Kilroy Realty (KRC) 10-Q 1 May 14 2014 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2014	Apr. 30, 2014
Entity Registrant Name	'KILROY REALTY CORP	'
Entity Central Index Key	'0001025996	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Document Type	'10-Q	'
Document Period End Date	31-Mar-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q1	'
Amendment Flag	'false	'
Entity Common Stock, Shares Outstanding	'	82,218,417
Kilroy Realty, L.P. [Member]	'	'
Entity Registrant Name	'Kilroy Realty, L.P.	'
Entity Central Index Key	'0001493976	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Non-accelerated Filer	'
Document Type	'10-Q	'
Document Period End Date	31-Mar-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q1	'
Amendment Flag	'false	'

Consolidated_Balance_Sheets_Un

Consolidated Balance Sheets (Unaudited) (USD $)	Mar. 31, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
REAL ESTATE ASSETS:	'		'
Land and improvements (Note 2)	$679,991		$657,491
Buildings and improvements (Note 2)	3,706,662		3,590,699
Undeveloped land and construction in progress	1,047,371		1,016,757
Total real estate held for investment	5,434,024		5,264,947
Accumulated depreciation and amortization	-854,977		-818,957
Total real estate assets held for investment, net ($60,575 and $234,532 of VIE, respectively, Note 1)	4,579,047		4,445,990
REAL ESTATE ASSETS AND OTHER ASSETS HELD FOR SALE, NET (Note 13)	28,272		213,100
CASH AND CASH EQUIVALENTS	95,534		35,377
RESTRICTED CASH (Notes 1 and 13)	33,717		49,780
MARKETABLE SECURITIES (Note 11)	11,001		10,008
CURRENT RECEIVABLES, NET (Note 4)	11,092		10,743
DEFERRED RENT RECEIVABLES, NET (Note 4)	130,750		127,123
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Notes 2 and 3)	188,466		186,622
DEFERRED FINANCING COSTS, NET	15,195		16,502
PREPAID EXPENSES AND OTHER ASSETS, NET	21,469		15,783
TOTAL ASSETS	5,114,543		5,111,028
LIABILITIES:	'		'
Secured debt (Notes 5 and 11)	556,946	[1]	560,434	[1]
Exchangeable senior notes, net (Notes 5 and 11)	169,528		168,372
Unsecured debt, net (Notes 5 and 11)	1,431,217		1,431,132
Unsecured line of credit (Notes 5 and 11)	0		45,000
Accounts payable, accrued expenses and other liabilities	187,631		198,467
Accrued distributions (Note 16)	31,456		31,490
Deferred revenue and acquisition-related intangible liabilities, net (Notes 2 and 3)	107,569		101,286
Rents received in advance and tenant security deposits	43,952		44,240
Liabilities of real estate assets held for sale (Note 13)	634		14,447
Total liabilities	2,528,933		2,594,868
COMMITMENTS AND CONTINGENCIES (Note 10)	'		'
Preferred stock, $.01 par value, 30,000,000 shares authorized:	'		'
Common stock, $.01 par value, 150,000,000 shares authorized, 82,218,332 and 82,153,944 shares issued and outstanding, respectively	822		822
Additional paid-in capital	2,479,740		2,478,975
Distributions in excess of earnings	-143,636		-210,896
Total stockholders’ equity	2,529,337		2,461,312
Noncontrolling interest :	'		'
Common units of the Operating Partnership (Note 6)	51,388		49,963
Noncontrolling interest in consolidated subsidiary (Notes 1 and 6)	4,885		4,885
Total noncontrolling interests	56,273		54,848
Total equity	2,585,610		2,516,160
TOTAL LIABILITIES AND EQUITY	5,114,543		5,111,028
Series G Cumulative Redeemable Preferred Stock	'		'
Preferred stock, $.01 par value, 30,000,000 shares authorized:	'		'
Cumulative Redeemable Preferred stock	96,155		96,155
Series H Cumulative Redeemable Preferred Stock	'		'
Preferred stock, $.01 par value, 30,000,000 shares authorized:	'		'
Cumulative Redeemable Preferred stock	$96,256		$96,256
[1]	Amounts reported include the amounts of unamortized debt premiums and discounts for the periods presented.

Consolidated_Balance_Sheets_Un1

Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Variable Interest Entity Consolidated Carrying Amounts, Real Estate Assets, net	$60,575,000	$234,532,000
Common stock, par value	$0.01	'
Common Stock [Member]	'	'
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	82,218,332	82,153,944
Common stock, shares outstanding	82,218,332	82,153,944
Preferred Stock [Member]	'	'
Preferred stock, par value	$0.01	$0.01
Preferred stock, shares authorized	30,000,000	30,000,000
Series G Cumulative Redeemable Preferred Stock	'	'
Preferred stock, par value	$0.01	$0.01
Preferred stock dividend rate percentage	6.88%	6.88%
Preferred stock, shares authorized	4,600,000	4,600,000
Preferred stock, shares issued	4,000,000	4,000,000
Preferred stock, shares outstanding	4,000,000	4,000,000
Preferred Stock Liquidation preference	100,000,000	100,000,000
Series H Cumulative Redeemable Preferred Stock	'	'
Preferred stock, par value	$0.01	$0.01
Preferred stock dividend rate percentage	6.38%	6.38%
Preferred stock, shares authorized	4,000,000	4,000,000
Preferred stock, shares issued	4,000,000	4,000,000
Preferred stock, shares outstanding	4,000,000	4,000,000
Preferred Stock Liquidation preference	$100,000,000	$100,000,000

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
REVENUES:	'	'
Rental income	$112,056	$101,607
Tenant reimbursements	11,572	9,130
Other property income (Note 12)	2,157	227
Total revenues	125,785	110,964
EXPENSES:	'	'
Property expenses	25,094	22,805
Real estate taxes	11,173	9,664
Provision for bad debts	0	95
Ground leases	762	847
General and administrative expenses	10,811	9,669
Acquisition-related expenses	228	655
Depreciation and amortization	49,202	47,701
Total expenses	97,270	91,436
OTHER (EXPENSES) INCOME:	'	'
Interest income and other net investment gains (Note 11)	177	392
Interest expense (Note 5)	-17,252	-19,734
Total other (expenses) income	-17,075	-19,342
INCOME FROM CONTINUING OPERATIONS	11,440	186
DISCONTINUED OPERATIONS (Note 13)	'	'
Income from discontinued operations	377	2,202
Net gain on dispositions of discontinued operations	90,115	0
Total income from discontinued operations	90,492	2,202
NET INCOME	101,932	2,388
Net (income) loss attributable to noncontrolling common units of the Operating Partnership	-2,087	22
NET INCOME ATTRIBUTABLE TO KILROY REALTY CORPORATION	99,845	2,410
Preferred dividends	-3,313	-3,313
NET INCOME (LOSS) AVAILABLE TO COMMON STOCKHOLDERS	$96,532	($903)
Income (loss) from continuing operations available to common stockholders per common share – basic (Note 14)	$0.09	($0.05)
Income (loss) from continuing operations available to common stockholders per common share – diluted (Note 14)	$0.09	($0.05)
Net income (loss) available to common stockholders per share – basic (Note 14)	$1.17	($0.02)
Net income (loss) available to common stockholders per share – diluted (Note 14)	$1.14	($0.02)
Weighted average common shares outstanding – basic (Note 14)	82,124,538	74,977,240
Weighted average common shares outstanding – diluted (Note 14)	84,140,070	74,977,240
Dividends declared per common share	$0.35	$0.35

Consolidated_Statements_of_Equ

Consolidated Statements of Equity (Unaudited) (USD $)	Total	Total Stockholders' Equity	Preferred Stock [Member]	Common Stock [Member]	Common Stock Additional Paid-in Capital	Common Stock Distributions in Excess of Earnings	Noncontrolling Interest [Member]	Kilroy Realty, L.P. [Member]
In Thousands, except Share data, unless otherwise specified
Beginning Balance at Dec. 31, 2012	$2,235,933	$2,189,630	$192,411	$749	$2,126,005	($129,535)	$46,303	'
Beginning Balance, shares at Dec. 31, 2012	'	'	'	74,926,981	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'	'
Net income	2,388	2,410	'	'	'	2,410	-22	2,388
Issuance of common stock, shares	'	'	'	453,679	'	'	'	'
Issuance of common stock	23,395	23,395	'	4	23,391	'	'	'
Issuance of share-based compensation awards, shares	'	'	'	0	'	'	'	'
Issuance of share-based compensation awards	336	336	'	'	336	'	'	'
Noncash amortization of share-based compensation	2,422	2,422	'	'	2,422	'	'	2,422
Repurchase of common stock and restricted stock units, shares	'	'	'	-33,534	'	'	'	'
Repurchase of common stock and restricted stock units	-1,199	-1,199	'	'	-1,199	'	'	'
Settlement of restricted stock units for shares of common stock, shares	'	'	'	2,579	'	'	'	'
Settlement of restricted stock units for shares of common stock	'	'	'	'	-10	'	'	'
Settlement of restricted stock units for common stock value	-10	-10	'	'	'	'	'	-10
Dividends, Preferred Stock	'	'	'	'	'	3,313	'	-3,313
Adjustment for noncontrolling interest	0	-1,893	'	'	-1,893	'	1,893	'
Preferred dividends	-3,313	-3,313	'	'	'	'	'	-3,313
Dividends declared per common share and common unit ($0.35 per share/unit)	-27,412	-26,773	'	'	'	-26,773	-639	'
Ending Balance at Mar. 31, 2013	2,232,540	2,185,005	192,411	753	2,149,052	-157,211	47,535	'
Ending Balance, shares at Mar. 31, 2013	'	'	'	75,349,705	'	'	'	'
Beginning Balance at Dec. 31, 2013	2,516,160	2,461,312	192,411	822	2,478,975	-210,896	54,848	'
Beginning Balance, shares at Dec. 31, 2013	'	'	'	82,153,944	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'	'
Net income	101,932	99,845	'	'	'	99,845	2,087	101,932
Noncash amortization of share-based compensation	2,233	2,233	'	'	2,233	'	'	2,233
Repurchase of common stock and restricted stock units, shares	'	'	'	-26,074	'	'	'	'
Repurchase of common stock and restricted stock units	-1,517	-1,517	'	'	-1,517	'	'	'
Settlement of restricted stock units for shares of common stock, shares	'	'	'	88,962	'	'	'	'
Settlement of restricted stock units for shares of common stock	'	'	'	'	0	'	'	'
Settlement of restricted stock units for common stock value	0	0	'	'	'	'	'	0
Exercise of stock options, net, units	'	'	'	1,000	'	'	'	'
Exercise of stock options, net	21	21	'	'	21	'	'	'
Exchange of common units of the Operating Parternship, shares	'	'	'	500	'	'	'	'
Exchange of common units of the Operating Partnership	'	28	'	'	28	'	-28	'
Dividends, Preferred Stock	'	'	'	'	'	3,313	'	-3,313
Preferred dividends	-3,313	-3,313	'	'	'	'	'	-3,313
Dividends declared per common share and common unit ($0.35 per share/unit)	-29,906	-29,272	'	'	'	-29,272	-634	'
Ending Balance at Mar. 31, 2014	$2,585,610	$2,529,337	$192,411	$822	$2,479,740	($143,636)	$56,273	'
Ending Balance, shares at Mar. 31, 2014	'	'	'	82,218,332	'	'	'	'

Consolidated_Statements_of_Equ1

Consolidated Statements of Equity (Unaudited) (Parenthetical) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Statement of Stockholders' Equity [Abstract]	'	'
Dividends declared per common share	$0.35	$0.35

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:	'	'
Net income	$101,932	$2,388
Adjustments to reconcile net income to net cash provided by operating activities (including discontinued operations):	'	'
Depreciation and amortization of building and improvements and leasing costs	48,717	50,011
Increase in provision for bad debts	0	95
Depreciation of furniture, fixtures and equipment	485	380
Noncash amortization of share-based compensation awards	2,502	2,234
Noncash amortization of deferred financing costs and debt discounts and premiums	1,256	1,413
Noncash amortization of net below market rents (Note 3)	-1,734	-2,047
Net gain on dispositions of discontinued operations (Note 13)	-90,115	0
Noncash amortization of deferred revenue related to tenant-funded tenant improvements	-2,353	-2,442
Straight-line rents	-3,959	-6,724
Net change in other operating assets	-5,949	-7,390
Net change in other operating liabilities	-5,701	18,581
Net cash provided by operating activities	45,081	56,499
CASH FLOWS FROM INVESTING ACTIVITIES:	'	'
Expenditures for acquisition of operating properties (Note 2)	-106,125	-85,692
Expenditures for operating properties	32,016	25,571
Expenditures for development and redevelopment properties and undeveloped land	-73,626	-73,369
Net proceeds received from dispositions of operating properties (Note 13)	309,824	0
(Increase) decrease in restricted cash (Notes 1 and 13)	-779	228,079
Net cash provided by investing activities	97,278	43,447
CASH FLOWS FROM FINANCING ACTIVITIES:	'	'
Net proceeds from issuance of common stock	0	23,395
Borrowings on unsecured line of credit	90,000	0
Repayments on unsecured line of credit	-135,000	-185,000
Principal payments on secured debt	-2,414	-84,918
Proceeds from the issuance of unsecured debt	0	299,901
Financing costs	-418	-2,870
Repurchase of common stock and restricted stock units	-1,517	-1,209
Proceeds from exercise of stock options	21	0
Dividends and distributions paid to common stockholders and common unitholders	-29,561	-26,956
Dividends and distributions paid to preferred stockholders and preferred unitholders	-3,313	-3,313
Net cash (used in) provided by financing activities	-82,202	19,030
Net increase in cash and cash equivalents	60,157	118,976
Cash and cash equivalents, beginning of period	35,377	16,700
Cash and cash equivalents, end of period	95,534	135,676
SUPPLEMENTAL CASH FLOWS INFORMATION:	'	'
Cash paid for interest, net of capitalized interest of $10,042 and $7,175 as of March 31, 2014 and 2013, respectively	14,106	11,303
NONCASH INVESTING TRANSACTIONS:	'	'
Accrual for expenditures for operating properties and development and redevelopment properties	64,709	42,140
Tenant improvements funded directly by tenants	4,470	1,426
Assumption of secured debt in connection with property acquisitions	0	95,496
Assumption of other assets and liabilities in connection with operating and development property acquisitions, net	0	422
NONCASH FINANCING TRANSACTIONS:	'	'
Accrual of dividends and distributions payable to common stockholders and common unitholders	29,906	27,011
Accrual of dividends and distributions payable to preferred stockholders and preferred unitholders	1,656	1,694
Grant date fair value of share-based compensation awards	0	8,451
Exchange of common units of the Operating Partnership into shares of the Company’s common stock	$28	$0

Consolidated_Balance_Sheets_KI

Consolidated Balance Sheets (KILROY REALTY, L.P.) (USD $)	Mar. 31, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
REAL ESTATE ASSETS:	'		'
Buildings and improvements (Note 2)	$3,706,662		$3,590,699
Undeveloped land and construction in progress	1,047,371		1,016,757
Total real estate held for investment	5,434,024		5,264,947
Accumulated depreciation and amortization	-854,977		-818,957
Total real estate assets held for investment, net ($60,575 and $234,532 of VIE, respectively, Note 1)	4,579,047		4,445,990
REAL ESTATE ASSETS AND OTHER ASSETS HELD FOR SALE, NET (Note 13)	28,272		213,100
CASH AND CASH EQUIVALENTS	95,534		35,377
RESTRICTED CASH (Notes 1 and 13)	33,717		49,780
MARKETABLE SECURITIES (Note 11)	11,001		10,008
CURRENT RECEIVABLES, NET (Note 4)	11,092		10,743
DEFERRED RENT RECEIVABLES, NET (Note 4)	130,750		127,123
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Notes 2 and 3)	188,466		186,622
DEFERRED FINANCING COSTS, NET	15,195		16,502
PREPAID EXPENSES AND OTHER ASSETS, NET	21,469		15,783
TOTAL ASSETS	5,114,543		5,111,028
LIABILITIES:	'		'
Secured debt (Notes 5 and 11)	556,946	[1]	560,434	[1]
Exchangeable senior notes, net (Notes 5 and 11)	169,528		168,372
Unsecured debt, net (Notes 5 and 11)	1,431,217		1,431,132
Unsecured line of credit (Notes 5 and 11)	0		45,000
Accounts payable, accrued expenses and other liabilities	187,631		198,467
Accrued distributions (Note 16)	31,456		31,490
Deferred revenue and acquisition-related intangible liabilities, net (Notes 2 and 3)	107,569		101,286
Liabilities of real estate assets held for sale (Note 13)	634		14,447
Total liabilities	2,528,933		2,594,868
COMMITMENTS AND CONTINGENCIES (Note 10)	'		'
Partners' Capital (Note 8):	'		'
TOTAL LIABILITIES AND EQUITY	5,114,543		5,111,028
Kilroy Realty, L.P. [Member]	'		'
REAL ESTATE ASSETS:	'		'
Land and improvements (Note 2)	679,991		657,491
Buildings and improvements (Note 2)	3,706,662		3,590,699
Undeveloped land and construction in progress	1,047,371		1,016,757
Total real estate held for investment	5,434,024		5,264,947
Accumulated depreciation and amortization	-854,977		-818,957
Total real estate assets held for investment, net ($60,575 and $234,532 of VIE, respectively, Note 1)	4,579,047		4,445,990
REAL ESTATE ASSETS AND OTHER ASSETS HELD FOR SALE, NET (Note 13)	28,272		213,100
CASH AND CASH EQUIVALENTS	95,534		35,377
RESTRICTED CASH (Notes 1 and 13)	33,717		49,780
MARKETABLE SECURITIES (Note 11)	11,001		10,008
CURRENT RECEIVABLES, NET (Note 4)	11,092		10,743
DEFERRED RENT RECEIVABLES, NET (Note 4)	130,750		127,123
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Notes 2 and 3)	188,466		186,622
DEFERRED FINANCING COSTS, NET	15,195		16,502
PREPAID EXPENSES AND OTHER ASSETS, NET	21,469		15,783
TOTAL ASSETS	5,114,543		5,111,028
LIABILITIES:	'		'
Secured debt (Notes 5 and 11)	556,946		560,434
Exchangeable senior notes, net (Notes 5 and 11)	169,528		168,372
Unsecured debt, net (Notes 5 and 11)	1,431,217		1,431,132
Unsecured line of credit (Notes 5 and 11)	0		45,000
Accounts payable, accrued expenses and other liabilities	187,631		198,467
Accrued distributions (Note 16)	31,456		31,490
Deferred revenue and acquisition-related intangible liabilities, net (Notes 2 and 3)	107,569		101,286
Rents received in advance and tenant security deposits	43,952		44,240
Liabilities of real estate assets held for sale (Note 13)	634		14,447
Total liabilities	2,528,933		2,594,868
Partners' Capital (Note 8):	'		'
Common units, 82,113,491 and 74,926,981 held by the general partner and 1,821,503 and 1,826,503 held by common limited partners issued and outstanding, respectively	2,384,746		2,315,361
Total partners' capital	2,577,157		2,507,772
Noncontrolling interest in consolidated subsidiaries (Notes 2 and 6)	8,453		8,388
Total capital	2,585,610		2,516,160
TOTAL LIABILITIES AND EQUITY	5,114,543		5,111,028
Series G Cumulative Redeemable Preferred Unit [Member] | Kilroy Realty, L.P. [Member]	'		'
Partners' Capital (Note 8):	'		'
Redeemable Preferred stock	96,155		96,155
Series H Cumulative Redeemable Preferred Unit [Member] | Kilroy Realty, L.P. [Member]	'		'
Partners' Capital (Note 8):	'		'
Redeemable Preferred stock	$96,256		$96,256
[1]	Amounts reported include the amounts of unamortized debt premiums and discounts for the periods presented.

Consolidated_Balance_Sheets_KI1

Consolidated Balance Sheets (KILROY REALTY, L.P.) (Parenthetical) (Kilroy Realty, L.P. [Member], USD $)	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014	Dec. 31, 2013
			Common Units [Member]	Common Units [Member]	Series G Cumulative Redeemable Preferred Unit [Member]	Series G Cumulative Redeemable Preferred Unit [Member]	Series H Cumulative Redeemable Preferred Unit [Member]	Series H Cumulative Redeemable Preferred Unit [Member]
Variable Interest Entity Consolidated Carrying Amounts, Real Estate Assets, net	$60,575,000	$234,532,000	'	'	'	'	'	'
Preferred Units, Issued	'	'	'	'	4,000,000	4,000,000	4,000,000	4,000,000
Preferred Units, Outstanding	'	'	'	'	4,000,000	4,000,000	4,000,000	4,000,000
Preferred stock dividend rate percentage	'	'	'	'	6.88%	6.88%	6.38%	6.38%
Preferred Stock Liquidation preference	'	'	'	'	$100,000,000	$100,000,000	$100,000,000	$100,000,000
General partner, units issued	'	'	82,218,332	82,153,944	'	'	'	'
General partners, units outstanding	'	'	82,218,332	82,153,944	'	'	'	'
Limited partners, units issued	'	'	1,804,200	1,805,200	'	'	'	'
Common units held by limited partners	'	'	1,804,200	1,805,200	'	'	'	'

Consolidated_Statements_of_Ope1

Consolidated Statements of Operations (KILROY REALTY, L.P.) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
REVENUES:	'	'
Rental income	$112,056	$101,607
Tenant reimbursements	11,572	9,130
Other property income (Note 12)	2,157	227
Total revenues	125,785	110,964
EXPENSES:	'	'
Property expenses	25,094	22,805
Real estate taxes	11,173	9,664
Provision for bad debts	0	95
Ground leases	762	847
General and administrative expenses	10,811	9,669
Acquisition-related expenses	228	655
Depreciation and amortization	49,202	47,701
Total expenses	97,270	91,436
OTHER (EXPENSES) INCOME:	'	'
Interest income and other net investment gains (Note 11)	177	392
Interest expense (Note 5)	-17,252	-19,734
Total other (expenses) income	-17,075	-19,342
INCOME FROM CONTINUING OPERATIONS	11,440	186
DISCONTINUED OPERATIONS (Note 13)	'	'
Income from discontinued operations	377	2,202
Net gain on dispositions of discontinued operations	90,115	0
Total income from discontinued operations	90,492	2,202
NET INCOME	101,932	2,388
NET INCOME ATTRIBUTABLE TO KILROY REALTY CORPORATION	99,845	2,410
Preferred dividends	-3,313	-3,313
NET INCOME (LOSS) AVAILABLE TO COMMON STOCKHOLDERS	96,532	-903
Income (loss) from continuing operations available to common unitholders per common unit - basic (Note 15)	$0.09	($0.05)
Income (loss) from continuing operations available to common unitholders per common unit - diluted (Note 15)	$0.09	($0.05)
Net income (loss) available to common unitholders per unit-basic (Note 14)	$1.17	($0.02)
Net income (loss) available to common unitholders per unit-diluted (Note 14)	$1.14	($0.02)
Weighted average common units outstanding - basic (Note 14)	82,124,538	74,977,240
Weighted average common units outstanding - diluted (Note 14)	84,140,070	74,977,240
Kilroy Realty, L.P. [Member]	'	'
REVENUES:	'	'
Rental income	112,056	101,607
Tenant reimbursements	11,572	9,130
Other property income (Note 12)	2,157	227
Total revenues	125,785	110,964
EXPENSES:	'	'
Property expenses	25,094	22,805
Real estate taxes	11,173	9,664
Provision for bad debts	0	95
Ground leases	762	847
General and administrative expenses	10,811	9,669
Acquisition-related expenses	228	655
Depreciation and amortization	49,202	47,701
Total expenses	97,270	91,436
OTHER (EXPENSES) INCOME:	'	'
Interest income and other net investment gains (Note 11)	177	392
Interest expense (Note 5)	-17,252	-19,734
Total other (expenses) income	-17,075	-19,342
INCOME FROM CONTINUING OPERATIONS	11,440	186
DISCONTINUED OPERATIONS (Note 13)	'	'
Income from discontinued operations	377	2,202
Net gain on dispositions of discontinued operations	90,115	0
Total income from discontinued operations	90,492	2,202
NET INCOME	101,932	2,388
Net income attributable to noncontrolling interests in consolidated subsidiaries	-65	-69
NET INCOME ATTRIBUTABLE TO KILROY REALTY CORPORATION	101,867	2,319
Preferred dividends	-3,313	-3,313
NET INCOME (LOSS) AVAILABLE TO COMMON STOCKHOLDERS	$98,554	($994)
Income (loss) from continuing operations available to common unitholders per common unit - basic (Note 15)	$0.09	($0.05)
Income (loss) from continuing operations available to common unitholders per common unit - diluted (Note 15)	$0.09	($0.05)
Net income (loss) available to common unitholders per unit-basic (Note 14)	$1.17	($0.02)
Net income (loss) available to common unitholders per unit-diluted (Note 14)	$1.14	($0.02)
Weighted average common units outstanding - basic (Note 14)	83,928,993	76,803,743
Weighted average common units outstanding - diluted (Note 14)	85,944,525	76,803,743
Dividends declared per common unit	$0.35	$0.35

Consolidated_Statements_of_Cap

Consolidated Statements of Capital (KILROY REALTY, L.P.) (Kilroy Realty, L.P. [Member], USD $)

3 Months Ended

3 Months Ended

In Thousands, except Share data, unless otherwise specified

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2013

Dec. 31, 2012

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Total Partners Capital [Member]

Total Partners Capital [Member]

Partners Capital Preferred Units [Member]

Partners Capital Preferred Units [Member]

Partners Capital Preferred Units [Member]

Partners Capital Preferred Units [Member]

Partners Capital Common Unit [Member]

Partners Capital Common Unit [Member]

Noncontrolling Interest In Consolidated Subsidiaries [Member]

Noncontrolling Interest In Consolidated Subsidiaries [Member]

Increase (Decrease) in Stockholders' Equity [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

'

Beginning Balance

$2,516,160

$2,235,933

$2,507,772

$2,232,654

$192,411

$192,411

$192,411

$192,411

$2,315,361

$2,040,243

$8,388

$3,279

Beginning Balance units

'

'

'

'

'

'

'

'

83,959,144

76,753,484

'

'

Net income

101,932

2,388

101,867

2,319

'

'

'

'

101,867

2,319

65

69

Issuance of common units

'

'

'

'

'

'

'

'

'

453,679

'

'

Issuance of common units

'

23,395

'

23,395

'

'

'

'

'

23,395

'

'

Issuance of share-based compensation awards, units

'

'

'

'

'

'

'

'

'

0

'

'

Partners' Capital Account, Unit-based Compensation

'

'

'

'

'

'

'

'

'

336

'

'

Issuance of share-based compensation awards

'

336

'

336

'

'

'

'

'

'

'

'

Noncash amortization of share-based compensation

2,233

2,422

2,233

2,422

'

'

'

'

2,233

2,422

'

'

Repurchase of common units and restricted stock units, shares

'

'

'

'

'

'

'

'

-26,074

-33,534

'

'

Repurchase of common units and restricted stock units

-1,517

1,199

-1,517

-1,199

'

'

'

'

-1,517

-1,199

'

'

Settlement of restricted stock units, shares

'

'

'

'

'

'

'

'

88,962

2,579

'

'

Settlement of restricted stock units

'

'

'

'

'

'

'

'

0

-10

'

'

Settlement of restricted stock units

0

-10

0

-10

'

'

'

'

'

'

'

'

Exercise of stock options, net, units

'

'

'

'

'

'

'

'

500

'

'

'

Exercise of stock options, net

21

'

21

'

'

'

'

'

21

'

'

'

Dividends, Preferred Stock

-3,313

-3,313

-3,313

-3,313

'

'

'

'

-3,313

-3,313

'

'

Partners' Capital Account, Distributions

'

'

'

'

'

'

'

'

-29,906

-27,412

'

'

Distributions declared per common unit ($1.05 per unit)

-29,906

-27,412

-29,906

-27,412

'

'

'

'

'

'

'

'

Ending Balance

$2,585,610

$2,232,540

$2,577,157

$2,229,192

$192,411

$192,411

$192,411

$192,411

$2,384,746

$2,036,781

$8,453

$3,348

Ending Balance units

'

'

'

'

'

'

'

'

84,022,532

77,176,208

'

'

Consolidated_Statements_of_Cap1

Consolidated Statements of Capital (KILROY REALTY, L.P.) (Parenthetical) (Kilroy Realty, L.P. [Member], USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Kilroy Realty, L.P. [Member]	'	'
Distributions Per Limited Partnership and General Partnership Unit, Outstanding, Basic	$0.35	$0.35

Consolidated_Statements_of_Cas1

Consolidated Statements of Cash Flows (KILROY REALTY, L.P.) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:	'	'
Net income	$101,932	$2,388
Adjustments to reconcile net income to net cash provided by operating activities (including discontinued operations):	'	'
Depreciation and amortization of building and improvements and leasing costs	48,717	50,011
Increase in provision for bad debts	0	95
Depreciation of furniture, fixtures and equipment	485	380
Noncash amortization of share-based compensation awards	2,502	2,234
Noncash amortization of deferred financing costs and debt discounts and premiums	1,256	1,413
Noncash amortization of net below market rents (Note 3)	-1,734	-2,047
Net gain on dispositions of discontinued operations (Note 13)	-90,115	0
Noncash amortization of deferred revenue related to tenant-funded tenant improvements	-2,353	-2,442
Straight-line rents	-3,959	-6,724
Net change in other operating assets	-5,949	-7,390
Net change in other operating liabilities	-5,701	18,581
Net cash provided by operating activities	45,081	56,499
CASH FLOWS FROM INVESTING ACTIVITIES:	'	'
Expenditures for acquisition of operating properties (Note 2)	-106,125	-85,692
Expenditures for operating properties	-32,016	-25,571
Expenditures for development and redevelopment properties and undeveloped land	-73,626	-73,369
Net proceeds received from dispositions of operating properties (Note 13)	309,824	0
(Increase) decrease in restricted cash (Notes 1 and 13)	-779	228,079
Net cash provided by investing activities	97,278	43,447
CASH FLOWS FROM FINANCING ACTIVITIES:	'	'
Borrowings on unsecured line of credit	90,000	0
Repayments on unsecured line of credit	-135,000	-185,000
Principal payments on secured debt	-2,414	-84,918
Proceeds from the issuance of unsecured debt	0	299,901
Financing costs	-418	-2,870
Repurchase of common stock and restricted stock units	-1,517	-1,209
Proceeds from exercise of stock options	21	0
Distributions paid to common unitholders	-29,561	-26,956
Distributions paid to preferred unitholders	-3,313	-3,313
Net cash (used in) provided by financing activities	-82,202	19,030
Net increase in cash and cash equivalents	60,157	118,976
Cash and cash equivalents, beginning of period	35,377	16,700
Cash and cash equivalents, end of period	95,534	135,676
SUPPLEMENTAL CASH FLOWS INFORMATION:	'	'
Cash paid for interest, net of capitalized interest of $10,042 and $7,175 as of March 31, 2014 and 2013, respectively	14,106	11,303
NONCASH INVESTING TRANSACTIONS:	'	'
Accrual for expenditures for operating properties and development and redevelopment properties	64,709	42,140
Tenant improvements funded directly by tenants	4,470	1,426
Assumption of secured debt in connection with property acquisitions	0	95,496
Assumption of other assets and liabilities in connection with operating and development property acquisitions, net	0	422
NONCASH FINANCING TRANSACTIONS:	'	'
Accrual of distributions payable to common unitholders	29,906	27,011
Accrual of distributions payable to preferred unitholders	1,656	1,694
Grant date fair value of share-based compensation awards	0	8,451
Kilroy Realty, L.P. [Member]	'	'
CASH FLOWS FROM OPERATING ACTIVITIES:	'	'
Net income	101,932	2,388
Adjustments to reconcile net income to net cash provided by operating activities (including discontinued operations):	'	'
Depreciation and amortization of building and improvements and leasing costs	48,717	50,011
Increase in provision for bad debts	0	95
Depreciation of furniture, fixtures and equipment	485	380
Noncash amortization of share-based compensation awards	2,502	2,234
Noncash amortization of deferred financing costs and debt discounts and premiums	1,256	1,413
Noncash amortization of net below market rents (Note 3)	-1,734	-2,047
Net gain on dispositions of discontinued operations (Note 13)	-90,115	0
Noncash amortization of deferred revenue related to tenant-funded tenant improvements	-2,353	-2,442
Straight-line rents	-3,959	-6,724
Net change in other operating assets	-5,949	-7,390
Net change in other operating liabilities	-5,701	18,581
Net cash provided by operating activities	45,081	56,499
CASH FLOWS FROM INVESTING ACTIVITIES:	'	'
Expenditures for acquisition of operating properties (Note 2)	-106,125	-85,692
Expenditures for operating properties	-32,016	-25,571
Expenditures for development and redevelopment properties and undeveloped land	-73,626	-73,369
Net proceeds received from dispositions of operating properties (Note 13)	309,824	0
(Increase) decrease in restricted cash (Notes 1 and 13)	-779	228,079
Net cash provided by investing activities	97,278	43,447
CASH FLOWS FROM FINANCING ACTIVITIES:	'	'
Proceeds from Issuance of common units	0	23,395
Borrowings on unsecured line of credit	90,000	0
Repayments on unsecured line of credit	-135,000	-185,000
Principal payments on secured debt	-2,414	-84,918
Proceeds from the issuance of unsecured debt	0	299,901
Financing costs	-418	-2,870
Repurchase of common stock and restricted stock units	-1,517	-1,209
Proceeds from exercise of stock options	21	0
Distributions paid to common unitholders	-29,561	-26,956
Distributions paid to preferred unitholders	-3,313	-3,313
Net cash (used in) provided by financing activities	-82,202	19,030
Net increase in cash and cash equivalents	60,157	118,976
Cash and cash equivalents, beginning of period	35,377	16,700
Cash and cash equivalents, end of period	95,534	135,676
SUPPLEMENTAL CASH FLOWS INFORMATION:	'	'
Cash paid for interest, net of capitalized interest of $10,042 and $7,175 as of March 31, 2014 and 2013, respectively	14,106	11,303
NONCASH INVESTING TRANSACTIONS:	'	'
Accrual for expenditures for operating properties and development and redevelopment properties	64,709	42,140
Tenant improvements funded directly by tenants	4,470	1,426
Assumption of secured debt in connection with property acquisitions	0	95,496
Assumption of other assets and liabilities in connection with operating and development property acquisitions, net	0	422
NONCASH FINANCING TRANSACTIONS:	'	'
Accrual of distributions payable to common unitholders	29,906	27,011
Accrual of distributions payable to preferred unitholders	1,656	1,694
Grant date fair value of share-based compensation awards	$0	$8,451

Consolidated_Statements_of_Cas2

Consolidated Statements of Cash Fiows (Kilroy Realty, L.P.) (Parenthetical) (Kilroy Realty, L.P. [Member], USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Kilroy Realty, L.P. [Member]	'	'
Interest Paid, Capitalized	$10,042	$7,175

Organization_and_Basis_of_Pres

Organization and Basis of Presentation	3 Months Ended
	Mar. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Organization and Basis of Presentation	'
	Organization and Basis of Presentation
	Organization
	Kilroy Realty Corporation (the “Company”) is a self-administered real estate investment trust (“REIT”) active in premier office submarkets along the West Coast. We own, develop, acquire and manage real estate assets, consisting primarily of Class A properties in the coastal regions of Los Angeles, Orange County, San Diego County, the San Francisco Bay Area and greater Seattle, 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”) and Kilroy Realty Finance Partnership, L.P. (the “Finance Partnership”). We 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 office properties at March 31, 2014:
		Number of		Rentable	Number of	Percentage
		Buildings		Square Feet	Tenants	Occupied
	Stabilized Office Properties	107		13,305,145	527	92.4	%
	Our stabilized portfolio includes all of our properties with the exception of real estate assets held for sale, undeveloped land, development and redevelopment properties currently under construction or committed for construction, and “lease-up” properties. 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 “lease-up” properties as properties we recently developed or redeveloped that have not yet reached 95% occupancy and are within one year following cessation of major construction activities. During the first quarter of 2014, we stabilized a redevelopment property in San Francisco, California. As a result, this property is included in our stabilized portfolio as of March 31, 2014.
	As of March 31, 2014, the following properties were excluded from our stabilized portfolio:
		Number of Properties	Estimated Rentable
			Square Feet
	Development properties under construction (1)	6	2,538,000
	_______________
	-1	Estimated rentable square feet upon completion.
	As of March 31, 2014, all of our properties and development and redevelopment projects and all of our business was conducted in the state of California with the exception of thirteen office properties located in the state of Washington. All of our properties and development and redevelopment projects are 100% owned, excluding a development project owned by Redwood City Partners, LLC, a consolidated subsidiary (see Note 6) and certain properties held in connection with potential like-kind exchanges pursuant to Section 1031 of the Code (“Section 1031 Exchanges”) to defer taxable gains on dispositions for federal and state income tax purposes that have been consolidated for financial reporting purposes.
	As of March 31, 2014, the Company owned a 97.9% common general partnership interest in the Operating Partnership. The remaining 2.1% common limited partnership interest in the Operating Partnership as of March 31, 2014 was owned by non-affiliated investors and certain of our executive officers and directors (see Note 6). Both the general and limited common partnership interests in the Operating Partnership are denominated in common units. The number of common units held by the Company is at all times 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”) (see Note 6).
	Kilroy Realty Finance, Inc., which is a wholly owned subsidiary of the Company, is the sole general partner of the Finance Partnership and owns a 1.0% common general partnership interest in the Finance Partnership. The Operating Partnership owns the remaining 99.0% common limited partnership interest. Kilroy Services, LLC (“KSLLC”), which is a wholly owned subsidiary of the Operating Partnership, is the entity through which we conduct substantially all of our development activities. With the exception of the Operating Partnership and Redwood City Partners, LLC, all of our subsidiaries are wholly owned.
	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, the Finance Partnership, KSLLC, Redwood City Partners, 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, the Finance Partnership, KSLLC, Redwood City Partners, LLC and all wholly-owned and controlled subsidiaries of the Operating Partnership. All intercompany balances and transactions have been eliminated in the consolidated financial statements.
	The accompanying interim financial statements have been prepared by management in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and in conjunction with the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures required for annual financial statements have been condensed or excluded pursuant to SEC rules and regulations. Accordingly, the interim financial statements do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, the accompanying interim financial statements reflect all adjustments of a normal and recurring nature that are considered necessary for a fair presentation of the results for the interim periods presented. However, the results of operations for the interim periods are not necessarily indicative of the results that may be expected for the year ending December 31, 2014. The interim financial statements for the Company and the Operating Partnership should be read in conjunction with the audited consolidated financial statements and notes thereto included in our annual report on Form 10-K for the year ended December 31, 2013.
	Certain amounts in the consolidated statements of operations for prior periods have been reclassified to reflect the activity of discontinued operations.
	Variable Interest Entities
	At March 31, 2014, the consolidated financial statements of the Company and the Operating Partnership included one variable interest entity (“VIE”), Redwood City Partners, LLC, in which we were deemed to be the primary beneficiary. This VIE was established in the second quarter of 2013 in connection with an undeveloped land acquisition. The impact of consolidating the VIE increased the Company’s total assets, liabilities and noncontrolling interests by approximately $61.6 million (of which $60.6 million related to real estate held for investment on our consolidated balance sheet), approximately $6.8 million and approximately $4.9 million, respectively, as of March 31, 2014. As of December 31, 2013, the consolidated financial statements of the Company and the Operating Partnership included four VIEs, in which we were deemed to be the primary beneficiary. One of the VIEs was Redwood City Partners, LLC and the remaining three VIEs were established during the third and fourth quarter of 2013 to facilitate a potential Section 1031 Exchange. During the three months ended March 31, 2014, the Section 1031 Exchanges were successfully completed and the three VIEs were terminated. As a result, $32.2 million of our restricted cash balance at December 31, 2013, which related to prior period disposition proceeds that were set aside to facilitate the Section 1031 Exchanges, was released from escrow. The impact of consolidating the VIEs increased the Company’s total assets, liabilities and noncontrolling interests by approximately $251.8 million (of which $234.5 million related to real estate held for investment on our consolidated balance sheet), approximately $12.1 million and approximately $4.9 million, respectively, as of December 31, 2013.
	Recent Accounting Pronouncements
	On April 10, 2014, the Financial Accounting Standards Board issued final guidance to change the criteria for reporting discontinued operations while enhancing disclosures in this area (Accounting Standards Update (“ASU”) No. 2014-08). Under the new guidance, only disposals representing a strategic shift, such as a major line of business, a major geographical area or a major equity investment, should be presented as discontinued operations. The guidance will be applied prospectively to new disposals and new classifications of disposal groups as held for sale after the effective date. The guidance is effective for annual financial statements with fiscal years beginning on or after December 15, 2014 with early adoption permitted for disposals or classifications as held for sale which have not been reported in financial statements previously issued or available for issuance. The Company will adopt the guidance effective January 1, 2015 and the guidance is not anticipated to have a material impact on our consolidated financial statements and notes to our consolidated financial statements.
	On March 13, 2014, the Emerging Issues Task Force (the “Task Force”) reached a final consensus to amend the accounting guidance for stock compensation tied to performance targets (Issue No. 13-D). The objective of this guidance is to clarify the accounting treatment of certain types of performance conditions in stock-based compensation awards, more specifically, when performance targets can be achieved after the requisite service period. The Task Force concluded that performance criteria subsequent to a service period vesting requirement should be treated as vesting conditions, and as a result, this type of performance condition may delay expense recognition until achievement of the performance target is probable. Issue No. 13-D will be effective for all entities for reporting periods (including interim periods) beginning after December 15, 2015, and early adoption is permitted. The adoption of this guidance is not anticipated to have a material impact on our consolidated financial statements or notes to our consolidated financial statements.

Acquisitions

Acquisitions	3 Months Ended
	Mar. 31, 2014
Business Combinations [Abstract]	'
Acquisitions	'
	Acquisitions
	Operating Properties
	During the three months ended March 31, 2014, we acquired the one operating office property, listed below, from an unrelated third party. The acquisition was funded with proceeds from the 2013 and 2014 dispositions (see Note 13).
	Property		Date of Acquisition	Number of	Rentable Square	Occupancy as of March 31, 2014	Purchase
				Buildings	Feet		Price
							(in millions)
	401 Terry Avenue North, Seattle, WA		March 13, 2014	1	140,605	100.00%	$	106.1
	The related assets, liabilities and results of operations of the acquired property are included in the consolidated financial statements as of the date of acquisition. The following table summarizes the estimated fair values of the assets acquired and liabilities assumed on the acquisition date:
		Total 2014
		Acquisitions
		(in thousands)
	Assets
	Land and improvements	$	22,500
	Buildings and improvements (1)	77,046
	Deferred leasing costs and acquisition-related intangible assets (2)	11,199
	Total assets acquired	110,745
	Liabilities
	Deferred revenue and acquisition-related intangible liabilities (3)	4,620
	Total liabilities assumed	4,620
	Net assets and liabilities acquired	$	106,125
	_______________
	-1	Represents buildings, building improvements and tenant improvements.
	-2	Represents in-place leases of approximately $9.3 million (with a weighted average amortization period of seven years) and leasing commissions of approximately $1.9 million (with a weighted average amortization period of seven years).
	-3	Represents below-market leases of approximately $4.6 million (with a weighted average amortization period of seven years).

Deferred_Leasing_Costs_and_Acq

Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, net	3 Months Ended
	Mar. 31, 2014
Intangible Assets and Liabilities 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, in-place leases and below-market ground lease obligation) and intangible liabilities (acquired value of below-market operating leases and above-market ground lease obligation) as of March 31, 2014 and December 31, 2013:
		March 31, 2014			December 31, 2013
		(in thousands)
	Deferred Leasing Costs and Acquisition-Related Intangible Assets, net:
	Deferred leasing costs	$	183,813		$	178,720
	Accumulated amortization	(68,152		)	(63,246		)
	Deferred leasing costs, net	115,661			115,474
	Above-market operating leases	27,351			27,635
	Accumulated amortization	(15,489		)	(14,283		)
	Above-market operating leases, net	11,862			13,352
	In-place leases	104,643			100,318
	Accumulated amortization	(44,175		)	(42,999		)
	In-place leases, net	60,468			57,319
	Below-market ground lease obligation	490			490
	Accumulated amortization	(15		)	(13		)
	Below-market ground lease obligation, net	475			477
	Total deferred leasing costs and acquisition-related intangible assets, net	$	188,466		$	186,622
	Acquisition-Related Intangible Liabilities, net: (1)
	Below-market operating leases	$	73,522		$	69,385
	Accumulated amortization	(28,316		)	(25,706		)
	Below-market operating leases, net	45,206			43,679
	Above-market ground lease obligation	6,320			6,320
	Accumulated amortization	(248		)	(223		)
	Above-market ground lease obligation, net	6,072			6,097
	Total acquisition-related intangible liabilities, net	$	51,278		$	49,776
	_______________
	-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, including amounts attributable to discontinued operations, for the three months ended March 31, 2014 and 2013:
		Three Months Ended March 31,
		2014			2013
		(in thousands)
	Deferred leasing costs (1)	$	6,780		$	7,844
	Above-market operating leases (2)	1,490			1,438
	In-place leases (1)	6,136			7,458
	Below-market ground lease obligation (3)	—			2
	Below-market operating leases (4)	(3,093		)	(3,485		)
	Above-market ground lease obligation (5)	(25		)	(25		)
	Total	$	11,288		$	13,232
	_______________
	-1	The amortization of deferred leasing costs related to lease incentives is recorded to rental income and other deferred leasing costs and in-place leases is recorded to depreciation and amortization expense in the consolidated statements of operations for the periods presented.
	-2	The amortization of above-market operating leases is recorded as a decrease to rental income in the consolidated statements of operations for the periods presented.
	-3	The amortization of the below-market ground lease obligation is recorded as an increase to ground lease expense in the consolidated statements of operations for the periods presented.
	-4	The amortization of below-market operating leases is recorded as an increase to rental income in the consolidated statements of operations for the periods presented.
	-5	The amortization of the 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 following table sets forth the estimated annual amortization expense related to deferred leasing costs and acquisition-related intangibles as of March 31, 2014 for future periods:
	Year	Deferred Leasing Costs			Above-Market Operating Leases (1)			In-Place Leases		Below-Market Ground Lease Obligation (2)		Below-Market Operating Leases (3)			Above-Market Ground Lease Obligation (4)
		(in thousands)
	Remaining 2014	$	20,006		$	3,830		$	15,274	$	6	$	(9,802	)	$	(76	)
	2015	22,162			2,918			13,562		8		(9,577		)	(101		)
	2016	19,351			1,891			10,475		8		(7,847		)	(101		)
	2017	16,742			1,573			8,774		8		(6,780		)	(101		)
	2018	13,416			973			5,689		8		(5,177		)	(101		)
	Thereafter	23,984			677			6,694		437		(6,023		)	(5,592		)
	Total	$	115,661		$	11,862		$	60,468	$	475	$	(45,206	)	$	(6,072	)
	_______________
	-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 ground lease obligations. Amounts will be recorded as an increase to ground lease expense in the consolidated statements of operations.
	-3	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.
	-4	Represents estimated annual amortization related to above-market ground lease obligations. Amounts will be recorded as a decrease to ground lease expense in the consolidated statements of operations.

Receivables

Receivables	3 Months Ended
	Mar. 31, 2014
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 March 31, 2014 and December 31, 2013:
		March 31, 2014			December 31, 2013
		(in thousands)
	Current receivables	$	13,226		$	12,866
	Allowance for uncollectible tenant receivables	(2,134		)	(2,123		)
	Current receivables, net	$	11,092		$	10,743
	Deferred Rent Receivables, net
	Deferred rent receivables, net consisted of the following as of March 31, 2014 and December 31, 2013:
		March 31, 2014			December 31, 2013
		(in thousands)
	Deferred rent receivables	$	132,740		$	129,198
	Allowance for deferred rent receivables	(1,990		)	(2,075		)
	Deferred rent receivables, net	$	130,750		$	127,123

Secured_and_Unsecured_Debt_of_

Secured and Unsecured Debt of the Operating Partnership (Kilroy Realty, L.P. [Member])	3 Months Ended
	Mar. 31, 2014
Kilroy Realty, L.P. [Member]	'
Debt Instrument [Line Items]	'
Secured and Unsecured Debt of the Operating Partnership	'
	Secured and Unsecured Debt of the Operating Partnership
	Secured Debt
	The following table sets forth the composition of our secured debt as of March 31, 2014 and December 31, 2013:
	Type of Debt	Annual Stated Interest Rate (1)		GAAP	Maturity Date		March 31, 2014 (3)				December 31, 2013 (3)
				Effective Rate (1)(2)
							(in thousands)
	Mortgage note payable	4.27%		4.27%	Feb-18		$	132,539			$	133,117
	Mortgage note payable (4)	4.48%		4.48%	Jul-27		97,000				97,000
	Mortgage note payable (4)	6.05%		3.50%	Jun-19		91,696				92,502
	Mortgage note payable	6.51%		6.51%	Feb-17		67,415				67,663
	Mortgage note payable (4)	5.23%		3.50%	Jan-16		54,120				54,570
	Mortgage note payable (4)	5.57%		3.25%	Feb-16		41,300				41,654
	Mortgage note payable (4)	5.09%		3.50%	Aug-15		34,712				34,845
	Mortgage note payable (4)	4.94%		4.00%	Apr-15		27,307				27,641
	Mortgage note payable	7.15%		7.15%	May-17		8,387				8,972
	Other	Various		Various	Various		2,470				2,470
	Total						$	556,946			$	560,434
	______________
	-1	All interest rates presented are fixed-rate interest rates.
	-2	This represents the rate at which interest expense is recorded for financial reporting purposes, which reflects the amortization of discounts/premiums, excluding debt issuance costs.
	-3	Amounts reported include the amounts of unamortized debt premiums and discounts for the periods presented.
	-4	The secured debt and the related properties that secure the 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.
	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.
	4.25% Exchangeable Senior Notes
	The table below summarizes the balance and significant terms of the Company’s 4.25% Exchangeable Notes due November 2014 (the “4.25% Exchangeable Notes”) outstanding as of March 31, 2014 and December 31, 2013.
		4.25% Exchangeable Notes
		March 31,			December 31,
		2014			2013
		(in thousands)
	Principal amount	$	172,500		$	172,500
	Unamortized discount	(2,972		)	(4,128		)
	Net carrying amount of liability component	$	169,528		$	168,372
	Carrying amount of equity component	$19,835
	Issuance date	Nov-09
	Maturity date	Nov-14
	Stated coupon rate (1)	4.25%
	Effective interest rate (2)	7.13%
	Exchange rate per $1,000 principal value of the 4.25% Exchangeable Notes, as adjusted (3)	27.8307
	Exchange price, as adjusted (3)	$35.93
	Number of shares on which the aggregate consideration to be delivered on conversion is determined (3)	4,800,796
	_______________
	-1	Interest on the 4.25% Exchangeable Notes is payable semi-annually in arrears on May 15th and November 15th of each year.
	-2	The rate at which we record interest expense for financial reporting purposes, which reflects the amortization of the discounts on the 4.25% Exchangeable Notes. This rate represents our conventional debt borrowing rate at the date of issuance.
	-3	The exchange rate, exchange price and the number of shares to be delivered upon conversion are subject to adjustment under certain circumstances including increases in our common dividends.
	The 4.25% Exchangeable Notes are exchangeable for shares of the Company’s common stock prior to maturity only upon the occurrence of certain events. During the three months ended March 31, 2014, the closing sale price per share of the common stock of the Company was more than 130% of the exchange price per share of the Company’s common stock for at least 20 trading days in the specified period. As a result, for the three month period ended March 31, 2014, the 4.25% Exchangeable Notes are exchangeable at the exchange rate stated above and may be exchangeable thereafter, if one or more of the events were again to occur during future measurement periods.
	For the three months ended March 31, 2014 and 2013, the per share average trading price of the Company’s common stock on the NYSE was higher than the $35.93 exchange price for the 4.25% Exchangeable Notes, as presented below:
		Three Months Ended March 31,
		2014		2013
	Per share average trading price of the Company’s common stock	$55.18		$51.14
	The 4.25% Exchangeable Notes were exchangeable as of March 31, 2014 and March 31, 2013. If the Exchangeable Notes were exchanged, the approximate fair value of the shares upon exchange at March 31, 2014 and 2013, using the per share average trading price presented in the table above, would have been as follows:
		Three Months Ended March 31,
		2014			2013
		(in thousands)
	Approximate fair value of shares upon exchange	$	270,602		$	247,300
	Principal amount of the 4.25% Exchangeable Notes	172,500			172,500
	Approximate fair value in excess amount of principal amount	$	98,102		$	74,800
	See Notes 14 and 15 for a discussion of the impact of the 4.25% Exchangeable Notes on our diluted earnings per share and unit calculations for the periods presented.
	Interest Expense for the Exchangeable Notes
	The unamortized discount on the 4.25% Exchangeable Notes is accreted as additional interest expense from the date of issuance through the maturity date of the applicable Exchangeable Notes. The following table summarizes the total interest expense attributable to the 4.25% Exchangeable Notes based on the respective effective interest rates, before the effect of capitalized interest, for the three months ended March 31, 2014 and 2013:
		Three Months Ended March 31,
		2014			2013
		(in thousands)
	Contractual interest payments	$	1,833		$	1,833
Amortization of discount	1,156			1,078
Interest expense attributable to the Exchangeable Notes	$	2,989		$	2,911
Capped Call Transactions
In connection with the offering of the 4.25% Exchangeable Notes, we entered into capped call option transactions (“capped calls”) to mitigate the dilutive impact of the potential exchange of the 4.25% Exchangeable Notes. The table below summarizes our capped call option positions for the 4.25% Exchangeable Notes as of March 31, 2014 and December 31, 2013.
	4.25% Exchangeable Notes
Referenced shares of common stock	4,800,796
Exchange price including effect of capped calls	$	42.81
The capped calls are expected to terminate upon the earlier of the maturity date of the 4.25% Exchangeable Notes or upon the date upon which the 4.25% Exchangeable Notes are no longer outstanding resulting from an exchange or repurchase by us. The initial cost of capped calls were recorded as a reduction to additional paid-in capital.
Unsecured Senior Notes
The following table summarizes the balance and significant terms of the registered unsecured senior notes issued by the Operating Partnership as of March 31, 2014 and December 31, 2013:
								Principal Amount as of
	Issuance date		Maturity date	Stated		Effective interest rate (1)		March 31,				December 31,
				coupon rate				2014				2013
								(in thousands)
3.800% Unsecured Senior Notes (2)	Jan-13		Jan-23	3.80%		3.80%		$	300,000			$	300,000
Unamortized discount								(87		)		(90		)
Net carrying amount								$	299,913			$	299,910
4.800% Unsecured Senior Notes (3)	Jul-11		Jul-18	4.80%		4.83%		$	325,000			$	325,000
Unamortized discount								(320		)		(339		)
Net carrying amount								$	324,680			$	324,661
6.625% Unsecured Senior Notes (4)	May-10		Jun-20	6.63%		6.74%		$	250,000			$	250,000
Unamortized discount								(1,313		)		(1,367		)
Net carrying amount								$	248,687			$	248,633
5.000% Unsecured Senior Notes (5)	Nov-10		Nov-15	5.00%		5.01%		$	325,000			$	325,000
Unamortized discount								(63		)		(73		)
Net carrying amount								$	324,937			$	324,927
________________________
-1	This represents the rate at which interest expense is recorded for financial reporting purposes, which reflects the amortization of initial issuance discounts, excluding debt issuance costs.
-2	Interest on the 3.800% unsecured senior notes is payable semi-annually in arrears on January 15th and July 15th of each year.
-3	Interest on the 4.800% unsecured senior notes is payable semi-annually in arrears on January 15th and July 15th of each year.
-4	Interest on the 6.625% unsecured senior notes is payable semi-annually in arrears on June 1st and December 1st of each year.
-5	Interest on the 5.000% unsecured senior notes is payable semi-annually in arrears on May 3rd and November 3rd of each year.
In addition to the registered unsecured senior note issuances listed above, we also had outstanding Series B unsecured senior notes with an aggregate principal balance of $83.0 million and effective interest rate of 6.45% as of March 31, 2014 and December 31, 2013, that mature in August 2014. The Series B notes require semi-annual interest payment each February 4th and August 4th of each year based on a fixed annual interest rate of 6.45%.
Term Loan Facility
The Company’s outstanding borrowings under the term loan facility were $150.0 million as of March 31, 2014 and December 31, 2013. The term loan facility bears interest at an annual rate of LIBOR plus 1.750%, which can vary depending on the Operating Partnership’s credit rating, and is scheduled to mature on March 29, 2016. Under the terms of the term loan facility, we may exercise an option to extend the maturity date by one year. We may elect to borrow up to an additional $100.0 million under an accordion option, subject to bank approval and obtaining commitments for any additional borrowing capacity.
Unsecured Revolving Credit Facility
The following table summarizes the balance and terms of our revolving credit facility as of March 31, 2014 and December 31, 2013:
	March 31,			December 31,
	2014			2013
	(in thousands)
Outstanding borrowings	$	—		$	45,000
Remaining borrowing capacity	500,000			455,000
Total borrowing capacity (1)	$	500,000		$	500,000
Interest rate (2)	—		%	1.62		%
Facility fee-annual rate (3)	0.30%
Maturity date (4)	Apr-17
_______________
-1	We may elect to borrow, subject to bank approval and obtaining commitments for any additional borrowing capacity, up to an additional $200.0 million under an accordion feature under the terms of the revolving credit facility.
-2	The revolving credit facility interest rate was calculated based on an annual rate of LIBOR plus 1.450% as of both March 31, 2014 and December 31, 2013.
-3	The facility fee is paid on a quarterly basis and is calculated based on the total borrowing capacity. In addition to the facility fee, from 2010 to 2012 we incurred debt origination and legal costs of which, as of March 31, 2014, approximately $4.5 million remains to be amortized through the maturity date of the revolving credit facility.
-4	Under the terms of the revolving credit facility, we may exercise an option to extend the maturity date by one year.
The Company intends to borrow amounts under the revolving credit facility from time to time for general corporate purposes, to fund potential acquisitions, to finance development and redevelopment expenditures and to potentially repay long-term debt.
Debt Covenants and Restrictions
The revolving credit facility, the term loan facility, the unsecured senior notes, and certain other secured debt arrangements contain covenants and restrictions requiring us to meet certain financial ratios and reporting requirements. Some of the more restrictive financial covenants include a maximum ratio of total debt to total asset value, a minimum fixed-charge coverage ratio, a minimum unsecured debt ratio and a minimum unencumbered asset pool debt service coverage ratio. Noncompliance with one or more of the covenants and restrictions could result in the full or partial principal balance of the associated debt becoming immediately due and payable. We believe we were in compliance with all of our debt covenants as of March 31, 2014.
Debt Maturities
The following table summarizes the stated debt maturities and scheduled amortization payments, excluding debt discounts and premiums, as of March 31, 2014:
Year	(in thousands)
Remaining 2014	$	262,932
2015	395,104
2016	249,431
2017	71,748
2018	451,728
Thereafter	718,011
Total (1)	$	2,148,954
________________________
-1	Includes gross principal balance of outstanding debt before impact of net unamortized premiums totaling approximately $8.7 million.
Capitalized Interest and Loan Fees
The following table sets forth gross interest expense reported in continuing operations, including debt discount/premium and loan cost amortization, net of capitalized interest, for the three months ended March 31, 2014 and 2013. 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.
	Three Months Ended March 31,
	2014			2013
	(in thousands)
Gross interest expense	$	28,034		$	27,466
Capitalized interest	(10,782		)	(7,732		)
Interest expense	$	17,252		$	19,734

Noncontrolling_Interests_on_th

Noncontrolling Interests on the Company's Consolidated Financial Statements	3 Months Ended
	Mar. 31, 2014
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 a 97.9%, 97.8% and 97.6% common general partnership interest in the Operating Partnership as of March 31, 2014, December 31, 2013 and March 31, 2013, respectively. The remaining 2.1%, 2.2% and 2.4% common limited partnership interest as of March 31, 2014, December 31, 2013 and March 31, 2013, respectively, was owned by non-affiliate investors and certain of our executive officers and directors in the form of noncontrolling common units. There were 1,804,200, 1,805,200 and 1,826,503 common units outstanding held by these investors, executive officers and directors as of March 31, 2014, December 31, 2013 and March 31, 2013, 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 $105.4 million and $90.8 million as of March 31, 2014 and December 31, 2013, 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 Variable Interest Entity
	The noncontrolling interest in consolidated subsidiary represents the third party equity interest in Redwood City Partners, LLC, a consolidated VIE. This noncontrolling interest was $4.9 million at March 31, 2014 and December 31, 2013.

Stockholders_Equity_of_the_Com

Stockholders' Equity of the Company	3 Months Ended
	Mar. 31, 2014
Equity [Abstract]	'
Stockholders' Equity of the Company	'
	Stockholders’ Equity of the Company
	At-The-Market Stock Offering Program
	Under our at-the-market stock offering program, which commenced in July 2011, we may offer and sell shares of our common stock having an aggregate gross sales price of up to $200.0 million from time to time in “at-the-market” offerings. Since commencement of the program, we have sold 2,183,261 shares of common stock having an aggregate gross sales price of $105.3 million. As of March 31, 2014, shares of common stock having an aggregate gross sales price of up to $94.7 million remain available to be sold under this program. Actual future sales will depend upon a variety of factors, including but not limited to market conditions, the trading price of the Company’s common stock and our capital needs. We have no obligation to sell the remaining shares available for sale under this program. There were no sales of our common stock under our at-the-market offering program for the three months ended March 31, 2014.

Partners_Capital_of_the_Operat

Partners' Capital of the Operating Partnership	3 Months Ended
	Mar. 31, 2014
Partners' Capital Notes [Abstract]	'
Common Units of the Operating Partnership	'
	Partners’ Capital of the Operating Partnership
	Common Units Outstanding
	The following table sets forth the number of common units held by the Company and the number of common units held by non-affiliate investors and certain of our executive officers and directors in the form of noncontrolling common units as well as the ownership interest held on each respective date:
		March 31, 2014		December 31, 2013		March 31, 2013
	Company owned common units in the Operating Partnership	82,218,332		82,153,944		75,349,705
	Company owned general partnership interest	97.9	%	97.8	%	97.6	%
	Noncontrolling common units of the Operating Partnership	1,804,200		1,805,200		1,826,503
	Ownership interest of noncontrolling interest	2.1	%	2.2	%	2.4	%
	For a further discussion of the noncontrolling common units as of March 31, 2014 and December 31, 2013, refer to Note 6.

ShareBased_Compensation

Share-Based Compensation	3 Months Ended
	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Share-Based Compensation	'
	Share-Based Compensation
	Stockholder Approved Equity Compensation Plans
	As of March 31, 2014, we maintained one share-based incentive compensation plan, the Kilroy Realty 2006 Incentive Award Plan as amended (the “2006 Plan”). As of March 31, 2014, no shares were available for grant under the 2006 Plan. Under applicable NYSE listing rules, we may not increase the 2006 Plan share limit without stockholder approval. At our Annual Meeting of Stockholders, on May 22, 2014, stockholders will be asked to approve an amendment and restatement of the 2006 Plan which includes an increase in the share limit to 7,120,000 shares.
	2014 Share-Based Compensation Grants
	On January 29, 2014, the Executive Compensation Committee of the Company’s Board of Directors granted to certain officers of the Company under the 2006 Plan 236,604 restricted stock units (“RSUs”), 119,098 RSUs that are subject to market and performance-based vesting requirements (the “2014 Performance-Based RSU Grant”) and 117,506 RSUs that are subject to time-based vesting requirements (the “2014 Time-Based RSU Grant”).
	2014 Performance-Based RSU Grant
	The 2014 Performance-Based RSUs are scheduled to vest at the end of a three year period based upon the achievement of pre-established levels of FFO per share (the “performance condition”) for the year ended December 31, 2014 and also based upon the average annual relative stockholder return targets (the “market condition”) for the three year period ending December 31, 2016. The 2014 Performance-Based RSUs are also subject to a three-year service vesting provision and will cliff vest at the end of the three-year period. The number of 2014 Performance-Based RSUs ultimately earned could fluctuate based upon the levels of achievement for both the FFO and relative stockholder return metrics. Compensation expense for the 2014 Performance-Based RSU Grant will be recorded on a straight-line basis over the three year period.
	Each 2014 Performance-Based RSU represents the right to receive one share of our common stock in the future. However, in the event that our stockholders do not approve an increase to the share limit under our 2006 Plan, as discussed above, then the 2014 Performance-Based RSUs may be cash settled based on the fair market value of our common stock on the applicable vesting date. As a result, until a sufficient amount of shares are authorized by our stockholders for issuance under the 2006 Plan to cover the payment of these awards, we are required to re-measure the fair value of the 2014 Performance-Based RSU Grant at each reporting date and record compensation expense based on the fair value at each reporting date for the cumulative portion of the performance period that has elapsed. The total fair value of the 2014 Performance-Based RSU Grant was $7.1 million at March 31, 2014 and was calculated using a Monte Carlo simulation pricing model based on the assumptions in the table below. The determination of the fair value of the 2014 Performance-Based RSU Grant takes into consideration the likelihood of achievement of both the performance condition and the market condition discussed above. For the three months ended March 31, 2014, we recorded compensation expense based upon the $63.44 fair value at March 31, 2014 because we did not have shares authorized for issuance by our stockholders under the 2006 Plan. The following table summarizes the assumptions utilized in the Monte Carlo simulation pricing model:
		Fair Value Assumptions as of March 31, 2014
	Fair value per share at March 31, 2014	$63.44
	Expected share price volatility	32.00%
	Risk-free interest rate	0.79%
	Remaining expected life	2.75 years
	The computation of expected volatility is based on a blend of the historical volatility of our shares of common stock over approximately six years as that is expected to be most consistent with future volatility and equates to a time period twice as long as the approximate three year performance period of the RSUs and implied volatility data based on the observed pricing of six month publicly-traded options on our shares of common stock. The risk-free interest rate is based on the yield curve on zero-coupon U.S. Treasury STRIP securities in effect at March 31, 2014. The expected dividend yield is estimated by examining the average of the historical dividend yield levels over the remaining 2.75 year term of the RSUs and our current annualized dividend yield as of March 31, 2014. The expected life of the RSUs is equal to the remaining 2.75 year vesting period at March 31, 2014.
	2014 Time-Based RSU Grant
	The 2014 Time-Based RSUs are scheduled to vest in four equal installments beginning on January 5, 2015 through January 5, 2018. Compensation expense for the 2014 Time-Based RSUs will be recognized on a straight-line basis over the four year service vesting period. Each 2014 Time-Based RSUs represents the right to receive one share of our common stock in the future. However, in the event that our stockholders do not approve an increase to the share limit under our 2006 Plan, as discussed above, then the 2014 Time-Based RSUs may be cash settled, based on the fair market value of our common stock on the applicable payment date. As a result, unless and until a sufficient amount of shares are authorized by our stockholders for issuance under the 2006 Plan to cover the payment of these awards, we are required to re-measure the fair value of the 2014 Time-Based RSUs at each reporting date and record compensation expense based on the fair value at each reporting date for the cumulative portion of the performance period that has elapsed. The total grant date fair value was $6.1 million, which was based on the $51.64 closing share price of the Company’s common stock on the NYSE on the grant date. At March 31, 2014, we recorded compensation expense based upon the $58.58 closing share price of the Company’s common stock on that date because we did not have shares authorized for issuance by our stockholders under the 2006 Plan.
	Share-Based Compensation Cost Recorded During the Period
	The total compensation cost for all share-based compensation programs was $2.9 million and $2.4 million for the three months ended March 31, 2014 and 2013, respectively. Of the total share-based compensation costs, $0.4 million and $0.2 million was capitalized as part of real estate assets for the three months ended March 31, 2014 and 2013, respectively. As of March 31, 2014, there was approximately $36.9 million of total unrecognized compensation cost related to nonvested incentive awards granted under share-based compensation arrangements that is expected to be recognized over a weighted-average period of 2.6 years. $13.6 million of the total unrecognized compensation cost as of March 31, 2014 relates to the 2014 Performance-Based and Time-Based RSU grants which require fair value re-measurement at each reporting period as discussed above. The remaining compensation cost related to these nonvested incentive awards had been recognized in periods prior to March 31, 2014.

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Commitments and Contingencies
	General
	As of March 31, 2014, we had commitments of approximately $733.6 million, excluding our ground lease commitments, for contracts and executed leases directly related to our operating and redevelopment properties.
	Environmental Matters
	We follow the policy of monitoring our 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 environmental liability with respect to the properties that would have a material adverse effect on our financial condition, results of operations and cash flow. Further, we are not aware of any environmental liability or any unasserted claim or assessment with respect to an environmental liability that we believe would require additional disclosure or the recording of a loss contingency.

Fair_Value_Measurements_and_Di

Fair Value Measurements and Disclosures	3 Months Ended
	Mar. 31, 2014
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 a recurring basis on our consolidated financial statements are the marketable securities related to our deferred compensation plan. The following table sets forth the fair value of our marketable securities as of March 31, 2014 and December 31, 2013:
		Fair Value (Level  1) (1)
		March 31, 2014		December 31, 2013
	Description	(in thousands)
	Marketable securities (2)	$	11,001	$	10,008
	_______________
	-1	Based on quoted prices in active markets for identical securities.
	-2	The marketable securities are held in a limited rabbi trust.
	We report the change in the fair value of the marketable securities at the end of each accounting period in interest income and other net investment gains in the consolidated statements of operations. We adjust the related deferred compensation plan liability to fair value at the end of each accounting period based on the performance of the benchmark funds selected by each participant, which results in a corresponding increase or decrease to compensation cost for the period.
	The following table sets forth the net gain on marketable securities recorded during the three months ended March 31, 2014 and 2013:
		Three Months Ended March 31,
		2014		2013
	Description	(in thousands)
	Net gain on marketable securities	$	154	$	356
	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 March 31, 2014 and December 31, 2013:
		March 31, 2014				December 31, 2013
		Carrying		Fair		Carrying		Fair
		Value		Value		Value		Value
		(in thousands)
	Liabilities
	Secured debt (1)	$	556,946	$	567,107	$	560,434	$	568,760
	Exchangeable senior notes, net (1)	169,528		175,403		168,372		178,190
	Unsecured debt, net (2)	1,431,217		1,506,815		1,431,132		1,523,052
	Unsecured line of credit (1)	—		—		45,000		45,012
	_______________
	-1	Fair value calculated using Level II inputs which are based on model-derived valuations in which significant inputs and significant value drivers are observable in active markets.
	-2	Fair value calculated using Level I and Level II inputs. Level I inputs are based on quoted prices for identical instruments in active markets. The carrying value and fair value of the Level I instruments was $873.5 million and $921.2 million, respectively, as of March 31, 2014. The carrying value and fair value of the Level I instruments as of December 31, 2013, was $873.5 million and $929.3 million, respectively. The carrying value and fair value of the Level II instruments was $557.7 million and $585.6 million, respectively, as of March 31, 2014. The carrying value and fair value of the Level II instruments as of December 31, 2013, was $557.7 million and $593.7 million, respectively.

Other_Significant_Events_Other

Other Significant Events Other Significant Events	3 Months Ended
	Mar. 31, 2014
Other Income and Expenses [Abstract]	'
Other Significant Events	'
	Other Significant Events
	In January 2014, a tenant at one of our San Diego, California operating properties exercised an early lease termination clause as permitted under the terms of their lease. As a result, the lease which encompasses approximately 79,000 rentable square feet and was scheduled to expire in February 2020, will terminate during the third quarter of 2014. The total lease termination fee of $5.7 million, of which the Company recorded $1.7 million during the three months ended March 31, 2014, will be recorded as other property income on a straight line basis through the early lease termination date. During the three months ended March 31, 2014, the Company also recognized approximately $0.4 million as a reduction to rental income due to the accelerated amortization of the deferred rent receivable and above market lease for this tenant.

Discontinued_Operations

Discontinued Operations	3 Months Ended
	Mar. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]	'
Discontinued Operations	'
	Discontinued Operations
	Real Estate Assets Held for Sale
	As of March 31, 2014, the following undeveloped land parcel was classified as held for sale:
	Location		City/Submarket	Property Type
	10850 Via Frontera, San Diego, CA		I-15 Corridor/Rancho Bernardo	Undeveloped Land
	On April 9, 2014 the Company completed the sale of the undeveloped land parcel. See Note 16 “Subsequent Events” for further details.
	The major classes of assets and liabilities of the properties held for sale as of March 31, 2014 were as follows:
	Real estate assets and other assets held for sale	(in thousands)
	Undeveloped land and construction in progress	$	28,030
	Prepaid expenses and other assets, net	242
	Real estate and other assets held for sale, net	$	28,272
	Liabilities of real estate assets held for sale
	Accounts payable, accrued expenses and other liabilities	$	634
	Liabilities of real estate assets held for sale	$	634
	Dispositions
	The following table summarizes the properties sold during the three months ended March 31, 2014:
	Location		City/Submarket	Property Type		Month of Disposition	Number of Buildings	Rentable Square Feet
	San Diego Properties, San Diego, CA (1)(2)		I-15 Corridor/Sorrento Mesa	Office		January	12	1,049,035
	________________________
	-1	The San Diego Properties included the following: 10020 Pacific Mesa Boulevard, 6055 Lusk Avenue, 5010 and 5005 Wateridge Vista Drive, 15435 and 15445 Innovation Drive, and 15051, 15073, 15231, 15253, 15333 and 15378 Avenue of Science.
	-2	These properties were held for sale as of December 31, 2013.
	At March 31, 2014 and December 31, 2013, approximately $15.3 million and $32.2 million, respectively, of net proceeds related to the buildings disposed of during the three months ended March 31, 2014 and the year ended December 31, 2013 were temporarily being held at a qualified intermediary, at our direction, for the purpose of facilitating Section 1031 Exchanges. The cash proceeds are included in restricted cash on the consolidated balance sheets at March 31, 2014 and December 31, 2013. In February 2014, we successfully completed one of the Section 1031 Exchanges and the $32.2 million cash proceeds were released from the qualified intermediary.
	For the three months ended March 31, 2014 and 2013, discontinued operations included the income of the twelve operating office properties sold during the three months ended March 31, 2014. For the three months ended March 31, 2013, discontinued operations also included the income from three operating office properties that were sold during 2013. The following table summarizes the revenue and expense components that comprise income from discontinued operations for the three months ended March 31, 2014 and 2013:
		Three Months Ended March 31,
		2014			2013
		(in thousands)
	Revenues:
	Rental income	$	458		$	5,773
	Tenant reimbursements	66			757
	Other property income	9			3
	Total revenues	533			6,533
	Expenses:
	Property expenses	87			968
	Real estate taxes	69			673
	Depreciation and amortization	—			2,690
	Total expenses	156			4,331
	Income from discontinued operations before net gain on dispositions of discontinued operations	377			2,202
	Net gain on dispositions of discontinued operations	90,115			—
	Total income from discontinued operations	$	90,492		$	2,202

Net_Income_Loss_Available_to_C

Net Income (Loss) Available to Common Stockholders Per Share of the Company	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Net Income (Loss) Available to Common Stockholders Per Share of the Company	'
	Net Income (Loss) 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 (loss) available to common stockholders for the three months ended March 31, 2014 and 2013:
		Three Months Ended March 31,
		2014			2013
		(in thousands, except share and
		per share amounts)
	Numerator:
	Income from continuing operations	$	11,440		$	186
	(Income) loss from continuing operations attributable to noncontrolling common units of the Operating Partnership	(172		)	72
	Preferred dividends	(3,313		)	(3,313		)
	Allocation to participating securities (1)	(427		)	(418		)
	Numerator for basic and diluted income (loss) from continuing operations available to common stockholders	7,528			(3,473		)
	Income from discontinued operations	90,492			2,202
	Income from discontinued operations attributable to noncontrolling common units of the Operating Partnership	(1,915		)	(50		)
	Numerator for basic and diluted net income (loss) available to common stockholders	$	96,105		$	(1,321	)
	Denominator:
	Basic weighted average vested shares outstanding	82,124,538			74,977,240
	Effect of dilutive securities	2,015,532			—
	Diluted weighted average vested shares and common share equivalents outstanding	84,140,070			74,977,240
	Basic earnings per share:
	Income (loss) from continuing operations available to common stockholders per share	$	0.09		$	(0.05	)
	Income from discontinued operations per common share	1.08			0.03
	Net income (loss) available to common stockholders per share	$	1.17		$	(0.02	)
	Diluted earnings per share:
	Income (loss) from continuing operations available to common stockholders per share	$	0.09		$	(0.05	)
	Income from discontinued operations per common share	1.05			0.03
	Net income (loss) available to common stockholders per share	$	1.14		$	(0.02	)
	________________________
	-1	Participating securities include nonvested shares, certain time-based RSUs and vested market-measure RSUs.
	The impact of the contingently issuable shares, which consist of the 4.25% Exchangeable Notes and 1,520,500 stock options, were considered in our diluted earnings per share calculation for the three months ended March 31, 2014 because we reported income from continuing operations attributable to common stockholders in the respective period and the effect was dilutive. The impact of the Exchangeable Notes and stock options was not considered in our diluted earnings per share calculation for the three months ended March 31, 2013 because we reported a loss from continuing operations attributable to common stockholders and the effect was anti-dilutive.
	The 2014 Performance-Based RSUs and our other nonvested market measure-based RSUs are not included in dilutive securities as of March 31, 2014 because they are not considered contingently issuable shares as not all the necessary performance conditions have been met. The impact of our nonvested market measure-based RSUs were not included in dilutive securities as of March 31, 2013 because they were not considered contingently issuable shares as not all the necessary performance conditions were met.

Net_Income_Loss_Available_to_C1

Net Income (Loss) Available to Common Unitholders Per Unit of the Operating Partnership	3 Months Ended
	Mar. 31, 2014
Earnings Per Unit [Abstract]	'
Net Income (Loss) Available to Common Unitholders per Unit of the Operating Partnership	'
	Net Income (Loss) 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 (loss) available to common unitholders for the three months ended March 31, 2014 and 2013:
		Three Months Ended March 31,
		2014			2013
		(in thousands, except unit and
		per unit amounts)
	Numerator:
	Income from continuing operations	$	11,440		$	186
	Income from continuing operations attributable to noncontrolling interests in consolidated subsidiaries	(65		)	(69		)
	Preferred distributions	(3,313		)	(3,313		)
	Allocation to participating securities (1)	(427		)	(418		)
	Numerator for basic and diluted income (loss) from continuing operations available to common unitholders	7,635			(3,614		)
	Income from discontinued operations	90,492			2,202
	Numerator for basic and diluted net income (loss) available to common unitholders	$	98,127		$	(1,412	)
	Denominator:
	Basic weighted average vested units outstanding	83,928,993			76,803,743
	Effect of dilutive securities	2,015,532			—
	Diluted weighted average vested units and common unit equivalents outstanding	85,944,525			76,803,743
	Basic earnings per unit:
	Income (loss) from continuing operations available to common unitholders per unit	$	0.09		$	(0.05	)
	Income from discontinued operations per common unit	1.08			0.03
	Net income (loss) available to common unitholders per unit	$	1.17		$	(0.02	)
	Diluted earnings per unit:
	Income (loss) from continuing operations available to common unitholders per unit	$	0.09		$	(0.05	)
	Income from discontinued operations per common unit	1.05			0.03
	Net income (loss) available to common unitholders per unit	$	1.14		$	(0.02	)
	________________________
	-1	Participating securities include nonvested shares, certain time-based RSUs and vested market-measure RSUs.
	The impact of the contingently issuable units, which consist of the 4.25% Exchangeable Notes and 1,520,500 stock options, were considered in our diluted earnings per unit calculation for the three months ended March 31, 2014 because the Operating Partnership reported income from continuing operations attributable to common unitholders in the respective period and the effect was dilutive. The impact of the Exchangeable Notes and stock options was not considered in our diluted earnings per share calculation for the three months ended March 31, 2013 because the Operating Partnership reported a loss from continuing operations attributable to common unitholders and the effect was anti-dilutive.
	The 2014 Performance-Based RSUs and our other nonvested market measure-based RSUs are not included in dilutive securities as of March 31, 2014 because they are not considered contingently issuable shares as not all the necessary performance conditions have been met. The impact of our nonvested market measure-based RSUs were not included in dilutive securities as of March 31, 2013 because they were not considered contingently issuable shares as not all the necessary performance conditions were met.

Subsequent_Events

Subsequent Events	3 Months Ended
	Mar. 31, 2014
Subsequent Events [Abstract]	'
Subsequent Events	'
	Subsequent Events
	On April 9, 2014, the Company sold an undeveloped land parcel located at 10850 Via Frontera in the Rancho Bernardo submarket of San Diego, California that was held for sale at March 31, 2014 for a gross sales price of $33.1 million.
	On April 16, 2014, aggregate dividends, distributions and dividend equivalents of $29.8 million were paid to common stockholders and common unitholders of record on March 31, 2014 and RSU holders of record on April 16, 2014.

Organization_and_Basis_of_Pres1

Organization and Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Consolidation Policy	'
	The consolidated financial statements of the Company include the consolidated financial position and results of operations of the Company, the Operating Partnership, the Finance Partnership, KSLLC, Redwood City Partners, 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, the Finance Partnership, KSLLC, Redwood City Partners, LLC and all wholly-owned and controlled subsidiaries of the Operating Partnership. All intercompany balances and transactions have been eliminated in the consolidated financial statements.
Basis of Accounting	'
	The accompanying interim financial statements have been prepared by management in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and in conjunction with the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures required for annual financial statements have been condensed or excluded pursuant to SEC rules and regulations. Accordingly, the interim financial statements do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, the accompanying interim financial statements reflect all adjustments of a normal and recurring nature that are considered necessary for a fair presentation of the results for the interim periods presented. However, the results of operations for the interim periods are not necessarily indicative of the results that may be expected for the year ending December 31, 2014. The interim financial statements for the Company and the Operating Partnership should be read in conjunction with the audited consolidated financial statements and notes thereto included in our annual report on Form 10-K for the year ended December 31, 2013.
	Certain amounts in the consolidated statements of operations for prior periods have been reclassified to reflect the activity of discontinued operations.
Partially Owned Entities and Variable Interest Entities	'
	At March 31, 2014, the consolidated financial statements of the Company and the Operating Partnership included one variable interest entity (“VIE”), Redwood City Partners, LLC, in which we were deemed to be the primary beneficiary. This VIE was established in the second quarter of 2013 in connection with an undeveloped land acquisition. The impact of consolidating the VIE increased the Company’s total assets, liabilities and noncontrolling interests by approximately $61.6 million (of which $60.6 million related to real estate held for investment on our consolidated balance sheet), approximately $6.8 million and approximately $4.9 million, respectively, as of March 31, 2014. As of December 31, 2013, the consolidated financial statements of the Company and the Operating Partnership included four VIEs, in which we were deemed to be the primary beneficiary. One of the VIEs was Redwood City Partners, LLC and the remaining three VIEs were established during the third and fourth quarter of 2013 to facilitate a potential Section 1031 Exchange. During the three months ended March 31, 2014, the Section 1031 Exchanges were successfully completed and the three VIEs were terminated. As a result, $32.2 million of our restricted cash balance at December 31, 2013, which related to prior period disposition proceeds that were set aside to facilitate the Section 1031 Exchanges, was released from escrow. The impact of consolidating the VIEs increased the Company’s total assets, liabilities and noncontrolling interests by approximately $251.8 million (of which $234.5 million related to real estate held for investment on our consolidated balance sheet), approximately $12.1 million and approximately $4.9 million, respectively, as of December 31, 2013.
Recent Accounting Pronouncements	'
	On April 10, 2014, the Financial Accounting Standards Board issued final guidance to change the criteria for reporting discontinued operations while enhancing disclosures in this area (Accounting Standards Update (“ASU”) No. 2014-08). Under the new guidance, only disposals representing a strategic shift, such as a major line of business, a major geographical area or a major equity investment, should be presented as discontinued operations. The guidance will be applied prospectively to new disposals and new classifications of disposal groups as held for sale after the effective date. The guidance is effective for annual financial statements with fiscal years beginning on or after December 15, 2014 with early adoption permitted for disposals or classifications as held for sale which have not been reported in financial statements previously issued or available for issuance. The Company will adopt the guidance effective January 1, 2015 and the guidance is not anticipated to have a material impact on our consolidated financial statements and notes to our consolidated financial statements.
	On March 13, 2014, the Emerging Issues Task Force (the “Task Force”) reached a final consensus to amend the accounting guidance for stock compensation tied to performance targets (Issue No. 13-D). The objective of this guidance is to clarify the accounting treatment of certain types of performance conditions in stock-based compensation awards, more specifically, when performance targets can be achieved after the requisite service period. The Task Force concluded that performance criteria subsequent to a service period vesting requirement should be treated as vesting conditions, and as a result, this type of performance condition may delay expense recognition until achievement of the performance target is probable. Issue No. 13-D will be effective for all entities for reporting periods (including interim periods) beginning after December 15, 2015, and early adoption is permitted. The adoption of this guidance is not anticipated to have a material impact on our consolidated financial statements or notes to our consolidated financial statements.

Organization_and_Basis_of_Pres2

Organization and Basis of Presentation (Tables)	3 Months Ended
	Mar. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Summary of real estate properties	'
		Number of		Rentable	Number of	Percentage
		Buildings		Square Feet	Tenants	Occupied
	Stabilized Office Properties	107		13,305,145	527	92.4	%
	Our stabilized portfolio includes all of our properties with the exception of real estate assets held for sale, undeveloped land, development and redevelopment properties currently under construction or committed for construction, and “lease-up” properties. 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 “lease-up” properties as properties we recently developed or redeveloped that have not yet reached 95% occupancy and are within one year following cessation of major construction activities. During the first quarter of 2014, we stabilized a redevelopment property in San Francisco, California. As a result, this property is included in our stabilized portfolio as of March 31, 2014.
	As of March 31, 2014, the following properties were excluded from our stabilized portfolio:
		Number of Properties	Estimated Rentable
			Square Feet
	Development properties under construction (1)	6	2,538,000
	_______________
	-1	Estimated rentable square feet upon completion.

Acquisitions_Tables

Acquisitions (Tables) (Office Properties Acquisitions [Member])	3 Months Ended
	Mar. 31, 2014
Office Properties Acquisitions [Member]	'
Business Acquisition [Line Items]	'
Acquired operating properties from unrelated third parties	'
	During the three months ended March 31, 2014, we acquired the one operating office property, listed below, from an unrelated third party. The acquisition was funded with proceeds from the 2013 and 2014 dispositions (see Note 13).
	Property		Date of Acquisition	Number of	Rentable Square	Occupancy as of March 31, 2014	Purchase
				Buildings	Feet		Price
							(in millions)
	401 Terry Avenue North, Seattle, WA		March 13, 2014	1	140,605	100.00%	$	106.1
Fair values of assets acquired and liabilities assumed	'
	The following table summarizes the estimated fair values of the assets acquired and liabilities assumed on the acquisition date:
		Total 2014
		Acquisitions
		(in thousands)
	Assets
	Land and improvements	$	22,500
	Buildings and improvements (1)	77,046
	Deferred leasing costs and acquisition-related intangible assets (2)	11,199
	Total assets acquired	110,745
	Liabilities
	Deferred revenue and acquisition-related intangible liabilities (3)	4,620
	Total liabilities assumed	4,620
	Net assets and liabilities acquired	$	106,125
	_______________
	-1	Represents buildings, building improvements and tenant improvements.
	-2	Represents in-place leases of approximately $9.3 million (with a weighted average amortization period of seven years) and leasing commissions of approximately $1.9 million (with a weighted average amortization period of seven years).
	-3	Represents below-market leases of approximately $4.6 million (with a weighted average amortization period of seven years).

Deferred_Leasing_Costs_and_Acq1

Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, net (Tables)	3 Months Ended
	Mar. 31, 2014
Intangible Assets and Liabilities Disclosure [Abstract]	'
Summary of identified deferred leasing costs and acquisition-related intangible assets and liabilities	'
	The following table summarizes our deferred leasing costs and acquisition-related intangible assets (acquired value of leasing costs, above-market operating leases, in-place leases and below-market ground lease obligation) and intangible liabilities (acquired value of below-market operating leases and above-market ground lease obligation) as of March 31, 2014 and December 31, 2013:
		March 31, 2014			December 31, 2013
		(in thousands)
	Deferred Leasing Costs and Acquisition-Related Intangible Assets, net:
	Deferred leasing costs	$	183,813		$	178,720
	Accumulated amortization	(68,152		)	(63,246		)
	Deferred leasing costs, net	115,661			115,474
	Above-market operating leases	27,351			27,635
	Accumulated amortization	(15,489		)	(14,283		)
	Above-market operating leases, net	11,862			13,352
	In-place leases	104,643			100,318
	Accumulated amortization	(44,175		)	(42,999		)
	In-place leases, net	60,468			57,319
	Below-market ground lease obligation	490			490
	Accumulated amortization	(15		)	(13		)
	Below-market ground lease obligation, net	475			477
	Total deferred leasing costs and acquisition-related intangible assets, net	$	188,466		$	186,622
	Acquisition-Related Intangible Liabilities, net: (1)
	Below-market operating leases	$	73,522		$	69,385
	Accumulated amortization	(28,316		)	(25,706		)
	Below-market operating leases, net	45,206			43,679
	Above-market ground lease obligation	6,320			6,320
	Accumulated amortization	(248		)	(223		)
	Above-market ground lease obligation, net	6,072			6,097
	Total acquisition-related intangible liabilities, net	$	51,278		$	49,776
	_______________
	-1	Included in deferred revenue and acquisition-related intangible liabilities, net in the consolidated balance sheets.
Schedule Of Finite Lived Intangible Assets and Liabilities Amortization Expense	'
	The following table sets forth amortization related to deferred leasing costs and acquisition-related intangibles, including amounts attributable to discontinued operations, for the three months ended March 31, 2014 and 2013:
		Three Months Ended March 31,
		2014			2013
		(in thousands)
	Deferred leasing costs (1)	$	6,780		$	7,844
	Above-market operating leases (2)	1,490			1,438
	In-place leases (1)	6,136			7,458
	Below-market ground lease obligation (3)	—			2
	Below-market operating leases (4)	(3,093		)	(3,485		)
	Above-market ground lease obligation (5)	(25		)	(25		)
	Total	$	11,288		$	13,232
	_______________
	-1	The amortization of deferred leasing costs related to lease incentives is recorded to rental income and other deferred leasing costs and in-place leases is recorded to depreciation and amortization expense in the consolidated statements of operations for the periods presented.
	-2	The amortization of above-market operating leases is recorded as a decrease to rental income in the consolidated statements of operations for the periods presented.
	-3	The amortization of the below-market ground lease obligation is recorded as an increase to ground lease expense in the consolidated statements of operations for the periods presented.
	-4	The amortization of below-market operating leases is recorded as an increase to rental income in the consolidated statements of operations for the periods presented.
	-5	The amortization of the above-market ground lease obligation is recorded as a decrease to ground lease expense in the consolidated statements of operations for the periods presented.
Schedule of Finite Lived Intangible Assets And Liabilities Future Amortization Expense	'
	The following table sets forth the estimated annual amortization expense related to deferred leasing costs and acquisition-related intangibles as of March 31, 2014 for future periods:
	Year	Deferred Leasing Costs			Above-Market Operating Leases (1)			In-Place Leases		Below-Market Ground Lease Obligation (2)		Below-Market Operating Leases (3)			Above-Market Ground Lease Obligation (4)
		(in thousands)
	Remaining 2014	$	20,006		$	3,830		$	15,274	$	6	$	(9,802	)	$	(76	)
	2015	22,162			2,918			13,562		8		(9,577		)	(101		)
	2016	19,351			1,891			10,475		8		(7,847		)	(101		)
	2017	16,742			1,573			8,774		8		(6,780		)	(101		)
	2018	13,416			973			5,689		8		(5,177		)	(101		)
	Thereafter	23,984			677			6,694		437		(6,023		)	(5,592		)
	Total	$	115,661		$	11,862		$	60,468	$	475	$	(45,206	)	$	(6,072	)
	_______________
	-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 ground lease obligations. Amounts will be recorded as an increase to ground lease expense in the consolidated statements of operations.
	-3	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.
	-4	Represents estimated annual amortization related to above-market ground lease obligations. Amounts will be recorded as a decrease to ground lease expense in the consolidated statements of operations.

Receivables_Tables

Receivables (Tables)	3 Months Ended
	Mar. 31, 2014
Receivables [Abstract]	'
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 March 31, 2014 and December 31, 2013:
		March 31, 2014			December 31, 2013
		(in thousands)
	Current receivables	$	13,226		$	12,866
	Allowance for uncollectible tenant receivables	(2,134		)	(2,123		)
	Current receivables, net	$	11,092		$	10,743
Deferred Rent Receivables, net	'
	Deferred rent receivables, net consisted of the following as of March 31, 2014 and December 31, 2013:
		March 31, 2014			December 31, 2013
		(in thousands)
	Deferred rent receivables	$	132,740		$	129,198
	Allowance for deferred rent receivables	(1,990		)	(2,075		)
	Deferred rent receivables, net	$	130,750		$	127,123

Secured_and_Unsecured_Debt_of_1

Secured and Unsecured Debt of the Operating Partnership (Tables) (Kilroy Realty, L.P. [Member])	3 Months Ended
	Mar. 31, 2014
Debt Instrument [Line Items]	'
Per Share Average Trading Price Of Companys Common Stock On Stock Exchange [Tables Text Block]	'
	For the three months ended March 31, 2014 and 2013, the per share average trading price of the Company’s common stock on the NYSE was higher than the $35.93 exchange price for the 4.25% Exchangeable Notes, as presented below:
		Three Months Ended March 31,
		2014		2013
	Per share average trading price of the Company’s common stock	$55.18		$51.14
Schedule of Debt Conversions, Fair Value Upon Conversion [Table Text Block]	'
	The 4.25% Exchangeable Notes were exchangeable as of March 31, 2014 and March 31, 2013. If the Exchangeable Notes were exchanged, the approximate fair value of the shares upon exchange at March 31, 2014 and 2013, using the per share average trading price presented in the table above, would have been as follows:
		Three Months Ended March 31,
		2014			2013
		(in thousands)
	Approximate fair value of shares upon exchange	$	270,602		$	247,300
	Principal amount of the 4.25% Exchangeable Notes	172,500			172,500
	Approximate fair value in excess amount of principal amount	$	98,102		$	74,800
Interest expense for the exchangeable notes	'
	The following table summarizes the total interest expense attributable to the 4.25% Exchangeable Notes based on the respective effective interest rates, before the effect of capitalized interest, for the three months ended March 31, 2014 and 2013:
		Three Months Ended March 31,
		2014			2013
		(in thousands)
	Contractual interest payments	$	1,833		$	1,833
	Amortization of discount	1,156			1,078
	Interest expense attributable to the Exchangeable Notes	$	2,989		$	2,911
Capped call Transactions	'
	The table below summarizes our capped call option positions for the 4.25% Exchangeable Notes as of March 31, 2014 and December 31, 2013.
		4.25% Exchangeable Notes
	Referenced shares of common stock	4,800,796
	Exchange price including effect of capped calls	$	42.81
Unsecured Revolving Credit Facility	'
	The following table summarizes the balance and terms of our revolving credit facility as of March 31, 2014 and December 31, 2013:
		March 31,			December 31,
		2014			2013
		(in thousands)
	Outstanding borrowings	$	—		$	45,000
	Remaining borrowing capacity	500,000			455,000
	Total borrowing capacity (1)	$	500,000		$	500,000
	Interest rate (2)	—		%	1.62		%
	Facility fee-annual rate (3)	0.30%
	Maturity date (4)	Apr-17
	_______________
	-1	We may elect to borrow, subject to bank approval and obtaining commitments for any additional borrowing capacity, up to an additional $200.0 million under an accordion feature under the terms of the revolving credit facility.
	-2	The revolving credit facility interest rate was calculated based on an annual rate of LIBOR plus 1.450% as of both March 31, 2014 and December 31, 2013.
	-3	The facility fee is paid on a quarterly basis and is calculated based on the total borrowing capacity. In addition to the facility fee, from 2010 to 2012 we incurred debt origination and legal costs of which, as of March 31, 2014, approximately $4.5 million remains to be amortized through the maturity date of the revolving credit facility.
	-4	Under the terms of the revolving credit facility, we may exercise an option to extend the maturity date by one year.
Stated debt maturities and scheduled amortization payments, excluding debt discounts	'
	The following table summarizes the stated debt maturities and scheduled amortization payments, excluding debt discounts and premiums, as of March 31, 2014:
	Year	(in thousands)
	Remaining 2014	$	262,932
	2015	395,104
	2016	249,431
	2017	71,748
	2018	451,728
	Thereafter	718,011
	Total (1)	$	2,148,954
	________________________
	-1	Includes gross principal balance of outstanding debt before impact of net unamortized premiums totaling approximately $8.7 million.
Capitalized interest and loan fees	'
	The following table sets forth gross interest expense reported in continuing operations, including debt discount/premium and loan cost amortization, net of capitalized interest, for the three months ended March 31, 2014 and 2013. 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.
		Three Months Ended March 31,
		2014			2013
		(in thousands)
	Gross interest expense	$	28,034		$	27,466
	Capitalized interest	(10,782		)	(7,732		)
	Interest expense	$	17,252		$	19,734
Senior Notes [Member]	'
Debt Instrument [Line Items]	'
Balance and significant terms of debt	'
	The following table summarizes the balance and significant terms of the registered unsecured senior notes issued by the Operating Partnership as of March 31, 2014 and December 31, 2013:
									Principal Amount as of
		Issuance date		Maturity date	Stated		Effective interest rate (1)		March 31,				December 31,
					coupon rate				2014				2013
									(in thousands)
	3.800% Unsecured Senior Notes (2)	Jan-13		Jan-23	3.80%		3.80%		$	300,000			$	300,000
	Unamortized discount								(87		)		(90		)
	Net carrying amount								$	299,913			$	299,910
	4.800% Unsecured Senior Notes (3)	Jul-11		Jul-18	4.80%		4.83%		$	325,000			$	325,000
	Unamortized discount								(320		)		(339		)
	Net carrying amount								$	324,680			$	324,661
	6.625% Unsecured Senior Notes (4)	May-10		Jun-20	6.63%		6.74%		$	250,000			$	250,000
	Unamortized discount								(1,313		)		(1,367		)
	Net carrying amount								$	248,687			$	248,633
	5.000% Unsecured Senior Notes (5)	Nov-10		Nov-15	5.00%		5.01%		$	325,000			$	325,000
	Unamortized discount								(63		)		(73		)
	Net carrying amount								$	324,937			$	324,927
	________________________
	-1	This represents the rate at which interest expense is recorded for financial reporting purposes, which reflects the amortization of initial issuance discounts, excluding debt issuance costs.
	-2	Interest on the 3.800% unsecured senior notes is payable semi-annually in arrears on January 15th and July 15th of each year.
	-3	Interest on the 4.800% unsecured senior notes is payable semi-annually in arrears on January 15th and July 15th of each year.
	-4	Interest on the 6.625% unsecured senior notes is payable semi-annually in arrears on June 1st and December 1st of each year.
	-5	Interest on the 5.000% unsecured senior notes is payable semi-annually in arrears on May 3rd and November 3rd of each year.
Secured Debt [Member]	'
Debt Instrument [Line Items]	'
Balance and significant terms of debt	'
	The following table sets forth the composition of our secured debt as of March 31, 2014 and December 31, 2013:
	Type of Debt	Annual Stated Interest Rate (1)		GAAP	Maturity Date		March 31, 2014 (3)				December 31, 2013 (3)
				Effective Rate (1)(2)
							(in thousands)
	Mortgage note payable	4.27%		4.27%	Feb-18		$	132,539			$	133,117
	Mortgage note payable (4)	4.48%		4.48%	Jul-27		97,000				97,000
	Mortgage note payable (4)	6.05%		3.50%	Jun-19		91,696				92,502
	Mortgage note payable	6.51%		6.51%	Feb-17		67,415				67,663
	Mortgage note payable (4)	5.23%		3.50%	Jan-16		54,120				54,570
	Mortgage note payable (4)	5.57%		3.25%	Feb-16		41,300				41,654
	Mortgage note payable (4)	5.09%		3.50%	Aug-15		34,712				34,845
	Mortgage note payable (4)	4.94%		4.00%	Apr-15		27,307				27,641
	Mortgage note payable	7.15%		7.15%	May-17		8,387				8,972
	Other	Various		Various	Various		2,470				2,470
	Total						$	556,946			$	560,434
	______________
	-1	All interest rates presented are fixed-rate interest rates.
	-2	This represents the rate at which interest expense is recorded for financial reporting purposes, which reflects the amortization of discounts/premiums, excluding debt issuance costs.
	-3	Amounts reported include the amounts of unamortized debt premiums and discounts for the periods presented.
	-4	The secured debt and the related properties that secure the 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.
Convertible Debt [Member]	'
Debt Instrument [Line Items]	'
Balance and significant terms of debt	'
	The table below summarizes the balance and significant terms of the Company’s 4.25% Exchangeable Notes due November 2014 (the “4.25% Exchangeable Notes”) outstanding as of March 31, 2014 and December 31, 2013.
		4.25% Exchangeable Notes
		March 31,			December 31,
		2014			2013
		(in thousands)
	Principal amount	$	172,500		$	172,500
	Unamortized discount	(2,972		)	(4,128		)
	Net carrying amount of liability component	$	169,528		$	168,372
	Carrying amount of equity component	$19,835
	Issuance date	Nov-09
	Maturity date	Nov-14
	Stated coupon rate (1)	4.25%
	Effective interest rate (2)	7.13%
	Exchange rate per $1,000 principal value of the 4.25% Exchangeable Notes, as adjusted (3)	27.8307
	Exchange price, as adjusted (3)	$35.93
	Number of shares on which the aggregate consideration to be delivered on conversion is determined (3)	4,800,796
	_______________
	-1	Interest on the 4.25% Exchangeable Notes is payable semi-annually in arrears on May 15th and November 15th of each year.
	-2	The rate at which we record interest expense for financial reporting purposes, which reflects the amortization of the discounts on the 4.25% Exchangeable Notes. This rate represents our conventional debt borrowing rate at the date of issuance.
	-3	The exchange rate, exchange price and the number of shares to be delivered upon conversion are subject to adjustment under certain circumstances including increases in our common dividends.

Partners_Capital_of_the_Operat1

Partners' Capital of the Operating Partnership Ownership Interest (Tables)	3 Months Ended
	Mar. 31, 2014
Noncontrolling Interest [Abstract]	'
Redeemable Noncontrolling Interest	'
	The following table sets forth the number of common units held by the Company and the number of common units held by non-affiliate investors and certain of our executive officers and directors in the form of noncontrolling common units as well as the ownership interest held on each respective date:
		March 31, 2014		December 31, 2013		March 31, 2013
	Company owned common units in the Operating Partnership	82,218,332		82,153,944		75,349,705
	Company owned general partnership interest	97.9	%	97.8	%	97.6	%
	Noncontrolling common units of the Operating Partnership	1,804,200		1,805,200		1,826,503
	Ownership interest of noncontrolling interest	2.1	%	2.2	%	2.4	%

ShareBased_Compensation_ShareB

Share-Based Compensation Share-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Schedule of Share-based Payment Award, Restricted Stock Units, Valuation Assumptions	'
	The following table summarizes the assumptions utilized in the Monte Carlo simulation pricing model:
		Fair Value Assumptions as of March 31, 2014
	Fair value per share at March 31, 2014	$63.44
	Expected share price volatility	32.00%
	Risk-free interest rate	0.79%
	Remaining expected life	2.75 years

Fair_Value_Measurements_and_Di1

Fair Value Measurements and Disclosures (Tables)	3 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Fair value of the company's marketable securities	'
	The following table sets forth the fair value of our marketable securities as of March 31, 2014 and December 31, 2013:
		Fair Value (Level  1) (1)
		March 31, 2014		December 31, 2013
	Description	(in thousands)
	Marketable securities (2)	$	11,001	$	10,008
	_______________
	-1	Based on quoted prices in active markets for identical securities.
	-2	The marketable securities are held in a limited rabbi trust.
Fair value adjustment of marketable securities and deferred compensation plan liability	'
	The following table sets forth the net gain on marketable securities recorded during the three months ended March 31, 2014 and 2013:
		Three Months Ended March 31,
		2014		2013
	Description	(in thousands)
	Net gain on marketable securities	$	154	$	356
Carrying value and fair value of company's remaining financial assets and liabilities	'
	The following table sets forth the carrying value and the fair value of our other financial instruments as of March 31, 2014 and December 31, 2013:
		March 31, 2014				December 31, 2013
		Carrying		Fair		Carrying		Fair
		Value		Value		Value		Value
		(in thousands)
	Liabilities
	Secured debt (1)	$	556,946	$	567,107	$	560,434	$	568,760
	Exchangeable senior notes, net (1)	169,528		175,403		168,372		178,190
	Unsecured debt, net (2)	1,431,217		1,506,815		1,431,132		1,523,052
	Unsecured line of credit (1)	—		—		45,000		45,012
	_______________
	-1	Fair value calculated using Level II inputs which are based on model-derived valuations in which significant inputs and significant value drivers are observable in active markets.
	-2	Fair value calculated using Level I and Level II inputs. Level I inputs are based on quoted prices for identical instruments in active markets. The carrying value and fair value of the Level I instruments was $873.5 million and $921.2 million, respectively, as of March 31, 2014. The carrying value and fair value of the Level I instruments as of December 31, 2013, was $873.5 million and $929.3 million, respectively. The carrying value and fair value of the Level II instruments was $557.7 million and $585.6 million, respectively, as of March 31, 2014. The carrying value and fair value of the Level II instruments as of December 31, 2013, was $557.7 million and $593.7 million, respectively.

Discontinued_Operations_Tables

Discontinued Operations (Tables)	3 Months Ended
	Mar. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]	'
Property Sold During The Period	'
	The following table summarizes the properties sold during the three months ended March 31, 2014:
	Location		City/Submarket	Property Type		Month of Disposition	Number of Buildings	Rentable Square Feet
	San Diego Properties, San Diego, CA (1)(2)		I-15 Corridor/Sorrento Mesa	Office		January	12	1,049,035
	________________________
	-1	The San Diego Properties included the following: 10020 Pacific Mesa Boulevard, 6055 Lusk Avenue, 5010 and 5005 Wateridge Vista Drive, 15435 and 15445 Innovation Drive, and 15051, 15073, 15231, 15253, 15333 and 15378 Avenue of Science.
	-2	These properties were held for sale as of December 31, 2013.
Assets Held-for-sale	'
	The major classes of assets and liabilities of the properties held for sale as of March 31, 2014 were as follows:
	Real estate assets and other assets held for sale	(in thousands)
	Undeveloped land and construction in progress	$	28,030
	Prepaid expenses and other assets, net	242
	Real estate and other assets held for sale, net	$	28,272
	Liabilities of real estate assets held for sale
	Accounts payable, accrued expenses and other liabilities	$	634
	Liabilities of real estate assets held for sale	$	634
	As of March 31, 2014, the following undeveloped land parcel was classified as held for sale:
	Location		City/Submarket	Property Type
	10850 Via Frontera, San Diego, CA		I-15 Corridor/Rancho Bernardo	Undeveloped Land
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures	'
	The following table summarizes the revenue and expense components that comprise income from discontinued operations for the three months ended March 31, 2014 and 2013:
		Three Months Ended March 31,
		2014			2013
		(in thousands)
	Revenues:
	Rental income	$	458		$	5,773
	Tenant reimbursements	66			757
	Other property income	9			3
	Total revenues	533			6,533
	Expenses:
	Property expenses	87			968
	Real estate taxes	69			673
	Depreciation and amortization	—			2,690
	Total expenses	156			4,331
	Income from discontinued operations before net gain on dispositions of discontinued operations	377			2,202
	Net gain on dispositions of discontinued operations	90,115			—
	Total income from discontinued operations	$	90,492		$	2,202

Net_Loss_Income_Available_to_C

Net (Loss) Income Available to Common Stockholders Per Share of the Company (Tables)	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Net income (loss) 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 (loss) available to common stockholders for the three months ended March 31, 2014 and 2013:
		Three Months Ended March 31,
		2014			2013
		(in thousands, except share and
		per share amounts)
	Numerator:
	Income from continuing operations	$	11,440		$	186
	(Income) loss from continuing operations attributable to noncontrolling common units of the Operating Partnership	(172		)	72
	Preferred dividends	(3,313		)	(3,313		)
	Allocation to participating securities (1)	(427		)	(418		)
	Numerator for basic and diluted income (loss) from continuing operations available to common stockholders	7,528			(3,473		)
	Income from discontinued operations	90,492			2,202
	Income from discontinued operations attributable to noncontrolling common units of the Operating Partnership	(1,915		)	(50		)
	Numerator for basic and diluted net income (loss) available to common stockholders	$	96,105		$	(1,321	)
	Denominator:
	Basic weighted average vested shares outstanding	82,124,538			74,977,240
	Effect of dilutive securities	2,015,532			—
	Diluted weighted average vested shares and common share equivalents outstanding	84,140,070			74,977,240
	Basic earnings per share:
	Income (loss) from continuing operations available to common stockholders per share	$	0.09		$	(0.05	)
	Income from discontinued operations per common share	1.08			0.03
	Net income (loss) available to common stockholders per share	$	1.17		$	(0.02	)
	Diluted earnings per share:
	Income (loss) from continuing operations available to common stockholders per share	$	0.09		$	(0.05	)
	Income from discontinued operations per common share	1.05			0.03
	Net income (loss) available to common stockholders per share	$	1.14		$	(0.02	)
	________________________
	-1	Participating securities include nonvested shares, certain time-based RSUs and vested market-measure RSUs.

Net_Income_Loss_Available_to_C2

Net Income (Loss) Available to Common Unitholders Per Unit of the Operating Partnership (Tables)	3 Months Ended
	Mar. 31, 2014
Net Income (Loss) Available To Common Unitholders [Line Items]	'
Net income (loss) 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 (loss) available to common stockholders for the three months ended March 31, 2014 and 2013:
		Three Months Ended March 31,
		2014			2013
		(in thousands, except share and
		per share amounts)
	Numerator:
	Income from continuing operations	$	11,440		$	186
	(Income) loss from continuing operations attributable to noncontrolling common units of the Operating Partnership	(172		)	72
	Preferred dividends	(3,313		)	(3,313		)
	Allocation to participating securities (1)	(427		)	(418		)
	Numerator for basic and diluted income (loss) from continuing operations available to common stockholders	7,528			(3,473		)
	Income from discontinued operations	90,492			2,202
	Income from discontinued operations attributable to noncontrolling common units of the Operating Partnership	(1,915		)	(50		)
	Numerator for basic and diluted net income (loss) available to common stockholders	$	96,105		$	(1,321	)
	Denominator:
	Basic weighted average vested shares outstanding	82,124,538			74,977,240
	Effect of dilutive securities	2,015,532			—
	Diluted weighted average vested shares and common share equivalents outstanding	84,140,070			74,977,240
	Basic earnings per share:
	Income (loss) from continuing operations available to common stockholders per share	$	0.09		$	(0.05	)
	Income from discontinued operations per common share	1.08			0.03
	Net income (loss) available to common stockholders per share	$	1.17		$	(0.02	)
	Diluted earnings per share:
	Income (loss) from continuing operations available to common stockholders per share	$	0.09		$	(0.05	)
	Income from discontinued operations per common share	1.05			0.03
	Net income (loss) available to common stockholders per share	$	1.14		$	(0.02	)
	________________________
	-1	Participating securities include nonvested shares, certain time-based RSUs and vested market-measure RSUs.
Kilroy Realty, L.P. [Member]	'
Net Income (Loss) Available To Common Unitholders [Line Items]	'
Net income (loss) 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 (loss) available to common unitholders for the three months ended March 31, 2014 and 2013:
		Three Months Ended March 31,
		2014			2013
		(in thousands, except unit and
		per unit amounts)
	Numerator:
	Income from continuing operations	$	11,440		$	186
	Income from continuing operations attributable to noncontrolling interests in consolidated subsidiaries	(65		)	(69		)
	Preferred distributions	(3,313		)	(3,313		)
	Allocation to participating securities (1)	(427		)	(418		)
	Numerator for basic and diluted income (loss) from continuing operations available to common unitholders	7,635			(3,614		)
	Income from discontinued operations	90,492			2,202
	Numerator for basic and diluted net income (loss) available to common unitholders	$	98,127		$	(1,412	)
	Denominator:
	Basic weighted average vested units outstanding	83,928,993			76,803,743
	Effect of dilutive securities	2,015,532			—
	Diluted weighted average vested units and common unit equivalents outstanding	85,944,525			76,803,743
	Basic earnings per unit:
	Income (loss) from continuing operations available to common unitholders per unit	$	0.09		$	(0.05	)
	Income from discontinued operations per common unit	1.08			0.03
	Net income (loss) available to common unitholders per unit	$	1.17		$	(0.02	)
	Diluted earnings per unit:
	Income (loss) from continuing operations available to common unitholders per unit	$	0.09		$	(0.05	)
	Income from discontinued operations per common unit	1.05			0.03
	Net income (loss) available to common unitholders per unit	$	1.14		$	(0.02	)
	________________________
	-1	Participating securities include nonvested shares, certain time-based RSUs and vested market-measure RSUs.

Organization_and_Basis_of_Pres3

Organization and Basis of Presentation (Details)	3 Months Ended
	Mar. 31, 2014
Real Estate Properties [Line Items]	'
Rentable square feet	79,000
Kilroy Realty Finance, Inc. [Member]	'
Real Estate Properties [Line Items]	'
Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest	1.00%
Development Properties [Member]	'
Real Estate Properties [Line Items]	'
Number of buildings	6	[1]
Rentable square feet	2,538,000	[1]
Office Properties [Member]	'
Real Estate Properties [Line Items]	'
Number of buildings	107
Rentable square feet	13,305,145
Number of Tenants	527
Percentage Occupied	92.40%
[1]	Estimated rentable square feet upon completion.

Organization_and_Basis_of_Pres4

Organization and Basis of Presentation (Details Textuals) (USD $)	3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]	'	'	'
Lease-Up Properties, Maximum Stabilized Occupacy, Percentage	95.00%	'	'
Percentage of general partnership interest owned by the company in the Operating Partnership	97.90%	97.80%	97.60%
Percentage of Common limited partnership interest owned by certain non-affiliated investors and certain directors and officers of the Company in the Operating Partnership	2.10%	2.20%	2.40%
Variable Interest Entity, Consolidated, Carrying Amount, Assets	$61,600,000	$251,800,000	'
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	6,800,000	12,100,000	'
Noncontrolling Interest in Variable Interest Entity	4,885,000	4,885,000	'
WASHINGTON	'	'	'
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]	'	'	'
Number of buildings	13	'	'
Kilroy Realty Finance, Inc. [Member]	'	'	'
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]	'	'	'
Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest	1.00%	'	'
Kilroy Realty, L.P. [Member]	'	'	'
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]	'	'	'
Percentage of limited partnership interest owned by Operating Partnership	99.00%	'	'
Real Estate Investment [Member]	'	'	'
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]	'	'	'
Variable Interest Entity, Consolidated, Carrying Amount, Assets	$60,600,000	$234,500,000	'

Acquisitions_Details

Acquisitions (Details) (USD $)	3 Months Ended
	Mar. 31, 2014
	sqft
Business Acquisition [Line Items]	'
Business Acquisition, Date of Acquisition Agreement	13-Mar-14
Rentable square feet	79,000
401 Terry Avenue North, Seattle, WA [Member]	'
Business Acquisition [Line Items]	'
Number of buildings	1
Rentable square feet	140,605
Occupancy as of March 31, 2014	100.00%
Purchase price	106,100,000
Office Properties Acquisitions [Member]	'
Business Acquisition [Line Items]	'
Number of buildings	1
Assets	'
Land and improvements	22,500,000
Buildings and improvements	77,046,000	[1]
Deferred leasing costs and acquisition-related intangible assets	11,199,000	[2]
Total assets acquired	110,745,000
Liabilities	'
Deferred revenue and acquisition-related intangible liabilities	4,620,000	[3]
Total liabilities assumed	4,620,000
Net assets and liabilities acquired	106,125,000
[1]	Represents buildings, building improvements and tenant improvements.
[2]	Represents in-place leases of approximately $9.3 million (with a weighted average amortization period of seven years) and leasing commissions of approximately $1.9 million (with a weighted average amortization period of seven years).
[3]	Represents below-market leases of approximately $4.6 million (with a weighted average amortization period of seven years).

Acquisitions_Details_Textuals

Acquisitions (Details Textuals) (USD $)	3 Months Ended
	Mar. 31, 2014
Business Acquisition [Line Items]	'
Below Market Lease, Acquired	$4,600,000
Acquired Finite-lived Intangible Liabilities, Weighted Average Useful Life	'7 years
Deferred Leasing Costs [Member]	'
Business Acquisition [Line Items]	'
Deferred leasing costs and acquisition-related intangible assets	1,900,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	'7 years
In-Place Leases [Member]	'
Business Acquisition [Line Items]	'
Deferred leasing costs and acquisition-related intangible assets	$9,300,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	'7 years

Deferred_Leasing_Costs_and_Acq2

Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, net (Details) (USD $)	Mar. 31, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred Leasing Costs and Acquisition-related Intangible Assets, Net	'		'
Total deferred leasing costs and acquisition-related intangible assets, net	$188,466		$186,622
Acquisition-related Intangible Liabilities, Net	'		'
Total acquisitions-related intangible liabilities, net	51,278	[1]	49,776	[1]
Deferred Leasing Costs [Member]	'		'
Deferred Leasing Costs and Acquisition-related Intangible Assets, Net	'		'
Finite-lived intangible assets, gross	183,813		178,720
Finite-lived intangible assets accumulated amortization	-68,152		-63,246
Finite-lived intangible assets, net	115,661		115,474
Above-Market Leases [Member]	'		'
Deferred Leasing Costs and Acquisition-related Intangible Assets, Net	'		'
Finite-lived intangible assets, gross	27,351		27,635
Finite-lived intangible assets accumulated amortization	-15,489		-14,283
Finite-lived intangible assets, net	11,862	[2]	13,352
In-Place Leases [Member]	'		'
Deferred Leasing Costs and Acquisition-related Intangible Assets, Net	'		'
Finite-lived intangible assets, gross	104,643		100,318
Finite-lived intangible assets accumulated amortization	-44,175		-42,999
Finite-lived intangible assets, net	60,468		57,319
Below Market Ground Lease Obligation [Member]	'		'
Deferred Leasing Costs and Acquisition-related Intangible Assets, Net	'		'
Finite-lived intangible assets, gross	490		490
Finite-lived intangible assets accumulated amortization	-15		-13
Finite-lived intangible assets, net	475	[3]	477
Below Market Lease [Member]	'		'
Acquisition-related Intangible Liabilities, Net	'		'
FiniteLivedIntangibleLiabilitiesGross	73,522		69,385
Accumulated amortization	-28,316		-25,706
Acquisition-related Intangible Liabilities, net	45,206	[1],[4]	43,679	[1]
Above-Market Ground Lease Obligation [Member]	'		'
Acquisition-related Intangible Liabilities, Net	'		'
FiniteLivedIntangibleLiabilitiesGross	6,320		6,320
Accumulated amortization	-248		-223
Acquisition-related Intangible Liabilities, net	$6,072	[1],[5]	$6,097	[1]
[1]	Included in deferred revenue and acquisition-related intangible liabilities, net in the consolidated balance sheets.
[2]	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.
[3]	Represents estimated annual amortization related to below-market ground lease obligations. Amounts will be recorded as an increase to ground lease expense in the consolidated statements of operations.
[4]	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.
[5]	Represents estimated annual amortization related to above-market ground lease obligations. Amounts will be recorded as a decrease to ground lease expense in the consolidated statements of operations.

Deferred_Leasing_Costs_and_Acq3

Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, net (Details 1) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013		Dec. 31, 2013
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 intangible assets	$11,288		$13,232		'
Deferred Leasing Costs [Member]	'		'		'
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 intangible assets	6,780	[1]	7,844	[1]	'
Estimated annual amortization related to acquisition-related intangibles	'		'		'
Remaining 2014	20,006		'		'
2015	22,162		'		'
2016	19,351		'		'
2017	16,742		'		'
2018	13,416		'		'
Thereafter	23,984		'		'
Finite-lived intangible assets, net	115,661		'		115,474
Above-Market Leases [Member]	'		'		'
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 intangible assets	1,490	[2]	1,438	[2]	'
Estimated annual amortization related to acquisition-related intangibles	'		'		'
Remaining 2014	3,830	[3]	'		'
2015	2,918	[3]	'		'
2016	1,891	[3]	'		'
2017	1,573	[3]	'		'
2018	973	[3]	'		'
Thereafter	677	[3]	'		'
Finite-lived intangible assets, net	11,862	[3]	'		13,352
In-Place Leases [Member]	'		'		'
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 intangible assets	6,136	[1]	7,458	[1]	'
Estimated annual amortization related to acquisition-related intangibles	'		'		'
Remaining 2014	15,274		'		'
2015	13,562		'		'
2016	10,475		'		'
2017	8,774		'		'
2018	5,689		'		'
Thereafter	6,694		'		'
Finite-lived intangible assets, net	60,468		'		57,319
Below Market Ground Lease Obligation [Member]	'		'		'
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 intangible assets	0	[4]	2	[4]	'
Estimated annual amortization related to acquisition-related intangibles	'		'		'
Remaining 2014	6	[5]	'		'
2015	8	[5]	'		'
2016	8	[5]	'		'
2017	8	[5]	'		'
2018	8	[5]	'		'
Thereafter	437	[5]	'		'
Finite-lived intangible assets, net	475	[5]	'		477
Below Market Leases [Member]	'		'		'
Amortization for the period related to deferred leasing costs and acquisition-related intangibles	'		'		'
Amortization for the period related to acquistion-related liabilities	-3,093	[6]	-3,485	[6]	'
Estimated annual amortization related to acquisition-related intangibles	'		'		'
Remaining 2014	-9,802	[7]	'		'
2015	-9,577	[7]	'		'
2016	-7,847	[7]	'		'
2017	-6,780	[7]	'		'
2018	-5,177	[7]	'		'
Thereafter	-6,023	[7]	'		'
Acquisition-related Intangible Liabilities, net	-45,206	[7],[8]	'		-43,679	[8]
Above-Market Ground Lease Obligation [Member]	'		'		'
Amortization for the period related to deferred leasing costs and acquisition-related intangibles	'		'		'
Amortization for the period related to acquistion-related liabilities	-25	[9]	-25	[9]	'
Estimated annual amortization related to acquisition-related intangibles	'		'		'
Remaining 2014	-76	[10]	'		'
2015	-101	[10]	'		'
2016	-101	[10]	'		'
2017	-101	[10]	'		'
2018	-101	[10]	'		'
Thereafter	-5,592	[10]	'		'
Acquisition-related Intangible Liabilities, net	($6,072)	[10],[8]	'		($6,097)	[8]
[1]	The amortization of deferred leasing costs related to lease incentives is recorded to rental income and other deferred leasing costs and in-place leases is recorded to depreciation and amortization expense in the consolidated statements of operations for the periods presented.
[2]	The amortization of above-market operating leases is recorded as a decrease to rental income in the consolidated statements of operations for the periods presented.
[3]	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.
[4]	The amortization of the below-market ground lease obligation is recorded as an increase to ground lease expense in the consolidated statements of operations for the periods presented.
[5]	Represents estimated annual amortization related to below-market ground lease obligations. Amounts will be recorded as an increase to ground lease expense in the consolidated statements of operations.
[6]	The amortization of below-market operating leases is recorded as an increase to rental income in the consolidated statements of operations for the periods presented.
[7]	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.
[8]	Included in deferred revenue and acquisition-related intangible liabilities, net in the consolidated balance sheets.
[9]	The amortization of the above-market ground lease obligation is recorded as a decrease to ground lease expense in the consolidated statements of operations for the periods presented.
[10]	Represents estimated annual amortization related to above-market ground lease obligations. Amounts will be recorded as a decrease to ground lease expense in the consolidated statements of operations.

Receivables_Details

Receivables (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current Receivables, net	'	'
Current receivables	$13,226	$12,866
Allowance for uncollectible tenant receivables	-2,134	-2,123
Current receivables, net	11,092	10,743
Deferred Rent Receivables, net	'	'
Deferred rent receivables	132,740	129,198
Allowance for deferred rent receivables	-1,990	-2,075
Deferred rent receivables, net	$130,750	$127,123

Secured_and_Unsecured_Debt_of_2

Secured and Unsecured Debt of the Operating Partnership (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Debt Instrument [Line Items]	'		'
Secured Debt	$556,946	[1]	$560,434	[1]
Secured Debt [Member] | 4.48% Mortgage Payable due July 1, 2027 [Member]	'		'
Debt Instrument [Line Items]	'		'
Annual Stated Interest Rate	4.48%	[2]	'
Effective interest rate	4.48%	[2],[3]	'
Maturity Date	1-Jul-27		'
Secured Debt	97,000	[1],[4]	97,000	[1],[4]
Kilroy Realty, L.P. [Member]	'		'
Debt Instrument [Line Items]	'		'
Secured Debt	556,946		560,434
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 4.27% Mortgage Payable due Feb. 01, 2018 [Member]	'		'
Debt Instrument [Line Items]	'		'
Annual Stated Interest Rate	4.27%	[2]	'
Effective interest rate	4.27%	[2],[3]	'
Maturity Date	1-Feb-18		'
Secured Debt	132,539	[1]	133,117	[1]
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 6.05% Mortgage Payable Due June 1, 2019 [Member]	'		'
Debt Instrument [Line Items]	'		'
Annual Stated Interest Rate	6.05%	[2]	'
Effective interest rate	3.50%	[2],[3]	'
Maturity Date	1-Jun-19		'
Secured Debt	91,696	[1],[4]	92,502	[1],[4]
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 6.51% Mortgage Payable due Feb. 01, 2017 [Member]	'		'
Debt Instrument [Line Items]	'		'
Annual Stated Interest Rate	6.51%	[2]	'
Effective interest rate	6.51%	[2],[3]	'
Maturity Date	1-Feb-17		'
Secured Debt	67,415	[1]	67,663	[1]
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 5.23% Mortgage Payable due Jan. 01, 2016 [Member]	'		'
Debt Instrument [Line Items]	'		'
Annual Stated Interest Rate	5.23%	[2]	'
Effective interest rate	3.50%	[2],[3]	'
Maturity Date	1-Jan-16		'
Secured Debt	54,120	[1],[4]	54,570	[1],[4]
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 5.57% Morgage Payable Due Feb. 11, 2016 [Member]	'		'
Debt Instrument [Line Items]	'		'
Annual Stated Interest Rate	5.57%	[2]	'
Effective interest rate	3.25%	[2],[3]	'
Maturity Date	11-Feb-16		'
Secured Debt	41,300	[1],[4]	41,654	[1],[4]
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 5.09% Mortgage Payable due Aug. 7, 2015 [Member]	'		'
Debt Instrument [Line Items]	'		'
Annual Stated Interest Rate	5.09%	[2]	'
Effective interest rate	3.50%	[2],[3]	'
Maturity Date	7-Aug-15		'
Secured Debt	34,712	[1],[4]	34,845	[1],[4]
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 4.94% Mortgage Payable due April 15, 2015 [Member]	'		'
Debt Instrument [Line Items]	'		'
Annual Stated Interest Rate	4.94%	[2]	'
Effective interest rate	4.00%	[2],[3]	'
Maturity Date	15-Apr-15		'
Secured Debt	27,307	[1],[4]	27,641	[1],[4]
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 7.15% Mortgage Payable due May 01, 2017 [Member]	'		'
Debt Instrument [Line Items]	'		'
Annual Stated Interest Rate	7.15%	[2]	'
Effective interest rate	7.15%	[2],[3]	'
Maturity Date	1-May-17		'
Secured Debt	8,387	[1]	8,972	[1]
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | Municipal Bonds [Member]	'		'
Debt Instrument [Line Items]	'		'
Secured Debt	$2,470	[1]	$2,470	[1]
[1]	Amounts reported include the amounts of unamortized debt premiums and discounts for the periods presented.
[2]	All interest rates presented are fixed-rate interest rates.
[3]	This represents the rate at which interest expense is recorded for financial reporting purposes, which reflects the amortization of discounts/premiums, excluding debt issuance costs.
[4]	The secured debt and the related properties that secure the 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.

Secured_and_Unsecured_Debt_of_3

Secured and Unsecured Debt of the Operating Partnership (Details 1) (USD $)	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013	Dec. 31, 2013
Debt Instrument [Line Items]	'		'	'
Unsecured debt	$1,431,217,000		'	$1,431,132,000
Balance and significant terms of the Exchangeable Notes outstanding	'		'	'
Net carrying amount of liability component	169,528,000		'	168,372,000
Per Share Average Trading Price Of Companys Common Stock On Stock Exchange Abstract	'		'	'
Average trading price of the Companys stock	$55.18		$51.14	'
Kilroy Realty, L.P. [Member]	'		'	'
Debt Instrument [Line Items]	'		'	'
Unsecured debt	1,431,217,000		'	1,431,132,000
Balance and significant terms of the Exchangeable Notes outstanding	'		'	'
Net carrying amount of liability component	169,528,000		'	168,372,000
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 6.05% Mortgage Payable Due June 1, 2019 [Member]	'		'	'
Balance and significant terms of the Exchangeable Notes outstanding	'		'	'
Maturity Date	1-Jun-19		'	'
Stated coupon rate	6.05%	[1]	'	'
Effective interest rate	3.50%	[1],[2]	'	'
Kilroy Realty, L.P. [Member] | Exchangeable Notes [Member]	'		'	'
Interest Expense for the Exchangeable Notes	'		'	'
Contractual interest payments	1,833,000		1,833,000	'
Amortization of discount	1,156,000		1,078,000	'
Interest expense attributable to the Exchangeable Notes	2,989,000		2,911,000	'
Kilroy Realty, L.P. [Member] | Exchangeable Notes [Member] | 4.25% Exchangeable Notes [Member]	'		'	'
Balance and significant terms of the Exchangeable Notes outstanding	'		'	'
Net carrying amount of liability component	169,528,000		'	168,372,000
Per Share Average Trading Price Of Companys Common Stock On Stock Exchange Abstract	'		'	'
Fair Value Of Shares Upon Conversion If Exchangeable Notes Were Converted On Specified Date	270,602,000		247,300,000	'
Debt Instrument, Convertible, If-converted Value in Excess of Principal	98,102,000		74,800,000	'
Capped call transactions	'		'	'
Referenced shares of common stock	4,800,796		'	'
Exchange price including effect of capped calls	42.81		'	'
Kilroy Realty, L.P. [Member] | Exchangeable Debt [Member] | 4.25% Exchangeable Notes [Member]	'		'	'
Balance and significant terms of the Exchangeable Notes outstanding	'		'	'
Principal amount	172,500,000		'	172,500,000
Unamortized discount	-2,972,000		'	-4,128,000
Carrying amount of equity component	$19,835,000		'	'
Stated coupon rate	4.25%	[3]	'	'
Effective interest rate	7.13%	[4]	'	'
Exchange rate per $1,000 principal value of the Exchangeable Notes, as adjusted	27.8307	[5]	'	'
Exchange price, as adjusted	$35.93	[5]	'	'
Number of Shares on which aggregate consideration to be delivered upon conversion is determined	4,800,796	[5]	'	'
Minimum percentage of exchange price	130.00%		'	'
[1]	All interest rates presented are fixed-rate interest rates.
[2]	This represents the rate at which interest expense is recorded for financial reporting purposes, which reflects the amortization of discounts/premiums, excluding debt issuance costs.
[3]	Interest on the 4.25% Exchangeable Notes is payable semi-annually in arrears on May 15th and November 15th of each year.
[4]	The rate at which we record interest expense for financial reporting purposes, which reflects the amortization of the discounts on the 4.25% Exchangeable Notes. This rate represents our conventional debt borrowing rate at the date of issuance.
[5]	The exchange rate, exchange price and the number of shares to be delivered upon conversion are subject to adjustment under certain circumstances including increases in our common dividends.

Unsecured_Senior_Notes_Details

Unsecured Senior Notes (Details 2) (USD $)	3 Months Ended
	Mar. 31, 2014		Dec. 31, 2013
Debt Instrument [Line Items]	'		'
Unsecured debt	$1,431,217,000		$1,431,132,000
Exchangeable senior notes, net	169,528,000		168,372,000
Kilroy Realty, L.P. [Member]	'		'
Debt Instrument [Line Items]	'		'
Unsecured debt	1,431,217,000		1,431,132,000
Exchangeable senior notes, net	169,528,000		168,372,000
Kilroy Realty, L.P. [Member] | Revolving Credit Facility [Member]	'		'
Debt Instrument [Line Items]	'		'
Debt Instrument, Contingent Additional Borrowings	200,000,000		'
Debt Instrument, Basis Spread on Variable Rate	1.45%		'
Kilroy Realty, L.P. [Member] | Three Point Eight Zero Zero Percent Unsecured Senior Note [Member] | Senior Notes [Member]	'		'
Debt Instrument [Line Items]	'		'
Unsecured debt	299,913,000		299,910,000
Stated coupon rate	3.80%		'
Debt Instrument, Unamortized Discount	-87,000		-90,000
Debt Instrument, Interest Rate, Effective Percentage	3.80%	[1],[2]	'
Debt Instrument, Face Amount	300,000,000		300,000,000
Kilroy Realty, L.P. [Member] | Exchangeable Note Two [Member] | Exchangeable Debt [Member]	'		'
Debt Instrument [Line Items]	'		'
Minimum percentage of exchange price	130.00%		'
Debt Instrument, Convertible, Number of Equity Instruments	4,800,796	[3]	'
Debt Instrument, Convertible, Conversion Ratio	27.8307	[3]	'
Debt Instrument, Convertible, Stock Price Trigger	$35.93	[3]	'
Debt Instrument, Convertible, Carrying Amount of Equity Component	19,835,000		'
Principal amount	172,500,000		172,500,000
Stated coupon rate	4.25%	[4]	'
Debt Instrument, Unamortized Discount	2,972,000		4,128,000
Debt Instrument, Interest Rate, Effective Percentage	7.13%	[5]	'
Kilroy Realty, L.P. [Member] | Exchangeable Note Two [Member] | Convertible Debt [Member]	'		'
Debt Instrument [Line Items]	'		'
Exchangeable senior notes, net	169,528,000		168,372,000
Kilroy Realty, L.P. [Member] | Six Point Four Five Percent Unsecured Senior Notes due Aug 4 2014 [Member] | Senior Notes [Member]	'		'
Debt Instrument [Line Items]	'		'
Unsecured debt	83,000,000		83,000,000
Maturity Date	4-Aug-14		'
Stated coupon rate	6.45%		'
Debt Instrument, Interest Rate, Effective Percentage	6.45%		'
Kilroy Realty, L.P. [Member] | One Hundred Fifty Million Term Loan Facility [Member] | Line of Credit [Member]	'		'
Debt Instrument [Line Items]	'		'
Debt Instrument, Contingent Additional Borrowings	100,000,000		'
Unsecured debt	150,000,000		150,000,000
Debt Instrument, Basis Spread on Variable Rate	1.75%		'
Kilroy Realty, L.P. [Member] | Four Point Eight Percent Unsecured Senior Notes Due July Fifteen Two Thousand Eighteen [Member] | Senior Notes [Member]	'		'
Debt Instrument [Line Items]	'		'
Unsecured debt	324,680,000		324,661,000
Stated coupon rate	4.80%		'
Debt Instrument, Unamortized Discount	-320,000		-339,000
Debt Instrument, Interest Rate, Effective Percentage	4.83%	[1],[6]	'
Debt Instrument, Face Amount	325,000,000		325,000,000
Kilroy Realty, L.P. [Member] | Six Point Six Two Five Percent Unsecured Senior Notes due June 1 2020 [Member] | Senior Notes [Member]	'		'
Debt Instrument [Line Items]	'		'
Unsecured debt	248,687,000		248,633,000
Stated coupon rate	6.63%		'
Debt Instrument, Unamortized Discount	-1,313,000		-1,367,000
Debt Instrument, Interest Rate, Effective Percentage	6.74%	[1],[7]	'
Debt Instrument, Face Amount	250,000,000		250,000,000
Kilroy Realty, L.P. [Member] | Five Percent Unsecured Senior Notes due Nov3 2015 [Member] | Senior Notes [Member]	'		'
Debt Instrument [Line Items]	'		'
Unsecured debt	324,937,000		324,927,000
Stated coupon rate	5.00%		'
Debt Instrument, Unamortized Discount	-63,000		-73,000
Debt Instrument, Interest Rate, Effective Percentage	5.01%	[1],[8]	'
Debt Instrument, Face Amount	$325,000,000		$325,000,000
[1]	This represents the rate at which interest expense is recorded for financial reporting purposes, which reflects the amortization of initial issuance discounts, excluding debt issuance costs.
[2]	Interest on the 3.800% unsecured senior notes is payable semi-annually in arrears on January 15th and July 15th of each year.
[3]	The exchange rate, exchange price and the number of shares to be delivered upon conversion are subject to adjustment under certain circumstances including increases in our common dividends.
[4]	Interest on the 4.25% Exchangeable Notes is payable semi-annually in arrears on May 15th and November 15th of each year.
[5]	The rate at which we record interest expense for financial reporting purposes, which reflects the amortization of the discounts on the 4.25% Exchangeable Notes. This rate represents our conventional debt borrowing rate at the date of issuance.
[6]	Interest on the 4.800% unsecured senior notes is payable semi-annually in arrears on January 15th and July 15th of each year.
[7]	Interest on the 6.625% unsecured senior notes is payable semi-annually in arrears on June 1st and December 1st of each year.
[8]	Interest on the 5.000% unsecured senior notes is payable semi-annually in arrears on May 3rd and November 3rd of each year.

Unsecured_Revolving_Credit_Fac

Unsecured Revolving Credit Facility (Details 3) (USD $)	3 Months Ended
	Mar. 31, 2014		Dec. 31, 2013
Line of Credit Facility [Line Items]	'		'
Unsecured debt	$1,431,217,000		$1,431,132,000
Terms of the Credit Facility	'		'
Unsecured line of credit	0		45,000,000
Kilroy Realty, L.P. [Member]	'		'
Line of Credit Facility [Line Items]	'		'
Unsecured debt	1,431,217,000		1,431,132,000
Terms of the Credit Facility	'		'
Unsecured line of credit	0		45,000,000
Kilroy Realty, L.P. [Member] | Revolving Credit Facility [Member]	'		'
Terms of the Credit Facility	'		'
Unsecured line of credit	0		45,000,000
Remaining borrowing capacity	500,000,000		455,000,000
Total borrowing capacity	500,000,000	[1]	500,000,000	[1]
Interest rate	0.00%		1.62%	[2]
Facility fee - annual rate	0.30%	[3]	'
Maturity date	3-Apr-17	[4]	'
Debt Instrument, Contingent Additional Borrowings	200,000,000		'
Debt Instrument, Basis Spread on Variable Rate	1.45%		'
Kilroy Realty, L.P. [Member] | Line of Credit [Member]	'		'
Terms of the Credit Facility	'		'
Unamortized Debt Issuance Cost	4,500,000		'
One Hundred Fifty Million Term Loan Facility [Member] | Kilroy Realty, L.P. [Member] | Line of Credit [Member]	'		'
Line of Credit Facility [Line Items]	'		'
Unsecured debt	150,000,000		150,000,000
Terms of the Credit Facility	'		'
Debt Instrument, Contingent Additional Borrowings	$100,000,000		'
Debt Instrument, Basis Spread on Variable Rate	1.75%		'
[1]	We may elect to borrow, subject to bank approval and obtaining commitments for any additional borrowing capacity, up to an additional $200.0 million under an accordion feature under the terms of the revolving credit facility.
[2]	The revolving credit facility interest rate was calculated based on an annual rate of LIBOR plus 1.450% as of both March 31, 2014 and December 31, 2013.
[3]	The facility fee is paid on a quarterly basis and is calculated based on the total borrowing capacity. In addition to the facility fee, from 2010 to 2012 we incurred debt origination and legal costs of which, as of March 31, 2014, approximately $4.5 million remains to be amortized through the maturity date of the revolving credit facility.
[4]	Under the terms of the revolving credit facility, we may exercise an option to extend the maturity date by one year.

Debt_Maturities_Details_4

Debt Maturities (Details 4) (Debt [Member], Kilroy Realty, L.P. [Member], USD $)	Mar. 31, 2014
Debt [Member] | Kilroy Realty, L.P. [Member]	'
Stated debt maturities and scheduled amortization payments, excluding debt discounts	'
Remaining 2014	$262,932,000
2015	395,104,000
2016	249,431,000
2017	71,748,000
2018	451,728,000
Thereafter	718,011,000
Total	2,148,954,000	[1]
Unamortized discount (premium)	($8,700,000)
[1]	Includes gross principal balance of outstanding debt before impact of net unamortized premiums totaling approximately $8.7 million.

Secured_and_Unsecured_Debt_of_4

Secured and Unsecured Debt of the Operating Partnership Capitalized Interest and Loan Fees (Details 5) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Capitalized Interest and Loan Fees [Line Items]	'	'
Interest Expense	$17,252	$19,734
Kilroy Realty, L.P. [Member]	'	'
Capitalized Interest and Loan Fees [Line Items]	'	'
Gross interest expense	28,034	27,466
Capitalized interest	-10,782	-7,732
Interest Expense	$17,252	$19,734

Noncontrolling_Interests_on_th1

Noncontrolling Interests on the Company's Consolidated Financial Statements (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Noncontrolling Interest [Abstract]	'	'	'
Percentage of general partnership interest owned by the company in the Operating Partnership	97.90%	97.80%	97.60%
Percentage of Common limited partnership interest owned by certain non-affiliated investors and certain directors and officers of the Company in the Operating Partnership	2.10%	2.20%	2.40%
Common units outstanding held by common limited partners	1,804,200	1,805,200	1,826,503
Common stock, par value	$0.01	'	'
Aggregate value upon redemption of outstanding noncontrolling common units	$105,400,000	$90,800,000	'
Noncontrolling Interest in Variable Interest Entity	$4,885,000	$4,885,000	'

Stockholders_Equity_of_the_Com1

Stockholders' Equity of the Company (Details) (USD $)	3 Months Ended					3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014
			Common Stock [Member]	Common Stock [Member]	Issuance of Equity - at the market offering [Member]	Issuance of Equity under ATM Program [Member]	Issuance of Equity under ATM Program [Member]
					Common Stock [Member]		Common Stock [Member]
Common Stock of the Company [Abstract]	'	'	'	'	'	'	'
At the Market Stock Offering Program Aggregate Value Of Common Stock	'	'	'	'	'	$200,000,000	'
Net proceeds from issuance of common stock	0	23,395,000	'	'	'	'	'
Common stock, shares issued	'	'	82,218,332	82,153,944	'	2,183,261	'
At Market Stock Aggregate Gross Sales Price of Common Stock	'	'	'	'	105,300,000	'	'
At the Market Stock Offering Program Remained Available For Issuance	'	'	'	'	'	'	$94,700,000

Partners_Capital_of_the_Operat2

Partners' Capital of the Operating Partnership (Details) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
General Partners' Capital Account [Abstract]	'	'	'
Net proceeds from issuance of common stock	$0	$23,395	'
Noncontrolling Interest, Ownership Percentage by Parent	97.90%	97.60%	97.80%
Common units held by limited partners	1,804,200	1,826,503	1,805,200
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	2.10%	2.40%	2.20%
Kilroy Realty, L.P. [Member] | Capital Units [Member]	'	'	'
General Partners' Capital Account [Abstract]	'	'	'
General Partners' Capital Account, Units Outstanding	82,218,332	75,349,705	82,153,944

ShareBased_Compensation_Detail

Share-Based Compensation (Details Textuals) (USD $)	3 Months Ended
In Millions, except Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Jan. 29, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	236,604	'	'
Share Price	$58.58	'	$51.64
Share-based Compensation Capitalized	$0.40	$0.20	'
Share-based Compensation, Unrecognized costs	36.9	'	'
Share-based Compensation, Unrecognized costs, weighted-average vesting period	'2 years 7 months	'	'
Allocated Share-based Compensation Expense	2.9	2.4	'
2014 RSU Grant [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Share-based Compensation, Unrecognized costs	13.6	'	'
Market Measure-Based Restricted Stock Units (RSUs) [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$63.44	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate	32.00%	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	0.79%	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	119,098	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	'2 years 9 months	'	'
Share-based Compensation Arrangement By Share-based Payment Award, Equity Instruments Other Than Options, Grants In Period, Grant Date Fair Value	7.1	'	'
Time-Based Restricted Stock Units (RSUs) [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	117,506	'	'
Share-based Compensation Arrangement By Share-based Payment Award, Equity Instruments Other Than Options, Grants In Period, Grant Date Fair Value	$6.10	'	'
Shareholder Meeting Date May 22, 2014 [Domain]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Requested	7,120,000	'	'

Commitments_and_Contingencies_

Commitments and Contingencies (Details 1) (USD $)	Mar. 31, 2014
In Millions, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]	'
Other Commitment	$733.60

Fair_Value_Measurements_and_Di2

Fair Value Measurements and Disclosures (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013	Dec. 31, 2013
Fair value adjustment of marketable securities and deferred compensation plan liability	'		'	'
Net gain on marketable securities	$154		$356	'
Trading Securities	11,001		'	10,008
Fair Value (Level 1) [Member]	'		'	'
Assets and Liabilities Reported at Fair Value	'		'	'
Marketable securities	$11,001	[1],[2]	'	$10,008	[1],[2]
[1]	The marketable securities are held in a limited rabbi trust.
[2]	Based on quoted prices in active markets for identical securities.

Fair_Value_Measurements_and_Di3

Fair Value Measurements and Disclosures (Details 1) (USD $)	Mar. 31, 2014		Dec. 31, 2013
Liabilities	'		'
Secured Debt	$556,946,000	[1]	$560,434,000	[1]
Exchangeable senior notes, net	169,528,000		168,372,000
Unsecured debt	1,431,217,000		1,431,132,000
Unsecured line of credit	0		45,000,000
Carrying Value [Member]	'		'
Liabilities	'		'
Secured Debt	556,946,000		560,434,000
Exchangeable senior notes, net	169,528,000		168,372,000
Unsecured debt	1,431,217,000		1,431,132,000
Unsecured line of credit	0		45,000,000
Fair Value [Member]	'		'
Liabilities	'		'
Secured Debt	567,107,000	[2]	568,760,000	[2]
Exchangeable senior notes, net	175,403,000	[2]	178,190,000	[2]
Unsecured debt	1,506,815,000	[3]	1,523,052,000	[3]
Unsecured line of credit	0	[2]	45,012,000	[2]
Fair Value (Level 2) [Member] | Carrying Value [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Debt Instrument, Fair Value Disclosure	557,700,000		557,700,000
Fair Value (Level 2) [Member] | Fair Value [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Debt Instrument, Fair Value Disclosure	585,600,000		593,700,000
Unsecured Debt [Member] | Fair Value (Level 1) [Member] | Carrying Value [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Debt Instrument, Fair Value Disclosure	873,500,000		873,500,000
Unsecured Debt [Member] | Fair Value (Level 1) [Member] | Fair Value [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Debt Instrument, Fair Value Disclosure	$921,200,000		$929,300,000
[1]	Amounts reported include the amounts of unamortized debt premiums and discounts for the periods presented.
[2]	Fair value calculated using Level II inputs which are based on model-derived valuations in which significant inputs and significant value drivers are observable in active markets.
[3]	Fair value calculated using Level I and Level II inputs. Level I inputs are based on quoted prices for identical instruments in active markets. The carrying value and fair value of the Level I instruments was $873.5 million and $921.2 million, respectively, as of March 31, 2014. The carrying value and fair value of the Level I instruments as of December 31, 2013, was $873.5 million and $929.3 million, respectively. The carrying value and fair value of the Level II instruments was $557.7 million and $585.6 million, respectively, as of March 31, 2014. The carrying value and fair value of the Level II instruments as of December 31, 2013, was $557.7 million and $593.7 million, respectively.

Other_Significant_Events_Detai

Other Significant Events (Details) (USD $)	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
	sqft
Other Significant Noncash Transactions [Line Items]	'		'
Net Rentable Area	79,000		'
Lease termination fee, total contract amount	$5,700,000		'
Amortization of Intangible Assets	11,288,000		13,232,000
Lease Termination	'		'
Other Significant Noncash Transactions [Line Items]	'		'
Lease Termination Fee, amount recognized in the quarter	1,700,000		'
Amortization of Intangible Assets	$400,000	[1]	'
[1]	The amortization of the below-market ground lease obligation is recorded as an increase to ground lease expense in the consolidated statements of operations for the periods presented.

Discontinued_Operations_Detail

Discontinued Operations (Details) (USD $)	3 Months Ended					3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014		Mar. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
	sqft		San Diego Properties, San Diego, CA [Member]		10850 Via Frontera San Diego CA [Member]	Restricted cash [Member]	Restricted cash [Member]
			building
			sqft
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'	'		'	'	'
Proceeds from Sale of Real Estate Held-for-investment	$309,824	$0	'		'	$15,300	$32,200
Number of buildings	'	'	12	[1],[2]	'	'	'
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]	'	'	'		'	'	'
Undeveloped land and construction in progress	'	'	'		28,030	'	'
Prepaid expenses and other assets, net	'	'	'		242	'	'
Real estate and other assets held for sale, net	'	'	'		28,272	'	'
Accounts payable, accrued Liabilities and other liabilities	'	'	'		634	'	'
Liabilities of real estate assets held for sale	'	'	'		634	'	'
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]	'	'	'		'	'	'
Rental income	458	5,773	'		'	'	'
Tenant reimbursements	66	757	'		'	'	'
Other property income	9	3	'		'	'	'
Total revenues	533	6,533	'		'	'	'
Property expenses	87	968	'		'	'	'
Real estate taxes	69	673	'		'	'	'
Depreciation and amortization	0	2,690	'		'	'	'
Total expenses	156	4,331	'		'	'	'
Income from discontinued operations	377	2,202	'		'	'	'
Net gain on dispositions of discontinued operations	90,115	0	'		'	'	'
Total income from discontinued operations	$90,492	$2,202	'		'	'	'
Net Rentable Area	79,000	'	1,049,035	[1],[2]	'	'	'
[1]	The San Diego Properties included the following: 10020 Pacific Mesa Boulevard, 6055 Lusk Avenue, 5010 and 5005 Wateridge Vista Drive, 15435 and 15445 Innovation Drive, and 15051, 15073, 15231, 15253, 15333 and 15378 Avenue of Science.
[2]	These properties were held for sale as of December 31, 2013.

Net_Loss_Income_Available_to_C1

Net (Loss) Income Available to Common Stockholders Per Share of the Company (Details) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Numerator:	'		'
Income from continuing operations	$11,440		$186
(Income) loss from continuing operations attributable to noncontrolling common units of the Operating Partnership	-172		72
Preferred distributions	-3,313		-3,313
Allocation to participating securities	-427	[1]	-418	[1]
Numerator for basic and diluted income (loss) from continuing operations available to common stockholders	7,528		-3,473
Income from discontinued operations	90,492		2,202
Income from discontinued operations attributable to noncontrolling common units of the Operating Partnership	-1,915		-50
Numerator for basic and diluted net income (loss) available to common stockholders	96,105		-1,321
Denominator:	'		'
Weighted average common shares outstanding – basic (Note 14)	82,124,538		74,977,240
Effect of dilutive securities	2,015,532		0
Weighted average common shares outstanding-diluted	84,140,070		74,977,240
Basic earnings per share:	'		'
Income (loss) from continuing operations available to common stockholders per common share – basic (Note 14)	$0.09		($0.05)
Income from discontinued operations per common share	$1.08		$0.03
Net income (loss) available to common stockholders per share-basic	$1.17		($0.02)
Diluted earnings per share:	'		'
Income (loss) from continuing operations available to common stockholders per common share – diluted (Note 14)	$0.09		($0.05)
Income from discontinued operations per common share	$1.05		$0.03
Net income (loss) available to common stockholders per share-diluted	$1.14		($0.02)
Stock options outstanding	1,520,500		'
Kilroy Realty, L.P. [Member]	'		'
Numerator:	'		'
Income from continuing operations	11,440		186
Preferred distributions	-3,313		-3,313
Allocation to participating securities	-427	[1]	-418	[1]
Numerator for basic and diluted income (loss) from continuing operations available to common stockholders	7,635		-3,614
Income from discontinued operations	90,492		2,202
Numerator for basic and diluted net income (loss) available to common stockholders	$98,127		($1,412)
Denominator:	'		'
Weighted average common shares outstanding – basic (Note 14)	83,928,993		76,803,743
Effect of dilutive securities	2,015,532		0
Weighted average common shares outstanding-diluted	85,944,525		76,803,743
Basic earnings per share:	'		'
Income (loss) from continuing operations available to common stockholders per common share – basic (Note 14)	$0.09		($0.05)
Income from discontinued operations per common share	$1.08		$0.03
Net income (loss) available to common stockholders per share-basic	$1.17		($0.02)
Diluted earnings per share:	'		'
Income (loss) from continuing operations available to common stockholders per common share – diluted (Note 14)	$0.09		($0.05)
Income from discontinued operations per common share	$1.05		$0.03
Net income (loss) available to common stockholders per share-diluted	$1.14		($0.02)
[1]	Participating securities include nonvested shares, certain time-based RSUs and vested market-measure RSUs.

Net_Income_Loss_Available_to_C3

Net Income (Loss) Available to Common Unitholders Per Unit of the Operating Partnership (Details) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Numerator:	'		'
Income from continuing operations	$11,440		$186
Preferred distributions	-3,313		-3,313
Allocation to participating securities	-427	[1]	-418	[1]
Numerator for basic and diluted income (loss) from continuing operations available to common unitholders	7,528		-3,473
Income from discontinued operations	90,492		2,202
Numerator for basic and diluted net income (loss) available to common unitholders	96,105		-1,321
Denominator:	'		'
Weighted average common units outstanding - basic (Note 14)	82,124,538		74,977,240
Effect of dilutive securities	2,015,532		0
Weighted average common units outstanding - diluted (Note 14)	84,140,070		74,977,240
Basic earnings per unit:	'		'
Income (loss) from continuing operations available to common unitholders per common unit - basic (Note 15)	$0.09		($0.05)
Income from discontinued operations per common unit	$1.08		$0.03
Net income (loss) available to common unitholders per unit-basic (Note 14)	$1.17		($0.02)
Diluted earnings per unit:	'		'
Income (loss) from continuing operations available to common unitholders per common unit - diluted (Note 15)	$0.09		($0.05)
Income from discontinued operations per common unit	$1.05		$0.03
Net income (loss) available to common unitholders per unit-diluted (Note 14)	$1.14		($0.02)
Stock options outstanding	1,520,500		'
Kilroy Realty, L.P. [Member]	'		'
Numerator:	'		'
Income from continuing operations	11,440		186
Income from continuing operations attributable to noncontrolling interests in consolidated subsidiaries	-65		-69
Preferred distributions	-3,313		-3,313
Allocation to participating securities	-427	[1]	-418	[1]
Numerator for basic and diluted income (loss) from continuing operations available to common unitholders	7,635		-3,614
Income from discontinued operations	90,492		2,202
Numerator for basic and diluted net income (loss) available to common unitholders	$98,127		($1,412)
Denominator:	'		'
Weighted average common units outstanding - basic (Note 14)	83,928,993		76,803,743
Effect of dilutive securities	2,015,532		0
Weighted average common units outstanding - diluted (Note 14)	85,944,525		76,803,743
Basic earnings per unit:	'		'
Income (loss) from continuing operations available to common unitholders per common unit - basic (Note 15)	$0.09		($0.05)
Income from discontinued operations per common unit	$1.08		$0.03
Net income (loss) available to common unitholders per unit-basic (Note 14)	$1.17		($0.02)
Diluted earnings per unit:	'		'
Income (loss) from continuing operations available to common unitholders per common unit - diluted (Note 15)	$0.09		($0.05)
Income from discontinued operations per common unit	$1.05		$0.03
Net income (loss) available to common unitholders per unit-diluted (Note 14)	$1.14		($0.02)
[1]	Participating securities include nonvested shares, certain time-based RSUs and vested market-measure RSUs.

Subsequent_Events_Details

Subsequent Events (Details) (USD $)	3 Months Ended		0 Months Ended	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Apr. 16, 2014	Apr. 09, 2014
			Subsequent Event [Member]	10850 Via Frontera San Diego CA [Member]
				Subsequent Event [Member]
Subsequent Event [Line Items]	'	'	'	'
Dispositions Sales Price	'	'	'	$33,100,000
Aggregate dividends, distributions, and dividend equivalents paid to common stockholders and common unitholders	$29,561,000	$26,956,000	$29,800,000	'