATED STATEMENTS OF CAPI

CONSOLIDATED STATEMENTS OF CAPITAL (KILROY REALTY, L.P.) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 238,288	$ 259,493	$ 658,910
Non-cash amortization of share-based compensation	43,721	34,793	40,960
Distributions to noncontrolling interests in consolidated property partnerships	(30,097)	(36,269)	(27,601)
Noncontrolling Interests in Consolidated Property Partnerships and Subsidiaries
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	26,047	26,878	30,766
Distributions to noncontrolling interests in consolidated property partnerships	(30,097)	(36,269)	(27,601)
Kilroy Realty L.P.
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	5,674,961	5,689,870	5,277,321
Net income	238,288	259,493	658,910
Issuance of share-based compensation awards	3,110	3,607	3,921
Non-cash amortization of share-based compensation	43,721	34,793	40,960
Exercise of stock options			383
Repurchase of common units and restricted stock units	(11,595)	(22,934)	(21,888)
Contributions from noncontrolling interests in consolidated property partnerships			1,559
Distributions to noncontrolling interests in consolidated property partnerships	(30,097)	(36,269)	(27,601)
Distributions declared per common unit	(258,695)	(253,599)	(243,695)
Ending balance	$ 5,659,693	$ 5,674,961	$ 5,689,870
Kilroy Realty L.P. | Partners’ Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)	118,028,605	117,614,743	117,186,401
Beginning balance	$ 5,490,571	$ 5,493,806	$ 5,079,818
Net income	214,324	234,898	634,307
Issuance of share-based compensation awards	3,110	3,607	3,921
Non-cash amortization of share-based compensation	$ 43,721	$ 34,793	$ 40,960
Exercise of stock options (in shares)			9,000
Exercise of stock options			$ 383
Settlement of restricted stock units (in shares)	664,600	745,248	785,805
Repurchase and cancellation of common units and restricted stock units (in shares)	(303,073)	(331,386)	(366,463)
Repurchase of common units and restricted stock units	$ (11,595)	$ (22,934)	$ (21,888)
Distributions declared per common unit	$ (258,695)	$ (253,599)	$ (243,695)
Ending balance (in shares)	118,390,132	118,028,605	117,614,743
Ending balance	$ 5,481,436	$ 5,490,571	$ 5,493,806
Kilroy Realty L.P. | Noncontrolling Interests in Consolidated Property Partnerships and Subsidiaries
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	184,390	196,064	197,503
Net income	23,964	24,595	24,603
Contributions from noncontrolling interests in consolidated property partnerships			1,559
Distributions to noncontrolling interests in consolidated property partnerships	(30,097)	(36,269)	(27,601)
Ending balance	$ 178,257	$ 184,390	$ 196,064

CONSOLIDATED STATEMENTS OF CA_2

CONSOLIDATED STATEMENTS OF CAPITAL (KILROY REALTY, L.P.) (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Kilroy Realty L.P.
Distributions declared per common unit (dollars per share)	$ 2.16	$ 2.12	$ 2.04

CONSOLIDATED STATEMENTS OF CA_3

CONSOLIDATED STATEMENTS OF CASH FLOWS (KILROY REALTY, L.P.) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 238,288	$ 259,493	$ 658,910
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of real estate assets and leasing costs	348,064	350,665	303,799
Depreciation of non-real estate furniture, fixtures and equipment	7,214	6,946	6,244
Revenue reversals (recoveries) for doubtful accounts, net (Notes 2 and 18)	11,553	(123)	1,433
Non-cash amortization of share-based compensation awards (Note 16)	36,858	28,347	33,800
Non-cash amortization of deferred financing costs and net debt discounts	5,200	3,657	2,831
Non-cash amortization of net below market rents (Note 7)	(6,648)	(10,476)	(6,904)
Gains on sales of depreciable operating properties (Note 4)	0	(17,329)	(463,128)
Loss on early extinguishment of debt (Note 10)	0	0	12,246
Non-cash amortization of deferred revenue related to tenant-funded tenant improvements (Note 11)	(19,181)	(19,321)	(17,247)
Straight-line rents	(19,262)	(46,231)	(53,745)
Amortization of right of use ground lease assets	1,024	772	1,241
Net change in other operating assets	2,322	(12,606)	(6,077)
Net change in other operating liabilities	(2,843)	48,441	43,000
Net cash provided by operating activities	602,589	592,235	516,403
CASH FLOWS FROM INVESTING ACTIVITIES:
Investments in certificates of deposit (Note 5)	(256,581)	0	0
Expenditures for development and redevelopment properties and undeveloped land	(446,426)	(453,774)	(552,837)
Expenditures for operating properties and other capital assets	(97,393)	(92,802)	(120,611)
Expenditures for acquisitions of development properties and undeveloped land (Note 3)	0	(40,033)	(586,927)
Net proceeds received from dispositions (Note 4)	0	33,416	1,048,927
Expenditures for acquisitions of operating properties	0	0	(537,429)
Decrease in acquisition-related deposits	0	0	1,000
Net cash used in investing activities	(800,400)	(553,193)	(747,877)
CASH FLOWS FROM FINANCING ACTIVITIES:
Principal payments and repayments of secured debt (Note 10)	(5,775)	(5,555)	(5,341)
Borrowings on unsecured debt (Note 10)	320,000	200,000	0
Proceeds from the issuance of secured debt (Note 10)	375,000	0	0
Repurchases of unsecured debt (Note 10)	(20,584)	0	0
Net proceeds from the issuance of unsecured debt (Note 10)	0	0	449,807
Repayments of unsecured debt (Note 10)	0	0	(312,105)
Financing costs (Note 10)	(10,924)	(6,432)	(12,032)
Proceeds from exercise of stock options	0	0	383
Repurchase of common stock and restricted stock units (Note 16)	(11,595)	(22,934)	(21,888)
Distributions to noncontrolling interests in consolidated property partnerships	(30,097)	(36,269)	(27,601)
Distributions paid to common unitholders	(255,430)	(247,556)	(237,355)
Contributions from noncontrolling interests in consolidated property partnerships	0	0	1,559
Net cash provided by (used in) financing activities	360,595	(118,746)	(164,573)
Net increase (decrease) in cash and cash equivalents and restricted cash	162,784	(79,704)	(396,047)
Cash and cash equivalents and restricted cash, beginning of year	347,379	427,083	823,130
Cash and cash equivalents and restricted cash, end of year	510,163	347,379	427,083
Kilroy Realty L.P.
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	238,288	259,493	658,910
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of real estate assets and leasing costs	348,064	350,665	303,799
Depreciation of non-real estate furniture, fixtures and equipment	7,214	6,946	6,244
Revenue reversals (recoveries) for doubtful accounts, net (Notes 2 and 18)	11,553	(123)	1,433
Non-cash amortization of share-based compensation awards (Note 16)	36,858	28,347	33,800
Non-cash amortization of deferred financing costs and net debt discounts	5,200	3,657	2,831
Non-cash amortization of net below market rents (Note 7)	(6,648)	(10,476)	(6,904)
Gains on sales of depreciable operating properties (Note 4)	0	(17,329)	(463,128)
Loss on early extinguishment of debt (Note 10)	0	0	12,246
Non-cash amortization of deferred revenue related to tenant-funded tenant improvements (Note 11)	(19,181)	(19,321)	(17,247)
Straight-line rents	(19,262)	(46,231)	(53,745)
Amortization of right of use ground lease assets	1,024	772	1,241
Net change in other operating assets	2,322	(12,606)	(6,077)
Net change in other operating liabilities	(2,843)	48,441	43,000
Net cash provided by operating activities	602,589	592,235	516,403
CASH FLOWS FROM INVESTING ACTIVITIES:
Investments in certificates of deposit (Note 5)	(256,581)	0	0
Expenditures for development and redevelopment properties and undeveloped land	(446,426)	(453,774)	(552,837)
Expenditures for operating properties and other capital assets	(97,393)	(92,802)	(120,611)
Expenditures for acquisitions of development properties and undeveloped land (Note 3)	0	(40,033)	(586,927)
Net proceeds received from dispositions (Note 4)	0	33,416	1,048,927
Expenditures for acquisitions of operating properties	0	0	(537,429)
Decrease in acquisition-related deposits	0	0	1,000
Net cash used in investing activities	(800,400)	(553,193)	(747,877)
CASH FLOWS FROM FINANCING ACTIVITIES:
Principal payments and repayments of secured debt (Note 10)	(5,775)	(5,555)	(5,341)
Borrowings on unsecured debt (Note 10)	320,000	200,000	0
Net proceeds from the issuance of unsecured debt (Note 10)	0	0	449,807
Repayments of unsecured debt (Note 10)	0	0	(312,105)
Financing costs (Note 10)	(10,924)	(6,432)	(12,032)
Proceeds from exercise of stock options	0	0	383
Repurchase of common stock and restricted stock units (Note 16)	(11,595)	(22,934)	(21,888)
Distributions to noncontrolling interests in consolidated property partnerships	(30,097)	(36,269)	(27,601)
Distributions paid to common unitholders	(255,430)	(247,556)	(237,355)
Contributions from noncontrolling interests in consolidated property partnerships	0	0	1,559
Net cash provided by (used in) financing activities	360,595	(118,746)	(164,573)
Net increase (decrease) in cash and cash equivalents and restricted cash	162,784	(79,704)	(396,047)
Cash and cash equivalents and restricted cash, beginning of year	347,379	427,083	823,130
Cash and cash equivalents and restricted cash, end of year	$ 510,163	$ 347,379	$ 427,083

Organization and Ownership

Organization and Ownership	12 Months Ended
	Dec. 31, 2023
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 property types in the United States. The Company has earned global recognition for sustainability, building operations, innovation and design. The Company’s approach to modern business environments helps drive creativity and productivity for some of the world’s leading technology, entertainment, life science and business services companies. We own, develop, acquire and manage real estate assets, consisting primarily of Class A properties in Los Angeles, San Diego, the San Francisco Bay Area, Seattle and Austin, 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, 2023: Number of Rentable Number of Percentage Occupied (unaudited) (1) Percentage Leased Stabilized Office Properties (2) 121 17,044,128 410 85.0 % 86.4 % _______________________ (1) Represents economic occupancy. (2) Includes stabilized life science and retail space. Number of Projects Number of Units 2023 Average Occupancy (unaudited) Stabilized Residential Properties 3 1,001 92.8 % 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, 2023, we added two development projects to our stabilized portfolio consisting of two buildings totaling 829,591 square feet of office space in San Diego, California and Austin, Texas. We did not have any properties held for sale at December 31, 2023. As of December 31, 2023, the following properties were excluded from our stabilized portfolio: Number of Estimated Rentable Square Feet (1) (unaudited) In-process development projects - under construction 1 875,000 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, 2023 was comprised of eight future development sites, representing approximately 64 gross acres of undeveloped land. As of December 31, 2023, 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 stabilized office property 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, 2023, 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, 2023, 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, 2023, 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, 2023 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, 2023
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, 2023 and 2022, 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, 2023 and 2022, 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, 2023, the two VIEs’ total assets, liabilities and noncontrolling interests included on our consolidated balance sheet were approximately $416.7 million (of which $350.0 million related to real estate held for investment), approximately $23.6 million and approximately $173.7 million, respectively. At 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 on our consolidated balance sheet), approximately $31.5 million and approximately $179.4 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, 2023 or 2022. 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 our capital 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 beginning upon substantial completion of the leased premises. 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 beginning upon substantial completion of the leased premises. 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 the executed termination agreement 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. Generally, our leases require our tenants to restore the leased space to standard office condition upon the expiration of the lease. In limited circumstances, tenants may negotiate to pay us a restoration fee in lieu of restoring the space. Restoration fee income, included in rental income, is recognized on a straight-line basis from the date of the executed restoration fee agreement through lease expiration when the amount of the fee is determinable and collectability of the fee is probable. Additional Rent - Reimbursements from Tenants Additional rent, consisting of amounts due from tenants for common area maintenance, real estate taxes and other recoverable costs, is 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 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 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. 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. 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, considering the current economic and business environment, including 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. This determination is performed on a quarterly basis and 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. Since these factors are beyond our control, actual results can differ from our estimates, and such differences could be material. For leases that are deemed probable of collection, revenue continues to be recorded on a straight-line basis over the lease term, and for some tenants may include an offsetting partial allowance for uncollectible accounts related to current tenant and deferred rent receivables that exhibit a certain level of collection risk based on the results of the assessment described above. 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. 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, including costs incurred during negotiation. When applicable, 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. 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 relative 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. 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. Evaluation of Asset Impairment When evaluating operating real estate assets to be held and used for potential impairment, we first evaluate whether there are any indicators of impairment. If any impairment indicators are present for a specific real estate asset, we then evaluate the regional market conditions that could reasonably affect the real estate asset. 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 real estate asset to the real estate asset’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 real estate asset, we perform an impairment loss calculation to determine if the fair value of the real estate asset is less than the net carrying value of the real estate asset. Our impairment loss calculation compares the net carrying amount of the real estate asset to the real estate asset’s estimated fair value, which may be based on estimated discounted future cash flow calculations or third-party valuations or appraisals. We recognize an impairment loss if the real estate asset's net carrying amount exceeds the real estate asset's estimated fair value. If we recognize an impairment loss, the estimated fair value of the real estate asset 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. 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, 2023, 2022, and 2021 was $300.1 million, $287.8 million, and $256.3 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, 2023 and 2022, 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 and 2021 are presented in continuing operations as they did not represent a strategic shift in the Company’s operations and financial results. We did not dispose of any properties during the year ended December 31, 2023. 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, including certificates of deposits, 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. We did not have any cash held at qualified intermediaries at December 31, 2023 and 2022. Marketable Securities Marketable securities reported in our consolidated balance sheets represent certificates of deposit with original maturities greater than three months and the assets held in connection with the Kilroy Realty Corporation 2007 Deferred Compensation Plan (the “Deferred Compensation Plan”) (see Note 17 “Employee Benefit Plans” for additional information. The Company intends to hold the certificates of deposit until their maturity. As a result, the certificates of deposit are classified as held-to-maturity securities. 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 into interest expense 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 12 “Noncontrolling Interests on the Company’s Consolidated Financial Statements” and see Note 13 “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’ contra

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2023
Business Combination and Asset Acquisition [Abstract]
Acquisitions	Acquisitions Development Project Acquisitions We did not acquire any development sites during the year ended December 31, 2023. The following table summarizes the development site acquired from unrelated third parties during the year ended December 31, 2022: 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 _______________________ (1) Excludes acquisition-related costs. (2) This property was added to our future development pipeline. Acquisition Costs

Dispositions

Dispositions	12 Months Ended
	Dec. 31, 2023
Discontinued Operations and Disposal Groups [Abstract]
Dispositions	Dispositions Operating Property Dispositions We did not dispose of any operating properties during the year ended December 31, 2023. The following table summarizes the operating properties sold during the years ended December 31, 2022 and 2021: 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 ____________________ (1) Represents gross sales price before broker commissions, closing costs, and purchase price credits. The total gains on the sales of the operating properties sold during the years ended December 31, 2022 and 2021 were $17.3 million and $463.1 million, respectively.

Marketable Securities

Marketable Securities	12 Months Ended
	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	Marketable Securities Marketable securities consisted of the following at December 31, 2023 and 2022: December 31, 2023 December 31, 2022 (in thousands) Deferred compensation plan assets $ 28,089 $ 23,547 Certificates of deposit (1) 256,581 — Total marketable securities $ 284,670 $ 23,547 ____________________ (1) The certificates of deposit have an original issuance term greater than three months but less than 12 months.

Receivables

Receivables	12 Months Ended
	Dec. 31, 2023
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, 2023 and 2022: December 31, 2023 December 31, 2022 (in thousands) Current receivables $ 15,176 $ 22,816 Allowance for uncollectible tenant receivables (1) (1,567) (2,233) Current receivables, net $ 13,609 $ 20,583 ____________________ (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. Deferred Rent Receivables, net Deferred rent receivables, net consisted of the following as of December 31, 2023 and 2022: December 31, 2023 December 31, 2022 (in thousands) Deferred rent receivables $ 461,707 $ 453,165 Allowance for deferred rent receivables (1) (728) (965) Deferred rent receivables, net $ 460,979 $ 452,200 ____________________ (1)

Deferred Leasing Costs and Acqu

Deferred Leasing Costs and Acquisition-Related Intangible Assets and Liabilities, net	12 Months Ended
	Dec. 31, 2023
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, 2023 and 2022: December 31, 2023 December 31, 2022 (in thousands) Deferred Leasing Costs and Acquisition-related Intangible Assets, net: Deferred leasing costs $ 297,871 $ 301,967 Accumulated amortization (122,680) (121,545) Deferred leasing costs, net 175,191 180,422 Above-market operating leases 260 260 Accumulated amortization (70) (39) Above-market operating leases, net 190 221 In-place leases 70,247 114,435 Accumulated amortization (15,923) (44,232) In-place leases, net 54,324 70,203 Total deferred leasing costs and acquisition-related intangible assets, net $ 229,705 $ 250,846 Acquisition-related Intangible Liabilities, net: (1) Below-market operating leases $ 39,159 $ 52,380 Accumulated amortization (8,402) (14,943) Below-market operating leases, net 30,757 37,437 Total acquisition-related intangible liabilities, net $ 30,757 $ 37,437 ____________________ (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, 2023, 2022 and 2021. Year Ended December 31, 2023 2022 2021 (in thousands) Deferred leasing costs $ 31,771 $ 31,059 $ 32,472 Above-market operating leases 31 31 8 In-place leases 15,878 31,647 14,562 Below-market operating leases (6,679) (10,508) (6,912) Total $ 41,001 $ 52,229 $ 40,130 The following table sets forth the estimated annual amortization expense related to deferred leasing costs and acquisition-related intangibles as of December 31, 2023 for future periods: Year Ending Deferred Leasing Costs Above-Market Operating Leases (1) In-Place Leases Below-Market Operating Leases (2) (in thousands) 2024 $ 29,855 $ 31 $ 6,676 $ (3,588) 2025 27,019 31 6,635 (3,570) 2026 23,974 31 6,311 (3,474) 2027 20,864 31 5,040 (3,099) 2028 18,824 31 5,014 (2,918) Thereafter 54,655 35 24,648 (14,108) Total $ 175,191 $ 190 $ 54,324 $ (30,757) ____________________ (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.

Prepaid Expenses and Other Asse

Prepaid Expenses and Other Assets, Net	12 Months Ended
	Dec. 31, 2023
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, 2023 and 2022: December 31, 2023 December 31, 2022 (in thousands) Furniture, fixtures and other long-lived assets, net $ 37,073 $ 41,538 Prepaid expenses and deferred financing costs, net 10,532 11,364 Other assets 5,464 9,527 Total prepaid expenses and other assets, net $ 53,069 $ 62,429

Secured and Unsecured Debt of t

Secured and Unsecured Debt of the Company	12 Months Ended
	Dec. 31, 2023
Debt Disclosure [Abstract]
Secured and Unsecured Debt of the Company	Secured and Unsecured Debt of the Company In this Note 9, 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, 2023 and 2022, the Operating Partnership had $4.3 billion and $4.0 billion, respectively, outstanding in total, including unamortized discounts and deferred financing costs, under these unsecured debt obligations. In addition, although the remaining $0.6 billion and $0.2 billion of the Operating Partnership’s debt as of December 31, 2023 and 2022, 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, 2023
Debt Instrument [Line Items]
Secured and Unsecured Debt of the Operating Partnership	Secured and Unsecured Debt of the Company In this Note 9, 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, 2023 and 2022, the Operating Partnership had $4.3 billion and $4.0 billion, respectively, outstanding in total, including unamortized discounts and deferred financing costs, under these unsecured debt obligations. In addition, although the remaining $0.6 billion and $0.2 billion of the Operating Partnership’s debt as of December 31, 2023 and 2022, 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 In July 2023, certain of the Operating Partnership’s subsidiaries entered into a $375.0 million mortgage loan transaction (the “Loan”) secured by, among other things, a deed of trust, assignment of leases and rents, security agreement and fixture filing encumbering two office buildings, 608 apartment units and over 95,000 square feet of retail at the Company’s One Paseo mixed-use campus in Del Mar, California. The Loan matures on August 10, 2034, bears interest at an annual rate of 5.90% and requires monthly interest payments only, which commenced on September 10, 2023. In addition, the Operating Partnership has entered into a guaranty in favor of the lender in connection with the Loan. The Loan is generally non-recourse to the Operating Partnership, but the lender has recourse to the Operating Partnership for certain recourse exceptions. The following table sets forth the composition of our secured debt as of December 31, 2023 and 2022: Annual Stated Interest Rate (1) GAAP Effective Rate (1)(2) Maturity Date December 31, Type of Debt 2023 2022 (in thousands) Mortgage note payable 3.57% 3.57% December 2026 $ 156,386 $ 159,973 Mortgage note payable (3) 4.48% 4.48% July 2027 81,308 83,496 Mortgage note payable 5.90% 5.90% August 2034 375,000 — Total secured debt $ 612,694 $ 243,469 Unamortized deferred financing costs (9,469) (531) Total secured debt, net $ 603,225 $ 242,938 ____________________ (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 $817.3 million as of December 31, 2023. 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, 2023, 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 Debt Early Redemption of $300.0 million Unsecured Senior Notes Due 2023 In October 2021, the Operating Partnership early redeemed, 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. Partial Repurchase of $425.0 million Unsecured Senior Notes Due 2024 During the year ended December 31, 2023, the Company completed open-market repurchases of $21.3 million of the Operating Partnership’s 3.450% $425.0 million unsecured senior notes due December 15, 2024 at a discount, leaving an aggregate remaining principal balance of $403.7 million. Issuance of $400.0 million Unsecured Senior Notes Due 2036 On January 12, 2024, the Operating Partnership issued $400.0 million aggregated principal amount of unsecured senior notes in a registered public offering. The unsecured senior notes, which are scheduled to mature on January 15, 2036, require semi-annual interest payments each January and July based on a stated interest rate of 6.250%. See Note 26 “Subsequent Events” for additional information. 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 unamortized discounts of $5.3 million and $6.4 million and unamortized deferred financing costs of $15.9 million and $19.1 million as of December 31, 2023 and 2022, respectively: Net Carrying Amount Issuance date Maturity date Stated Effective interest rate (1) 2023 2022 (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 (3,422) (3,770) Net carrying amount $ 446,578 $ 446,230 2.500% Unsecured Senior Notes (2) August 2020 November 2032 2.500% 2.560% $ 425,000 $ 425,000 Unamortized discount and deferred financing costs (4,735) (5,268) Net carrying amount $ 420,265 $ 419,732 4.270% Unsecured Senior Notes (3) April 2020 January 2031 4.270% 4.270% $ 350,000 $ 350,000 Unamortized discount and deferred financing costs (1,282) (1,463) Net carrying amount $ 348,718 $ 348,537 3.050% Unsecured Senior Notes (4) September 2019 February 2030 3.050% 3.064% $ 500,000 $ 500,000 Unamortized discount and deferred financing costs (3,629) (4,221) Net carrying amount $ 496,371 $ 495,779 4.750% Unsecured Senior Notes (5) November 2018 December 2028 4.750% 4.800% $ 400,000 $ 400,000 Unamortized discount and deferred financing costs (2,468) (2,963) Net carrying amount $ 397,532 $ 397,037 4.350% Unsecured Senior Notes (3) October 2018 October 2026 4.350% 4.350% $ 200,000 $ 200,000 Unamortized discount and deferred financing costs (488) (663) Net carrying amount $ 199,512 $ 199,337 4.300% Unsecured Senior Notes (3) July 2018 July 2026 4.300% 4.300% $ 50,000 $ 50,000 Unamortized discount and deferred financing costs (113) (157) Net carrying amount $ 49,887 $ 49,843 3.450% Unsecured Senior Notes (5) December 2017 December 2024 3.450% 3.470% $ 403,712 $ 425,000 Unamortized discount and deferred financing costs (558) (1,148) Net carrying amount $ 403,154 $ 423,852 3.450% Unsecured Senior Notes (6) February 2017 February 2029 3.450% 3.450% $ 75,000 $ 75,000 Unamortized discount and deferred financing costs (219) (262) Net carrying amount $ 74,781 $ 74,738 3.350% Unsecured Senior Notes (6) February 2017 February 2027 3.350% 3.350% $ 175,000 $ 175,000 Unamortized discount and deferred financing costs (363) (478) Net carrying amount $ 174,637 $ 174,522 4.375% Unsecured Senior Notes (7) September 2015 October 2025 4.375% 4.444% $ 400,000 $ 400,000 Unamortized discount and deferred financing costs (969) (1,523) Net carrying amount $ 399,031 $ 398,477 4.250% Unsecured Senior Notes (4) July 2014 August 2029 4.250% 4.350% $ 400,000 $ 400,000 Unamortized discount and deferred financing costs (2,971) (3,503) Net carrying amount $ 397,029 $ 396,497 Total Unsecured Senior Notes, Net $ 3,807,495 $ 3,824,581 ____________________ (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 The following table summarizes the balance and terms of our unsecured revolving credit facility as of December 31, 2023 and 2022: December 31, 2023 December 31, 2022 (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) 6.38 % 5.20 % Facility fee-annual rate (3) 0.200% Maturity date July 31, 2025 ____________________ (1) Total borrowing capacity is reduced by the amount of our outstanding letters of credit which total approximately $5.2 million as of December 31, 2023. 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 pursuant to the terms of the unsecured revolving credit facility. (2) Our unsecured revolving credit facility interest rate was calculated using a contractual rate of Secured Overnight Financing Rate (“SOFR”) plus a SOFR adjustment of 0.10% (“Adjusted SOFR”) and a margin of 0.900% based on our credit rating as of December 31, 2023 and 2022. We may be entitled to a temporary 0.01% reduction in the interest rate provided we meet certain sustainability goals with respect to the ongoing reduction of greenhouse gas emissions. (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, 2023 and 2022, $3.2 million and $5.3 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. (4) The maturity date may be extended by two six-month periods, at the Company’s option. 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, the Operating Partnership entered into the first amendment to its unsecured term loan facility agreement to (i) exercise the accordion feature under the term loan agreement to provide for $100.0 million of additional term loan commitments and (ii) increase the borrowing capacity under the accordion feature to provide additional term loan commitments or add one or more tranches of term loans up to an aggregate amount of $650.0 million. In March 2023, the Operating Partnership further amended the unsecured term loan facility agreement to exercise the accordion feature to provide for $20.0 million of additional term loan commitments, bringing the total borrowing capacity of the unsecured term loan facility to $520.0 million. The following table summarizes the balance and terms of our unsecured term loan facility as of December 31, 2023: December 31, 2023 December 31, 2022 (in thousands) Outstanding borrowings $ 520,000 $ 200,000 Remaining borrowing capacity — 200,000 Total borrowing capacity (1) $ 520,000 $ 400,000 Interest rate (2) 6.41 % 5.23 % Undrawn facility fee-annual rate (3) 0.200% Maturity date (4) October 3, 2024 ____________________ (1) We may elect to borrow, subject to bank approval and obtaining commitments for any additional borrowing capacity, up to an additional $130.0 million and $100.0 million as of December 31, 2023 and December 31, 2022, respectively, under an accordion feature pursuant to the terms of the unsecured term loan facility (2) Our unsecured term loan facility interest rate was calculated using a contractual rate of Adjusted SOFR plus a margin of 0.950% based on our credit rating as of December 31, 2023 and 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, 2023 and 2022, $2.3 million and $4.5 million, respectively, of unamortized deferred financing costs remained to be amortized through the maturity date of our unsecured term loan facility. (4) The maturity date may be extended by two twelve-month periods, at the Company’s option. 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 maximum ratio of secured debt to total asset value, 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 were in compliance with all of our debt covenants as of December 31, 2023 and 2022. Debt Maturities The following table summarizes the stated debt maturities and scheduled amortization payments for all outstanding debt as of December 31, 2023: Year (in thousands) 2024 (1) $ 929,718 2025 406,246 2026 401,317 2027 249,125 2028 400,000 Thereafter 2,575,000 Total aggregate principal value (2) $ 4,961,406 ________________________ (1) Includes the $520.0 million currently outstanding on the unsecured term loan facility maturing on October 3, 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, 2023: $27.7 million of unamortized deferred financing costs for the unsecured term loan facility, unsecured senior notes and secured debt and $5.3 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, 2023, 2022 and 2021. 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, 2023 2022 2021 (in thousands) Gross interest expense $ 192,983 $ 161,761 $ 158,756 Capitalized interest and deferred financing costs (78,767) (77,483) (80,201) Interest expense $ 114,216 $ 84,278 $ 78,555

Deferred Revenue and Acquisitio

Deferred Revenue and Acquisition-Related Intangible Liabilities, net	12 Months Ended
	Dec. 31, 2023
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, 2023 and 2022: December 31, 2023 2022 (in thousands) Deferred revenue related to tenant-funded tenant improvements $ 97,802 $ 111,453 Other deferred revenue 45,079 47,069 Acquisition-related intangible liabilities, net (1) 30,757 37,437 Total $ 173,638 $ 195,959 _____________________ (1) See Note 7 “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, 2023, 2022, and 2021, $20.7 million, $19.3 million and $16.5 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, 2023 for the next five years and thereafter: Year Ending (in thousands) 2024 $ 17,299 2025 14,280 2026 12,390 2027 11,136 2028 9,764 Thereafter 32,933 Total $ 97,802

Noncontrolling Interests on the

Noncontrolling Interests on the Company’s Consolidated Financial Statements	12 Months Ended
	Dec. 31, 2023
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, 2023 and 2022. The remaining approximate 1.0% common limited partnership interest as of December 31, 2023 and 2022 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, 2023 and 2022, 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 $47.0 million and $44.7 million as of December 31, 2023 and 2022, 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, 2023 and 2022 were $173.7 million and $179.4 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 $4.6 million and $5.0 million as of December 31, 2023 and 2022, respectively.

Noncontrolling Interests on t_2

Noncontrolling Interests on the Operating Partnership’s Consolidated Financial Statements	12 Months Ended
	Dec. 31, 2023
Noncontrolling Interest [Line Items]
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, 2023 and 2022. The remaining approximate 1.0% common limited partnership interest as of December 31, 2023 and 2022 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, 2023 and 2022, 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 $47.0 million and $44.7 million as of December 31, 2023 and 2022, 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, 2023 and 2022 were $173.7 million and $179.4 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 $4.6 million and $5.0 million as of December 31, 2023 and 2022, respectively.
Kilroy Realty L.P.
Noncontrolling Interest [Line Items]
Noncontrolling Interests on the Operating Partnership’s Consolidated Financial Statements	Noncontrolling Interests on the Operating Partnership’s Consolidated Financial Statements 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 12 for additional information regarding these consolidated property partnerships.

Stockholders' Equity of the Com

Stockholders' Equity of the Company	12 Months Ended
	Dec. 31, 2023
Equity [Abstract]
Stockholders' Equity of the Company	Stockholders’ Equity of the Company Common Stock Common Stock Repurchases As of December 31, 2023, 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, 2023, 2022 and 2021. 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, 2023 and 2022: December 31, 2023 2022 (in thousands) Dividends and Distributions payable to: Common stockholders $ 63,309 $ 63,114 Noncontrolling common unitholders of the Operating Partnership 621 621 RSU holders (1) 510 550 Total accrued dividends and distribution to common stockholders and noncontrolling unitholders $ 64,440 $ 64,285 _____________________ (1) The amount includes the value of the dividend equivalents that will be paid with additional RSUs (see Note 16 “Share-Based and Other Compensation” for additional information). December 31, 2023 2022 Outstanding Shares and Units: Common stock 117,239,558 116,878,031 Noncontrolling common units 1,150,574 1,150,574 RSUs (1) 908,336 984,006 _____________________ (1) The amount includes nonvested RSUs. Does not include 1,083,086 and 1,123,554 market measure-based RSUs because not all the necessary performance conditions have been met as of December 31, 2023 and 2022, respectively. Refer to Note 16 “Share-Based and Other Compensation” for additional information.

Partners' Capital of the Operat

Partners' Capital of the Operating Partnership	12 Months Ended
	Dec. 31, 2023
Partners' Capital [Abstract]
Partners' Capital of the Operating Partnership	Partners’ Capital of the Operating Partnership Common Units 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, 2023 December 31, 2022 Company owned common units in the Operating Partnership 117,239,558 116,878,031 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, 2023 and 2022, refer to Note 12 “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, 2023 and 2022: December 31, 2023 December 31, 2022 (in thousands) Distributions payable to: General partner $ 63,309 $ 63,114 Common limited partners 621 621 RSU holders (1) 510 550 Total accrued distributions to common unitholders $ 64,440 $ 64,285 _____________________ (1) The amount includes the value of the dividend equivalents that will be paid with additional RSUs (see Note 16 “Share-Based and Other Compensation” for additional information). December 31, 2023 December 31, 2022 Outstanding Units: Common units held by the general partner 117,239,558 116,878,031 Common units held by the limited partners 1,150,574 1,150,574 RSUs (1) 908,336 984,006 _____________________ (1)

Share-Based and Other Compensat

Share-Based and Other Compensation	12 Months Ended
	Dec. 31, 2023
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, 2023, 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 12.6 million shares of our common stock for possible issuance under our 2006 Plan. As of December 31, 2023, approximately 2.8 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. Executive Transitions On March 30, 2023, John Kilroy, the Chairman of the Board of Directors and then Chief Executive Officer of the Company and the Operating Partnership, our “former CEO”, announced his retirement effective December 31, 2023, which was subsequently deferred to January 21, 2024 (the “Retirement Date”). Additionally, as previously disclosed, the Company and our former President entered into a separation agreement in 2022 under which he continued to serve as an officer of the Company until the scheduled expiration date of his employment agreement on March 1, 2023. For our former CEO, the vesting of all unvested share-based compensation awards was accelerated through the Retirement Date and the final number of restricted stock units (“RSUs”) subject to market and/or performance-based vesting requirements vested was based upon a shortened performance period ending on the Retirement Date. Share-based compensation expense for these awards was recognized based on the actual achievement of market and/or performance-based vesting requirements for the shortened performance periods. For our former President, the vesting of all unvested share-based compensation awards was accelerated through March 1, 2023 and the final number of RSUs earned that were subject to market and/or performance-based vesting requirements was based upon the actual achievement of the market and/or performance conditions for a shortened performance period ended on March 1, 2023. For the year ended December 31, 2023, we recognized $27.3 million of stock compensation expense related to the accelerated vesting of awards for our former CEO and former President. 2023, 2022 and 2021 Annual Performance-Based RSU Grants During each of the three years in the period ended December 31, 2023, 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 2023-2025, 2022-2024 and 2021-2023 for the awards granted during the years ended December 31, 2023, 2022, and 2021, 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 our former CEO, whose compensation expense was recognized on an accelerated basis due to clauses that render a portion of the vesting conditions to be non-substantive and accelerated through his Retirement Date. The 2023 FFO Performance Condition was achieved at 175% of target for one participant and 150% of target for all other participants. The 2022 FFO Performance Condition was achieved at 175% of target for one participant and 150% of target for all other participants. The number of 2023 and 2022 Performance-Based RSUs ultimately earned could fluctuate from the target number of Performance-Based RSUs granted during 2023 and 2022 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 2021 Performance-Based RSUs completed the performance measurement period and based on the combined results of the 2021 FFO Performance Condition, the Debt to EBITDA Ratio Performance Condition and the Market Condition, the 2021 Performance-Based RSUs achieved at 262.5% of target for one participant and 200% 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 2023, 2022 and 2021 Performance-Based RSUs takes into consideration the likelihood of achievement of the 2023, 2022 and 2021 Market Condition and the share price on the grant date of the 2023, 2022 and 2021 Performance-Based RSUs, respectively, as discussed above. The following table summarizes the estimated number of RSUs earned for the 2023 and 2022 Performance-Based RSUs and the actual number of RSUs earned for the 2021 Performance-Based RSUs and the assumptions utilized in the Monte Carlo simulation pricing models: 2023 2022 2021 Service vesting period February 6, 2023 - January, 2026 January 28, 2022 - January, 2025 February 18, 2021 - January, 2024 Target RSUs granted 300,007 193,111 172,430 Estimated RSUs earned (1) 570,006 406,319 401,580 Fair Value Assumptions: Valuation date February 6, 2023 January 28, 2022 February 18, 2021 Fair value on valuation date (in millions) $12.0 $12.7 $10.6 Fair value per share on valuation date (2) $40.10 $67.62 $63.93 Expected share price volatility 35.0 % 36.0 % 35.0 % Risk-free interest rate 4.12 % 1.35 % 0.20 % _____________________ (1) Estimated RSUs earned for the 2023 Performance-Based RSUs are based on the actual achievement of the 2023 FFO Performance Condition and assumes the target level of achievement for the 2023 Debt to EBITDA Ratio Performance Condition and the target level of achievement of the 2023 Market Condition. Estimated RSUs earned for the 2022 Performance-Based RSUs are based on the actual achievement of the 2022 FFO Performance Condition and assume target level achievement of the 2022 Market Condition and maximum level of achievement of the 2022 Debt to EBITDA Ratio Performance Condition. The 2021 Performance-Based RSUs earned are based on actual performance of the 2021 Performance Conditions and the 2021 Market Condition. (2) For one participant, the fair value per share on the valuation date for their 2023, 2022, and 2021 Performance-Based RSUs is $40.43, $70.00 and $66.95, 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 Summary of Performance and Market-Measure Based RSUs A summary of our performance and market-measure based RSU activity from January 1, 2023 through December 31, 2023 is presented below: Nonvested RSUs Vested RSUs Total RSUs Amount Weighted-Average Outstanding at January 1, 2023 1,123,554 $ 66.85 29,705 1,153,259 Granted 483,113 39.65 53,537 536,650 Vested (230,741) 76.67 230,741 — Settled (1) — — (296,688) (296,688) Issuance of dividend equivalents (2) 67,122 32.98 6,292 73,414 Canceled (359,962) 61.00 (4) (359,966) Outstanding as of December 31, 2023 (3) 1,083,086 $ 52.47 23,583 1,106,669 ____________________ (1) Represents vested RSUs that were settled in shares of the Company’s common stock. Total shares settled include 144,178 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, 2023 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, 2023, 2022 and 2021 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 2023 483,113 $ 39.65 (290,570) $ 11,105 2022 310,484 $ 63.05 (241,184) $ 15,200 2021 281,333 $ 57.85 (252,098) $ 14,299 ____________________ (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 2023, 2022 and 2021 Time-Based RSU Grants During each of the three years in the period ended December 31, 2023, 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. Compensation expense for the annual 2023, 2022, and 2021Time-Based RSUs is recognized on a straight-line basis over the requisite service period, which is generally the explicit service period. However, our former CEO had a shorter service period for his 2023, 2022 and 2021 Time-Based RSUs due to clauses that render a portion of the vesting conditions to be non-substantive as well as the accelerated vesting of these awards through his Retirement Date. 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: 2023 Time-Based RSU Grant 2022 Time-Based RSU Grant 2021 Time-Based RSU Grant Service vesting period February 6, 2023 - January 5, 2026 January 28, 2022 - January 5, 2025 January & February 2021 - January 5, 2024 RSUs granted 217,059 158,170 160,277 Fair value on valuation date (in millions) $ 8.6 $ 10.0 $ 9.1 Weighted average fair value per share $ 39.65 $ 63.05 $ 57.07 Date of valuation February 6, 2023 January 28, 2022 January 29, February 18, 2021 Summary of Time-Based RSUs A summary of our time-based RSU activity from January 1, 2023 through December 31, 2023 is presented below: Nonvested RSUs Vested RSUs Total RSUs Amount Weighted Average Fair Value Outstanding at January 1, 2023 443,367 $ 61.27 510,934 954,301 Granted 247,017 38.12 — 247,017 Vested (305,653) 63.49 305,653 — Settled (1) — — (368,717) (368,717) Issuance of dividend equivalents (2) 22,383 32.13 37,681 60,064 Forfeited (5,804) 50.39 — (5,804) Canceled (3) — — (2,108) (2,108) Outstanding as of December 31, 2023 401,310 $ 43.86 483,443 884,753 ____________________ (1) Represents vested RSUs that were settled in shares of the Company’s common stock. Total shares settled include 161,731 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, 2023, 2022 and 2021 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) 2023 247,017 $ 38.12 (343,334) $ 12,425 2022 177,099 $ 62.58 (294,867) $ 19,890 2021 172,181 $ 57.83 (144,838) $ 8,605 ____________________ (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 $43.7 million, $34.8 million and $41.0 million for the years ended December 31, 2023, 2022 and 2021, respectively. Share-based compensation costs for the year ended December 31, 2023 includes $27.3 million

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2023
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, 2023, 2022, and 2021, we contributed $1.7 million, $1.6 million and $1.5 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, certain 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 20 “Fair Value Measurements and Disclosures” for further discussion of our Deferred Compensation Plan assets as of December 31, 2023 and 2022. Our liability of $25.0 million and $23.4 million under the Deferred Compensation Plan was fully funded as of December 31, 2023 and 2022, respectively.

Rental Income and Future Minimu

Rental Income and Future Minimum Rent	12 Months Ended
	Dec. 31, 2023
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, 2023 and 2022: Year Ended December 31, 2023 2022 Fixed lease payments $ 944,618 $ 923,257 Variable lease payments 184,672 162,638 Net collectability (reversals) recoveries (1) (11,553) 123 Total rental income $ 1,117,737 $ 1,086,018 ____________________ (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, 2023 for future periods is summarized as follows: Year Ending (in thousands) 2024 $ 806,250 2025 800,821 2026 755,071 2027 698,993 2028 658,993 Thereafter 2,042,634 Total (1) $ 5,762,762 ____________________ (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, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies General As of December 31, 2023, we had commitments of approximately $335.9 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, 2022, 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, 2023: 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, 2023, the weighted average remaining lease term of our ground leases is 63 years. For the years ended December 31, 2023, 2022 and 2021, variable lease costs totaling $4.0 million, $3.6 million and $2.6 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, 2023 for future periods is as follows: Year Ending (in thousands) 2024 $ 6,737 2025 6,773 2026 6,810 2027 6,851 2028 6,870 Thereafter 363,350 Total undiscounted cash flows (1)(2)(3)(4)(5)(6) $ 397,391 Present value discount (273,038) Ground lease liabilities $ 124,353 ________________________ (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, 2023. (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, 2023 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, 2023 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, 2023 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 flows, or that we believe would require additional disclosure or the recording of a loss contingency. As of December 31, 2023 and 2022, we had accrued environmental remediation liabilities of approximately $76.6 million and $80.5 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, 2023 and 2022 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 flows, financial condition, or results of operations. Insurance

Fair Value Measurements and Dis

Fair Value Measurements and Disclosures	12 Months Ended
	Dec. 31, 2023
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 17 “Employee Benefit Plans” for additional information). The following table sets forth the fair value of our Deferred Compensation Plan assets as of December 31, 2023 and 2022: Fair Value (Level 1) (1) 2023 2022 Description (in thousands) Deferred Compensation Plan assets (2) $ 28,089 $ 23,547 ____________________ (1) Based on quoted prices in active markets for identical securities. (2) The Deferred Compensation Plan assets 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, 2023 and 2022: December 31, 2023 2022 Carrying Value Fair Value (1) Carrying Value Fair Value (1) (in thousands) Assets Certificates of deposit (2) $ 256,581 $ 256,581 $ — $ — Liabilities Secured debt, net $ 603,225 $ 585,826 $ 242,938 $ 225,847 Unsecured debt, net 4,325,153 3,927,104 4,020,058 3,500,420 _______________ (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. (2)

Net Income Available to Common

Net Income Available to Common Stockholders Per Share of the Company	12 Months Ended
	Dec. 31, 2023
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, 2023, 2022 and 2021: Year Ended December 31, 2023 2022 2021 (in thousands, except unit and per unit amounts) Numerator: Net income available to common stockholders $ 212,241 $ 232,615 $ 628,144 Allocation to participating securities (1) (1,233) (1,272) (1,516) Numerator for basic and diluted net income available to common stockholders $ 211,008 $ 231,343 $ 626,628 Denominator: Basic weighted average vested shares outstanding 117,160,173 116,806,575 116,429,130 Effect of dilutive securities 346,082 413,472 519,513 Diluted weighted average vested shares and common stock equivalents outstanding 117,506,255 117,220,047 116,948,643 Basic earnings per share: Net income available to common stockholders per share $ 1.80 $ 1.98 $ 5.38 Diluted earnings per share: Net income available to common stockholders per share $ 1.80 $ 1.97 $ 5.36 _____________________ (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, 2023, 2022, and 2021. Certain market measure-based RSUs are not included in dilutive securities as of December 31, 2023, 2022 and 2021 as not all performance metrics had been met by the end of the applicable reporting periods. Additionally, certain unvested time-based RSUs are not included in dilutive securities for the year December 31, 2023, as they were anti-dilutive.

Net Income Available to Commo_2

Net Income Available to Common Unitholders Per Unit of the Operating Partnership	12 Months Ended
	Dec. 31, 2023
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, 2023, 2022 and 2021: Year Ended December 31, 2023 2022 2021 (in thousands, except unit and per unit amounts) Numerator: Net income available to common stockholders $ 212,241 $ 232,615 $ 628,144 Allocation to participating securities (1) (1,233) (1,272) (1,516) Numerator for basic and diluted net income available to common stockholders $ 211,008 $ 231,343 $ 626,628 Denominator: Basic weighted average vested shares outstanding 117,160,173 116,806,575 116,429,130 Effect of dilutive securities 346,082 413,472 519,513 Diluted weighted average vested shares and common stock equivalents outstanding 117,506,255 117,220,047 116,948,643 Basic earnings per share: Net income available to common stockholders per share $ 1.80 $ 1.98 $ 5.38 Diluted earnings per share: Net income available to common stockholders per share $ 1.80 $ 1.97 $ 5.36 _____________________ (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, 2023, 2022, and 2021. Certain market measure-based RSUs are not included in dilutive securities as of December 31, 2023, 2022 and 2021 as not all performance metrics had been met by the end of the applicable reporting periods. Additionally, certain unvested time-based RSUs are not included in dilutive securities for the year December 31, 2023, as they were anti-dilutive.
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, 2023, 2022 and 2021: Year Ended December 31, 2023 2022 2021 (in thousands, except unit and per unit amounts) Numerator: Net income available to common unitholders $ 214,324 $ 234,898 $ 634,307 Allocation to participating securities (1) (1,233) (1,272) (1,516) Numerator for basic and diluted net income available to common unitholders $ 213,091 $ 233,626 $ 632,791 Denominator: Basic weighted average vested units outstanding 118,310,747 117,957,149 117,579,704 Effect of dilutive securities 346,082 413,472 519,513 Diluted weighted average vested units and common unit equivalents outstanding 118,656,829 118,370,621 118,099,217 Basic earnings per unit: Net income available to common unitholders per unit $ 1.80 $ 1.98 $ 5.38 Diluted earnings per unit: Net income available to common unitholders per unit $ 1.80 $ 1.97 $ 5.36 ____________________ (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, 2023, 2022 and 2021. Certain market measure-based RSUs are not included in dilutive securities as of December 31, 2023, 2022 and 2021 as not all performance metrics had been met by the end of the applicable reporting periods. Additionally, certain unvested time-based RSUs are not included in dilutive securities for the year December 31, 2023, as they were anti-dilutive.

Supplemental Cash Flow Informat

Supplemental Cash Flow Information of the Company	12 Months Ended
	Dec. 31, 2023
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information of the Company	Supplemental Cash Flows Information of the Company Supplemental cash flows information as follows (in thousands): Year Ended December 31, 2023 2022 2021 SUPPLEMENTAL CASH FLOWS INFORMATION: Cash paid for interest, net of capitalized interest of $74,052, $72,973, and $75,802 as of December 31, 2023, 2022 and 2021, respectively $ 105,767 $ 79,634 $ 77,028 Cash paid for amounts included in the measurement of ground lease liabilities $ 6,733 $ 6,447 $ 6,209 NON-CASH INVESTING TRANSACTIONS: Accrual for expenditures for operating properties and development and redevelopment properties $ 95,575 $ 97,729 $ 119,829 Tenant improvements funded directly by tenants $ 7,364 $ 6,772 $ 20,070 Assumption of accrued liabilities in connection with acquisitions $ — $ — $ 37,572 Initial measurement of operating right of use ground lease assets (Note 19) $ — $ — $ 46,430 Initial measurement of operating ground lease liabilities (Note 19) $ — $ — $ 46,430 NON-CASH FINANCING TRANSACTIONS: Accrual of dividends and distributions payable to common stockholders and common unitholders (Notes 14 and 26) $ 64,440 $ 64,285 $ 61,850 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, 2023, 2022 and 2021. Year Ended December 31, 2023 2022 2021 (in thousands) RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH: Cash and cash equivalents at beginning of period $ 347,379 $ 414,077 $ 731,991 Restricted cash at beginning of period — 13,006 91,139 Cash and cash equivalents and restricted cash at beginning of period $ 347,379 $ 427,083 $ 823,130 Cash and cash equivalents at end of period $ 510,163 $ 347,379 $ 414,077 Restricted cash at end of period — — 13,006 Cash and cash equivalents and restricted cash at end of period $ 510,163 $ 347,379 $ 427,083

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information of the Operating Partnership	12 Months Ended
	Dec. 31, 2023
Other Significant Noncash Transactions [Line Items]
Supplemental Cash Flow Information of the Operating Partnership	Supplemental Cash Flows Information of the Company Supplemental cash flows information as follows (in thousands): Year Ended December 31, 2023 2022 2021 SUPPLEMENTAL CASH FLOWS INFORMATION: Cash paid for interest, net of capitalized interest of $74,052, $72,973, and $75,802 as of December 31, 2023, 2022 and 2021, respectively $ 105,767 $ 79,634 $ 77,028 Cash paid for amounts included in the measurement of ground lease liabilities $ 6,733 $ 6,447 $ 6,209 NON-CASH INVESTING TRANSACTIONS: Accrual for expenditures for operating properties and development and redevelopment properties $ 95,575 $ 97,729 $ 119,829 Tenant improvements funded directly by tenants $ 7,364 $ 6,772 $ 20,070 Assumption of accrued liabilities in connection with acquisitions $ — $ — $ 37,572 Initial measurement of operating right of use ground lease assets (Note 19) $ — $ — $ 46,430 Initial measurement of operating ground lease liabilities (Note 19) $ — $ — $ 46,430 NON-CASH FINANCING TRANSACTIONS: Accrual of dividends and distributions payable to common stockholders and common unitholders (Notes 14 and 26) $ 64,440 $ 64,285 $ 61,850 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, 2023, 2022 and 2021. Year Ended December 31, 2023 2022 2021 (in thousands) RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH: Cash and cash equivalents at beginning of period $ 347,379 $ 414,077 $ 731,991 Restricted cash at beginning of period — 13,006 91,139 Cash and cash equivalents and restricted cash at beginning of period $ 347,379 $ 427,083 $ 823,130 Cash and cash equivalents at end of period $ 510,163 $ 347,379 $ 414,077 Restricted cash at end of period — — 13,006 Cash and cash equivalents and restricted cash at end of period $ 510,163 $ 347,379 $ 427,083
Kilroy Realty L.P.
Other Significant Noncash Transactions [Line Items]
Supplemental Cash Flow Information of the Operating Partnership	Supplemental Cash Flows Information of the Operating Partnership: Supplemental cash flows information as follows (in thousands): Year Ended December 31, 2023 2022 2021 SUPPLEMENTAL CASH FLOWS INFORMATION: Cash paid for interest, net of capitalized interest of $74,052, $72,973, and $75,802 as of December 31, 2023, 2022 and 2021, respectively $ 105,767 $ 79,634 $ 77,028 Cash paid for amounts included in the measurement of ground lease liabilities $ 6,733 $ 6,447 $ 6,209 NON-CASH INVESTING TRANSACTIONS: Accrual for expenditures for operating properties and development and redevelopment properties $ 95,575 $ 97,729 $ 119,829 Tenant improvements funded directly by tenants $ 7,364 $ 6,772 $ 20,070 Assumption of accrued liabilities in connection with acquisitions $ — $ — $ 37,572 Initial measurement of operating right of use ground lease assets (Note 19) $ — $ — $ 46,430 Initial measurement of operating ground lease liabilities (Note 19) $ — $ — $ 46,430 NON-CASH FINANCING TRANSACTIONS: Accrual of distributions payable to common unitholders (Notes 15 and 26) $ 64,440 $ 64,285 $ 61,850 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, 2023, 2022 and 2021. Year Ended December 31, 2023 2022 2021 (in thousands) RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH: Cash and cash equivalents at beginning of period $ 347,379 $ 414,077 $ 731,991 Restricted cash at beginning of period — 13,006 91,139 Cash and cash equivalents and restricted cash at beginning of period $ 347,379 $ 427,083 $ 823,130 Cash and cash equivalents at end of period $ 510,163 $ 347,379 $ 414,077 Restricted cash at end of period — — 13,006 Cash and cash equivalents and restricted cash at end of period $ 510,163 $ 347,379 $ 427,083

Tax Treatment of Distributions

Tax Treatment of Distributions	12 Months Ended
	Dec. 31, 2023
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, 2023, 2022 and 2021 as follows: Year Ended December 31, Dividends 2023 2022 2021 Dividends declared per share of common stock $ 2.160 $ 2.120 $ 2.040 Less: Dividends declared in the current year and paid in the following year (0.540) (0.540) (0.520) Add: Dividends declared in the prior year and paid in the current year 0.540 0.520 0.500 Dividends paid per share of common stock $ 2.160 $ 2.100 $ 2.020 The unaudited income tax treatment for the dividends to common stockholders reportable for the years ended December 31, 2023, 2022 and 2021 as identified in the table above was as follows: Year Ended December 31, Shares of Common Stock 2023 2022 2021 Ordinary income (1) $ 2.087 96.63 % $ 1.865 88.80 % $ 1.338 66.22 % Qualified dividend 0.001 0.04 % 0.001 0.02 % 0.003 0.15 % Return of capital 0.069 3.21 % 0.230 10.99 % 0.551 27.30 % Capital gains (2) 0.003 0.12 % 0.004 0.19 % 0.075 3.72 % Unrecaptured section 1250 gains — — % — — % 0.053 2.61 % $ 2.160 100.00 % $ 2.100 100.00 % $ 2.020 100.00 % ____________________ (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, 2023, 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, 2023
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On January 12, 2024, the Operating Partnership issued $400.0 million aggregated principal amount of unsecured senior notes in a registered public offering. The unsecured senior notes, which are scheduled to mature on January 15, 2036, require semi-annual interest payments each January and July based on a stated interest rate of 6.250%. On January 21, 2024, John Kilroy retired as the Company’s CEO while remaining Chair of the Board of Directors through the end of his current term. On January 22, 2024, Angela Aman joined the Company as CEO and a member of the Board of Directors and was granted

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2023
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, 2023, 2022 and 2021 (in thousands) Balance at Charged to Costs and Expenses (1) Deductions (2) Balance Allowance for Uncollectible Tenant Receivables for the year ended 2023 – Allowance for uncollectible tenant receivables $ 2,233 $ 1,524 $ (2,190) $ 1,567 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 Allowance for Deferred Rent Receivables for the year ended 2023 – Allowance for deferred rent $ 965 $ 667 $ (904) $ 728 2022 – Allowance for deferred rent 612 864 (511) 965 2021 – Allowance for deferred rent 804 320 (512) 612 ____________________ (1) Amounts do not reflect leases deemed not probable of collection for which we reversed the associated revenue under Topic 842. (2) For the years ended December 31, 2023 and 2021, includes reversals of allowance for doubtful accounts for tenants with an allowance at January 1, 2023 and 2021, respectively, that were subsequently deemed not probable of collection and transitioned to a cash basis of reporting within the same year.

Schedule III - Real Estate and

Schedule III - Real Estate and Accumulated Depreciation	12 Months Ended
	Dec. 31, 2023
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, 2023 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 $ 1,856 $ 150,718 $ 32,889 $ 183,607 $ 20,163 35 2019 A 166,207 2240 E. Imperial Highway, El Segundo, CA 1,044 11,763 29,928 1,048 41,687 42,735 31,759 35 1983 C 122,870 2250 E. Imperial Highway, El Segundo, CA 2,579 29,062 36,750 2,547 65,844 68,391 61,662 35 1983 C 298,728 2260 E. Imperial Highway, El Segundo, CA 2,518 28,370 37,076 2,547 65,417 67,964 25,231 35 2012 C 298,728 909 N. Pacific Coast Highway, El Segundo, CA 3,577 34,042 56,012 3,565 90,066 93,631 55,148 35 2005 C 244,880 999 N. Pacific Coast Highway, El Segundo, CA 1,407 34,326 18,722 1,407 53,048 54,455 33,803 35 2003 C 138,389 1350 Ivar Ave., Los Angeles, CA 1,575 — 14,193 1,575 14,193 15,768 1,282 35 2020 C 16,448 1355 Vine St., Los Angeles, CA 17,588 — 121,115 17,588 121,115 138,703 11,167 35 2020 C 183,129 1375 Vine St., Los Angeles, CA 15,578 — 103,942 15,578 103,942 119,520 9,536 35 2020 C 159,236 1395 Vine St., Los Angeles, CA 278 — 3,271 278 3,271 3,549 294 35 2020 C 2,575 1500 N. El Centro Ave., Los Angeles, CA (4) 9,235 21 61,932 9,235 61,953 71,188 17,709 35 2016 C 113,447 1525 N. Gower St., Los Angeles, CA (4) 1,318 3 9,768 1,318 9,771 11,089 2,570 35 2016 C 9,610 1575 N. Gower St., Los Angeles, CA (4) 22,153 51 119,769 22,153 119,820 141,973 26,547 35 2016 C 264,430 6115 W. Sunset Blvd., Los Angeles, CA (4) 1,313 3 17,409 2,455 16,270 18,725 5,545 35 2015 C 26,238 6121 W. Sunset Blvd., Los Angeles, CA (4) 11,120 4,256 44,167 8,703 50,840 59,543 13,304 35 2015 C 93,418 6255 W. Sunset Blvd., Los Angeles, CA 18,111 60,320 53,475 18,111 113,795 131,906 58,714 35 2012 A 332,100 3750 Kilroy Airport Way, Long Beach, CA — 1,941 13,645 — 15,586 15,586 12,686 35 1989 C 10,718 3760 Kilroy Airport Way, Long Beach, CA — 17,467 23,013 — 40,480 40,480 32,535 35 1989 C 166,761 3780 Kilroy Airport Way, Long Beach, CA — 22,319 39,083 — 61,402 61,402 48,266 35 1989 C 221,452 3800 Kilroy Airport Way, Long Beach, CA — 19,408 24,516 — 43,924 43,924 31,475 35 2000 C 192,476 3840 Kilroy Airport Way, Long Beach, CA — 13,586 29,143 — 42,729 42,729 19,775 35 1999 C 138,441 3880 Kilroy Airport Way, Long Beach, CA — 9,704 12,202 — 21,906 21,906 7,278 35 2013 C 96,923 3900 Kilroy Airport Way, Long Beach, CA — 12,615 17,754 — 30,369 30,369 22,085 35 1997 A 130,935 8560 W. Sunset Blvd., West Hollywood, CA 9,720 50,956 7,497 9,720 58,453 68,173 14,898 35 2016 A 76,558 8570 W. Sunset Blvd., West Hollywood, CA 31,693 27,974 7,266 31,693 35,240 66,933 8,817 35 2016 A 49,276 8580 W. Sunset Blvd., West Hollywood, CA 10,013 3,695 1,828 10,013 5,523 15,536 1,558 35 2016 A 6,875 8590 W. Sunset Blvd., West Hollywood, CA 39,954 27,884 5,769 39,954 33,653 73,607 8,532 35 2016 A 56,750 12100 W. Olympic Blvd., Los Angeles, CA $156,386 (5) 352 45,611 26,036 9,633 62,366 71,999 36,818 35 2003 C 155,679 12200 W. Olympic Blvd., Los Angeles, CA (5) 4,329 35,488 27,917 3,977 63,757 67,734 49,193 35 2000 C 154,544 12233 W. Olympic Blvd., Los Angeles, CA 22,100 53,170 6,909 22,100 60,079 82,179 22,114 35 2012 A 156,746 12312 W. Olympic Blvd., Los Angeles, CA (5) 3,325 12,202 12,671 3,399 24,799 28,198 19,563 35 1997 A 76,644 2100/2110 Colorado Ave., Santa Monica, CA 5,474 26,087 18,285 5,476 44,370 49,846 31,892 35 1997 A 104,853 501 Santa Monica Blvd., Santa Monica, CA 4,547 12,044 19,357 4,551 31,397 35,948 23,853 35 1998 A 78,509 12225 El Camino Real, Del Mar, CA 1,700 9,633 4,434 1,673 14,094 15,767 10,912 35 1998 A 58,401 KILROY REALTY CORPORATION AND KILROY REALTY, L.P. SCHEDULE III – REAL ESTATE AND ACCUMULATED DEPRECIATION – (Continued) December 31, 2023 Initial Cost Gross Amounts at Which Property Location Encumb- Land and Improve- Buildings Costs Land and Improve- Buildings Total Accumulated Depreci- ation Life (1) Date of Acquisition (A)/ Construction (C) (2) Rentable Square Feet (3) (unaudited) ($ in thousands) 12235 El Camino Real, Del Mar, CA 1,507 8,543 9,985 1,540 18,495 20,035 13,792 35 1998 A 53,751 12340 El Camino Real, Del Mar, CA 4,201 — 35,629 4,201 35,629 39,830 4,585 35 2022 C 109,307 12390 El Camino Real, Del Mar, CA 3,453 11,981 12,348 3,453 24,329 27,782 14,393 35 2000 C 73,238 12770 El Camino Real, Del Mar, CA 9,360 — 35,029 9,360 35,029 44,389 8,314 35 2016 C 75,035 12780 El Camino Real, Del Mar, CA 18,398 54,954 24,127 18,398 79,081 97,479 28,749 35 2013 A 140,591 12790 El Camino Real, Del Mar, CA 10,252 21,236 17,031 10,252 38,267 48,519 12,315 35 2013 A 87,944 12830 El Camino Real, Del Mar, CA $375,000 (6) 28,645 — 113,007 28,645 113,007 141,652 12,713 35 2021 C 196,444 12860 El Camino Real, Del Mar, CA (6) 11,326 — 51,844 11,326 51,844 63,170 6,012 35 2021 C 92,042 12348 High Bluff Dr., Del Mar, CA 1,629 3,096 8,504 1,629 11,600 13,229 8,741 35 1999 C 39,192 12400 High Bluff Dr., Del Mar, CA 15,167 — 49,456 15,167 49,456 64,623 11,382 35 2022 C 216,518 3579 Valley Centre Dr., Del Mar, CA 2,167 6,897 11,556 2,858 17,762 20,620 12,032 35 1999 C 54,960 3611 Valley Centre Dr., Del Mar, CA 4,184 19,352 29,641 5,259 47,918 53,177 33,359 35 2000 C 132,425 3661 Valley Centre Dr., Del Mar, CA 4,038 21,144 20,770 4,725 41,227 45,952 29,457 35 2001 C 131,662 3721 Valley Centre Dr., Del Mar, CA 4,297 18,967 17,124 4,254 36,134 40,388 23,912 35 2003 C 115,193 3811 Valley Centre Dr., Del Mar, CA 3,452 16,152 21,985 4,457 37,132 41,589 26,896 35 2000 C 118,912 3745 Paseo Place, Del Mar, CA (Retail) (6) 24,358 — 75,649 24,358 75,649 100,007 11,192 35 2019 C 95,871 13480 Evening Creek Dr. North, San Diego, CA 7,997 — 67,178 7,997 67,178 75,175 27,665 35 2008 C 143,401 13500 Evening Creek Dr. North, San Diego, CA 7,581 35,903 25,140 7,580 61,044 68,624 34,020 35 2004 A 143,749 13520 Evening Creek Dr. North, San Diego, CA 7,581 35,903 25,728 7,580 61,632 69,212 36,164 35 2004 A 146,701 2100 Kettner Blvd., San Diego, CA 19,861 — 105,759 19,861 105,759 125,620 3,873 35 2022 C 206,527 2305 Historic Decatur Rd., San Diego, CA 5,240 22,220 10,816 5,240 33,036 38,276 16,858 35 2010 A 107,456 4690 Executive Dr., San Diego, CA (7) — — 6,880 — 6,880 6,880 408 35 1999 A — 9455 Towne Centre Dr., San Diego, CA 6,081 — 80,080 6,081 80,080 86,161 7,363 35 2021 C 160,444 9514 Towne Centre Dr., San Diego, CA 4,928 — 47,563 4,928 47,563 52,491 685 35 2023 C 70,616 4100 Bohannon Dr., Menlo Park, CA 4,835 15,526 1,524 4,860 17,025 21,885 6,650 35 2012 A 47,643 4200 Bohannon Dr., Menlo Park, CA 4,798 15,406 8,370 4,662 23,912 28,574 9,495 35 2012 A 43,600 4300 Bohannon Dr., Menlo Park, CA 6,527 20,958 8,097 6,470 29,112 35,582 11,649 35 2012 A 63,430 4400 Bohannon Dr., Menlo Park, CA (8) — — 3,245 — 3,245 3,245 2,117 35 2012 A — 4500 Bohannon Dr., Menlo Park, CA 6,527 20,957 4,782 6,470 25,796 32,266 10,623 35 2012 A 63,429 4600 Bohannon Dr., Menlo Park, CA 4,798 15,406 5,286 4,939 20,551 25,490 8,884 35 2012 A 48,413 4700 Bohannon Dr., Menlo Park, CA 6,527 20,958 1,576 6,470 22,591 29,061 9,106 35 2012 A 63,429 1290 - 1300 Terra Bella Ave., Mountain View, CA 28,730 27,555 13,461 28,730 41,016 69,746 9,462 35 2016 A 114,175 680 E. Middlefield Rd., Mountain View, CA 34,755 — 56,759 34,755 56,759 91,514 17,536 35 2014 C 171,676 KILROY REALTY CORPORATION AND KILROY REALTY, L.P. SCHEDULE III – REAL ESTATE AND ACCUMULATED DEPRECIATION – (Continued) December 31, 2023 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) 690 E. Middlefield Rd., Mountain View, CA 34,605 — 56,515 34,605 56,515 91,120 17,461 35 2014 C 171,215 1701 Page Mill Rd., Palo Alto, CA — 99,522 111 — 99,633 99,633 21,015 35 2016 A 128,688 3150 Porter Dr., Palo Alto, CA — 21,715 6,446 — 28,161 28,161 6,276 35 2016 A 36,886 900 Jefferson Ave., Redwood City, CA (9) 16,668 — 109,612 18,063 108,217 126,280 31,253 35 2015 C 228,505 900 Middlefield Rd., Redwood City, CA (9) 7,959 — 50,285 8,626 49,618 58,244 14,031 35 2015 C 118,764 100 Hooper St., San Francisco, CA 78,564 — 197,034 85,510 190,088 275,598 29,788 35 2018 C 417,914 100 First St., San Francisco, CA (10) 49,150 131,238 81,437 49,150 212,675 261,825 106,267 35 2010 A 480,457 303 Second St., San Francisco, CA (11) 63,550 154,153 116,103 63,550 270,256 333,806 134,337 35 2010 A 784,658 201 Third St., San Francisco, CA 19,260 84,018 78,410 19,260 162,428 181,688 94,189 35 2011 A 346,538 360 Third St., San Francisco, CA — 88,235 127,866 28,504 187,597 216,101 74,839 35 2011 A 436,357 250 Brannan St., San Francisco, CA 7,630 22,770 10,773 7,630 33,543 41,173 15,259 35 2011 A 100,850 301 Brannan St., San Francisco, CA 5,910 22,450 16,987 5,910 39,437 45,347 15,826 35 2011 A 82,834 333 Brannan St., San Francisco, CA 18,645 — 80,643 18,645 80,643 99,288 18,703 35 2016 C 185,602 345 Brannan St., San Francisco, CA 29,405 113,179 1,260 29,403 114,441 143,844 16,912 35 2018 A 110,050 350 Mission St., San Francisco, CA 52,815 — 212,738 52,815 212,738 265,553 51,190 35 2016 C 455,340 345 Oyster Point Blvd., South San Francisco, CA 13,745 18,575 — 13,745 18,575 32,320 3,392 35 2018 A 40,410 347 Oyster Point Blvd., South San Francisco, CA 14,071 18,289 44 14,071 18,333 32,404 3,354 35 2018 A 39,780 349 Oyster Point Blvd., South San Francisco, CA 23,112 22,601 352 23,112 22,953 46,065 5,440 35 2018 A 65,340 350 Oyster Point Blvd., South San Francisco, CA 23,719 — 177,245 23,719 177,245 200,964 11,889 35 2021 C 234,892 352 Oyster Point Blvd., South San Francisco, CA 23,449 — 165,720 23,449 165,720 189,169 11,662 35 2021 C 232,215 354 Oyster Point Blvd., South San Francisco, CA 19,538 — 141,126 19,538 141,126 160,664 11,708 35 2021 C 193,472 505 Mathilda Ave., Sunnyvale, CA 37,843 1,163 50,450 37,943 51,513 89,456 13,584 35 2014 C 212,322 555 Mathilda Ave., Sunnyvale, CA 37,843 1,163 50,447 37,943 51,510 89,453 13,583 35 2014 C 212,322 599 Mathilda Ave., Sunnyvale, CA 13,538 12,559 71 13,538 12,630 26,168 5,800 35 2012 A 76,031 605 Mathilda Ave., Sunnyvale, CA 29,014 891 77,281 29,090 78,096 107,186 30,299 35 2014 C 162,785 601 108th Ave., Bellevue, WA — 214,095 88,698 42,680 260,113 302,793 118,339 35 2011 A 490,738 10900 NE 4th St., Bellevue, WA 25,080 150,877 52,662 25,080 203,539 228,619 89,219 35 2012 A 428,557 2001 W. 8th Ave., Seattle, WA 84,076 371,154 3,216 84,076 374,370 458,446 29,772 35 2021 A 539,226 333 Dexter Ave. North, Seattle, WA 42,854 — 328,064 42,854 328,064 370,918 27,405 35 2022 C 618,766 701 N. 34th St., Seattle, WA — 48,027 9,743 — 57,770 57,770 24,961 35 2012 A 141,860 801 N. 34th St., Seattle, WA — 58,537 23,304 — 81,841 81,841 30,106 35 2012 A 173,615 837 N. 34th St., Seattle, WA — 37,404 6,734 — 44,138 44,138 18,088 35 2012 A 112,487 320 Westlake Ave. North, Seattle, WA 81,308 (12) 14,710 82,018 15,064 14,710 97,082 111,792 33,902 35 2013 A 184,644 321 Terry Ave. North, Seattle, WA (12) 10,430 60,003 10,779 10,430 70,782 81,212 25,693 35 2013 A 135,755 401 Terry Ave. North, Seattle, WA 22,500 77,046 32 22,500 77,078 99,578 24,632 35 2014 A 174,530 KILROY REALTY CORPORATION AND KILROY REALTY, L.P. SCHEDULE III – REAL ESTATE AND ACCUMULATED DEPRECIATION – (Continued) December 31, 2023 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) 200 W. 6th St., Austin, TX — — 644,210 — 644,210 644,210 17,688 35 2023 C 758,975 Residential Properties: 1550 N. El Centro Ave., Los Angeles, CA (4) 16,970 39 137,456 16,970 137,495 154,465 30,007 35 2016 C — 6390 De Longpre Ave., Hollywood, CA 12,112 — 162,908 12,112 162,908 175,020 12,788 35 2021 C — 3200 Paseo Village Way, Del Mar, CA (6) 106,419 — 270,807 106,419 270,807 377,226 30,561 35 2020 C — TOTAL OPERATING PROPERTIES 612,694 1,651,703 2,959,869 5,595,272 1,743,170 8,463,674 10,206,844 2,518,304 17,044,128 Undeveloped land and construction in progress — 913,363 — 1,121,441 913,363 1,121,441 2,034,804 — — TOTAL ALL PROPERTIES $ 612,694 (13) $ 2,565,066 $ 2,959,869 $ 6,716,713 $ 2,656,533 $ 9,585,115 $ 12,241,648 $ 2,518,304 17,044,128 ____________________ (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 $156.4 million mortgage note. (6) These properties secure a $375.0 million mortgage note. (7) This property was taken out of the stabilized portfolio in the first quarter of 2022 for redevelopment in phases. (8) This property was taken out of the stabilized portfolio in the fourth quarter of 2022 for redevelopment. (9) These properties are owned by Redwood City Partners LLC, a consolidated property partnership. (10) This property is owned by 100 First Street Member LLC, a consolidated property partnership. (11) This property is owned by 303 Second Street Member LLC, a consolidated property partnership. (12) These properties secure a $81.3 million mortgage note. (13) Represents gross aggregate principal amount before the effect of the deferred financing costs of $9.5 million as of December 31, 2023. As of December 31, 2023, the aggregate gross cost of property included above for federal income tax purposes approximated $10.1 billion. The following table reconciles the historical cost of total real estate held for investment from January 1, 2021 to December 31, 2023: Year Ended December 31, 2023 2022 2021 (in thousands) Total real estate held for investment, beginning of year $ 11,732,183 $ 11,292,693 $ 10,190,046 Additions during period: Acquisitions — 40,033 1,131,248 Improvements, etc. 511,866 439,759 547,468 Total additions during period 511,866 479,792 1,678,716 Deductions during period: Cost of real estate sold — (32,855) (572,985) Other (2,401) (7,447) (3,084) Total deductions during period (2,401) (40,302) (576,069) Total real estate held for investment, end of year $ 12,241,648 $ 11,732,183 $ 11,292,693 The following table reconciles the accumulated depreciation from January 1, 2021 to December 31, 2023: Year Ended December 31, 2023 2022 2021 (in thousands) Accumulated depreciation, beginning of year $ 2,218,710 $ 2,003,656 $ 1,798,646 Additions during period: Depreciation of real estate 300,119 287,799 256,304 Total additions during period 300,119 287,799 256,304 Deductions during period: Write-offs due to sale — (19,114) (38,156) Other (525) (53,631) (13,138) Total deductions during period (525) (72,745) (51,294) Accumulated depreciation, end of year $ 2,518,304 $ 2,218,710 $ 2,003,656

Basis of Presentation and Sig_2

Basis of Presentation and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2023
Basis of Presentation and Significant Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation
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 our capital 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 beginning upon substantial completion of the leased premises. 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 beginning upon substantial completion of the leased premises. 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 the executed termination agreement 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. Generally, our leases require our tenants to restore the leased space to standard office condition upon the expiration of the lease. In limited circumstances, tenants may negotiate to pay us a restoration fee in lieu of restoring the space. Restoration fee income, included in rental income, is recognized on a straight-line basis from the date of the executed restoration fee agreement through lease expiration when the amount of the fee is determinable and collectability of the fee is probable. Additional Rent - Reimbursements from Tenants Additional rent, consisting of amounts due from tenants for common area maintenance, real estate taxes and other recoverable costs, is 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 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 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. 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. 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, considering the current economic and business environment, including 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. This determination is performed on a quarterly basis and 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. Since these factors are beyond our control, actual results can differ from our estimates, and such differences could be material. For leases that are deemed probable of collection, revenue continues to be recorded on a straight-line basis over the lease term, and for some tenants may include an offsetting partial allowance for uncollectible accounts related to current tenant and deferred rent receivables that exhibit a certain level of collection risk based on the results of the assessment described above. 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-
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, including costs incurred during negotiation. When applicable, 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. 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 relative 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, 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. 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. Evaluation of Asset Impairment When evaluating operating real estate assets to be held and used for potential impairment, we first evaluate whether there are any indicators of impairment. If any impairment indicators are present for a specific real estate asset, we then evaluate the regional market conditions that could reasonably affect the real estate asset. 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 real estate asset to the real estate asset’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 real estate asset, we perform an impairment loss calculation to determine if the fair value of the real estate asset is less than the net carrying value of the real estate asset. Our impairment loss calculation compares the net carrying amount of the real estate asset to the real estate asset’s estimated fair value, which may be based on estimated discounted future cash flow calculations or third-party valuations or appraisals. We recognize an impairment loss if the real estate asset's net carrying amount exceeds the real estate asset's estimated fair value. If we recognize an impairment loss, the estimated fair value of the real estate asset 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. 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, 2023 and 2022, 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 and 2021 are presented in continuing operations as they did not represent a strategic shift in the Company’s operations and financial results. We did not dispose of any properties during the year ended December 31, 2023. 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, including certificates of deposits, with original maturities of three months or less to be cash equivalents.
Restricted Cash	Restricted Cash
Marketable Securities	Marketable securities reported in our consolidated balance sheets represent certificates of deposit with original maturities greater than three months and the assets held in connection with the Kilroy Realty Corporation 2007 Deferred Compensation Plan (the “Deferred Compensation Plan”) (see Note 17 “Employee Benefit Plans” for additional information. The Company intends to hold the certificates of deposit until their maturity. As a result, the certificates of deposit are classified as held-to-maturity securities. 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 into interest expense 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 12 “Noncontrolling Interests on the Company’s Consolidated Financial Statements” and see Note 13 “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 the impact of 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 12 “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 any at-the-market stock offering programs (see Note 14 “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 20, “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 the marketable securities held in connection with our Deferred Compensation Plan. 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 certificates of deposit, 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 flows. 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, certificates of deposit and accounts payable approximate fair value due to their short-term maturities of 12 months or less.
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, 2023, 2022 and 2021, and we were not subject to any federal income taxes (see Note 25 “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 federal 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, 2023, 2022 and 2021 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	Segments
Concentration of Credit Risk	Concentration of Credit Risk
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2023-07 “Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures.” This ASU is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. The Company is currently evaluating the impact of adopting this ASU on our consolidated financial statements and disclosures.

Organization and Ownership (Tab

Organization and Ownership (Tables)	12 Months Ended
	Dec. 31, 2023
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, 2023: Number of Rentable Number of Percentage Occupied (unaudited) (1) Percentage Leased Stabilized Office Properties (2) 121 17,044,128 410 85.0 % 86.4 % _______________________ (1) Represents economic occupancy. (2) Includes stabilized life science and retail space. Number of Projects Number of Units 2023 Average Occupancy (unaudited) Stabilized Residential Properties 3 1,001 92.8 % Number of Estimated Rentable Square Feet (1) (unaudited) In-process development projects - under construction 1 875,000 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, 2023
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, 2023, 2022, and 2021 was $300.1 million, $287.8 million, and $256.3 million, respectively. Asset Description Depreciable Lives Buildings and improvements 25 – 40 years Tenant improvements 1 – 20 years (1) ____________________ (1)

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2023
Business Combination and Asset Acquisition [Abstract]
Schedule of Acquisitions	The following table summarizes the development site acquired from unrelated third parties during the year ended December 31, 2022: 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 _______________________ (1) Excludes acquisition-related costs. (2) This property was added to our future development pipeline.

Dispositions (Tables)

Dispositions (Tables)	12 Months Ended
	Dec. 31, 2023
Discontinued Operations and Disposal Groups [Abstract]
Schedule of Operating Properties and Land Dispositions	The following table summarizes the operating properties sold during the years ended December 31, 2022 and 2021: 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 ____________________ (1) Represents gross sales price before broker commissions, closing costs, and purchase price credits.

Marketable Securities (Tables)

Marketable Securities (Tables)	12 Months Ended
	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Schedule of Marketable Securities	Marketable securities consisted of the following at December 31, 2023 and 2022: December 31, 2023 December 31, 2022 (in thousands) Deferred compensation plan assets $ 28,089 $ 23,547 Certificates of deposit (1) 256,581 — Total marketable securities $ 284,670 $ 23,547 ____________________ (1) The certificates of deposit have an original issuance term greater than three months but less than 12 months.

Receivables (Tables)

Receivables (Tables)	12 Months Ended
	Dec. 31, 2023
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, 2023 and 2022: December 31, 2023 December 31, 2022 (in thousands) Current receivables $ 15,176 $ 22,816 Allowance for uncollectible tenant receivables (1) (1,567) (2,233) Current receivables, net $ 13,609 $ 20,583 ____________________ (1)
Schedule of Deferred Rent Receivables, Net	Deferred rent receivables, net consisted of the following as of December 31, 2023 and 2022: December 31, 2023 December 31, 2022 (in thousands) Deferred rent receivables $ 461,707 $ 453,165 Allowance for deferred rent receivables (1) (728) (965) Deferred rent receivables, net $ 460,979 $ 452,200 ____________________ (1)

Deferred Leasing Costs and Ac_2

Deferred Leasing Costs and Acquisition-Related Intangible Assets and Liabilities, net (Tables)	12 Months Ended
	Dec. 31, 2023
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, 2023 and 2022: December 31, 2023 December 31, 2022 (in thousands) Deferred Leasing Costs and Acquisition-related Intangible Assets, net: Deferred leasing costs $ 297,871 $ 301,967 Accumulated amortization (122,680) (121,545) Deferred leasing costs, net 175,191 180,422 Above-market operating leases 260 260 Accumulated amortization (70) (39) Above-market operating leases, net 190 221 In-place leases 70,247 114,435 Accumulated amortization (15,923) (44,232) In-place leases, net 54,324 70,203 Total deferred leasing costs and acquisition-related intangible assets, net $ 229,705 $ 250,846 Acquisition-related Intangible Liabilities, net: (1) Below-market operating leases $ 39,159 $ 52,380 Accumulated amortization (8,402) (14,943) Below-market operating leases, net 30,757 37,437 Total acquisition-related intangible liabilities, net $ 30,757 $ 37,437 ____________________ (1)
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, 2023, 2022 and 2021. Year Ended December 31, 2023 2022 2021 (in thousands) Deferred leasing costs $ 31,771 $ 31,059 $ 32,472 Above-market operating leases 31 31 8 In-place leases 15,878 31,647 14,562 Below-market operating leases (6,679) (10,508) (6,912) Total $ 41,001 $ 52,229 $ 40,130
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, 2023 for future periods: Year Ending Deferred Leasing Costs Above-Market Operating Leases (1) In-Place Leases Below-Market Operating Leases (2) (in thousands) 2024 $ 29,855 $ 31 $ 6,676 $ (3,588) 2025 27,019 31 6,635 (3,570) 2026 23,974 31 6,311 (3,474) 2027 20,864 31 5,040 (3,099) 2028 18,824 31 5,014 (2,918) Thereafter 54,655 35 24,648 (14,108) Total $ 175,191 $ 190 $ 54,324 $ (30,757) ____________________ (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.

Prepaid Expenses and Other As_2

Prepaid Expenses and Other Assets, Net (Tables)	12 Months Ended
	Dec. 31, 2023
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, 2023 and 2022: December 31, 2023 December 31, 2022 (in thousands) Furniture, fixtures and other long-lived assets, net $ 37,073 $ 41,538 Prepaid expenses and deferred financing costs, net 10,532 11,364 Other assets 5,464 9,527 Total prepaid expenses and other assets, net $ 53,069 $ 62,429

Secured and Unsecured Debt of_3

Secured and Unsecured Debt of the Operating Partnership (Tables) - Kilroy Realty L.P.	12 Months Ended
	Dec. 31, 2023
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, 2023 and 2022: December 31, 2023 December 31, 2022 (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) 6.38 % 5.20 % Facility fee-annual rate (3) 0.200% Maturity date July 31, 2025 ____________________ (1) Total borrowing capacity is reduced by the amount of our outstanding letters of credit which total approximately $5.2 million as of December 31, 2023. 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 pursuant to the terms of the unsecured revolving credit facility. (2) Our unsecured revolving credit facility interest rate was calculated using a contractual rate of Secured Overnight Financing Rate (“SOFR”) plus a SOFR adjustment of 0.10% (“Adjusted SOFR”) and a margin of 0.900% based on our credit rating as of December 31, 2023 and 2022. We may be entitled to a temporary 0.01% reduction in the interest rate provided we meet certain sustainability goals with respect to the ongoing reduction of greenhouse gas emissions. (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, 2023 and 2022, $3.2 million and $5.3 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. (4) The following table summarizes the balance and terms of our unsecured term loan facility as of December 31, 2023: December 31, 2023 December 31, 2022 (in thousands) Outstanding borrowings $ 520,000 $ 200,000 Remaining borrowing capacity — 200,000 Total borrowing capacity (1) $ 520,000 $ 400,000 Interest rate (2) 6.41 % 5.23 % Undrawn facility fee-annual rate (3) 0.200% Maturity date (4) October 3, 2024 ____________________ (1) We may elect to borrow, subject to bank approval and obtaining commitments for any additional borrowing capacity, up to an additional $130.0 million and $100.0 million as of December 31, 2023 and December 31, 2022, respectively, under an accordion feature pursuant to the terms of the unsecured term loan facility (2) Our unsecured term loan facility interest rate was calculated using a contractual rate of Adjusted SOFR plus a margin of 0.950% based on our credit rating as of December 31, 2023 and 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, 2023 and 2022, $2.3 million and $4.5 million, respectively, of unamortized deferred financing costs remained to be amortized through the maturity date of our unsecured term loan facility. (4) The maturity date may be extended by two twelve-month periods, at the Company’s option.
Schedule of Debt Maturities	The following table summarizes the stated debt maturities and scheduled amortization payments for all outstanding debt as of December 31, 2023: Year (in thousands) 2024 (1) $ 929,718 2025 406,246 2026 401,317 2027 249,125 2028 400,000 Thereafter 2,575,000 Total aggregate principal value (2) $ 4,961,406 ________________________ (1) Includes the $520.0 million currently outstanding on the unsecured term loan facility maturing on October 3, 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, 2023: $27.7 million of unamortized deferred financing costs for the unsecured term loan facility, unsecured senior notes and secured debt and $5.3 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, 2023, 2022 and 2021. 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, 2023 2022 2021 (in thousands) Gross interest expense $ 192,983 $ 161,761 $ 158,756 Capitalized interest and deferred financing costs (78,767) (77,483) (80,201) Interest expense $ 114,216 $ 84,278 $ 78,555
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, 2023 and 2022: Annual Stated Interest Rate (1) GAAP Effective Rate (1)(2) Maturity Date December 31, Type of Debt 2023 2022 (in thousands) Mortgage note payable 3.57% 3.57% December 2026 $ 156,386 $ 159,973 Mortgage note payable (3) 4.48% 4.48% July 2027 81,308 83,496 Mortgage note payable 5.90% 5.90% August 2034 375,000 — Total secured debt $ 612,694 $ 243,469 Unamortized deferred financing costs (9,469) (531) Total secured debt, net $ 603,225 $ 242,938 ____________________ (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)
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 unamortized discounts of $5.3 million and $6.4 million and unamortized deferred financing costs of $15.9 million and $19.1 million as of December 31, 2023 and 2022, respectively: Net Carrying Amount Issuance date Maturity date Stated Effective interest rate (1) 2023 2022 (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 (3,422) (3,770) Net carrying amount $ 446,578 $ 446,230 2.500% Unsecured Senior Notes (2) August 2020 November 2032 2.500% 2.560% $ 425,000 $ 425,000 Unamortized discount and deferred financing costs (4,735) (5,268) Net carrying amount $ 420,265 $ 419,732 4.270% Unsecured Senior Notes (3) April 2020 January 2031 4.270% 4.270% $ 350,000 $ 350,000 Unamortized discount and deferred financing costs (1,282) (1,463) Net carrying amount $ 348,718 $ 348,537 3.050% Unsecured Senior Notes (4) September 2019 February 2030 3.050% 3.064% $ 500,000 $ 500,000 Unamortized discount and deferred financing costs (3,629) (4,221) Net carrying amount $ 496,371 $ 495,779 4.750% Unsecured Senior Notes (5) November 2018 December 2028 4.750% 4.800% $ 400,000 $ 400,000 Unamortized discount and deferred financing costs (2,468) (2,963) Net carrying amount $ 397,532 $ 397,037 4.350% Unsecured Senior Notes (3) October 2018 October 2026 4.350% 4.350% $ 200,000 $ 200,000 Unamortized discount and deferred financing costs (488) (663) Net carrying amount $ 199,512 $ 199,337 4.300% Unsecured Senior Notes (3) July 2018 July 2026 4.300% 4.300% $ 50,000 $ 50,000 Unamortized discount and deferred financing costs (113) (157) Net carrying amount $ 49,887 $ 49,843 3.450% Unsecured Senior Notes (5) December 2017 December 2024 3.450% 3.470% $ 403,712 $ 425,000 Unamortized discount and deferred financing costs (558) (1,148) Net carrying amount $ 403,154 $ 423,852 3.450% Unsecured Senior Notes (6) February 2017 February 2029 3.450% 3.450% $ 75,000 $ 75,000 Unamortized discount and deferred financing costs (219) (262) Net carrying amount $ 74,781 $ 74,738 3.350% Unsecured Senior Notes (6) February 2017 February 2027 3.350% 3.350% $ 175,000 $ 175,000 Unamortized discount and deferred financing costs (363) (478) Net carrying amount $ 174,637 $ 174,522 4.375% Unsecured Senior Notes (7) September 2015 October 2025 4.375% 4.444% $ 400,000 $ 400,000 Unamortized discount and deferred financing costs (969) (1,523) Net carrying amount $ 399,031 $ 398,477 4.250% Unsecured Senior Notes (4) July 2014 August 2029 4.250% 4.350% $ 400,000 $ 400,000 Unamortized discount and deferred financing costs (2,971) (3,503) Net carrying amount $ 397,029 $ 396,497 Total Unsecured Senior Notes, Net $ 3,807,495 $ 3,824,581 ____________________ (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, 2023
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, 2023 and 2022: December 31, 2023 2022 (in thousands) Deferred revenue related to tenant-funded tenant improvements $ 97,802 $ 111,453 Other deferred revenue 45,079 47,069 Acquisition-related intangible liabilities, net (1) 30,757 37,437 Total $ 173,638 $ 195,959 _____________________ (1) See Note 7 “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, 2023 for the next five years and thereafter: Year Ending (in thousands) 2024 $ 17,299 2025 14,280 2026 12,390 2027 11,136 2028 9,764 Thereafter 32,933 Total $ 97,802

Stockholders' Equity of the C_2

Stockholders' Equity of the Company (Tables)	12 Months Ended
	Dec. 31, 2023
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, 2023 and 2022: December 31, 2023 2022 (in thousands) Dividends and Distributions payable to: Common stockholders $ 63,309 $ 63,114 Noncontrolling common unitholders of the Operating Partnership 621 621 RSU holders (1) 510 550 Total accrued dividends and distribution to common stockholders and noncontrolling unitholders $ 64,440 $ 64,285 _____________________ (1) The amount includes the value of the dividend equivalents that will be paid with additional RSUs (see Note 16 “Share-Based and Other Compensation” for additional information).
Schedule of Outstanding Shares of Common Stock, Preferred Stock and Noncontrolling Units	December 31, 2023 2022 Outstanding Shares and Units: Common stock 117,239,558 116,878,031 Noncontrolling common units 1,150,574 1,150,574 RSUs (1) 908,336 984,006 _____________________ (1) The amount includes nonvested RSUs. Does not include 1,083,086 and 1,123,554 market measure-based RSUs because not all the necessary performance conditions have been met as of December 31, 2023 and 2022, respectively. Refer to Note 16 “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, 2023
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, 2023 and 2022: December 31, 2023 2022 (in thousands) Dividends and Distributions payable to: Common stockholders $ 63,309 $ 63,114 Noncontrolling common unitholders of the Operating Partnership 621 621 RSU holders (1) 510 550 Total accrued dividends and distribution to common stockholders and noncontrolling unitholders $ 64,440 $ 64,285 _____________________ (1) The amount includes the value of the dividend equivalents that will be paid with additional RSUs (see Note 16 “Share-Based and Other Compensation” for additional information).
Schedule of Outstanding Shares of Common Stock, Preferred Stock and Noncontrolling Units	December 31, 2023 2022 Outstanding Shares and Units: Common stock 117,239,558 116,878,031 Noncontrolling common units 1,150,574 1,150,574 RSUs (1) 908,336 984,006 _____________________ (1) The amount includes nonvested RSUs. Does not include 1,083,086 and 1,123,554 market measure-based RSUs because not all the necessary performance conditions have been met as of December 31, 2023 and 2022, respectively. Refer to Note 16 “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, 2023 December 31, 2022 Company owned common units in the Operating Partnership 117,239,558 116,878,031 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, 2023 and 2022: December 31, 2023 December 31, 2022 (in thousands) Distributions payable to: General partner $ 63,309 $ 63,114 Common limited partners 621 621 RSU holders (1) 510 550 Total accrued distributions to common unitholders $ 64,440 $ 64,285 _____________________ (1) The amount includes the value of the dividend equivalents that will be paid with additional RSUs (see Note 16 “Share-Based and Other Compensation” for additional information).
Schedule of Outstanding Shares of Common Stock, Preferred Stock and Noncontrolling Units	December 31, 2023 December 31, 2022 Outstanding Units: Common units held by the general partner 117,239,558 116,878,031 Common units held by the limited partners 1,150,574 1,150,574 RSUs (1) 908,336 984,006 _____________________ (1)

Share-Based and Other Compens_2

Share-Based and Other Compensation (Tables)	12 Months Ended
	Dec. 31, 2023
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: 2023 Time-Based RSU Grant 2022 Time-Based RSU Grant 2021 Time-Based RSU Grant Service vesting period February 6, 2023 - January 5, 2026 January 28, 2022 - January 5, 2025 January & February 2021 - January 5, 2024 RSUs granted 217,059 158,170 160,277 Fair value on valuation date (in millions) $ 8.6 $ 10.0 $ 9.1 Weighted average fair value per share $ 39.65 $ 63.05 $ 57.07 Date of valuation February 6, 2023 January 28, 2022 January 29, February 18, 2021
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 2023 and 2022 Performance-Based RSUs and the actual number of RSUs earned for the 2021 Performance-Based RSUs and the assumptions utilized in the Monte Carlo simulation pricing models: 2023 2022 2021 Service vesting period February 6, 2023 - January, 2026 January 28, 2022 - January, 2025 February 18, 2021 - January, 2024 Target RSUs granted 300,007 193,111 172,430 Estimated RSUs earned (1) 570,006 406,319 401,580 Fair Value Assumptions: Valuation date February 6, 2023 January 28, 2022 February 18, 2021 Fair value on valuation date (in millions) $12.0 $12.7 $10.6 Fair value per share on valuation date (2) $40.10 $67.62 $63.93 Expected share price volatility 35.0 % 36.0 % 35.0 % Risk-free interest rate 4.12 % 1.35 % 0.20 % _____________________ (1) Estimated RSUs earned for the 2023 Performance-Based RSUs are based on the actual achievement of the 2023 FFO Performance Condition and assumes the target level of achievement for the 2023 Debt to EBITDA Ratio Performance Condition and the target level of achievement of the 2023 Market Condition. Estimated RSUs earned for the 2022 Performance-Based RSUs are based on the actual achievement of the 2022 FFO Performance Condition and assume target level achievement of the 2022 Market Condition and maximum level of achievement of the 2022 Debt to EBITDA Ratio Performance Condition. The 2021 Performance-Based RSUs earned are based on actual performance of the 2021 Performance Conditions and the 2021 Market Condition. (2) For one participant, the fair value per share on the valuation date for their 2023, 2022, and 2021 Performance-Based RSUs is $40.43, $70.00 and $66.95, respectively.
Market measure-based Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Restricted Stock Units Award Activity	A summary of our performance and market-measure based RSU activity from January 1, 2023 through December 31, 2023 is presented below: Nonvested RSUs Vested RSUs Total RSUs Amount Weighted-Average Outstanding at January 1, 2023 1,123,554 $ 66.85 29,705 1,153,259 Granted 483,113 39.65 53,537 536,650 Vested (230,741) 76.67 230,741 — Settled (1) — — (296,688) (296,688) Issuance of dividend equivalents (2) 67,122 32.98 6,292 73,414 Canceled (359,962) 61.00 (4) (359,966) Outstanding as of December 31, 2023 (3) 1,083,086 $ 52.47 23,583 1,106,669 ____________________ (1) Represents vested RSUs that were settled in shares of the Company’s common stock. Total shares settled include 144,178 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, 2023 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, 2023, 2022 and 2021 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 2023 483,113 $ 39.65 (290,570) $ 11,105 2022 310,484 $ 63.05 (241,184) $ 15,200 2021 281,333 $ 57.85 (252,098) $ 14,299 ____________________ (1)
RSUs granted
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Restricted Stock Units Award Activity	A summary of our time-based RSU activity from January 1, 2023 through December 31, 2023 is presented below: Nonvested RSUs Vested RSUs Total RSUs Amount Weighted Average Fair Value Outstanding at January 1, 2023 443,367 $ 61.27 510,934 954,301 Granted 247,017 38.12 — 247,017 Vested (305,653) 63.49 305,653 — Settled (1) — — (368,717) (368,717) Issuance of dividend equivalents (2) 22,383 32.13 37,681 60,064 Forfeited (5,804) 50.39 — (5,804) Canceled (3) — — (2,108) (2,108) Outstanding as of December 31, 2023 401,310 $ 43.86 483,443 884,753 ____________________ (1) Represents vested RSUs that were settled in shares of the Company’s common stock. Total shares settled include 161,731 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, 2023, 2022 and 2021 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) 2023 247,017 $ 38.12 (343,334) $ 12,425 2022 177,099 $ 62.58 (294,867) $ 19,890 2021 172,181 $ 57.83 (144,838) $ 8,605 ____________________

Rental Income and Future Mini_2

Rental Income and Future Minimum Rent (Tables)	12 Months Ended
	Dec. 31, 2023
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, 2023 and 2022: Year Ended December 31, 2023 2022 Fixed lease payments $ 944,618 $ 923,257 Variable lease payments 184,672 162,638 Net collectability (reversals) recoveries (1) (11,553) 123 Total rental income $ 1,117,737 $ 1,086,018 ____________________ (1)
Schedule of 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, 2023 for future periods is summarized as follows: Year Ending (in thousands) 2024 $ 806,250 2025 800,821 2026 755,071 2027 698,993 2028 658,993 Thereafter 2,042,634 Total (1) $ 5,762,762 ____________________ (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, 2023
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, 2023: 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, 2023 for future periods is as follows: Year Ending (in thousands) 2024 $ 6,737 2025 6,773 2026 6,810 2027 6,851 2028 6,870 Thereafter 363,350 Total undiscounted cash flows (1)(2)(3)(4)(5)(6) $ 397,391 Present value discount (273,038) Ground lease liabilities $ 124,353 ________________________ (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, 2023. (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, 2023 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, 2023 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, 2023 and no subsequent changes for the remainder of the lease term since we cannot predict future CPI adjustments.

Fair Value Measurements and D_2

Fair Value Measurements and Disclosures (Tables)	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Schedule of Fair Value of the Company's Deferred Compensation Plan Assets	The following table sets forth the fair value of our Deferred Compensation Plan assets as of December 31, 2023 and 2022: Fair Value (Level 1) (1) 2023 2022 Description (in thousands) Deferred Compensation Plan assets (2) $ 28,089 $ 23,547 ____________________ (1) Based on quoted prices in active markets for identical securities. (2) The Deferred Compensation Plan assets are held in a limited rabbi trust.
Schedule of 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, 2023 and 2022: December 31, 2023 2022 Carrying Value Fair Value (1) Carrying Value Fair Value (1) (in thousands) Assets Certificates of deposit (2) $ 256,581 $ 256,581 $ — $ — Liabilities Secured debt, net $ 603,225 $ 585,826 $ 242,938 $ 225,847 Unsecured debt, net 4,325,153 3,927,104 4,020,058 3,500,420 _______________ (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. (2)

Net Income Available to Commo_3

Net Income Available to Common Stockholders Per Share of the Company (Tables)	12 Months Ended
	Dec. 31, 2023
Earnings Per Share [Abstract]
Schedule of 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, 2023, 2022 and 2021: Year Ended December 31, 2023 2022 2021 (in thousands, except unit and per unit amounts) Numerator: Net income available to common stockholders $ 212,241 $ 232,615 $ 628,144 Allocation to participating securities (1) (1,233) (1,272) (1,516) Numerator for basic and diluted net income available to common stockholders $ 211,008 $ 231,343 $ 626,628 Denominator: Basic weighted average vested shares outstanding 117,160,173 116,806,575 116,429,130 Effect of dilutive securities 346,082 413,472 519,513 Diluted weighted average vested shares and common stock equivalents outstanding 117,506,255 117,220,047 116,948,643 Basic earnings per share: Net income available to common stockholders per share $ 1.80 $ 1.98 $ 5.38 Diluted earnings per share: Net income available to common stockholders per share $ 1.80 $ 1.97 $ 5.36 _____________________ (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, 2023
Net Income Available To Common Unitholders [Line Items]
Schedule of 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, 2023, 2022 and 2021: Year Ended December 31, 2023 2022 2021 (in thousands, except unit and per unit amounts) Numerator: Net income available to common stockholders $ 212,241 $ 232,615 $ 628,144 Allocation to participating securities (1) (1,233) (1,272) (1,516) Numerator for basic and diluted net income available to common stockholders $ 211,008 $ 231,343 $ 626,628 Denominator: Basic weighted average vested shares outstanding 117,160,173 116,806,575 116,429,130 Effect of dilutive securities 346,082 413,472 519,513 Diluted weighted average vested shares and common stock equivalents outstanding 117,506,255 117,220,047 116,948,643 Basic earnings per share: Net income available to common stockholders per share $ 1.80 $ 1.98 $ 5.38 Diluted earnings per share: Net income available to common stockholders per share $ 1.80 $ 1.97 $ 5.36 _____________________ (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]
Schedule of 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, 2023, 2022 and 2021: Year Ended December 31, 2023 2022 2021 (in thousands, except unit and per unit amounts) Numerator: Net income available to common unitholders $ 214,324 $ 234,898 $ 634,307 Allocation to participating securities (1) (1,233) (1,272) (1,516) Numerator for basic and diluted net income available to common unitholders $ 213,091 $ 233,626 $ 632,791 Denominator: Basic weighted average vested units outstanding 118,310,747 117,957,149 117,579,704 Effect of dilutive securities 346,082 413,472 519,513 Diluted weighted average vested units and common unit equivalents outstanding 118,656,829 118,370,621 118,099,217 Basic earnings per unit: Net income available to common unitholders per unit $ 1.80 $ 1.98 $ 5.38 Diluted earnings per unit: Net income available to common unitholders per unit $ 1.80 $ 1.97 $ 5.36 ____________________ (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, 2023
Supplemental Cash Flow Elements [Abstract]
Schedule of Supplemental Cash Flows	Supplemental cash flows information as follows (in thousands): Year Ended December 31, 2023 2022 2021 SUPPLEMENTAL CASH FLOWS INFORMATION: Cash paid for interest, net of capitalized interest of $74,052, $72,973, and $75,802 as of December 31, 2023, 2022 and 2021, respectively $ 105,767 $ 79,634 $ 77,028 Cash paid for amounts included in the measurement of ground lease liabilities $ 6,733 $ 6,447 $ 6,209 NON-CASH INVESTING TRANSACTIONS: Accrual for expenditures for operating properties and development and redevelopment properties $ 95,575 $ 97,729 $ 119,829 Tenant improvements funded directly by tenants $ 7,364 $ 6,772 $ 20,070 Assumption of accrued liabilities in connection with acquisitions $ — $ — $ 37,572 Initial measurement of operating right of use ground lease assets (Note 19) $ — $ — $ 46,430 Initial measurement of operating ground lease liabilities (Note 19) $ — $ — $ 46,430 NON-CASH FINANCING TRANSACTIONS: Accrual of dividends and distributions payable to common stockholders and common unitholders (Notes 14 and 26) $ 64,440 $ 64,285 $ 61,850
Schedule of 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, 2023, 2022 and 2021. Year Ended December 31, 2023 2022 2021 (in thousands) RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH: Cash and cash equivalents at beginning of period $ 347,379 $ 414,077 $ 731,991 Restricted cash at beginning of period — 13,006 91,139 Cash and cash equivalents and restricted cash at beginning of period $ 347,379 $ 427,083 $ 823,130 Cash and cash equivalents at end of period $ 510,163 $ 347,379 $ 414,077 Restricted cash at end of period — — 13,006 Cash and cash equivalents and restricted cash at end of period $ 510,163 $ 347,379 $ 427,083
Schedule of 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, 2023, 2022 and 2021. Year Ended December 31, 2023 2022 2021 (in thousands) RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH: Cash and cash equivalents at beginning of period $ 347,379 $ 414,077 $ 731,991 Restricted cash at beginning of period — 13,006 91,139 Cash and cash equivalents and restricted cash at beginning of period $ 347,379 $ 427,083 $ 823,130 Cash and cash equivalents at end of period $ 510,163 $ 347,379 $ 414,077 Restricted cash at end of period — — 13,006 Cash and cash equivalents and restricted cash at end of period $ 510,163 $ 347,379 $ 427,083

Supplemental Cash Flow Inform_4

Supplemental Cash Flow Information of the Operating Partnership (Tables)	12 Months Ended
	Dec. 31, 2023
Other Significant Noncash Transactions [Line Items]
Schedule of Supplemental Cash Flows	Supplemental cash flows information as follows (in thousands): Year Ended December 31, 2023 2022 2021 SUPPLEMENTAL CASH FLOWS INFORMATION: Cash paid for interest, net of capitalized interest of $74,052, $72,973, and $75,802 as of December 31, 2023, 2022 and 2021, respectively $ 105,767 $ 79,634 $ 77,028 Cash paid for amounts included in the measurement of ground lease liabilities $ 6,733 $ 6,447 $ 6,209 NON-CASH INVESTING TRANSACTIONS: Accrual for expenditures for operating properties and development and redevelopment properties $ 95,575 $ 97,729 $ 119,829 Tenant improvements funded directly by tenants $ 7,364 $ 6,772 $ 20,070 Assumption of accrued liabilities in connection with acquisitions $ — $ — $ 37,572 Initial measurement of operating right of use ground lease assets (Note 19) $ — $ — $ 46,430 Initial measurement of operating ground lease liabilities (Note 19) $ — $ — $ 46,430 NON-CASH FINANCING TRANSACTIONS: Accrual of dividends and distributions payable to common stockholders and common unitholders (Notes 14 and 26) $ 64,440 $ 64,285 $ 61,850
Schedule of 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, 2023, 2022 and 2021. Year Ended December 31, 2023 2022 2021 (in thousands) RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH: Cash and cash equivalents at beginning of period $ 347,379 $ 414,077 $ 731,991 Restricted cash at beginning of period — 13,006 91,139 Cash and cash equivalents and restricted cash at beginning of period $ 347,379 $ 427,083 $ 823,130 Cash and cash equivalents at end of period $ 510,163 $ 347,379 $ 414,077 Restricted cash at end of period — — 13,006 Cash and cash equivalents and restricted cash at end of period $ 510,163 $ 347,379 $ 427,083
Schedule of 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, 2023, 2022 and 2021. Year Ended December 31, 2023 2022 2021 (in thousands) RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH: Cash and cash equivalents at beginning of period $ 347,379 $ 414,077 $ 731,991 Restricted cash at beginning of period — 13,006 91,139 Cash and cash equivalents and restricted cash at beginning of period $ 347,379 $ 427,083 $ 823,130 Cash and cash equivalents at end of period $ 510,163 $ 347,379 $ 414,077 Restricted cash at end of period — — 13,006 Cash and cash equivalents and restricted cash at end of period $ 510,163 $ 347,379 $ 427,083
Kilroy Realty L.P.
Other Significant Noncash Transactions [Line Items]
Schedule of Supplemental Cash Flows	Supplemental cash flows information as follows (in thousands): Year Ended December 31, 2023 2022 2021 SUPPLEMENTAL CASH FLOWS INFORMATION: Cash paid for interest, net of capitalized interest of $74,052, $72,973, and $75,802 as of December 31, 2023, 2022 and 2021, respectively $ 105,767 $ 79,634 $ 77,028 Cash paid for amounts included in the measurement of ground lease liabilities $ 6,733 $ 6,447 $ 6,209 NON-CASH INVESTING TRANSACTIONS: Accrual for expenditures for operating properties and development and redevelopment properties $ 95,575 $ 97,729 $ 119,829 Tenant improvements funded directly by tenants $ 7,364 $ 6,772 $ 20,070 Assumption of accrued liabilities in connection with acquisitions $ — $ — $ 37,572 Initial measurement of operating right of use ground lease assets (Note 19) $ — $ — $ 46,430 Initial measurement of operating ground lease liabilities (Note 19) $ — $ — $ 46,430 NON-CASH FINANCING TRANSACTIONS: Accrual of distributions payable to common unitholders (Notes 15 and 26) $ 64,440 $ 64,285 $ 61,850
Schedule of 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, 2023, 2022 and 2021. Year Ended December 31, 2023 2022 2021 (in thousands) RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH: Cash and cash equivalents at beginning of period $ 347,379 $ 414,077 $ 731,991 Restricted cash at beginning of period — 13,006 91,139 Cash and cash equivalents and restricted cash at beginning of period $ 347,379 $ 427,083 $ 823,130 Cash and cash equivalents at end of period $ 510,163 $ 347,379 $ 414,077 Restricted cash at end of period — — 13,006 Cash and cash equivalents and restricted cash at end of period $ 510,163 $ 347,379 $ 427,083
Schedule of 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, 2023, 2022 and 2021. Year Ended December 31, 2023 2022 2021 (in thousands) RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH: Cash and cash equivalents at beginning of period $ 347,379 $ 414,077 $ 731,991 Restricted cash at beginning of period — 13,006 91,139 Cash and cash equivalents and restricted cash at beginning of period $ 347,379 $ 427,083 $ 823,130 Cash and cash equivalents at end of period $ 510,163 $ 347,379 $ 414,077 Restricted cash at end of period — — 13,006 Cash and cash equivalents and restricted cash at end of period $ 510,163 $ 347,379 $ 427,083

Tax Treatment of Distributions

Tax Treatment of Distributions (Tables)	12 Months Ended
	Dec. 31, 2023
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, 2023, 2022 and 2021 as follows: Year Ended December 31, Dividends 2023 2022 2021 Dividends declared per share of common stock $ 2.160 $ 2.120 $ 2.040 Less: Dividends declared in the current year and paid in the following year (0.540) (0.540) (0.520) Add: Dividends declared in the prior year and paid in the current year 0.540 0.520 0.500 Dividends paid per share of common stock $ 2.160 $ 2.100 $ 2.020
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, 2023, 2022 and 2021 as identified in the table above was as follows: Year Ended December 31, Shares of Common Stock 2023 2022 2021 Ordinary income (1) $ 2.087 96.63 % $ 1.865 88.80 % $ 1.338 66.22 % Qualified dividend 0.001 0.04 % 0.001 0.02 % 0.003 0.15 % Return of capital 0.069 3.21 % 0.230 10.99 % 0.551 27.30 % Capital gains (2) 0.003 0.12 % 0.004 0.19 % 0.075 3.72 % Unrecaptured section 1250 gains — — % — — % 0.053 2.61 % $ 2.160 100.00 % $ 2.100 100.00 % $ 2.020 100.00 % ____________________ (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, 2023, 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, 2023 ft² development_project tenant building property
Real Estate Properties [Line Items]
Rentable Square Feet (unaudited)	17,044,128
Stabilized Office Properties
Real Estate Properties [Line Items]
Number of Buildings | building	121
Rentable Square Feet (unaudited)	17,044,128
Number of Tenants | tenant	410
Percentage Occupied (unaudited)	85%
Percentage Leased (unaudited)	86.40%
Stabilized Residential Properties
Real Estate Properties [Line Items]
Number of Projects | property	3
Number of Units | property	1,001
2023 Average Occupancy (unaudited)	92.80%
In-process development projects - under construction
Real Estate Properties [Line Items]
Rentable Square Feet (unaudited)	875,000
Number of Projects | development_project	1
In-process redevelopment projects - under construction
Real Estate Properties [Line Items]
Rentable Square Feet (unaudited)	100,000
Number of Projects | development_project	2

Organization and Ownership - Na

Organization and Ownership - Narrative (Details)	12 Months Ended
	Dec. 31, 2023 a ft² development_site property development_project property_partnership building	Dec. 31, 2022
Real Estate Properties [Line Items]
Lease-up properties occupancy percentage	95%
Lease-up properties occupancy duration	1 year
Rentable square feet | ft²	17,044,128
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 | Non-Affiliated Investors and Certain Executive Officer and Directors
Real Estate Properties [Line Items]
Ownership interest (percent)	1%	1%
San Francisco, California
Real Estate Properties [Line Items]
Number of properties	1
Redwood City, California | Redwood LLC
Real Estate Properties [Line Items]
Number of properties	2
Future Development Site
Real Estate Properties [Line Items]
Number of future development sites | development_site	8
Area of undeveloped land | a	64
Stabilized Office Properties
Real Estate Properties [Line Items]
Number of buildings | building	121
Rentable square feet | ft²	17,044,128
Stabilized Office Properties | Washington
Real Estate Properties [Line Items]
Number of properties	10
Stabilized Office Properties | Texas
Real Estate Properties [Line Items]
Number of properties	1
Future development project | Washington
Real Estate Properties [Line Items]
Number of properties | development_site	1
Future development project | Texas
Real Estate Properties [Line Items]
Number of properties | development_site	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	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
Development Project - Stabilized Office Property | San Diego, CA and Austin, Texas
Real Estate Properties [Line Items]
Number of development projects added during the period | development_project	2
Number of buildings | building	2
Rentable square feet | ft²	829,591

Basis of Presentation and Sig_4

Basis of Presentation and Significant Accounting Policies - Narrative (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) development_site variableInterestEntity property property_partnership segment investment	Dec. 31, 2022 USD ($) property investment variableInterestEntity	Dec. 31, 2021 USD ($)
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Assets	$ 11,401,045,000	$ 10,796,987,000
Liabilities	5,741,352,000	5,122,026,000
Noncontrolling interest in consolidated subsidiary	$ 178,257,000	$ 184,390,000
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	$ 300,100,000	$ 287,800,000	$ 256,300,000
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
Stabilized Office Properties | Texas
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of buildings | property	1
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
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	$ 416,700,000	$ 438,700,000
Liabilities	23,600,000	31,500,000
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	173,700,000	179,400,000
Variable Interest Entity, Primary Beneficiary | Real estate investment
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Assets	$ 350,000,000	$ 362,700,000

Acquisitions - Operating Proper

Acquisitions - Operating Property and Development Project Acquisitions (Details) - Development properties - USD ($) $ in Millions		12 Months Ended
	Mar. 09, 2022	Dec. 31, 2022
Schedule of Asset Acquisitions, by Acquisition [Line Items]
Purchase price		$ 40
10615 Burnet Road, Austin, TX
Schedule of Asset Acquisitions, by Acquisition [Line Items]
Purchase price	$ 40

Acquisitions - Narrative (Detai

Acquisitions - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Business Combination and Asset Acquisition [Abstract]
Acquisition costs, capitalized	$ 0	$ 0.2

Dispositions - Operating Proper

Dispositions - Operating Property Dispositions (Details) $ in Thousands	1 Months Ended			12 Months Ended
	Aug. 31, 2022 USD ($) ft² building	Dec. 31, 2021 USD ($) ft² building	Mar. 31, 2021 USD ($) ft² building	Dec. 31, 2023 USD ($) ft²	Dec. 31, 2022 USD ($) ft² building	Dec. 31, 2021 USD ($) ft² building
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Rentable square feet | ft²				17,044,128
Gains on sales of operating properties | $				$ 0	$ 17,329	$ 463,128
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 | building					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 | building	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 | building		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 | building			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 | building		2				2
Rentable square feet | ft²		102,376				102,376
Sales price | $		$ 37,000

Marketable Securities (Details)

Marketable Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Deferred compensation plan assets	$ 28,089	$ 23,547
Certificates of deposit	256,581	0
Total marketable securities	$ 284,670	$ 23,547

Receivables - Current Receivabl

Receivables - Current Receivables and Deferred Rent Receivables (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current Receivables, net
Current receivables	$ 15,176	$ 22,816
Allowance for uncollectible tenant receivables	(1,567)	(2,233)
Current receivables, net	13,609	20,583
Deferred Rent Receivables, net
Deferred rent receivables	461,707	453,165
Allowance for deferred rent receivables	(728)	(965)
Deferred rent receivables, net	$ 460,979	$ 452,200

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, 2023	Dec. 31, 2022
Deferred Leasing Costs and Acquisition-related Intangible Assets, net:
Total deferred leasing costs and acquisition-related intangible assets, net	$ 229,705	$ 250,846
Acquisition-related Intangible Liabilities, net:
Below-market operating leases	39,159	52,380
Accumulated amortization	(8,402)	(14,943)
Acquisition-related intangible liabilities, net	30,757	37,437
Total acquisition-related intangible liabilities, net	30,757	37,437
Deferred Leasing Costs
Deferred Leasing Costs and Acquisition-related Intangible Assets, net:
Finite-lived intangible assets, gross	297,871	301,967
Accumulated amortization	(122,680)	(121,545)
Finite-lived intangible assets, net	175,191	180,422
Above-market operating leases
Deferred Leasing Costs and Acquisition-related Intangible Assets, net:
Finite-lived intangible assets, gross	260	260
Accumulated amortization	(70)	(39)
Finite-lived intangible assets, net	190	221
In-Place Leases
Deferred Leasing Costs and Acquisition-related Intangible Assets, net:
Finite-lived intangible assets, gross	70,247	114,435
Accumulated amortization	(15,923)	(44,232)
Finite-lived intangible assets, net	$ 54,324	$ 70,203

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, 2023	Dec. 31, 2022	Dec. 31, 2021
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	$ 41,001	$ 52,229	$ 40,130
Estimated annual amortization related to acquisition-related intangible liabilities
Below-market operating leases, 2024	(3,588)
Below-market operating leases, 2025	(3,570)
Below-market operating leases, 2026	(3,474)
Below-market operating leases, 2027	(3,099)
Below-market operating leases, 2028	(2,918)
Below-market operating leases, thereafter	(14,108)
Below-market operating leases	(30,757)	(37,437)
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	31,771	31,059	32,472
Estimated annual amortization related to acquisition-related intangible assets
Finite-lived intangible assets, 2024	29,855
Finite-lived intangible assets, 2025	27,019
Finite-lived intangible assets, 2026	23,974
Finite-lived intangible assets, 2027	20,864
Finite-lived intangible assets, 2028	18,824
Finite-lived intangible assets, thereafter	54,655
Finite-lived intangible assets, net	175,191	180,422
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	31	8
Estimated annual amortization related to acquisition-related intangible assets
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, 2028	31
Finite-lived intangible assets, thereafter	35
Finite-lived intangible assets, net	190	221
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	15,878	31,647	14,562
Estimated annual amortization related to acquisition-related intangible assets
Finite-lived intangible assets, 2024	6,676
Finite-lived intangible assets, 2025	6,635
Finite-lived intangible assets, 2026	6,311
Finite-lived intangible assets, 2027	5,040
Finite-lived intangible assets, 2028	5,014
Finite-lived intangible assets, thereafter	24,648
Finite-lived intangible assets, net	54,324	70,203
Below-market operating leases
Amortization for the period related to deferred leasing costs and acquisition-related intangibles
Amortization of intangible liabilities	$ (6,679)	$ (10,508)	$ (6,912)

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, 2023	Dec. 31, 2022
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Furniture, fixtures and other long-lived assets, net	$ 37,073	$ 41,538
Prepaid expenses and deferred financing costs, net	10,532	11,364
Other assets	5,464	9,527
Total prepaid expenses and other assets, net	$ 53,069	$ 62,429

Secured and Unsecured Debt of_4

Secured and Unsecured Debt of the Company (Details) $ in Thousands	Dec. 31, 2023 USD ($) debt_covenant	Dec. 31, 2022 USD ($)
Debt Instrument [Line Items]
Secured debt	$ 603,225	$ 242,938
Number of debt covenants impacting payment of dividends during event of default | debt_covenant	1
Unsecured debt
Debt Instrument [Line Items]
Long-term debt	$ 4,300,000	$ 4,000,000

Secured and Unsecured Debt of_5

Secured and Unsecured Debt of the Operating Partnership - Secured Debt and Additional Information (Details)	1 Months Ended	12 Months Ended
	Oct. 31, 2022 USD ($) extension_option	Dec. 31, 2023 USD ($) extension_option	Dec. 31, 2022 USD ($) extension_option	Dec. 31, 2021 USD ($)	Jul. 31, 2023 USD ($) ft² apartment_unit office_building	Mar. 31, 2023 USD ($)	Jan. 31, 2023 USD ($)
Debt Instrument [Line Items]
Net proceeds from the issuance of unsecured debt (Note 10)		$ 0	$ 0	$ 449,807,000
Secured Debt
Secured debt		603,225,000	242,938,000
Term Loan
Debt Instrument [Line Items]
Line of credit facility, accordion feature, higher borrowing capacity option							$ 100,000,000
Line of credit facility, maximum borrowing capacity							$ 650,000,000
Line of credit facility, additional borrowing capacity						$ 20,000,000
Unsecured debt
Secured Debt
Total secured debt, net		4,300,000,000	4,000,000,000
Unsecured debt | Unsecured Term Loan Facility
Debt Instrument [Line Items]
Principal amount of debt	$ 400,000,000
Net proceeds from the issuance of unsecured debt (Note 10)	$ 200,000,000
Number of extension options | extension_option	2
Extension period (in months)	12 months
Kilroy Realty L.P.
Debt Instrument [Line Items]
Number of buildings | office_building					2
Number of apartment units | apartment_unit					608
Area of Retail (in square feet) | ft²					95,000
Net proceeds from the issuance of unsecured debt (Note 10)		0	0	$ 449,807,000
Secured Debt
Long-term debt, gross		4,961,406,000
Secured debt		603,225,000	242,938,000
Kilroy Realty L.P. | 3.57% Mortgage Payable due December 2026
Secured Debt
Long-term debt, gross		156,400,000
Kilroy Realty L.P. | 5.90% Mortgage Payable due August 2034
Secured Debt
Long-term debt, gross		375,000,000
Kilroy Realty L.P. | Secured debt
Secured Debt
Secured debt		612,694,000	243,469,000
Unamortized deferred financing costs		(9,469,000)	(531,000)
Total secured debt, net		603,225,000	242,938,000
Net book value of properties pledged as collateral for secured debt		$ 817,300,000
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		$ 156,386,000	159,973,000
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		$ 81,308,000	83,496,000
Kilroy Realty L.P. | Secured debt | 5.90% Mortgage Payable due August 2034
Debt Instrument [Line Items]
Principal amount of debt					$ 375,000,000
Secured Debt
Stated interest rate		5.90%			5.90%
Effective interest rate		5.90%
Long-term debt, gross		$ 375,000,000	$ 0
Kilroy Realty L.P. | Unsecured debt | Unsecured Term Loan Facility
Debt Instrument [Line Items]
Principal amount of debt						$ 520,000,000
Number of extension options | extension_option		2	2
Extension period (in months)		12 months	12 months
Secured Debt
Total secured debt, net		$ 520,000,000
Kilroy Realty L.P. | Unsecured debt | Unsecured Term Loan Facility | Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Basis spread on SOFR and LIBOR	0.95%
Kilroy Realty L.P. | Line of credit | Unsecured Term Loan Facility
Debt Instrument [Line Items]
Contingent additional borrowings	$ 100,000,000	130,000,000	$ 100,000,000
Line of credit facility, maximum borrowing capacity		520,000,000	400,000,000
Secured Debt
Unamortized deferred financing costs		$ (2,300,000)	$ (4,500,000)
Kilroy Realty L.P. | Line of credit | Unsecured Term Loan Facility | Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Basis spread on SOFR and LIBOR		0.95%	0.95%

Secured and Unsecured Debt of_6

Secured and Unsecured Debt of the Operating Partnership - Unsecured Senior Notes - Registered Offerings and Private Placement (Details) - USD ($)	1 Months Ended	12 Months Ended
	Oct. 31, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Jan. 12, 2024
Debt Instrument [Line Items]
Loss on early extinguishment of debt		$ 0	$ 0	$ 12,246,000
Repurchases of unsecured debt		20,584,000	0	0
Kilroy Realty L.P.
Debt Instrument [Line Items]
Loss on early extinguishment of debt		0	$ 0	$ 12,246,000
Long-term debt, gross		$ 4,961,406,000
Kilroy Realty L.P. | Unsecured debt | 3.800% Unsecured Senior Notes Due 2023
Debt Instrument [Line Items]
Stated interest rate	3.80%
Debt redemption, principal amount	$ 300,000,000
Loss on early extinguishment of debt	(12,200,000)
Premium paid to the note holders at the redemption date	12,100,000
Write-off of unamortized discount and unamortized deferred financing costs	$ 100,000
Kilroy Realty L.P. | Unsecured debt | 3.450% Unsecured Senior Notes Due 2024
Debt Instrument [Line Items]
Stated interest rate		3.45%
Repurchases of unsecured debt		$ 21,300,000
Principal amount of debt		425,000,000
Long-term debt, gross		$ 403,712,000
Kilroy Realty L.P. | Unsecured debt | 6.250% Unsecured Senior Notes Due 2036 | Subsequent event
Debt Instrument [Line Items]
Stated interest rate					6.25%
Principal amount of debt					$ 400,000,000

Secured and Unsecured Debt of_7

Secured and Unsecured Debt of the Operating Partnership - Unsecured Senior Notes (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Unsecured debt, net	$ 4,325,153	$ 4,020,058
Unsecured debt | Unsecured Senior Notes
Debt Instrument [Line Items]
Unamortized discount (premium), net	5,300	6,400
Unamortized debt issuance expense	15,900	19,100
Kilroy Realty L.P.
Debt Instrument [Line Items]
Long-term debt, gross	4,961,406
Unsecured debt, net	4,325,153	4,020,058
Kilroy Realty L.P. | Unsecured debt
Debt Instrument [Line Items]
Unsecured debt, net	$ 3,807,495	3,824,581
Kilroy Realty L.P. | Unsecured debt | 2.650% Unsecured Senior Notes
Debt Instrument [Line Items]
Stated coupon rate	2.65%
Effective interest rate	2.654%
Long-term debt, gross	$ 450,000	450,000
Unamortized discount and deferred financing costs	(3,422)	(3,770)
Unsecured debt, net	$ 446,578	446,230
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	(4,735)	(5,268)
Unsecured debt, net	$ 420,265	419,732
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	(1,282)	(1,463)
Unsecured debt, net	$ 348,718	348,537
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	(3,629)	(4,221)
Unsecured debt, net	$ 496,371	495,779
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	(2,468)	(2,963)
Unsecured debt, net	$ 397,532	397,037
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	(488)	(663)
Unsecured debt, net	$ 199,512	199,337
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	(113)	(157)
Unsecured debt, net	$ 49,887	49,843
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	$ 403,712
Unamortized discount and deferred financing costs	(558)	(1,148)
Unsecured debt, net	$ 403,154	423,852
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	(219)	(262)
Unsecured debt, net	$ 74,781	74,738
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	(363)	(478)
Unsecured debt, net	$ 174,637	174,522
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	(969)	(1,523)
Unsecured debt, net	$ 399,031	398,477
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	(2,971)	(3,503)
Unsecured debt, net	$ 397,029	$ 396,497

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 ($) extension_option	Dec. 31, 2023 USD ($) extension_option	Dec. 31, 2022 USD ($) extension_option	Dec. 31, 2021 USD ($)	Mar. 31, 2023 USD ($)
Debt Instrument [Line Items]
Proceeds from the issuance of unsecured debt		$ 0	$ 0	$ 449,807,000
Kilroy Realty L.P.
Debt Instrument [Line Items]
Proceeds from the issuance of unsecured debt		0	0	$ 449,807,000
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
Number of extension options | extension_option		2	2
Extension period (in months)		6 months	6 months
Contingent additional borrowings		$ 500,000,000	$ 500,000,000
Revolving credit facility | Kilroy Realty L.P. | Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Variable rate (percent)		0.90%	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	2
Extension period (in months)		12 months	12 months
Principal amount of debt					$ 520,000,000
Unsecured debt | Kilroy Realty L.P. | Unsecured Term Loan Facility | Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Variable rate (percent)	0.95%
Line of credit | Kilroy Realty L.P. | Unsecured Term Loan Facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 520,000,000	$ 400,000,000
Contingent additional borrowings	$ 100,000,000	$ 130,000,000	$ 100,000,000
Line of credit | Kilroy Realty L.P. | Unsecured Term Loan Facility | Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Variable rate (percent)		0.95%	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.	12 Months Ended
	Dec. 31, 2023 USD ($) extension_option	Dec. 31, 2022 USD ($) extension_option	Oct. 31, 2022 USD ($)
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
Interest rate	6.38%	5.20%
Facility fee-annual rate (percent)	0.20%	0.20%
Outstanding letters of credit	$ 5,200,000
Contingent additional borrowings	$ 500,000,000	$ 500,000,000
Debt instrument, reduction interest rate	0.01%	0.01%
Unamortized debt issuance expense	$ 3,200,000	$ 5,300,000
Number of extension options | extension_option	2	2
Extension period (in months)	6 months	6 months
Revolving credit facility | Secured Overnight Financing Rate (SOFR)
Terms of the Credit Facility
Basis spread on SOFR and LIBOR	0.90%	0.90%
Term loan facility | Unsecured Term Loan Facility
Terms of the Credit Facility
Outstanding borrowings	$ 520,000,000	$ 200,000,000
Remaining borrowing capacity	0	200,000,000
Total borrowing capacity	$ 520,000,000	$ 400,000,000
Interest rate	6.41%	5.23%
Undrawn facility fee-annual rate	0.20%	0.20%
Contingent additional borrowings	$ 130,000,000	$ 100,000,000	$ 100,000,000
Unamortized debt issuance expense	$ 2,300,000	$ 4,500,000
Term loan facility | Unsecured Term Loan Facility | Secured Overnight Financing Rate (SOFR)
Terms of the Credit Facility
Basis spread on SOFR and LIBOR	0.95%	0.95%
Revolving Credit Facility and Term Loan Facility | Adjusted SOFR
Terms of the Credit Facility
Basis spread on SOFR and LIBOR	0.10%	0.10%

Secured and Unsecured Debt o_10

Secured and Unsecured Debt of the Operating Partnership - Debt Covenants and Restrictions (Details)	Dec. 31, 2023 debt_covenant
Kilroy Realty L.P.
Debt Instrument [Line Items]
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, 2023 USD ($) extension_option	Dec. 31, 2022 USD ($) extension_option
Unsecured debt
Stated debt maturities and scheduled amortization payments, excluding debt discounts
Long-term debt		$ 4,300,000	$ 4,000,000
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
2024		929,718
2025		406,246
2026		401,317
2027		249,125
2028		400,000
Thereafter		2,575,000
Total aggregate principal value		4,961,406
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		27,700
Kilroy Realty L.P. | Unsecured senior notes
Stated debt maturities and scheduled amortization payments, excluding debt discounts
Unamortized discount		5,300
Kilroy Realty L.P. | Unsecured Term Loan Facility | Unsecured debt
Stated debt maturities and scheduled amortization payments, excluding debt discounts
Long-term debt		$ 520,000
Number of extension options | extension_option		2	2
Extension period (in months)		12 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, 2023	Dec. 31, 2022	Dec. 31, 2021
Capitalized Interest and Loan Fees [Line Items]
Interest expense	$ 114,216	$ 84,278	$ 78,555
Kilroy Realty L.P.
Capitalized Interest and Loan Fees [Line Items]
Gross interest expense	192,983	161,761	158,756
Capitalized interest and deferred financing costs	(78,767)	(77,483)	(80,201)
Interest expense	$ 114,216	$ 84,278	$ 78,555

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, 2023	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Deferred revenue related to tenant-funded tenant improvements	$ 97,802	$ 111,453
Other deferred revenue	45,079	47,069
Acquisition-related intangible liabilities, net	30,757	37,437
Deferred revenue and acquisition-related intangible liabilities, net	$ 173,638	$ 195,959

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, 2023	Dec. 31, 2022	Dec. 31, 2021
Deferred Revenue, Future Amortization Recognized By Year [Abstract]
Total	$ 97,802	$ 111,453
Tenant funded tenant improvements
Disaggregation of Revenue [Line Items]
Deferred revenues amortized and recognized as rental income	20,700	$ 19,300	$ 16,500
Deferred Revenue, Future Amortization Recognized By Year [Abstract]
2024	17,299
2025	14,280
2026	12,390
2027	11,136
2028	9,764
Thereafter	32,933
Total	$ 97,802

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, 2023 USD ($) trading_day $ / shares shares	Dec. 31, 2022 USD ($) trading_day $ / shares shares	Aug. 30, 2016 rEITSubsidiary company
Noncontrolling Interest [Line Items]
Conversion ratio	1
Common stock, par value ( in 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	$ 47,000	$ 44,700
Noncontrolling interest in consolidated subsidiary	$ 178,257	$ 184,390
Non-Affiliated Investors and Certain Executive Officer and Directors | Common Units
Noncontrolling Interest [Line Items]
Noncontrolling common units ( in shares ) | shares	1,150,574	1,150,574
Kilroy Realty L.P. | Common Units
Noncontrolling Interest [Line Items]
Conversion ratio	1
Kilroy Realty L.P. | Common Units
Noncontrolling Interest [Line Items]
Noncontrolling common units ( in shares ) | shares	1,150,574	1,150,574
Operating Partnership
Noncontrolling Interest [Line Items]
Ownership interest (percent)	99%	99%
Operating Partnership | Non-Affiliated Investors and Certain Executive Officer and Directors
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	$ 173,700	$ 179,400
Redwood LLC
Noncontrolling Interest [Line Items]
Noncontrolling interest in consolidated subsidiary	$ 4,600	$ 5,000

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) - shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Equity [Abstract]
Stock repurchase program, number of shares authorized to be repurchased (in shares)	4,935,826
Stock repurchased during period (in shares)	0	0	0

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, 2023	Dec. 31, 2022
Dividends and Distributions payable to:
Accrued distributions (Notes 15 and 26)	$ 64,440	$ 64,285
Outstanding Shares and Units:
Common stock (in shares)	117,239,558	116,878,031
Restricted Stock Units (RSUs)
Outstanding Shares and Units:
RSUs (in shares)	908,336	984,006
Kilroy Realty L.P.
Dividends and Distributions payable to:
Accrued distributions (Notes 15 and 26)	$ 64,440	$ 64,285
Kilroy Realty L.P. | Restricted Stock Units (RSUs)
Dividends and Distributions payable to:
Accrued distributions (Notes 15 and 26)	$ 510	$ 550
Kilroy Realty L.P. | Market measure-based Restricted Stock Units (RSUs)
Outstanding Shares and Units:
Number of RSUs outstanding (in shares)	1,083,086	1,123,554
Kilroy Realty L.P. | Common Units
Outstanding Shares and Units:
Noncontrolling common units ( in shares )	1,150,574	1,150,574
Noncontrolling common units | Common Units
Outstanding Shares and Units:
Noncontrolling common units ( in shares )	1,150,574	1,150,574
Common stockholders and noncontrolling unitholders
Dividends and Distributions payable to:
Accrued distributions (Notes 15 and 26)	$ 64,440	$ 64,285
Common stockholders
Dividends and Distributions payable to:
Accrued distributions (Notes 15 and 26)	$ 63,309	$ 63,114
Outstanding Shares and Units:
Common stock (in shares)	117,239,558	116,878,031
Common Units
Dividends and Distributions payable to:
Accrued distributions (Notes 15 and 26)	$ 621	$ 621

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, 2023	Dec. 31, 2022
Accrued distributions
Accrued distributions (Notes 15 and 26)	$ 64,440	$ 64,285
Operating Partnership
General Partners' Capital Account
Ownership interest (percent)	99%	99%
Kilroy Realty L.P.
Accrued distributions
Accrued distributions (Notes 15 and 26)	$ 64,440	$ 64,285
Kilroy Realty L.P. | Restricted Stock Units (RSUs)
Accrued distributions
Accrued distributions (Notes 15 and 26)	$ 510	$ 550
RSUs (in shares)	908,336	984,006
Kilroy Realty L.P. | Market measure-based Restricted Stock Units (RSUs)
Accrued distributions
Number of RSUs outstanding (in shares)	1,083,086	1,123,554
Kilroy Realty L.P. | Partners’ Capital
Accrued distributions
Accrued distributions (Notes 15 and 26)	$ 64,440	$ 64,285
Kilroy Realty L.P. | Partners capital general partner
Accrued distributions
Accrued distributions (Notes 15 and 26)	63,309	63,114
Kilroy Realty L.P. | Partners capital limited partner
Accrued distributions
Accrued distributions (Notes 15 and 26)	$ 621	$ 621
Non-Affiliated Investors | Operating Partnership
General Partners' Capital Account
Ownership interest (percent)	1%	1%
Common Units | Kilroy Realty L.P.
General Partners' Capital Account
Company owned common units in the Operating Partnership (in shares)	117,239,558	116,878,031
Non-affiliated investors and other common units of the Operating Partnership (in shares)	1,150,574	1,150,574
Common Units | 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, 2023 compensation_plan shares
Share-Based Payment Arrangement [Abstract]
Number of share-based incentive compensation plans | compensation_plan	1
Effective registration shares (in shares)	12.6
Number of shares available for grant (in shares)	2.8

Share-Based and Other Compens_4

Share-Based and Other Compensation - (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)
Chief Executive Officer and Former President
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation expense related to accelerated	$ 27.3

Share-Based and Other Compens_5

Share-Based and Other Compensation - Annual Performance-Based RSU Grants (Details) $ / shares in Units, $ in Millions				12 Months Ended
	Feb. 06, 2023 USD ($) $ / shares shares	Jan. 28, 2022 USD ($) $ / shares shares	Feb. 18, 2021 USD ($) $ / shares shares	Dec. 31, 2023 participant	Dec. 31, 2022	Dec. 31, 2021
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
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 shares issuable per RSU				1
2023 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
Fair value per share on valuation date ( in dollars per share) | $ / shares	$ 40.10
Expected share price volatility	35%
Risk-free interest rate	4.12%
2023 Performance-Based RSUs | One Participant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value per share on valuation date ( in dollars per share) | $ / shares	$ 40.43
2023 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	300,007
2023 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	570,006
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 ( in 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 ( in 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		406,319
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				262.50%
Performance-based RSUs achievement target, all other participants, percent				200%
Fair value on valuation date | $			$ 10.6
Fair value per share on valuation date ( in 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 ( in 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 RSUs earned
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Estimated RSUs earned (in shares) | shares			401,580

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, 2023	Dec. 31, 2022	Dec. 31, 2021
Market measure-based Restricted Stock Units (RSUs)
Weighted-Average Fair Value Per Share
Outstanding beginning balance ( in dollars per share)	$ 66.85
Granted ( in dollars per share)	39.65
Vested (in dollars per share)	76.67
Issuance of dividend equivalents ( in dollars per share)	32.98
Canceled (in dollars per share)	61
Outstanding ending balance (in dollars per share)	$ 52.47	$ 66.85
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)	1,123,554
Granted (in shares)	483,113	310,484	281,333
Vested (in shares)	230,741
Issuance of dividend equivalents (in shares)	67,122
Canceled (in shares)	(359,962)
Number of RSUs outstanding, ending balance (in shares)	1,083,086	1,123,554
Weighted-Average Fair Value Per Share
Granted ( in dollars per share)	$ 39.65	$ 63.05	$ 57.85
Vested Restricted Stock Units RSU
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Vested (in shares)	290,570	241,184	252,098
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)	29,705
Granted (in shares)	53,537
Vested (in shares)	230,741
Settled (in shares)	(296,688)
Issuance of dividend equivalents (in shares)	6,292
Canceled (in shares)	(4)
Vested RSUs, ending balance (in shares)	23,583	29,705
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)	1,153,259
Granted (in shares)	536,650
Vested (in shares)	0
Settled (in shares)	(296,688)
Issuance of dividend equivalents (in shares)	73,414
Canceled (in shares)	(359,966)
Total RSUs, ending balance (in shares)	1,106,669	1,153,259
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)	144,178

Share-Based and Other Compens_7

Share-Based and Other Compensation - Market-Measure Based RSUs (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Vested RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested (in shares)	(290,570)	(241,184)	(252,098)
Market measure-based Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value per share on valuation date ( in dollars per share)	$ 39.65
Market measure-based Restricted Stock Units (RSUs) | Nonvested Restricted Stock Units RSU
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	483,113	310,484	281,333
Fair value per share on valuation date ( in dollars per share)	$ 39.65	$ 63.05	$ 57.85
Vested (in shares)	(230,741)
Market measure-based Restricted Stock Units (RSUs) | Vested RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	53,537
Vested (in shares)	(230,741)
Total Fair Value at Vest Date	$ 11,105	$ 15,200	$ 14,299

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
	Feb. 06, 2023 USD ($) $ / shares shares	Jan. 28, 2022 USD ($) $ / shares shares	Feb. 28, 2021 USD ($) $ / shares shares	Dec. 31, 2023 installment shares
Time-Based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				3 years
Number of installments | installment				3
Right to receive number of shares (in shares)				1
RSUs granted | Executive officer share-based compensation programs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	217,059	158,170	160,277
Fair value on valuation date | $	$ 8.6	$ 10	$ 9.1
Weighted average fair value per share (in dollars per share) | $ / shares	$ 39.65	$ 63.05	$ 57.07

Share-Based and Other Compens_9

Share-Based and Other Compensation - Summary of Time-Based RSUs (Details) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Vested RSUs
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Vested (in shares)	(290,570)	(241,184)	(252,098)
RSUs granted | 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)	443,367
Granted (in shares)	247,017
Vested (in shares)	(305,653)
Issuance of dividend equivalents (in shares)	22,383
Forfeited (in shares)	(5,804)
Number of RSUs outstanding, ending balance (in shares)	401,310	443,367
Weighted Average Fair Value Per Share
Outstanding beginning balance ( in dollars per share)	$ 61.27
Granted ( in dollars per share)	38.12
Vested (in dollars per share)	63.49
Issuance of dividend equivalents ( in dollars per share)	32.13
Forfeited (in dollars per share)	50.39
Outstanding ending balance (in dollars per share)	$ 43.86	$ 61.27
RSUs granted | 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)	510,934
Granted (in shares)	0
Vested (in shares)	(305,653)
Settled (in shares)	(368,717)
Issuance of dividend equivalents (in shares)	37,681
Forfeited (in shares)	0
Canceled (in shares)	(2,108)
Vested RSUs, ending balance (in shares)	483,443	510,934
RSUs granted | 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)	(161,731)
RSUs granted | 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)	954,301
Granted (in shares)	247,017
Vested (in shares)	0
Settled (in shares)	(368,717)
Issuance of dividend equivalents (in shares)	60,064
Forfeited (in shares)	(5,804)
Canceled (in shares)	(2,108)
Total RSUs, ending balance (in shares)	884,753	954,301

Share-Based and Other Compen_10

Share-Based and Other Compensation - Time-Based RSUs (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Vested Restricted Stock Units RSU
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested (in shares)	(290,570)	(241,184)	(252,098)
Restricted Stock Units (RSUs) | Nonvested Restricted Stock Units RSU
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	247,017	177,099	172,181
Fair value per share on valuation date ( in dollars per share)	$ 38.12	$ 62.58	$ 57.83
Restricted Stock Units (RSUs) | Vested Restricted Stock Units RSU
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested (in shares)	(343,334)	(294,867)	(144,838)
Total Fair Value at Vest Date	$ 12,425	$ 19,890	$ 8,605

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, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 43.7	$ 34.8	$ 41
Share-based compensation expense capitalized	6.9	$ 6.4	$ 7.2
Share-based compensation not yet recognized	$ 18.2
Share-based compensation not yet recognized period of recognition	1 year 7 months 6 days
Severance
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 27.3

Employee Benefit Plans (Details

Employee Benefit Plans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
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	$ 1,700,000	$ 1,600,000	$ 1,500,000
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	$ 25,000,000	$ 23,400,000

Rental Income and Future Mini_3

Rental Income and Future Minimum Rent - Rental income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Fixed lease payments	$ 944,618	$ 923,257
Variable lease payments	184,672	162,638
Net collectability recoveries (reversals)	(11,553)	123
Total rental income	$ 1,117,737	$ 1,086,018	$ 948,994

Rental Income and Future Mini_4

Rental Income and Future Minimum Rent - Future Contractual Minimum Rent (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Future contractual minimum rent under operating lease
2024	$ 806,250
2025	800,821
2026	755,071
2027	698,993
2028	658,993
Thereafter	2,042,634
Total	$ 5,762,762

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) ground_lease	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Long-term Purchase Commitment [Line Items]
Commitments for contracts and executed leases, operating and redevelopment and development properties	$ 335.9
Weighted average discount rate	4.65%
Weighted average remaining lease term	63 years
Variable lease, cost	$ 4	$ 3.6	$ 2.6
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration]	consolidated balance sheet
Environmental matters
Long-term Purchase Commitment [Line Items]
Accrued environmental remediation liabilities	$ 76.6	$ 80.5
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, 2023	Dec. 31, 2022
Minimum commitment under our ground leases
2024	$ 6,737
2025	6,773
2026	6,810
2027	6,851
2028	6,870
Thereafter	363,350
Total undiscounted cash flows	397,391
Present value discount	(273,038)
Ground lease liabilities	$ 124,353	$ 124,994
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, 2023	Dec. 31, 2022
Fair value, measurements, recurring | Fair Value (Level 1)
Assets and Liabilities Reported at Fair Value
Deferred compensation plan assets	$ 28,089	$ 23,547

Fair Value Measurements and D_4

Fair Value Measurements and Disclosures - Financial Instruments Disclosed at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Carrying Value | Secured debt, net
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of debt, net	$ 603,225	$ 242,938
Carrying Value | Unsecured debt, net
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of debt, net	4,325,153	4,020,058
Carrying Value | Certificates of Deposit
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value	256,581	0
Fair value | Secured debt, net | Fair value (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of debt, net	585,826	225,847
Fair value | Unsecured debt, net | Fair value (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of debt, net	3,927,104	3,500,420
Fair value | Certificates of Deposit
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value	$ 256,581	$ 0

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, 2023	Dec. 31, 2022	Dec. 31, 2021
Numerator:
Net income available to common stockholders	$ 212,241	$ 232,615	$ 628,144
Allocation to participating securities	(1,233)	(1,272)	(1,516)
Numerator for basic and diluted net income available to common stockholders	$ 211,008	$ 231,343	$ 626,628
Denominator:
Basic weighted average vested shares outstanding (in shares)	117,160,173	116,806,575	116,429,130
Effect of dilutive securities (in shares)	346,082	413,472	519,513
Diluted weighted average vested shares and common stock/ unit equivalents outstanding (in shares)	117,506,255	117,220,047	116,948,643
Basic earnings per share:
Net income available to common stockholders per share - basic ( in dollars per share)	$ 1.80	$ 1.98	$ 5.38
Diluted earnings per share:
Net income available to common stockholders per share - diluted (in dollars per share)	$ 1.80	$ 1.97	$ 5.36

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, 2023	Dec. 31, 2022	Dec. 31, 2021
Numerator:
Net income available to common unitholders	$ 212,241	$ 232,615	$ 628,144
Allocation to participating securities	(1,233)	(1,272)	(1,516)
Numerator for basic and diluted net income available to common unitholders	$ 211,008	$ 231,343	$ 626,628
Denominator:
Basic weighted average vested units outstanding (in shares)	117,160,173	116,806,575	116,429,130
Effect of dilutive securities (in shares)	346,082	413,472	519,513
Diluted weighted average vested shares and common stock/ unit equivalents outstanding (in shares)	117,506,255	117,220,047	116,948,643
Basic earnings per unit:
Net income available to common unitholders per unit (in dollars per share)	$ 1.80	$ 1.98	$ 5.38
Diluted earnings per unit:
Net income available to common unitholders per unit (in dollars per share)	$ 1.80	$ 1.97	$ 5.36
Kilroy Realty L.P.
Numerator:
Net income available to common unitholders	$ 214,324	$ 234,898	$ 634,307
Allocation to participating securities	(1,233)	(1,272)	(1,516)
Numerator for basic and diluted net income available to common unitholders	$ 213,091	$ 233,626	$ 632,791
Denominator:
Basic weighted average vested units outstanding (in shares)	118,310,747	117,957,149	117,579,704
Effect of dilutive securities (in shares)	346,082	413,472	519,513
Diluted weighted average vested shares and common stock/ unit equivalents outstanding (in shares)	118,656,829	118,370,621	118,099,217
Basic earnings per unit:
Net income available to common unitholders per unit (in dollars per share)	$ 1.80	$ 1.98	$ 5.38
Diluted earnings per unit:
Net income available to common unitholders per unit (in dollars per share)	$ 1.80	$ 1.97	$ 5.36

Supplemental Cash Flow Inform_5

Supplemental Cash Flow Information of the Company - Supplemental Cash Flow (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
SUPPLEMENTAL CASH FLOWS INFORMATION:
Capitalized interest	$ 74,052	$ 72,973	$ 75,802
Cash paid for interest, net of capitalized interest of $74,052, $72,973, and $75,802 as of December 31, 2023, 2022 and 2021, respectively	105,767	79,634	77,028
Cash paid for amounts included in the measurement of ground lease liabilities	6,733	6,447	6,209
NON-CASH INVESTING TRANSACTIONS:
Accrual for expenditures for operating properties and development and redevelopment properties	95,575	97,729	119,829
Tenant improvements funded directly by tenants	7,364	6,772	20,070
Assumption of accrued liabilities in connection with acquisitions	0	0	37,572
Initial measurement of operating right of use ground lease assets (Note 19)	0	0	46,430
Initial measurement of operating ground lease liabilities (Note 19)	0	0	46,430
NON-CASH FINANCING TRANSACTIONS:
Accrual of dividends and distributions payable to common stockholders and common unitholders (Notes 14 and 26)	$ 64,440	$ 64,285	$ 61,850

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, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH:
Cash and cash equivalents	$ 510,163	$ 347,379	$ 414,077	$ 731,991
Restricted cash	0	0	13,006	91,139
Cash and cash equivalents and restricted cash	$ 510,163	$ 347,379	$ 427,083	$ 823,130

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, 2023	Dec. 31, 2022	Dec. 31, 2021
SUPPLEMENTAL CASH FLOWS INFORMATION:
Capitalized interest	$ 74,052	$ 72,973	$ 75,802
Cash paid for interest, net of capitalized interest of $74,052, $72,973, and $75,802 as of December 31, 2023, 2022 and 2021, respectively	105,767	79,634	77,028
Cash paid for amounts included in the measurement of ground lease liabilities	6,733	6,447	6,209
NON-CASH INVESTING TRANSACTIONS:
Accrual for expenditures for operating properties and development and redevelopment properties	95,575	97,729	119,829
Tenant improvements funded directly by tenants	7,364	6,772	20,070
Assumption of accrued liabilities in connection with acquisitions	0	0	37,572
Initial measurement of operating right of use ground lease assets (Note 19)	0	0	46,430
Initial measurement of operating ground lease liabilities (Note 19)	0	0	46,430
NON-CASH FINANCING TRANSACTIONS:
Accrual of distributions payable to common unitholders (Notes 15 and 26)	64,440	64,285	61,850
Kilroy Realty L.P.
SUPPLEMENTAL CASH FLOWS INFORMATION:
Capitalized interest	74,052	72,973	75,802
Cash paid for interest, net of capitalized interest of $74,052, $72,973, and $75,802 as of December 31, 2023, 2022 and 2021, respectively	105,767	79,634	77,028
Cash paid for amounts included in the measurement of ground lease liabilities	6,733	6,447	6,209
NON-CASH INVESTING TRANSACTIONS:
Accrual for expenditures for operating properties and development and redevelopment properties	95,575	97,729	119,829
Tenant improvements funded directly by tenants	7,364	6,772	20,070
Assumption of accrued liabilities in connection with acquisitions	0	0	37,572
Initial measurement of operating right of use ground lease assets (Note 19)	0	0	46,430
Initial measurement of operating ground lease liabilities (Note 19)	0	0	46,430
NON-CASH FINANCING TRANSACTIONS:
Accrual of distributions payable to common unitholders (Notes 15 and 26)	$ 64,440	$ 64,285	$ 61,850

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, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH:
Cash and cash equivalents	$ 510,163	$ 347,379	$ 414,077	$ 731,991
Restricted cash	0	0	13,006	91,139
Cash and cash equivalents and restricted cash	510,163	347,379	427,083	823,130
Kilroy Realty L.P.
RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH:
Cash and cash equivalents	510,163	347,379	414,077	731,991
Restricted cash	0	0	13,006	91,139
Cash and cash equivalents and restricted cash	$ 510,163	$ 347,379	$ 427,083	$ 823,130

Tax Treatment of Distribution_2

Tax Treatment of Distributions - Dividends (Details) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Class of Stock [Line Items]
Dividends declared per share of common stock ( in dollars per share)	$ 2.16	$ 2.12	$ 2.04
Common Stock
Class of Stock [Line Items]
Dividends declared per share of common stock ( in dollars per share)	2.160	2.120	2.040
Less: Dividends declared in the current year and paid in the following year ( in dollars per share)	(0.540)	(0.540)	(0.520)
Add: Dividends declared in the prior year and paid in the current year ( in dollars per share)	0.540	0.520	0.500
Dividends paid per share of common stock (in dollars per share)	$ 2.160	$ 2.100	$ 2.020

Tax Treatment of Distribution_3

Tax Treatment of Distributions - Dividends Tax Treatment (Details) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
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 (in dollars per share)	$ 2.160	$ 2.100	$ 2.020
Ordinary income | Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per share of common stock (in dollars per share)	$ 2.087	$ 1.865	$ 1.338
Dividends paid per share of common stock, percentage	96.63%	88.80%	66.22%
Qualified dividend | Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per share of common stock (in dollars per share)	$ 0.001	$ 0.001	$ 0.003
Dividends paid per share of common stock, percentage	0.04%	0.02%	0.15%
Return of capital | Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per share of common stock (in dollars per share)	$ 0.069	$ 0.230	$ 0.551
Dividends paid per share of common stock, percentage	3.21%	10.99%	27.30%
Capital gains | Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per share of common stock (in dollars per share)	$ 0.003	$ 0.004	$ 0.075
Dividends paid per share of common stock, percentage	0.12%	0.19%	3.72%
Unrecaptured section 1250 gains | Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per share of common stock (in dollars per share)	$ 0	$ 0	$ 0.053
Dividends paid per share of common stock, percentage	0%	0%	2.61%
Tax treatment | Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per share of common stock (in dollars per share)	$ 2.160	$ 2.100	$ 2.020
Dividends paid per share of common stock, percentage	100%	100%	100%

Subsequent Events (Details)

Subsequent Events (Details) - shares	Jan. 22, 2024	Dec. 31, 2023
Subsequent Event [Line Items]
Number of shares available for grant (in shares)		2,800,000
Subsequent event | Kilroy Realty 2006 Incentive Award Plan | Time-Based Restricted Stock Units (RSUs) | Chief Executive Officer
Subsequent Event [Line Items]
Number of shares available for grant (in shares)	101,627
Vesting period	1 year

Schedule II - Valuation and Q_2

Schedule II - Valuation and Qualifying Accounts - Allowances (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Uncollectible tenant receivables
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 2,233	$ 2,062	$ 1,799
Charged to Costs and Expenses	1,524	1,447	1,532
Deductions	(2,190)	(1,276)	(1,269)
Balance at End of Period	1,567	2,233	2,062
Allowance for deferred rent
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	965	612	804
Charged to Costs and Expenses	667	864	320
Deductions	(904)	(511)	(512)
Balance at End of Period	$ 728	$ 965	$ 612

Schedule III - Real Estate an_2

Schedule III - Real Estate and Accumulated Depreciation - Schedule of Real Estate and Accumulated Depreciation (Details) $ in Thousands	Dec. 31, 2023 USD ($) ft²	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, encumbrances	$ 612,694
Initial cost, land and improvements	2,565,066
Initial cost, buildings and Improvements	2,959,869
Costs Capitalized Subsequent  to Acquisition/ Improvement	6,716,713
Land and improvements, gross	2,656,533
Buildings and improvements, gross	9,585,115
Land and improvements and buildings and improvements, gross	12,241,648
Accumulated Depreciation	$ 2,518,304	$ 2,218,710	$ 2,003,656	$ 1,798,646
Rentable square feet (unaudited) | ft²	17,044,128
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	1,856
Land and improvements, gross	150,718
Buildings and improvements, gross	32,889
Land and improvements and buildings and improvements, gross	183,607
Accumulated Depreciation	$ 20,163
Depreciation life	35 years
Rentable square feet (unaudited) | ft²	166,207
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	29,928
Land and improvements, gross	1,048
Buildings and improvements, gross	41,687
Land and improvements and buildings and improvements, gross	42,735
Accumulated Depreciation	$ 31,759
Depreciation life	35 years
Rentable square feet (unaudited) | 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	36,750
Land and improvements, gross	2,547
Buildings and improvements, gross	65,844
Land and improvements and buildings and improvements, gross	68,391
Accumulated Depreciation	$ 61,662
Depreciation life	35 years
Rentable square feet (unaudited) | 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	37,076
Land and improvements, gross	2,547
Buildings and improvements, gross	65,417
Land and improvements and buildings and improvements, gross	67,964
Accumulated Depreciation	$ 25,231
Depreciation life	35 years
Rentable square feet (unaudited) | 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	56,012
Land and improvements, gross	3,565
Buildings and improvements, gross	90,066
Land and improvements and buildings and improvements, gross	93,631
Accumulated Depreciation	$ 55,148
Depreciation life	35 years
Rentable square feet (unaudited) | 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	18,722
Land and improvements, gross	1,407
Buildings and improvements, gross	53,048
Land and improvements and buildings and improvements, gross	54,455
Accumulated Depreciation	$ 33,803
Depreciation life	35 years
Rentable square feet (unaudited) | 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	14,193
Land and improvements, gross	1,575
Buildings and improvements, gross	14,193
Land and improvements and buildings and improvements, gross	15,768
Accumulated Depreciation	$ 1,282
Depreciation life	35 years
Rentable square feet (unaudited) | 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	121,115
Land and improvements, gross	17,588
Buildings and improvements, gross	121,115
Land and improvements and buildings and improvements, gross	138,703
Accumulated Depreciation	$ 11,167
Depreciation life	35 years
Rentable square feet (unaudited) | 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	103,942
Land and improvements, gross	15,578
Buildings and improvements, gross	103,942
Land and improvements and buildings and improvements, gross	119,520
Accumulated Depreciation	$ 9,536
Depreciation life	35 years
Rentable square feet (unaudited) | 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	3,271
Land and improvements, gross	278
Buildings and improvements, gross	3,271
Land and improvements and buildings and improvements, gross	3,549
Accumulated Depreciation	$ 294
Depreciation life	35 years
Rentable square feet (unaudited) | 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	61,932
Land and improvements, gross	9,235
Buildings and improvements, gross	61,953
Land and improvements and buildings and improvements, gross	71,188
Accumulated Depreciation	$ 17,709
Depreciation life	35 years
Rentable square feet (unaudited) | 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	9,768
Land and improvements, gross	1,318
Buildings and improvements, gross	9,771
Land and improvements and buildings and improvements, gross	11,089
Accumulated Depreciation	$ 2,570
Depreciation life	35 years
Rentable square feet (unaudited) | 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	119,769
Land and improvements, gross	22,153
Buildings and improvements, gross	119,820
Land and improvements and buildings and improvements, gross	141,973
Accumulated Depreciation	$ 26,547
Depreciation life	35 years
Rentable square feet (unaudited) | 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	17,409
Land and improvements, gross	2,455
Buildings and improvements, gross	16,270
Land and improvements and buildings and improvements, gross	18,725
Accumulated Depreciation	$ 5,545
Depreciation life	35 years
Rentable square feet (unaudited) | 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	44,167
Land and improvements, gross	8,703
Buildings and improvements, gross	50,840
Land and improvements and buildings and improvements, gross	59,543
Accumulated Depreciation	$ 13,304
Depreciation life	35 years
Rentable square feet (unaudited) | 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	53,475
Land and improvements, gross	18,111
Buildings and improvements, gross	113,795
Land and improvements and buildings and improvements, gross	131,906
Accumulated Depreciation	$ 58,714
Depreciation life	35 years
Rentable square feet (unaudited) | ft²	332,100
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	13,645
Land and improvements, gross	0
Buildings and improvements, gross	15,586
Land and improvements and buildings and improvements, gross	15,586
Accumulated Depreciation	$ 12,686
Depreciation life	35 years
Rentable square feet (unaudited) | 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	23,013
Land and improvements, gross	0
Buildings and improvements, gross	40,480
Land and improvements and buildings and improvements, gross	40,480
Accumulated Depreciation	$ 32,535
Depreciation life	35 years
Rentable square feet (unaudited) | 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	39,083
Land and improvements, gross	0
Buildings and improvements, gross	61,402
Land and improvements and buildings and improvements, gross	61,402
Accumulated Depreciation	$ 48,266
Depreciation life	35 years
Rentable square feet (unaudited) | 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	24,516
Land and improvements, gross	0
Buildings and improvements, gross	43,924
Land and improvements and buildings and improvements, gross	43,924
Accumulated Depreciation	$ 31,475
Depreciation life	35 years
Rentable square feet (unaudited) | 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	29,143
Land and improvements, gross	0
Buildings and improvements, gross	42,729
Land and improvements and buildings and improvements, gross	42,729
Accumulated Depreciation	$ 19,775
Depreciation life	35 years
Rentable square feet (unaudited) | 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	12,202
Land and improvements, gross	0
Buildings and improvements, gross	21,906
Land and improvements and buildings and improvements, gross	21,906
Accumulated Depreciation	$ 7,278
Depreciation life	35 years
Rentable square feet (unaudited) | 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	17,754
Land and improvements, gross	0
Buildings and improvements, gross	30,369
Land and improvements and buildings and improvements, gross	30,369
Accumulated Depreciation	$ 22,085
Depreciation life	35 years
Rentable square feet (unaudited) | 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	7,497
Land and improvements, gross	9,720
Buildings and improvements, gross	58,453
Land and improvements and buildings and improvements, gross	68,173
Accumulated Depreciation	$ 14,898
Depreciation life	35 years
Rentable square feet (unaudited) | 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	7,266
Land and improvements, gross	31,693
Buildings and improvements, gross	35,240
Land and improvements and buildings and improvements, gross	66,933
Accumulated Depreciation	$ 8,817
Depreciation life	35 years
Rentable square feet (unaudited) | 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	1,828
Land and improvements, gross	10,013
Buildings and improvements, gross	5,523
Land and improvements and buildings and improvements, gross	15,536
Accumulated Depreciation	$ 1,558
Depreciation life	35 years
Rentable square feet (unaudited) | 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	5,769
Land and improvements, gross	39,954
Buildings and improvements, gross	33,653
Land and improvements and buildings and improvements, gross	73,607
Accumulated Depreciation	$ 8,532
Depreciation life	35 years
Rentable square feet (unaudited) | 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	26,036
Land and improvements, gross	9,633
Buildings and improvements, gross	62,366
Land and improvements and buildings and improvements, gross	71,999
Accumulated Depreciation	$ 36,818
Depreciation life	35 years
Rentable square feet (unaudited) | 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	27,917
Land and improvements, gross	3,977
Buildings and improvements, gross	63,757
Land and improvements and buildings and improvements, gross	67,734
Accumulated Depreciation	$ 49,193
Depreciation life	35 years
Rentable square feet (unaudited) | 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	6,909
Land and improvements, gross	22,100
Buildings and improvements, gross	60,079
Land and improvements and buildings and improvements, gross	82,179
Accumulated Depreciation	$ 22,114
Depreciation life	35 years
Rentable square feet (unaudited) | 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	$ 19,563
Depreciation life	35 years
Rentable square feet (unaudited) | 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	18,285
Land and improvements, gross	5,476
Buildings and improvements, gross	44,370
Land and improvements and buildings and improvements, gross	49,846
Accumulated Depreciation	$ 31,892
Depreciation life	35 years
Rentable square feet (unaudited) | 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	19,357
Land and improvements, gross	4,551
Buildings and improvements, gross	31,397
Land and improvements and buildings and improvements, gross	35,948
Accumulated Depreciation	$ 23,853
Depreciation life	35 years
Rentable square feet (unaudited) | 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	4,434
Land and improvements, gross	1,673
Buildings and improvements, gross	14,094
Land and improvements and buildings and improvements, gross	15,767
Accumulated Depreciation	$ 10,912
Depreciation life	35 years
Rentable square feet (unaudited) | 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	9,985
Land and improvements, gross	1,540
Buildings and improvements, gross	18,495
Land and improvements and buildings and improvements, gross	20,035
Accumulated Depreciation	$ 13,792
Depreciation life	35 years
Rentable square feet (unaudited) | 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	35,629
Land and improvements, gross	4,201
Buildings and improvements, gross	35,629
Land and improvements and buildings and improvements, gross	39,830
Accumulated Depreciation	$ 4,585
Depreciation life	35 years
Rentable square feet (unaudited) | 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	12,348
Land and improvements, gross	3,453
Buildings and improvements, gross	24,329
Land and improvements and buildings and improvements, gross	27,782
Accumulated Depreciation	$ 14,393
Depreciation life	35 years
Rentable square feet (unaudited) | 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	35,029
Land and improvements, gross	9,360
Buildings and improvements, gross	35,029
Land and improvements and buildings and improvements, gross	44,389
Accumulated Depreciation	$ 8,314
Depreciation life	35 years
Rentable square feet (unaudited) | 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	$ 28,749
Depreciation life	35 years
Rentable square feet (unaudited) | 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	17,031
Land and improvements, gross	10,252
Buildings and improvements, gross	38,267
Land and improvements and buildings and improvements, gross	48,519
Accumulated Depreciation	$ 12,315
Depreciation life	35 years
Rentable square feet (unaudited) | 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	113,007
Land and improvements, gross	28,645
Buildings and improvements, gross	113,007
Land and improvements and buildings and improvements, gross	141,652
Accumulated Depreciation	$ 12,713
Depreciation life	35 years
Rentable square feet (unaudited) | 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	51,844
Land and improvements, gross	11,326
Buildings and improvements, gross	51,844
Land and improvements and buildings and improvements, gross	63,170
Accumulated Depreciation	$ 6,012
Depreciation life	35 years
Rentable square feet (unaudited) | 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	8,504
Land and improvements, gross	1,629
Buildings and improvements, gross	11,600
Land and improvements and buildings and improvements, gross	13,229
Accumulated Depreciation	$ 8,741
Depreciation life	35 years
Rentable square feet (unaudited) | ft²	39,192
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	49,456
Land and improvements, gross	15,167
Buildings and improvements, gross	49,456
Land and improvements and buildings and improvements, gross	64,623
Accumulated Depreciation	$ 11,382
Depreciation life	35 years
Rentable square feet (unaudited) | 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	11,556
Land and improvements, gross	2,858
Buildings and improvements, gross	17,762
Land and improvements and buildings and improvements, gross	20,620
Accumulated Depreciation	$ 12,032
Depreciation life	35 years
Rentable square feet (unaudited) | 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	29,641
Land and improvements, gross	5,259
Buildings and improvements, gross	47,918
Land and improvements and buildings and improvements, gross	53,177
Accumulated Depreciation	$ 33,359
Depreciation life	35 years
Rentable square feet (unaudited) | 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	20,770
Land and improvements, gross	4,725
Buildings and improvements, gross	41,227
Land and improvements and buildings and improvements, gross	45,952
Accumulated Depreciation	$ 29,457
Depreciation life	35 years
Rentable square feet (unaudited) | 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	17,124
Land and improvements, gross	4,254
Buildings and improvements, gross	36,134
Land and improvements and buildings and improvements, gross	40,388
Accumulated Depreciation	$ 23,912
Depreciation life	35 years
Rentable square feet (unaudited) | 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	21,985
Land and improvements, gross	4,457
Buildings and improvements, gross	37,132
Land and improvements and buildings and improvements, gross	41,589
Accumulated Depreciation	$ 26,896
Depreciation life	35 years
Rentable square feet (unaudited) | 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	75,649
Land and improvements, gross	24,358
Buildings and improvements, gross	75,649
Land and improvements and buildings and improvements, gross	100,007
Accumulated Depreciation	$ 11,192
Depreciation life	35 years
Rentable square feet (unaudited) | 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	67,178
Land and improvements, gross	7,997
Buildings and improvements, gross	67,178
Land and improvements and buildings and improvements, gross	75,175
Accumulated Depreciation	$ 27,665
Depreciation life	35 years
Rentable square feet (unaudited) | 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	25,140
Land and improvements, gross	7,580
Buildings and improvements, gross	61,044
Land and improvements and buildings and improvements, gross	68,624
Accumulated Depreciation	$ 34,020
Depreciation life	35 years
Rentable square feet (unaudited) | 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	25,728
Land and improvements, gross	7,580
Buildings and improvements, gross	61,632
Land and improvements and buildings and improvements, gross	69,212
Accumulated Depreciation	$ 36,164
Depreciation life	35 years
Rentable square feet (unaudited) | 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	105,759
Land and improvements, gross	19,861
Buildings and improvements, gross	105,759
Land and improvements and buildings and improvements, gross	125,620
Accumulated Depreciation	$ 3,873
Depreciation life	35 years
Rentable square feet (unaudited) | ft²	206,527
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	10,816
Land and improvements, gross	5,240
Buildings and improvements, gross	33,036
Land and improvements and buildings and improvements, gross	38,276
Accumulated Depreciation	$ 16,858
Depreciation life	35 years
Rentable square feet (unaudited) | 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	6,880
Land and improvements, gross	0
Buildings and improvements, gross	6,880
Land and improvements and buildings and improvements, gross	6,880
Accumulated Depreciation	$ 408
Depreciation life	35 years
Rentable square feet (unaudited) | 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	80,080
Land and improvements, gross	6,081
Buildings and improvements, gross	80,080
Land and improvements and buildings and improvements, gross	86,161
Accumulated Depreciation	$ 7,363
Depreciation life	35 years
Rentable square feet (unaudited) | ft²	160,444
9514 Towne Centre Dr., San Diego, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, land and improvements	$ 4,928
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	47,563
Land and improvements, gross	4,928
Buildings and improvements, gross	47,563
Land and improvements and buildings and improvements, gross	52,491
Accumulated Depreciation	$ 685
Depreciation life	35 years
Rentable square feet (unaudited) | ft²	70,616
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	1,524
Land and improvements, gross	4,860
Buildings and improvements, gross	17,025
Land and improvements and buildings and improvements, gross	21,885
Accumulated Depreciation	$ 6,650
Depreciation life	35 years
Rentable square feet (unaudited) | ft²	47,643
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	8,370
Land and improvements, gross	4,662
Buildings and improvements, gross	23,912
Land and improvements and buildings and improvements, gross	28,574
Accumulated Depreciation	$ 9,495
Depreciation life	35 years
Rentable square feet (unaudited) | ft²	43,600
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	8,097
Land and improvements, gross	6,470
Buildings and improvements, gross	29,112
Land and improvements and buildings and improvements, gross	35,582
Accumulated Depreciation	$ 11,649
Depreciation life	35 years
Rentable square feet (unaudited) | ft²	63,430
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	3,245
Land and improvements, gross	0
Buildings and improvements, gross	3,245
Land and improvements and buildings and improvements, gross	3,245
Accumulated Depreciation	$ 2,117
Depreciation life	35 years
Rentable square feet (unaudited) | 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	4,782
Land and improvements, gross	6,470
Buildings and improvements, gross	25,796
Land and improvements and buildings and improvements, gross	32,266
Accumulated Depreciation	$ 10,623
Depreciation life	35 years
Rentable square feet (unaudited) | ft²	63,429
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	5,286
Land and improvements, gross	4,939
Buildings and improvements, gross	20,551
Land and improvements and buildings and improvements, gross	25,490
Accumulated Depreciation	$ 8,884
Depreciation life	35 years
Rentable square feet (unaudited) | ft²	48,413
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	1,576
Land and improvements, gross	6,470
Buildings and improvements, gross	22,591
Land and improvements and buildings and improvements, gross	29,061
Accumulated Depreciation	$ 9,106
Depreciation life	35 years
Rentable square feet (unaudited) | ft²	63,429
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	13,461
Land and improvements, gross	28,730
Buildings and improvements, gross	41,016
Land and improvements and buildings and improvements, gross	69,746
Accumulated Depreciation	$ 9,462
Depreciation life	35 years
Rentable square feet (unaudited) | 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	$ 17,536
Depreciation life	35 years
Rentable square feet (unaudited) | 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	$ 17,461
Depreciation life	35 years
Rentable square feet (unaudited) | 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	111
Land and improvements, gross	0
Buildings and improvements, gross	99,633
Land and improvements and buildings and improvements, gross	99,633
Accumulated Depreciation	$ 21,015
Depreciation life	35 years
Rentable square feet (unaudited) | 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	6,446
Land and improvements, gross	0
Buildings and improvements, gross	28,161
Land and improvements and buildings and improvements, gross	28,161
Accumulated Depreciation	$ 6,276
Depreciation life	35 years
Rentable square feet (unaudited) | 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	109,612
Land and improvements, gross	18,063
Buildings and improvements, gross	108,217
Land and improvements and buildings and improvements, gross	126,280
Accumulated Depreciation	$ 31,253
Depreciation life	35 years
Rentable square feet (unaudited) | 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	50,285
Land and improvements, gross	8,626
Buildings and improvements, gross	49,618
Land and improvements and buildings and improvements, gross	58,244
Accumulated Depreciation	$ 14,031
Depreciation life	35 years
Rentable square feet (unaudited) | 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	197,034
Land and improvements, gross	85,510
Buildings and improvements, gross	190,088
Land and improvements and buildings and improvements, gross	275,598
Accumulated Depreciation	$ 29,788
Depreciation life	35 years
Rentable square feet (unaudited) | 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	81,437
Land and improvements, gross	49,150
Buildings and improvements, gross	212,675
Land and improvements and buildings and improvements, gross	261,825
Accumulated Depreciation	$ 106,267
Depreciation life	35 years
Rentable square feet (unaudited) | 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	116,103
Land and improvements, gross	63,550
Buildings and improvements, gross	270,256
Land and improvements and buildings and improvements, gross	333,806
Accumulated Depreciation	$ 134,337
Depreciation life	35 years
Rentable square feet (unaudited) | 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	78,410
Land and improvements, gross	19,260
Buildings and improvements, gross	162,428
Land and improvements and buildings and improvements, gross	181,688
Accumulated Depreciation	$ 94,189
Depreciation life	35 years
Rentable square feet (unaudited) | 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	127,866
Land and improvements, gross	28,504
Buildings and improvements, gross	187,597
Land and improvements and buildings and improvements, gross	216,101
Accumulated Depreciation	$ 74,839
Depreciation life	35 years
Rentable square feet (unaudited) | ft²	436,357
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	10,773
Land and improvements, gross	7,630
Buildings and improvements, gross	33,543
Land and improvements and buildings and improvements, gross	41,173
Accumulated Depreciation	$ 15,259
Depreciation life	35 years
Rentable square feet (unaudited) | 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	16,987
Land and improvements, gross	5,910
Buildings and improvements, gross	39,437
Land and improvements and buildings and improvements, gross	45,347
Accumulated Depreciation	$ 15,826
Depreciation life	35 years
Rentable square feet (unaudited) | 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	80,643
Land and improvements, gross	18,645
Buildings and improvements, gross	80,643
Land and improvements and buildings and improvements, gross	99,288
Accumulated Depreciation	$ 18,703
Depreciation life	35 years
Rentable square feet (unaudited) | 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	1,260
Land and improvements, gross	29,403
Buildings and improvements, gross	114,441
Land and improvements and buildings and improvements, gross	143,844
Accumulated Depreciation	$ 16,912
Depreciation life	35 years
Rentable square feet (unaudited) | 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	212,738
Land and improvements, gross	52,815
Buildings and improvements, gross	212,738
Land and improvements and buildings and improvements, gross	265,553
Accumulated Depreciation	$ 51,190
Depreciation life	35 years
Rentable square feet (unaudited) | 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	$ 3,392
Depreciation life	35 years
Rentable square feet (unaudited) | 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	$ 3,354
Depreciation life	35 years
Rentable square feet (unaudited) | 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	352
Land and improvements, gross	23,112
Buildings and improvements, gross	22,953
Land and improvements and buildings and improvements, gross	46,065
Accumulated Depreciation	$ 5,440
Depreciation life	35 years
Rentable square feet (unaudited) | 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	177,245
Land and improvements, gross	23,719
Buildings and improvements, gross	177,245
Land and improvements and buildings and improvements, gross	200,964
Accumulated Depreciation	$ 11,889
Depreciation life	35 years
Rentable square feet (unaudited) | 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	165,720
Land and improvements, gross	23,449
Buildings and improvements, gross	165,720
Land and improvements and buildings and improvements, gross	189,169
Accumulated Depreciation	$ 11,662
Depreciation life	35 years
Rentable square feet (unaudited) | 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	141,126
Land and improvements, gross	19,538
Buildings and improvements, gross	141,126
Land and improvements and buildings and improvements, gross	160,664
Accumulated Depreciation	$ 11,708
Depreciation life	35 years
Rentable square feet (unaudited) | 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	$ 13,584
Depreciation life	35 years
Rentable square feet (unaudited) | 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	$ 13,583
Depreciation life	35 years
Rentable square feet (unaudited) | 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	$ 5,800
Depreciation life	35 years
Rentable square feet (unaudited) | 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	$ 30,299
Depreciation life	35 years
Rentable square feet (unaudited) | 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	88,698
Land and improvements, gross	42,680
Buildings and improvements, gross	260,113
Land and improvements and buildings and improvements, gross	302,793
Accumulated Depreciation	$ 118,339
Depreciation life	35 years
Rentable square feet (unaudited) | 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	52,662
Land and improvements, gross	25,080
Buildings and improvements, gross	203,539
Land and improvements and buildings and improvements, gross	228,619
Accumulated Depreciation	$ 89,219
Depreciation life	35 years
Rentable square feet (unaudited) | 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	3,216
Land and improvements, gross	84,076
Buildings and improvements, gross	374,370
Land and improvements and buildings and improvements, gross	458,446
Accumulated Depreciation	$ 29,772
Depreciation life	35 years
Rentable square feet (unaudited) | ft²	539,226
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	328,064
Land and improvements, gross	42,854
Buildings and improvements, gross	328,064
Land and improvements and buildings and improvements, gross	370,918
Accumulated Depreciation	$ 27,405
Depreciation life	35 years
Rentable square feet (unaudited) | ft²	618,766
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	9,743
Land and improvements, gross	0
Buildings and improvements, gross	57,770
Land and improvements and buildings and improvements, gross	57,770
Accumulated Depreciation	$ 24,961
Depreciation life	35 years
Rentable square feet (unaudited) | 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	23,304
Land and improvements, gross	0
Buildings and improvements, gross	81,841
Land and improvements and buildings and improvements, gross	81,841
Accumulated Depreciation	$ 30,106
Depreciation life	35 years
Rentable square feet (unaudited) | 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	6,734
Land and improvements, gross	0
Buildings and improvements, gross	44,138
Land and improvements and buildings and improvements, gross	44,138
Accumulated Depreciation	$ 18,088
Depreciation life	35 years
Rentable square feet (unaudited) | 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	15,064
Land and improvements, gross	14,710
Buildings and improvements, gross	97,082
Land and improvements and buildings and improvements, gross	111,792
Accumulated Depreciation	$ 33,902
Depreciation life	35 years
Rentable square feet (unaudited) | 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	10,779
Land and improvements, gross	10,430
Buildings and improvements, gross	70,782
Land and improvements and buildings and improvements, gross	81,212
Accumulated Depreciation	$ 25,693
Depreciation life	35 years
Rentable square feet (unaudited) | 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	32
Land and improvements, gross	22,500
Buildings and improvements, gross	77,078
Land and improvements and buildings and improvements, gross	99,578
Accumulated Depreciation	$ 24,632
Depreciation life	35 years
Rentable square feet (unaudited) | ft²	174,530
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	644,210
Land and improvements, gross	0
Buildings and improvements, gross	644,210
Land and improvements and buildings and improvements, gross	644,210
Accumulated Depreciation	$ 17,688
Depreciation life	35 years
Rentable square feet (unaudited) | ft²	758,975
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	137,456
Land and improvements, gross	16,970
Buildings and improvements, gross	137,495
Land and improvements and buildings and improvements, gross	154,465
Accumulated Depreciation	$ 30,007
Depreciation life	35 years
Rentable square feet (unaudited) | 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	162,908
Land and improvements, gross	12,112
Buildings and improvements, gross	162,908
Land and improvements and buildings and improvements, gross	175,020
Accumulated Depreciation	$ 12,788
Depreciation life	35 years
Rentable square feet (unaudited) | 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	270,807
Land and improvements, gross	106,419
Buildings and improvements, gross	270,807
Land and improvements and buildings and improvements, gross	377,226
Accumulated Depreciation	$ 30,561
Depreciation life	35 years
Rentable square feet (unaudited) | ft²	0
Office Building | 12830 El Camino Real, Del Mar, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, encumbrances	$ 375,000
Office Building | 12100, 12200 and 12312 W. Olympic Blvd., Los Angeles, CA
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, encumbrances	156,386
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	81,308
Operating Properties
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, encumbrances	612,694
Initial cost, land and improvements	1,651,703
Initial cost, buildings and Improvements	2,959,869
Costs Capitalized Subsequent  to Acquisition/ Improvement	5,595,272
Land and improvements, gross	1,743,170
Buildings and improvements, gross	8,463,674
Land and improvements and buildings and improvements, gross	10,206,844
Accumulated Depreciation	$ 2,518,304
Rentable square feet (unaudited) | ft²	17,044,128
Undeveloped land and construction in progress
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, encumbrances	$ 0
Initial cost, land and improvements	913,363
Initial cost, buildings and Improvements	0
Costs Capitalized Subsequent  to Acquisition/ Improvement	1,121,441
Land and improvements, gross	913,363
Buildings and improvements, gross	1,121,441
Land and improvements and buildings and improvements, gross	2,034,804
Accumulated Depreciation	$ 0
Rentable square feet (unaudited) | ft²	0

Schedule III - Real Estate an_3

Schedule III - Real Estate and Accumulated Depreciation - Narrative (Details) $ in Thousands	Dec. 31, 2023 USD ($) property	Dec. 31, 2022 USD ($)
Real Estate and Accumulated Depreciation [Line Items]
Initial cost, encumbrances	$ 612,694
Investment in real estate, federal Income tax basis	10,100,000
Kilroy Realty L.P.
Real Estate and Accumulated Depreciation [Line Items]
Long-term debt, gross	4,961,406
Kilroy Realty L.P. | Secured debt
Real Estate and Accumulated Depreciation [Line Items]
Unamortized debt issuance expense	9,469	$ 531
3.57% Mortgage Payable due December 2026 | Kilroy Realty L.P.
Real Estate and Accumulated Depreciation [Line Items]
Long-term debt, gross	156,400
3.57% Mortgage Payable due December 2026 | Kilroy Realty L.P. | Secured debt
Real Estate and Accumulated Depreciation [Line Items]
Long-term debt, gross	156,386	159,973
4.48% Mortgage Payable due July 2027 | Kilroy Realty L.P. | Secured debt
Real Estate and Accumulated Depreciation [Line Items]
Long-term debt, gross	81,308	83,496
5.90% Mortgage Payable due August 2034 | Kilroy Realty L.P.
Real Estate and Accumulated Depreciation [Line Items]
Long-term debt, gross	375,000
5.90% Mortgage Payable due August 2034 | Kilroy Realty L.P. | Secured debt
Real Estate and Accumulated Depreciation [Line Items]
Long-term debt, gross	375,000	$ 0
Office Building
Real Estate and Accumulated Depreciation [Line Items]
Unamortized debt issuance expense	$ 9,500
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, 2023	Dec. 31, 2022	Dec. 31, 2021
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate [Roll Forward]
Total real estate held for investment, beginning of year	$ 11,732,183	$ 11,292,693	$ 10,190,046
Acquisitions	0	40,033	1,131,248
Improvements, etc.	511,866	439,759	547,468
Total additions during period	511,866	479,792	1,678,716
Cost of real estate sold	0	(32,855)	(572,985)
Other	(2,401)	(7,447)	(3,084)
Total deductions during period	(2,401)	(40,302)	(576,069)
Total real estate held for investment, end of year	$ 12,241,648	$ 11,732,183	$ 11,292,693

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, 2023	Dec. 31, 2022	Dec. 31, 2021
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation [Roll Forward]
Accumulated depreciation, beginning of year	$ 2,218,710	$ 2,003,656	$ 1,798,646
Depreciation of real estate	300,119	287,799	256,304
Total additions during period	300,119	287,799	256,304
Write-offs due to sale	0	(19,114)	(38,156)
Other	(525)	(53,631)	(13,138)
Total deductions during period	(525)	(72,745)	(51,294)
Accumulated depreciation, end of year	$ 2,518,304	$ 2,218,710	$ 2,003,656