Kilroy Realty (KRC) 10-K 10 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information Document (USD $)	12 Months Ended
	Dec. 31, 2014	Feb. 06, 2015	Jun. 30, 2014
Entity Information [Line Items]
Entity Registrant Name	KILROY REALTY CORP
Entity Central Index Key	1025996
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding		86,377,404
Entity Public Float			$5,152,002,640
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Kilroy Realty, L.P. [Member]
Entity Information [Line Items]
Entity Registrant Name	Kilroy Realty, L.P.
Entity Central Index Key	1493976
Current Fiscal Year End Date	-19
Entity Filer Category	Non-accelerated Filer
Document Type	10-K
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Amendment Flag	FALSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
REAL ESTATE ASSETS (Notes 3 and 18):
Land and improvements	$877,633		$657,491
Buildings and improvements	4,059,639		3,590,699
Undeveloped land and construction in progress	1,120,660		1,016,757
Total real estate held for investment	6,057,932		5,264,947
Accumulated depreciation and amortization	-947,664		-818,957
Total real estate held for investment, net ($211,755 and $234,532 of VIE, Note 2)	5,110,268		4,445,990
REAL ESTATE ASSETS AND OTHER ASSETS HELD FOR SALE, NET (Note 18)	8,211		213,100
CASH AND CASH EQUIVALENTS	23,781		35,377
RESTRICTED CASH (Note 18)	75,185		49,780
MARKETABLE SECURITIES (Notes 13 and 16)	11,971		10,008
CURRENT RECEIVABLES, NET (Note 5)	7,229	[1]	10,743
DEFERRED RENT RECEIVABLES, NET (Note 5)	156,416		127,123
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Notes 3 and 4)	201,926		186,622
DEFERRED FINANCING COSTS, NET (Notes 2 and 7)	18,374		16,502
PREPAID EXPENSES AND OTHER ASSETS, NET	20,375		15,783
TOTAL ASSETS	5,633,736		5,111,028
LIABILITIES:
Secured debt (Notes 3, 6, 7 and 16)	546,292		560,434
Exchangeable senior notes, net (Notes 6, 7 and 16)	0		168,372
Unsecured debt, net (Notes 6, 7 and 16)	1,783,121		1,431,132
Unsecured line of credit (Notes 6, 7 and 16)	140,000		45,000
Accounts payable, accrued expenses and other liabilities (Note 15)	225,830		198,467
Accrued distributions (Note 10)	32,899		31,490
Deferred revenue and acquisition-related intangible liabilities, net (Notes 3, 4 and 8)	132,239		101,286
Rents received in advance and tenant security deposits	49,363		44,240
Liabilities and deferred revenue of real estate assets held for sale (Note 18)	56		14,447
Total liabilities	2,909,800		2,594,868
COMMITMENTS AND CONTINGENCIES (Note 15)
Preferred stock, $.01 par value, 30,000,000 shares authorized:
Common stock, $.01 par value, 150,000,000 shares authorized, 86,259,684 and 82,153,944 shares issued and outstanding, respectively	863		822
Additional paid-in capital	2,635,900		2,478,975
Distributions in excess of earnings	162,964		210,896
Total stockholders' equity	2,666,210		2,461,312
Noncontrolling interest:
Common units of the Operating Partnership	51,864		49,963
Noncontrolling interest in consolidated subsidiary	5,862		4,885
Total noncontrolling interests	57,726		54,848
Total equity	2,723,936		2,516,160
TOTAL LIABILITIES AND EQUITY	5,633,736		5,111,028
Series G Cumulative Redeemable Preferred Stock
Preferred stock, $.01 par value, 30,000,000 shares authorized:
Redeemable Preferred stock	96,155		96,155
Series H Cumulative Redeemable Preferred Stock
Preferred stock, $.01 par value, 30,000,000 shares authorized:
Redeemable Preferred stock	$96,256		$96,256
[1]	Excludes current receivables, net related to real estate held for sale.

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013
VIE Asset Amount	$219,600,000		$251,800,000
Common stock, par value	$0.01
Common stock, shares outstanding	86,259,684	[1]	82,153,944	[1]
Common Stock
Common stock, par value	$0.01		$0.01
Common stock, shares authorized	150,000,000		150,000,000
Common stock, shares issued	86,259,684		82,153,944
Common stock, shares outstanding	86,259,684		82,153,944
Preferred Stock [Member]
Preferred stock, shares authorized	30,000,000		30,000,000
Preferred stock, par value	$0.01		$0.01
Series G Cumulative Redeemable Preferred Stock
Preferred stock, shares authorized	4,600,000		4,600,000
Preferred stock, par value	$0.01		$0.01
Preferred stock, shares outstanding	4,000,000		4,000,000
Preferred stock dividend rate (percentage)	6.88%		6.88%
Preferred stock liquidation preference	100,000,000		100,000,000
Series H Cumulative Redeemable Preferred Stock
Preferred stock, shares authorized	4,000,000		4,000,000
Preferred stock, par value	$0.01		$0.01
Preferred stock, shares outstanding	4,000,000		4,000,000
Preferred stock dividend rate (percentage)	6.38%		6.38%
Preferred stock liquidation preference	100,000,000		100,000,000
Real Estate Investment [Member]
VIE Asset Amount	$211,800,000		$234,500,000
[1]	The amount includes nonvested shares.

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
REVENUES:
Rental income	$466,328	$411,899	$342,164
Tenant reimbursements	46,717	38,047	29,667
Other property income (Note 15 and 17)	8,680	7,165	1,487
Total revenues	521,725	457,111	373,318
EXPENSES:
Property expenses	100,514	94,115	73,998
Real estate taxes	45,197	39,417	31,562
Provision for bad debts	58	396	153
Ground leases (Note 4 and 15)	3,075	3,504	3,168
General and administrative expenses	46,152	39,660	36,188
Acquisition-related expenses	1,479	1,962	4,937
Depreciation and amortization (Notes 2 and 4)	202,417	188,887	150,521
Total expenses	398,892	367,941	300,527
OTHER (EXPENSES) INCOME:
Interest income and other net investment gains (Note 16)	561	1,635	848
Interest expense (Note 7)	-67,571	-75,870	-79,114
Total other (expenses) income	-67,010	-74,235	-78,266
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE GAIN ON SALE OF LAND	55,823	14,935	-5,475
Gain on sale of land (Note 18)	3,490	0	0
INCOME (LOSS) FROM CONTINUING OPERATIONS	59,313	14,935	-5,475
DISCONTINUED OPERATIONS (Note 18)
Income from discontinued operations	2,573	17,378	23,331
Net gain on dispositions of discontinued operations (Note 18)	121,922	12,252	259,245
Total income from discontinued operations	124,495	29,630	282,576
NET INCOME	183,808	44,565	277,101
Net income attributable to noncontrolling common units of the Operating Partnership	3,589	685	6,187
NET INCOME ATTRIBUTABLE TO KILROY REALTY	180,219	43,880	270,914
PREFERRED DISTRIBUTIONS AND DIVIDENDS:
Distributions to noncontrolling cumulative redeemable preferred units of the Operating Partnership (Note 9)	0	0	-3,541
Preferred dividends (Note 10)	-13,250	-13,250	-10,567
Original issuance costs of redeemed preferred stock and preferred units (Notes 9 and 11)	0	0	-6,980
Total preferred distributions	-13,250	-13,250	-21,088
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	$166,969	$30,630	$249,826
Income (loss) from continuing operations available to common stockholders per share of common stock b basic (Note 19)	$0.52	$0	($0.40)
Income (loss) from continuing operations available to common stockholders per share (dollars per share)	$0.51	$0	($0.40)
Net income available to common stockholders per share-basic (Note 19)	$1.99	$0.37	$3.56
Net income available to common stockholders per share-diluted (Note 19)	$1.95	$0.37	$3.56
Weighted average common shares outstanding-basic (Note 19)	83,090,235	77,343,853	69,639,623
Weighted average common shares outstanding-diluted (Note 19)	84,967,720	77,343,853	69,639,623

Consolidated_Statements_of_Equ

Consolidated Statements of Equity (USD $)		Total		Total Stockholders' Equity	Preferred Stock [Member]	Common Stock	Common Stock Additional Paid-in Capital	Common Stock Distributions in Excess of Earnings	Noncontrolling Interests - Common Units of the Operating Partnership	Series E and Series F Cumulative Redeemable Preferred Stock	Series E and Series F Cumulative Redeemable Preferred Stock	Series E and Series F Cumulative Redeemable Preferred Stock	Series E and Series F Cumulative Redeemable Preferred Stock	Series G and Series H Preferred Stock [Member]	Series G and Series H Preferred Stock [Member]	Series G and Series H Preferred Stock [Member]	Series A Preferred Units [Member]	Series A Preferred Units [Member]
In Thousands, except Share data, unless otherwise specified											Total Stockholders' Equity	Preferred Stock [Member]	Common Stock Distributions in Excess of Earnings		Total Stockholders' Equity	Preferred Stock [Member]		Common Stock Distributions in Excess of Earnings
Beginning Balance at Dec. 31, 2011		$1,327,482		$1,293,717	$121,582	$588	$1,448,997	($277,450)	$33,765
Beginning Balance, shares at Dec. 31, 2011						58,819,717
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		277,101		270,914				270,914	6,187
Stock redeemed during period, value		-2,062		-2,062						-126,500	-126,500	-121,582	-4,918					-2,062
Issuance of common stock, shares (Note 10)						16,024,618
Issuance of share-based compensation awards, shares (Note 12)						62,137
Issuance of share-based compensation awards		1,291		1,291			1,291
Noncash amortization of share-based compensation		8,537		8,537			8,537
Exercise of stock options, shares						10,000
Issuance of common stock (Note 10)		672,102		672,102		161	671,941							192,411	192,411	192,411
Exchange Of Common Units Of The Operating Partnership Into Shares Of The Companys Common Stock		0		231			-231		231
Exercise of stock options		-129		-129			-129
Noncontrolling Interest, Increase from Business Combination		5,604							5,604
Repurchase of common stock and restricted stock units (Note 12)		-877		-877			-877
Repurchase of common stock and restricted stock units, shares (Note 12)						-22,312
Settlement of restricted stock units for shares of common stock (Note 12)		784		784			784
Settlement of restricted stock units for shares of common stock, shares (Note 12)						27,821
Exchange of common units of the Operating Partnership, shares (Note 10)						5,000
Adjustment for noncontrolling interest (Note 2)		0		-3,460			3,460		-3,460
Preferred distributions		-14,108		-14,108				-14,108
Dividends declared per common share and common unit ($1.40 per share/ unit for 2010, 2011 and $1.63 per share/unit for 2009)		-104,393		-101,911				-101,911	-2,482
Ending Balance at Dec. 31, 2012		2,235,933		2,189,630	192,411	749	2,126,005	-129,535	46,303
Ending Balance, shares at Dec. 31, 2012						74,926,981
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		44,565		43,880				43,880	685
Issuance of common stock, shares (Note 10)						7,215,838
Issuance of share-based compensation awards		1,448		1,448			1,448
Noncash amortization of share-based compensation		9,563		9,563			9,563
Exercise of stock options, shares						473
Issuance of common stock (Note 10)		349,951		349,951		72	349,879
Exercise of stock options		-128		-128			-128
Noncontrolling Interest, Increase from Business Combination		4,885							4,885
Repurchase of common stock and restricted stock units (Note 12)		-2,521		-2,521			-2,521
Repurchase of common stock and restricted stock units, shares (Note 12)						-42,896
Settlement of restricted stock units for shares of common stock (Note 12)		-1		-1		-1	0
Settlement of restricted stock units for shares of common stock, shares (Note 12)						37,245
Exchange of common units of the Operating Partnership (Note 10)		0		450			450		-450
Exchange of common units of the Operating Partnership, shares (Note 10)						16,303
Adjustment for noncontrolling interest (Note 2)		0		5,977			5,977		-5,977
Preferred distributions		-13,250		-13,250				-13,250
Dividends declared per common share and common unit ($1.40 per share/ unit for 2010, 2011 and $1.63 per share/unit for 2009)		-114,543		-111,991				-111,991	-2,552
Ending Balance at Dec. 31, 2013		2,516,160		2,461,312	192,411	822	2,478,975	-210,896	54,848
Ending Balance, shares at Dec. 31, 2013		82,153,944	[1]			82,153,944
Beginning Balance at Sep. 30, 2013
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	[2]	23,047
Shares of Common stock exercised in the capped call option						404,136
Ending Balance at Dec. 31, 2013		2,516,160			192,411	822
Ending Balance, shares at Dec. 31, 2013		82,153,944	[1]			82,153,944
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares of Common stock exercised in the capped call option						111,206
Ending Balance at Sep. 30, 2014
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	[1]			82,153,944
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		183,808		180,219				180,219	3,589
Issuance of common stock, shares (Note 10)						1,950,599
Issuance of share-based compensation awards		1,692		1,692			1,692
Noncash amortization of share-based compensation		14,471		14,471			14,471
Exercise of stock options, shares						495,000
Issuance of common stock (Note 10)		123,860		123,860		20	123,840
Exercise of stock options				-21,092		-5	-21,087
Noncontrolling Interest, Increase from Business Combination		977							977
Repurchase of common stock and restricted stock units (Note 12)		-3,533		-3,533			-3,533
Repurchase of common stock and restricted stock units, shares (Note 12)						-58,045
Settlement of restricted stock units for shares of common stock (Note 12)		1		1			1
Stock Issued During Period, Shares, Conversion of Convertible Securities						2,091,323
Stock Issued During Period, Value, Conversion of Convertible Securities		223		223		21	202
Shares of Common stock exercised in the capped call option						515,342
Shares of Common Stock Issued in Capped Call, Value		0		0		-5	5
Settlement of restricted stock units for shares of common stock, shares (Note 12)						141,205
Exchange of common units of the Operating Partnership (Note 10)		0		28			28		-28
Exchange of common units of the Operating Partnership, shares (Note 10)						1,000
Adjustment for noncontrolling interest (Note 2)		0		866			866		-866
Preferred distributions		-13,250		-13,250				-13,250
Dividends declared per common share and common unit ($1.40 per share/ unit for 2010, 2011 and $1.63 per share/unit for 2009)		-121,563		-119,037				-119,037	-2,526
Ending Balance at Dec. 31, 2014		2,723,936		2,666,210	192,411	863	2,635,900	-162,964	57,726
Ending Balance, shares at Dec. 31, 2014		86,259,684	[1]			86,259,684
Beginning Balance at Sep. 30, 2014
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	[2]	31,430
Stock Issued During Period, Shares, Conversion of Convertible Securities						1,660,053
Ending Balance at Dec. 31, 2014		$2,723,936			$192,411	$863
Ending Balance, shares at Dec. 31, 2014		86,259,684	[1]			86,259,684
[1]	The amount includes nonvested shares.
[2]	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common stockholders per share does not equal the annual number reported on the consolidated statements of operations due to the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended DecemberB 31,B 2014 and 2013.

Consolidated_Statements_of_Equ1

Consolidated Statements of Equity (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2011
Statement of Stockholders' Equity [Abstract]
Dividends declared per common share	$1.40	$1.40	$1.40

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$183,808	$44,565	$277,101
Adjustments to reconcile net income to net cash provided by operating activities (including discontinued operations):
Depreciation and amortization of buildings and improvements and leasing costs	202,108	199,558	168,687
Increase (decrease) in provision for bad debts	58	396	-42
Depreciation of furniture, fixtures and equipment	2,370	1,929	1,213
Noncash amortization of share-based compensation awards (Note 12)	12,095	8,616	7,670
Noncash amortization of deferred financing costs and debt discounts and premiums	4,315	5,315	8,433
Noncash amortization of net below market rents (Note 4)	-8,328	-7,777	-6,699
Net gain on dispositions of discontinued operations (Note 18)	-121,922	-12,252	-259,245
Gain on sale of land (Note 18)	3,490	0	0
Noncash amortization of deferred revenue related to tenant-funded tenant improvements (Note 8)	-10,979	-10,713	-9,136
Straight-line rents	-31,782	-24,135	-21,530
Net change in other operating assets	367	-4,615	-1,297
Net change in other operating liabilities	16,633	40,137	17,320
Insurance proceeds received for property damage and other, net	0	-448	-1,751
Net cash provided by operating activities	245,253	240,576	180,724
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for acquisitions of operating properties, net of cash acquired (Note 3)	204,546	202,682	454,841
Expenditures for acquisitions of development and redevelopment properties (Note 3)	-147,182	-102,769	-333,942
Payments for Capital Improvements	132,080	129,873	86,377
Payments to Develop Real Estate Assets	417,784	320,141	83,310
Net proceeds received from dispositions of operating properties and land (Note 18)	427,544	21,178	263,572
Insurance proceeds received for property damage	0	448	1,751
(Increase) decrease in acquisition-related deposits	-1,983	-2,596	5,000
(Increase) decrease in restricted cash (Note 18)	-25,405	229,915	-18,359
Net cash used in investing activities	-501,436	-506,520	-706,506
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from issuance of common stock (Note 10)	102,229	349,951	672,102
Borrowings on unsecured line of credit	505,000	55,000	704,000
Repayments on unsecured line of credit	-410,000	-195,000	-701,000
Proceeds from the issuance of unsecured debt (Note 7)	395,528	299,901	150,000
Repayments of exchangeable senior notes (Note 7)	-172,500	0	-148,000
Principal payments on secured debt	-9,845	-93,688	-106,262
Net proceeds from issuance of Series G and Series H preferred stock (Note 10)	0	0	192,411
Proceeds from the issuance of secured debt	0	0	97,000
Financing costs	-8,648	-4,384	-7,963
Repurchase of common stock and restricted stock units	-3,533	-2,520	-1,661
Proceeds from exercise of stock options	21,092	128	129
Dividends and distributions paid to common stockholders and common unitholders	-118,463	-111,517	-97,386
Dividends and distributions paid to preferred stockholders and preferred unitholders	-13,250	-13,250	-14,165
Net cash provided by financing activities	244,587	284,621	537,705
Net increase (decrease) in cash and cash equivalents	-11,596	18,677	11,923
Cash and cash equivalents, beginning of period	35,377	16,700	4,777
Cash and cash equivalents, end of period	23,781	35,377	16,700
SUPPLEMENTAL CASH FLOWS INFORMATION:
Cash paid for interest, net of capitalized interest of $44,385, $32,742, and $17,657 as of December 31, 2014, 2013 and 2012, respectively	58,944	65,157	71,633
NONCASH INVESTING TRANSACTIONS:
Accrual for expenditures for operating properties and development and redevelopment properties	77,091	73,482	54,198
Tenant improvements funded directly by tenants to third parties	42,906	7,633	17,719
Assumption of secured debt with property acquisition (Notes 3 and 7)	0	95,496	221,032
Assumption of other assets and liabilities in connection with operating and development property acquisitions, net (Note 3)	14,917	1,811	37,535
Contribution of land, net of related liabilities, by noncontrolling interest to consolidated subsidiary	0	4,885	0
NONCASH FINANCING TRANSACTIONS:
Accrual of dividends and distributions payable to common stockholders and common unitholders (Note 10)	31,243	29,378	26,863
Accrual of dividends and distributions payable to preferred stockholders and preferred unitholders (Note 10)	1,656	1,694	1,694
Grant date fair value of share-based compensation awards (Note 12)	20,739	10,721	31,396
Issuance of common units in the Operating Partnership in connection with an operating property acquisition (Note 3)	0	0	5,604
Exchange of common units of the Operating Partnership into shares of the Companybs common stock (Note 10)	28	450	231
Series A Preferred Units [Member]
CASH FLOWS FROM FINANCING ACTIVITIES:
Payments for Repurchase of Redeemable Preferred Stock	0	0	-75,000
Series E and Series F Cumulative Redeemable Preferred Stock
CASH FLOWS FROM FINANCING ACTIVITIES:
Payments for Repurchase of Redeemable Preferred Stock	0	0	-126,500
Subsidiaries [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	183,808	44,565	277,101
Adjustments to reconcile net income to net cash provided by operating activities (including discontinued operations):
Depreciation and amortization of buildings and improvements and leasing costs	202,108	199,558	168,687
Increase (decrease) in provision for bad debts	58	396	-42
Depreciation of furniture, fixtures and equipment	2,370	1,929	1,213
Noncash amortization of share-based compensation awards (Note 12)	12,095	8,616	7,670
Noncash amortization of deferred financing costs and debt discounts and premiums	4,315	5,315	8,433
Noncash amortization of net below market rents (Note 4)	-8,328	-7,777	-6,699
Net gain on dispositions of discontinued operations (Note 18)	-121,922	-12,252	-259,245
Gain on sale of land (Note 18)	3,490	0	0
Noncash amortization of deferred revenue related to tenant-funded tenant improvements (Note 8)	-10,979	-10,713	-9,136
Straight-line rents	-31,782	-24,135	-21,530
Net change in other operating assets	367	-4,615	-1,297
Net change in other operating liabilities	16,633	40,137	17,320
Insurance proceeds received for property damage and other, net	0	-448	-1,751
Net cash provided by operating activities	245,253	240,576	180,724
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for acquisitions of operating properties, net of cash acquired (Note 3)	204,546	202,682	454,841
Expenditures for acquisitions of development and redevelopment properties (Note 3)	-147,182	-102,769	-333,942
Payments for Capital Improvements	132,080	129,873	86,377
Payments to Develop Real Estate Assets	417,784	320,141	83,310
Net proceeds received from dispositions of operating properties and land (Note 18)	427,544	21,178	263,572
Insurance proceeds received for property damage	0	448	1,751
(Increase) decrease in acquisition-related deposits	-1,983	-2,596	5,000
(Increase) decrease in restricted cash (Note 18)	-25,405	229,915	-18,359
Net cash used in investing activities	-501,436	-506,520	-706,506
CASH FLOWS FROM FINANCING ACTIVITIES:
Borrowings on unsecured line of credit	505,000	55,000	704,000
Repayments on unsecured line of credit	-410,000	-195,000	-701,000
Proceeds from the issuance of unsecured debt (Note 7)	395,528	299,901	150,000
Repayments of exchangeable senior notes (Note 7)	-172,500	0	-148,000
Principal payments on secured debt	-9,845	-93,688	-106,262
Borrowings on unsecured debt (Note 7)	39,000	0	0
Repayments of unsecured debt (Note 7)	83,000	0	0
Net proceeds from issuance of Series G and Series H preferred stock (Note 10)	0	0	192,411
Proceeds from the issuance of secured debt	0	0	97,000
Financing costs	-8,648	-4,384	-7,963
Repurchase of common stock and restricted stock units	-3,533	-2,520	-1,661
Proceeds from exercise of stock options	21,092	128	129
Contributions from noncontrolling interests in consolidated subsidiary	977	0	0
Dividends and distributions paid to common stockholders and common unitholders	-118,463	-111,517	-97,386
Dividends and distributions paid to preferred stockholders and preferred unitholders	-13,250	-13,250	-14,165
Net cash provided by financing activities	244,587	284,621	537,705
Net increase (decrease) in cash and cash equivalents	-11,596	18,677	11,923
Cash and cash equivalents, beginning of period	35,377	16,700	4,777
Cash and cash equivalents, end of period	23,781	35,377	16,700
SUPPLEMENTAL CASH FLOWS INFORMATION:
Cash paid for interest, net of capitalized interest of $44,385, $32,742, and $17,657 as of December 31, 2014, 2013 and 2012, respectively	58,944	65,157	71,633
NONCASH INVESTING TRANSACTIONS:
Accrual for expenditures for operating properties and development and redevelopment properties	77,091	73,482	54,198
Tenant improvements funded directly by tenants to third parties	42,906	7,633	17,719
Assumption of secured debt with property acquisition (Notes 3 and 7)	0	95,496	221,032
Assumption of other assets and liabilities in connection with operating and development property acquisitions, net (Note 3)	14,917	1,811	37,535
Contribution of land, net of related liabilities, by noncontrolling interest to consolidated subsidiary	0	4,885	0
NONCASH FINANCING TRANSACTIONS:
Accrual of dividends and distributions payable to common stockholders and common unitholders (Note 10)	31,243	29,378	26,863
Accrual of dividends and distributions payable to preferred stockholders and preferred unitholders (Note 10)	1,656	1,694	1,694
Grant date fair value of share-based compensation awards (Note 12)	20,739	10,721	31,396
Issuance of common units in connection with a development property acquisition (Notes 3 and 11)	21,631	0	0
Issuance of common units in the Operating Partnership in connection with an operating property acquisition (Note 3)	0	0	5,604
Subsidiaries [Member] | Series A Preferred Units [Member]
CASH FLOWS FROM FINANCING ACTIVITIES:
Payments for Repurchase of Redeemable Preferred Stock	$0	$0	($75,000)

Consolidated_Statements_of_Cas1

Consolidated Statements of Cash Flows (Parenthetical) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Cash Flows [Abstract]
Capitalized interest	$44,385	$32,742	$17,657

Consolidated_Balance_Sheets_KI

Consolidated Balance Sheets (KILROY REALTY, L.P.) (USD $)	Dec. 31, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
REAL ESTATE ASSETS (Notes 3 and 18):
Land and improvements	$877,633		$657,491
Buildings and improvements	4,059,639		3,590,699
Undeveloped land and construction in progress	1,120,660		1,016,757
Total real estate held for investment	6,057,932		5,264,947
Accumulated depreciation and amortization	-947,664		-818,957
Total real estate held for investment, net ($211,755 and $234,532 of VIE, Note 2)	5,110,268		4,445,990
REAL ESTATE ASSETS AND OTHER ASSETS HELD FOR SALE, NET (Note 18)	8,211		213,100
CASH AND CASH EQUIVALENTS	23,781		35,377
RESTRICTED CASH (Note 18)	75,185		49,780
MARKETABLE SECURITIES (Notes 13 and 16)	11,971		10,008
CURRENT RECEIVABLES, NET (Note 5)	7,229	[1]	10,743
DEFERRED RENT RECEIVABLES, NET (Note 5)	156,416		127,123
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Notes 3 and 4)	201,926		186,622
DEFERRED FINANCING COSTS, NET (Notes 2 and 7)	18,374		16,502
PREPAID EXPENSES AND OTHER ASSETS, NET	20,375		15,783
Total Assets	5,633,736		5,111,028
LIABILITIES:
Secured debt (Notes 3, 6, 7 and 16)	546,292		560,434
Exchangeable senior notes, net (Notes 6, 7 and 16)	0		168,372
Unsecured debt, net (Notes 6, 7 and 16)	1,783,121		1,431,132
Unsecured line of credit (Notes 6, 7 and 16)	140,000		45,000
Accounts payable, accrued expenses and other liabilities (Note 15)	225,830		198,467
Accrued distributions (Note 11)	-32,899		-31,490
Deferred revenue and acquisition-related intangible liabilities, net (Notes 3, 4 and 8)	132,239		101,286
Rents received in advance and tenant security deposits	49,363		44,240
Liabilities and deferred revenue of real estate assets held for sale (Note 18)	56		14,447
Total liabilities	2,909,800		2,594,868
COMMITMENTS AND CONTINGENCIES (Note 15)
Partners' Capital:
TOTAL LIABILITIES AND EQUITY	5,633,736		5,111,028
Kilroy Realty, L.P. [Member]
REAL ESTATE ASSETS (Notes 3 and 18):
Land and improvements	877,633		657,491
Buildings and improvements	4,059,639		3,590,699
Undeveloped land and construction in progress	1,120,660		1,016,757
Total real estate held for investment	6,057,932		5,264,947
Accumulated depreciation and amortization	-947,664		-818,957
Total real estate held for investment, net ($211,755 and $234,532 of VIE, Note 2)	5,110,268		4,445,990
REAL ESTATE ASSETS AND OTHER ASSETS HELD FOR SALE, NET (Note 18)	8,211		213,100
CASH AND CASH EQUIVALENTS	23,781		35,377
RESTRICTED CASH (Note 18)	75,185		49,780
MARKETABLE SECURITIES (Notes 13 and 16)	11,971		10,008
CURRENT RECEIVABLES, NET (Note 5)	7,229		10,743
DEFERRED RENT RECEIVABLES, NET (Note 5)	156,416		127,123
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Notes 3 and 4)	201,926		186,622
DEFERRED FINANCING COSTS, NET (Notes 2 and 7)	18,374		16,502
PREPAID EXPENSES AND OTHER ASSETS, NET	20,375		15,783
Total Assets	5,633,736		5,111,028
LIABILITIES:
Secured debt (Notes 3, 6, 7 and 16)	546,292		560,434
Exchangeable senior notes, net (Notes 6, 7 and 16)	0		168,372
Unsecured debt, net (Notes 6, 7 and 16)	1,783,121		1,431,132
Unsecured line of credit (Notes 6, 7 and 16)	140,000		45,000
Accounts payable, accrued expenses and other liabilities (Note 15)	225,830		198,467
Accrued distributions (Note 11)	-32,899		-31,490
Deferred revenue and acquisition-related intangible liabilities, net (Notes 3, 4 and 8)	132,239		101,286
Rents received in advance and tenant security deposits	49,363		44,240
Liabilities and deferred revenue of real estate assets held for sale (Note 18)	56		14,447
Total liabilities	2,909,800		2,594,868
COMMITMENTS AND CONTINGENCIES (Note 15)
Partners' Capital:
Common units, 86,259,684 and 82,153,944 held by the general partner and 1,804,200 and 1,805,200 held by common limited partners issued and outstanding, respectively	2,521,900		2,315,361
Total Partners' Capital	2,714,311		2,507,772
Noncontrolling interests in consolidated subsidiaries (Notes 2, 3 and 9)	9,625		8,388
Total capital	2,723,936		2,516,160
TOTAL LIABILITIES AND EQUITY	5,633,736		5,111,028
Series H Cumulative Redeemable Preferred Unit [Member] | Kilroy Realty, L.P. [Member]
Partners' Capital:
Preferred Units, Preferred Partners' Capital Accounts	96,256		96,256
Series G Cumulative Redeemable Preferred Unit [Member] | Kilroy Realty, L.P. [Member]
Partners' Capital:
Preferred Units, Preferred Partners' Capital Accounts	$96,155		$96,155
[1]	Excludes current receivables, net related to real estate held for sale.

Consolidated_Balance_Sheets_KI1

Consolidated Balance Sheets (KILROY REALTY, L.P.) (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Variable Interest Entity, Consolidated, Carrying Amount, Assets	$219,600,000	$251,800,000
Noncontrolling common units of the Operating Partnership	1,804,200	1,805,200
Kilroy Realty, L.P. [Member]
Variable Interest Entity Consolidated Carrying Amounts, Real Estate Assets, net	211,755,000	234,532,000
Kilroy Realty, L.P. [Member] | Capital Units [Member]
General Partners' Capital Account, Units Issued	86,259,684	82,153,944
General Partners' Capital Account, Units Outstanding	86,259,684	82,153,944
Limited Partners' Capital Account, Units Issued	1,804,200	1,805,200
Noncontrolling common units of the Operating Partnership	1,804,200	1,805,200
Kilroy Realty, L.P. [Member] | Series G Cumulative Redeemable Preferred Unit [Member]
Preferred stock dividend rate (percentage)	6.88%	6.88%
Preferred Units, Issued	4,000,000	4,000,000
Preferred units outstanding	4,000,000	4,000,000
Preferred stock liquidation preference	100,000,000	100,000,000
Kilroy Realty, L.P. [Member] | Series H Cumulative Redeemable Preferred Unit [Member]
Preferred stock dividend rate (percentage)	6.38%	6.38%
Preferred Units, Issued	4,000,000	4,000,000
Preferred units outstanding	4,000,000	4,000,000
Preferred stock liquidation preference	$100,000,000	$100,000,000

Consolidated_Statements_of_Ope1

Consolidated Statements of Operations (KILROY REALTY, L.P.) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
REVENUES:
Rental income	$466,328	$411,899	$342,164
Tenant reimbursements	46,717	38,047	29,667
Other property income (Note 15 and 17)	8,680	7,165	1,487
Total revenues	521,725	457,111	373,318
EXPENSES:
Property expenses	100,514	94,115	73,998
Real estate taxes	45,197	39,417	31,562
Provision for bad debts	58	396	153
Ground leases (Note 4 and 15)	3,075	3,504	3,168
General and administrative expenses	46,152	39,660	36,188
Acquisition-related expenses	1,479	1,962	4,937
Depreciation and amortization (Notes 2 and 4)	202,417	188,887	150,521
Total expenses	398,892	367,941	300,527
OTHER (EXPENSES) INCOME:
Interest income and other net investment gains (Note 16)	561	1,635	848
Interest expense (Note 7)	-67,571	-75,870	-79,114
Total other (expenses) income	-67,010	-74,235	-78,266
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest, Before Gain on Sale of Real Estate	55,823	14,935	-5,475
Gain on sale of land (Note 18)	3,490	0	0
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	59,313	14,935	-5,475
DISCONTINUED OPERATIONS (Note 18)
Income from discontinued operations	2,573	17,378	23,331
Net gain on dispositions of discontinued operations (Note 18)	121,922	12,252	259,245
Income from discontinued operations	124,495	29,630	282,576
NET INCOME	183,808	44,565	277,101
NET INCOME ATTRIBUTABLE TO KILROY REALTY	180,219	43,880	270,914
Original issuance costs of redeemed preferred units (Notes 9 and 11)	0	0	-6,980
Total preferred distributions	13,250	13,250	21,088
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	166,969	30,630	249,826
Income (Loss) from Continuing Operations, Per Basic Share	$0.52	$0	($0.40)
Loss from continuing operations available to common unitholders per unit-diluted (Note 19)	$0.51	$0	($0.40)
Net income available to common unitholders per unit (dollars per unit)	$1.99	$0.37	$3.56
Net income available to common unitholders per unit (dollars per unit)	$1.95	$0.37	$3.56
Weighted average common units outstanding - basic (Note 19)	83,090,235	77,343,853	69,639,623
Weighted average common units outstanding - diluted (Note 19)	84,967,720	77,343,853	69,639,623
Kilroy Realty, L.P. [Member]
REVENUES:
Rental income	466,328	411,899	342,164
Tenant reimbursements	46,717	38,047	29,667
Other property income (Note 15 and 17)	8,680	7,165	1,487
Total revenues	521,725	457,111	373,318
EXPENSES:
Property expenses	100,514	94,115	73,998
Real estate taxes	45,197	39,417	31,562
Provision for bad debts	58	396	153
Ground leases (Note 4 and 15)	3,075	3,504	3,168
General and administrative expenses	46,152	39,660	36,188
Acquisition-related expenses	1,479	1,962	4,937
Depreciation and amortization (Notes 2 and 4)	202,417	188,887	150,521
Total expenses	398,892	367,941	300,527
OTHER (EXPENSES) INCOME:
Interest income and other net investment gains (Note 16)	561	1,635	848
Interest expense (Note 7)	-67,571	-75,870	-79,114
Total other (expenses) income	-67,010	-74,235	-78,266
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest, Before Gain on Sale of Real Estate	55,823	14,935	-5,475
Gain on sale of land (Note 18)	3,490	0	0
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	59,313	14,935	-5,475
DISCONTINUED OPERATIONS (Note 18)
Income from discontinued operations	2,573	17,378	23,331
Net gain on dispositions of discontinued operations (Note 18)	121,922	12,252	259,245
Income from discontinued operations	124,495	29,630	282,576
NET INCOME	183,808	44,565	277,101
Net income attributable to noncontrolling interests in consolidated subsidiaries	-260	-224	-638
NET INCOME ATTRIBUTABLE TO KILROY REALTY	183,548	44,341	276,463
Preferred distributions (Note 11)	-13,250	-13,250	-14,108
Original issuance costs of redeemed preferred units (Notes 9 and 11)	0	0	-6,980
Total preferred distributions	13,250	13,250	21,088
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	$170,298	$31,091	$255,375
Income (Loss) from Continuing Operations, Per Basic Share	$0.52	$0	($0.40)
Loss from continuing operations available to common unitholders per unit-diluted (Note 19)	$0.51	$0	($0.40)
Net income available to common unitholders per unit (dollars per unit)	$1.99	$0.37	$3.56
Net income available to common unitholders per unit (dollars per unit)	$1.94	$0.37	$3.56
Weighted average common units outstanding - basic (Note 19)	84,894,498	79,166,260	71,403,258
Weighted average common units outstanding - diluted (Note 19)	86,771,983	79,166,260	71,403,258
Distributions declared per common unit	$1.40	$1.40

Consolidated_Statements_of_Cap

Consolidated Statements of Capital (KILROY REALTY, L.P.) (USD $)	3 Months Ended								12 Months Ended			9 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014		Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2013		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2014	Dec. 31, 2011
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$31,430	[1]	$101,932	[1]	$23,047	[1]	$2,388	[1]	$183,808	$44,565	$277,101
Stock Issued During Period, Value, New Issues									123,860	349,951	672,102
Stock Redeemed or Called During Period, Value											-2,062
Original issuance costs of redeemed preferred units (Notes 9 and 11)									0	0	6,980
Noncontrolling Interest, Increase from Business Combination									977	4,885	5,604
Noncash amortization of share-based compensation									14,471	9,563	8,537
Preferred distributions									-13,250	-13,250	-14,108
Stock Issued During Period, Value, Conversion of Convertible Securities									223
Stock Issued During Period, Value, Restricted Stock Award, Gross									-1	1	-784
Series A Preferred Units [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Original issuance costs of redeemed preferred units (Notes 9 and 11)											2,100
Noncontrolling Interest In Consolidated Subsidiaries [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income									3,589	685	6,187
Noncontrolling Interest, Increase from Business Combination									977	4,885	5,604
Kilroy Realty, L.P. [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			2,516,160				2,235,933		2,516,160	2,235,933	1,327,482	2,516,160
Net income	31,430	[2]	101,932	[2]	23,047	[2]	2,388	[2]	183,808	44,565	277,101
Partners' Capital Account, Sale of Units											192,411
Stock Redeemed or Called During Period, Value											-2,062
Original issuance costs of redeemed preferred units (Notes 9 and 11)									0	0	6,980
Issuance of common units (Note 11)									123,860	349,951	672,102
Noncontrolling Interest, Increase from Business Combination									977	4,885
Issuance of share-based compensation awards (Note 12)									1,692	1,448	1,291
Noncash amortization of share-based compensation									14,471	9,563	8,537
Repurchase of common units and restricted stock units (Note 12)									3,533	2,521	877
Preferred distributions									-13,250	-13,250	-14,108
Distributions declared per common unit ($1.40 per unit)									-121,563	-114,543	-104,393
Settlement of restricted stock units for shares of common stock									-1	1
Partners' Capital Account, Redemptions									223
Stock Issued During Period, Value, Restricted Stock Award, Gross											-784
Exercise of stock options									21,092	128	129
Ending Balance	2,723,936				2,516,160				2,723,936	2,516,160	2,235,933
Kilroy Realty, L.P. [Member] | Partners Capital Common Unit [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock Issued During Period, Value, New Issues											192,411
Partners' Capital Account, Sale of Units											192,411
Stock Redeemed or Called During Period, Value											-121,582
Partners' Capital Account, Units, Redeemed											-4,918,000
Issuance of common units, units											16,024,618
Partners' Capital Account, Redemptions											-126,500
Kilroy Realty, L.P. [Member] | Total Partners Capital [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			2,507,772				2,232,654		2,507,772	2,232,654	1,324,841	2,507,772
Net income									183,548	44,341	276,463
Stock Redeemed or Called During Period, Value											-2,062
Issuance of common units (Note 11)									123,860	349,951	672,102
Issuance of share-based compensation awards (Note 12)									1,692	1,448	1,291
Noncash amortization of share-based compensation									14,471	9,563	8,537
Repurchase of common units and restricted stock units (Note 12)									3,533	2,521	877
Preferred distributions									-13,250	-13,250	-14,108
Distributions declared per common unit ($1.40 per unit)									-121,563	-114,543	-104,393
Settlement of restricted stock units for shares of common stock									-1	1
Stock Issued During Period, Value, Restricted Stock Award, Gross											-784
Exercise of stock options										128	129
Ending Balance	2,714,311				2,507,772				2,714,311	2,507,772	2,232,654
Kilroy Realty, L.P. [Member] | Partners Capital Preferred Units [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance													121,582
Ending Balance	192,411				192,411				192,411	192,411	192,411		121,582
Kilroy Realty, L.P. [Member] | Partners Capital Common Unit [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			2,315,361				2,040,243		2,315,361	2,040,243	1,203,259	2,315,361
Beginning Balance units			83,959,144				76,753,484		83,959,144	76,753,484	60,537,848	83,959,144
Net income									183,548	44,341	276,463
Stock Redeemed or Called During Period, Value											-2,062
Issuance of common units (Note 11)									123,860	349,951	672,102
Stock Issued During Period, Shares, Acquisitions											118,372
Partners' Capital Account, Acquisitions											5,604
Issuance of common units, units									1,950,599	7,210,838
Issuance of share-based compensation awards (Note 12)									1,692	1,448	1,291
Issuance of share-based compensation awards, units (Note 12)											62,137
Noncash amortization of share-based compensation									14,471	9,563	8,537
Repurchase of common units and restricted stock units (Note 12)									3,533	2,521	877
Stock Issued During Period, Shares, Restricted Stock Award, Gross											27,821
Repurchase of common units and restricted stock units, units (Note 12)									58,045	42,896	22,312
Preferred distributions									-13,250	-13,250	-14,108
General Partners' Capital Account, Period Distribution Amount									121,563	114,543
Distributions declared per common unit ($1.40 per unit)											-104,393
Stock Issued During Period, Shares, Conversion of Convertible Securities									2,091,323
Stock Issued During Period, Value, Conversion of Convertible Securities									223
Partners' Capital Account, Redemptions									223
Shares of Common stock exercised in the capped call option									515,342
Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt												0
Settlement of restricted stock units for shares of common stock units									141,205	37,245
Stock Issued During Period, Value, Restricted Stock Award, Gross									-1	1	-784
Exercise of stock options									21,092	128	129
Exercise of stock options, units									495,000	473	5,000
Ending Balance	2,521,900				2,315,361				2,521,900	2,315,361	2,040,243
Ending Balance units	88,063,884				83,959,144				88,063,884	83,959,144	76,753,484
Kilroy Realty, L.P. [Member] | Noncontrolling Interest In Consolidated Subsidiaries [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			8,388				3,279		8,388	3,279	2,641	8,388
Net income									260	224	638
Noncontrolling Interest, Increase from Business Combination									977	4,885
Ending Balance	$9,625				$8,388				$9,625	$8,388	$3,279
[1]	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common stockholders per share does not equal the annual number reported on the consolidated statements of operations due to the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended DecemberB 31,B 2014 and 2013.
[2]	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common unitholders per unit does not equal the annual number reported on the consolidated statements of operations due to the impact of the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended DecemberB 31,B 2014 and 2013.

Consolidated_Statements_of_Cap1

Consolidated Statements of Capital (KILROY REALTY, L.P.) - Parenthetical (Kilroy Realty, L.P. [Member], USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2011
Kilroy Realty, L.P. [Member]
Distributions declared per common unit	$1.40	$1.40	$1.40

Consolidated_Statements_of_Cas2

Consolidated Statements of Cash Flows (KILROY REALTY, L.P.) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Capitalized interest	$44,385	$32,742	$17,657
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	183,808	44,565	277,101
Adjustments to reconcile net income to net cash provided by operating activities (including discontinued operations):
Depreciation and amortization of buildings and improvements and leasing costs	202,108	199,558	168,687
Increase (decrease) in provision for bad debts	58	396	-42
Depreciation of furniture, fixtures and equipment	2,370	1,929	1,213
Noncash amortization of share-based compensation awards (Note 12)	12,095	8,616	7,670
Noncash amortization of deferred financing costs and debt discounts and premiums	4,315	5,315	8,433
Noncash amortization of net below market rents (Note 4)	-8,328	-7,777	-6,699
Net gain on dispositions of discontinued operations (Note 18)	-121,922	-12,252	-259,245
Gain on sale of land (Note 18)	-3,490	0	0
Noncash amortization of deferred revenue related to tenant-funded tenant improvements (Note 8)	-10,979	-10,713	-9,136
Straight-line rents	-31,782	-24,135	-21,530
Net change in other operating assets	367	-4,615	-1,297
Net change in other operating liabilities	16,633	40,137	17,320
Insurance proceeds received for property damage and other, net	0	-448	-1,751
Net cash provided by operating activities	245,253	240,576	180,724
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for acquisitions of operating properties, net of cash acquired (Note 3)	-204,546	-202,682	-454,841
Expenditures for acquisitions of development and redevelopment properties (Note 3)	-147,182	-102,769	-333,942
Expenditures for operating properties	-132,080	-129,873	-86,377
Expenditures for development and redevelopment properties and undeveloped land	-417,784	-320,141	-83,310
Net proceeds received from dispositions of operating properties and land (Note 18)	427,544	21,178	263,572
Insurance proceeds received for property damage	0	448	1,751
(Increase) decrease in acquisition-related deposits	-1,983	-2,596	5,000
(Increase) decrease in restricted cash (Note 18)	-25,405	229,915	-18,359
Net cash used in investing activities	-501,436	-506,520	-706,506
CASH FLOWS FROM FINANCING ACTIVITIES:
Borrowings on unsecured line of credit	505,000	55,000	704,000
Repayments on unsecured line of credit	-410,000	-195,000	-701,000
Proceeds from the issuance of unsecured debt (Note 7)	395,528	299,901	150,000
Repayments of exchangeable senior notes (Note 7)	-172,500	0	-148,000
Principal payments on secured debt	-9,845	-93,688	-106,262
Net proceeds from issuance of Series G and Series H preferred stock (Note 10)	0	0	192,411
Proceeds from the issuance of secured debt	0	0	97,000
Financing costs	-8,648	-4,384	-7,963
Repurchase/redemption of common units and restricted stock units	-3,533	-2,520	-1,661
Proceeds from exercise of stock options	21,092	128	129
Distributions paid to common unitholders	-118,463	-111,517	-97,386
Distributions paid to preferred unitholders	-13,250	-13,250	-14,165
Net cash provided by financing activities	244,587	284,621	537,705
Net increase (decrease) in cash and cash equivalents	-11,596	18,677	11,923
Cash and cash equivalents, beginning of period	35,377	16,700	4,777
Cash and cash equivalents, end of period	23,781	35,377	16,700
SUPPLEMENTAL CASH FLOWS INFORMATION:
Cash paid for interest, net of capitalized interest of $44,385, $32,742, and $17,657 as of December 31, 2014, 2013 and 2012, respectively	58,944	65,157	71,633
NONCASH INVESTING TRANSACTIONS:
Accrual for expenditures for operating properties and development and redevelopment properties	77,091	73,482	54,198
Tenant improvements funded directly by tenants to third parties	42,906	7,633	17,719
Assumption of secured debt with property acquisition (Notes 3 and 7)	0	95,496	221,032
Assumption of other assets and liabilities in connection with operating and development property acquisitions, net (Note 3)	14,917	1,811	37,535
Contribution of land, net of related liabilities, by noncontrolling interest to consolidated subsidiary	0	4,885	0
NONCASH FINANCING TRANSACTIONS:
Accrual of dividends distributions payable to common unitholders (Note 11)	31,243	29,378	26,863
Accrual of distributions payable to preferred unitholders (Note 11)	1,656	1,694	1,694
Grant date fair value of share-based compensation awards (Note 12)	20,739	10,721	31,396
Issuance of common units in the Operating Partnership in connection with an operating property acquisition (Note 3)	0	0	5,604
Series A Preferred Units [Member]
CASH FLOWS FROM FINANCING ACTIVITIES:
Payments for Repurchase of Redeemable Preferred Stock	0	0	-75,000
Kilroy Realty, L.P. [Member]
Capitalized interest	44,385	32,742	17,657
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	183,808	44,565	277,101
Adjustments to reconcile net income to net cash provided by operating activities (including discontinued operations):
Depreciation and amortization of buildings and improvements and leasing costs	202,108	199,558	168,687
Increase (decrease) in provision for bad debts	58	396	-42
Depreciation of furniture, fixtures and equipment	2,370	1,929	1,213
Noncash amortization of share-based compensation awards (Note 12)	12,095	8,616	7,670
Noncash amortization of deferred financing costs and debt discounts and premiums	4,315	5,315	8,433
Noncash amortization of net below market rents (Note 4)	-8,328	-7,777	-6,699
Net gain on dispositions of discontinued operations (Note 18)	-121,922	-12,252	-259,245
Gain on sale of land (Note 18)	-3,490	0	0
Noncash amortization of deferred revenue related to tenant-funded tenant improvements (Note 8)	-10,979	-10,713	-9,136
Straight-line rents	-31,782	-24,135	-21,530
Net change in other operating assets	367	-4,615	-1,297
Net change in other operating liabilities	16,633	40,137	17,320
Insurance proceeds received for property damage and other, net	0	-448	-1,751
Net cash provided by operating activities	245,253	240,576	180,724
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for acquisitions of operating properties, net of cash acquired (Note 3)	-204,546	-202,682	-454,841
Expenditures for acquisitions of development and redevelopment properties (Note 3)	-147,182	-102,769	-333,942
Expenditures for operating properties	-132,080	-129,873	-86,377
Expenditures for development and redevelopment properties and undeveloped land	-417,784	-320,141	-83,310
Net proceeds received from dispositions of operating properties and land (Note 18)	427,544	21,178	263,572
Insurance proceeds received for property damage	0	448	1,751
(Increase) decrease in acquisition-related deposits	-1,983	-2,596	5,000
(Increase) decrease in restricted cash (Note 18)	-25,405	229,915	-18,359
Net cash used in investing activities	-501,436	-506,520	-706,506
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from issuance of common units (Note 11)	102,229	349,951	672,102
Borrowings on unsecured line of credit	505,000	55,000	704,000
Repayments on unsecured line of credit	-410,000	-195,000	-701,000
Proceeds from the issuance of unsecured debt (Note 7)	395,528	299,901	150,000
Repayments of exchangeable senior notes (Note 7)	-172,500	0	-148,000
Principal payments on secured debt	-9,845	-93,688	-106,262
Borrowings on unsecured debt (Note 7)	39,000	0	0
Repayments of unsecured debt (Note 7)	-83,000	0	0
Net proceeds from issuance of Series G and Series H preferred stock (Note 10)	0	0	192,411
Proceeds from the issuance of secured debt	0	0	97,000
Financing costs	-8,648	-4,384	-7,963
Repurchase/redemption of common units and restricted stock units	-3,533	-2,520	-1,661
Proceeds from exercise of stock options	21,092	128	129
Contributions from noncontrolling interests in consolidated subsidiary	977	0	0
Distributions paid to common unitholders	-118,463	-111,517	-97,386
Distributions paid to preferred unitholders	-13,250	-13,250	-14,165
Net cash provided by financing activities	244,587	284,621	537,705
Net increase (decrease) in cash and cash equivalents	-11,596	18,677	11,923
Cash and cash equivalents, beginning of period	35,377	16,700	4,777
Cash and cash equivalents, end of period	23,781	35,377	16,700
SUPPLEMENTAL CASH FLOWS INFORMATION:
Cash paid for interest, net of capitalized interest of $44,385, $32,742, and $17,657 as of December 31, 2014, 2013 and 2012, respectively	58,944	65,157	71,633
NONCASH INVESTING TRANSACTIONS:
Accrual for expenditures for operating properties and development and redevelopment properties	77,091	73,482	54,198
Tenant improvements funded directly by tenants to third parties	42,906	7,633	17,719
Assumption of secured debt with property acquisition (Notes 3 and 7)	0	95,496	221,032
Assumption of other assets and liabilities in connection with operating and development property acquisitions, net (Note 3)	14,917	1,811	37,535
Contribution of land, net of related liabilities, by noncontrolling interest to consolidated subsidiary	0	4,885	0
NONCASH FINANCING TRANSACTIONS:
Accrual of dividends distributions payable to common unitholders (Note 11)	31,243	29,378	26,863
Accrual of distributions payable to preferred unitholders (Note 11)	1,656	1,694	1,694
Grant date fair value of share-based compensation awards (Note 12)	20,739	10,721	31,396
Issuance of common units in connection with a development property acquisition (Notes 3 and 11)	21,631	0	0
Issuance of common units in the Operating Partnership in connection with an operating property acquisition (Note 3)	0	0	5,604
Kilroy Realty, L.P. [Member] | Series E and Series F Cumulative Redeemable Preferred Units [Member]
CASH FLOWS FROM FINANCING ACTIVITIES:
Payments for Repurchase of Redeemable Preferred Stock	0	0	-126,500
Kilroy Realty, L.P. [Member] | Series A Preferred Units [Member]
CASH FLOWS FROM FINANCING ACTIVITIES:
Payments for Repurchase of Redeemable Preferred Stock	$0	$0	($75,000)

Organization_and_Ownership

Organization and Ownership	12 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Ownership	Organization and Ownership
	Kilroy Realty Corporation (the “Company”) is a self-administered real estate investment trust (“REIT”) active in premier office 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 generally conduct substantially all of our operations through the Operating Partnership. Unless stated otherwise or the context indicates otherwise, the terms “Kilroy Realty Corporation” or the “Company,” “we,” “our,” and “us” refer to Kilroy Realty Corporation and its consolidated subsidiaries and the term “Operating Partnership” refers to Kilroy Realty, L.P. and its consolidated subsidiaries. The descriptions of our business, employees, and properties apply to both the Company and the Operating Partnership.
	Our stabilized portfolio of operating properties was comprised of the following office properties at December 31, 2014:
		Number of		Rentable	Number of	Percentage
		Buildings		Square Feet	Tenants	Occupied
				(unaudited)
	Stabilized Office Properties	111		14,096,617	526	94.4	%
	Our stabilized portfolio includes all of our properties with the exception of development and redevelopment properties currently under construction or committed for construction, “lease-up” properties, undeveloped land, and real estate assets held for sale. We define redevelopment properties as those properties for which we expect to spend significant development and construction costs on the existing or acquired buildings pursuant to a formal plan, the intended result of which is a higher economic return on the property. As of December 31, 2014, we had no redevelopment projects. 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. There were no operating properties in “lease-up” as of December 31, 2014. As of December 31, 2014, we had one land parcel held for sale. During the year ended December 31, 2014, we stabilized a redevelopment project in San Francisco, California, a development project consisting of three office buildings encompassing 587,429 square feet and a development project consisting of two office buildings encompassing 340,913 square feet, both in the San Francisco Bay Area, California. As a result, these projects are now included in our stabilized portfolio as of December 31, 2014.
	As of December 31, 2014, the following properties were excluded from our stabilized portfolio:
		Number of	Estimated Rentable
		Properties/Projects	Square Feet (unaudited) (1)
	Development projects under construction	6	1,732,000
	_______________
	-1	Estimated rentable square feet upon completion.
	Our stabilized portfolio also excludes our future development pipeline, which is comprised of nine potential development sites, representing approximately 104 gross acres of undeveloped land.
	As of December 31, 2014, all of our properties and development projects were owned 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 projects are 100% owned, excluding a development project owned by Redwood City Partners, LLC (“Redwood LLC”), a consolidated subsidiary (see Note 2 “Basis of Presentation and Significant Accounting Policies” and Note 3 “Acquisitions” for additional information) and certain properties held at qualified intermediaries for potential future transactions that are intended to qualify as 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, which have been consolidated for financial reporting purposes (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information).
	As of December 31, 2014, the Company owned a 98.0% common general partnership interest in the Operating Partnership. The remaining 2.0% common limited partnership interest in the Operating Partnership as of December 31, 2014 was owned by non-affiliated investors and certain of our executive officers and directors. Both the general and limited common partnership interests in the Operating Partnership are denominated in common units. Generally, the number of common units held by the Company is equivalent to the number of outstanding shares of the Company’s common stock, and the rights of all the common units to quarterly distributions and payments in liquidation mirror those of the Company’s common stockholders. The common limited partners have certain redemption rights as provided in the Operating Partnership’s Seventh Amended and Restated Agreement of Limited Partnership, as amended, the “Partnership Agreement” (see Note 9 “Noncontrolling Interests on the Company’s Consolidated Financial Statements” for additional information).
	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 generally conduct substantially all of our development activities. With the exception of the Operating Partnership and Redwood LLC, all of our subsidiaries are wholly owned.

Basis_of_Presentation_and_Sign

Basis of Presentation and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Basis of Presentation and Significant Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	Basis of Presentation and Significant Accounting Policies
	Basis of Presentation
	The consolidated financial statements of the Company include the consolidated financial position and results of operations of the Company, the Operating Partnership, the Finance Partnership, KSLLC, Redwood LLC and all of our wholly owned and controlled subsidiaries. The consolidated financial statements of the Operating Partnership include the consolidated financial position and results of operations of the Operating Partnership, the Finance Partnership, KSLLC, Redwood 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.
	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 December 31, 2014, the consolidated financial statements of the Company and the Operating Partnership included two variable interest entities (“VIEs”), in which we were deemed to be the primary beneficiary. One VIE, Redwood LLC, was established in the second quarter of 2013 in connection with an undeveloped land acquisition (see Note 3 “Acquisitions” for additional information regarding the Redwood City, California acquisition). The other VIE was established during the fourth quarter of 2014 to facilitate potential future Section 1031 Exchanges to defer taxable gains on dispositions for federal and state income tax purposes. The impact of consolidating the VIEs increased the Company’s total assets, liabilities and noncontrolling interests by approximately $219.6 million (of which $211.8 million related to real estate held for investment on our consolidated balance sheet), approximately $23.4 million and approximately $5.9 million, respectively, as of December 31, 2014. During January 2015, the Company successfully completed the Section 1031 Exchange and the related VIE was terminated. As a result, $59.2 million of our restricted cash balance at December 31, 2014, which related to prior period disposition proceeds that were set aside to facilitate the Section 1031 Exchanges, was released from escrow.
	At 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 LLC and the remaining three were established during the third and fourth quarter of 2013 to facilitate potential Section 1031 Exchanges. During the three months ended March 31, 2014, these three Section 1031 Exchanges were successfully completed and the three VIEs, excluding Redwood LLC, 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.
	Our accounting policy is to consolidate entities in which we have a controlling financial interest and significant decision making control over the entity's operations. In determining whether we have a controlling financial interest in a partially owned entity and the requirement to consolidate the accounts of that entity, we consider factors such as ownership interest, board representation, management representation, size of our investment (including loans), authority to control decisions, and contractual and substantive participating rights of the members. In addition to evaluating control rights, we consolidate entities in which the other members have no substantive kick-out rights to remove the Company as the managing member.
	We also evaluate whether the entity is a variable interest entity (“VIE”) and whether we are the primary beneficiary. VIEs are entities in which the equity investors do not have sufficient equity at risk to finance their endeavors without additional financial support or the holders of the equity investment at risk do not have a controlling financial interest. We are deemed to be the primary beneficiary of a VIE when we have the power to direct the activities of the VIE that most significantly impact the VIEs’ economic performance and the obligation to absorb losses or receive benefits that could potentially be significant to the VIE.
	If the requirements for consolidation are not met, the Company would account for investments under the equity method of accounting if we have the ability to exercise significant influence over the entity. Equity method investments would be initially recorded at cost and subsequently adjusted for our share of net income or loss and cash contributions and distributions each period. The Company did not have any equity method investments at December 31, 2014 or December 31, 2013.
	Significant Accounting Policies
	Acquisitions
	We record the acquired tangible and intangible assets and assumed liabilities of acquisitions of operating properties and development and redevelopment opportunities that meet the accounting criteria to be accounted for as business combinations at fair value at the acquisition date. The acquired assets and assumed liabilities for an acquisition generally include but are not limited to (i) land and improvements, buildings and improvements, undeveloped land and construction in progress and (ii) identified tangible and intangible assets and liabilities associated with in-place leases, including tenant improvements, leasing costs, value of above-market and below-market operating leases and ground leases, acquired in-place lease values and tenant relationships, if any. Any debt assumed and equity (including common units of the Operating Partnership) issued in connection with a property acquisition is recorded at fair value on the date of acquisition.
	The fair value of land and improvements is derived from comparable sales of land and improvements within the same submarket and/or region. The fair value of buildings and improvements, tenant improvements and leasing costs considers the value of the property as if it was vacant as well as current replacement costs and other relevant market rate information.
	The fair value of the above-market or below-market component of an acquired in-place operating lease is based upon the present value (calculated using a market discount rate) of the difference between (i) the contractual rents to be paid pursuant to the lease over its remaining non-cancellable lease term and (ii) our estimate of the rents that would be paid using fair market rental rates and rent escalations at the date of acquisition measured over the remaining non-cancellable term of the lease for above-market operating leases and the initial non-cancellable term plus the term of any below-market fixed rate renewal options, if applicable, for below-market operating leases. Our below-market operating leases generally do not include fixed rate or below-market renewal options. The amounts recorded for above-market operating leases are included in deferred leasing costs and acquisition-related intangible assets, net on the balance sheet and are amortized on a straight-line basis as a reduction of rental income over the remaining term of the applicable leases. The amounts recorded for below-market operating leases are included in deferred revenue and acquisition-related intangible liabilities, net on the balance sheet and are amortized on a straight-line basis as an increase to rental income over the remaining term of the applicable leases plus the term of any below-market fixed rate renewal options, if applicable.
	The fair value of acquired in-place leases is derived based on our assessment of lost revenue and costs incurred for the period required to lease the “assumed vacant” property to the occupancy level when purchased. The amount recorded for acquired in-place leases is included in deferred leasing costs and acquisition-related intangible assets, net on the balance sheet and amortized as an increase to depreciation and amortization expense over the remaining term of the applicable leases. Fully amortized intangible assets are written off each quarter.
	We record the acquisition of undeveloped land that does not meet the accounting criteria to be accounted for as business combinations and the subsequent acquisition of the fee interest in land and improvements underlying our properties at the purchase price paid and capitalize the associated acquisition costs. During the years ended December 31, 2014, 2013 and 2012 we capitalized $4.5 million, $2.3 million and $0.7 million, respectively, in acquisition costs associated with the development acquisitions.
	Operating Properties
	Operating properties are generally carried at historical cost less accumulated depreciation. Properties held for sale are reported at the lower of the carrying value or the fair value less estimated cost to sell. The cost of operating properties includes the purchase price or development costs of the properties. Costs incurred for the renovation and betterment of the operating properties are capitalized to our investment in that property. Maintenance and repairs are charged to expense as incurred.
	When evaluating properties to be held and used for potential impairment, we first evaluate whether there are any indicators of impairment for any of our properties. If any impairment indicators are present for a specific property, we then perform an undiscounted cash flow analysis and compare the net carrying amount of the property to the property’s estimated undiscounted future cash flow over the anticipated holding period. If the estimated undiscounted future cash flow is less than the net carrying amount of the property, we then perform an impairment loss calculation to determine if the fair value of the property is less than the net carrying value of the property. Our impairment loss calculation compares the net carrying amount of the property to the property’s estimated fair value, which may be based on estimated discounted future cash flow calculations or third-party valuations or appraisals. We would recognize an impairment loss if the asset’s net carrying amount exceeds the asset’s estimated fair value. If we were to recognize an impairment loss, the estimated fair value of the asset (less costs to sell for assets held for sale) would become its new cost basis. For a depreciable long-lived asset, the new cost basis would be depreciated (amortized) over the remaining useful life of that asset. We did not record any impairment losses for the periods presented.
	Cost Capitalization
	All costs clearly associated with the development, redevelopment and construction of a property are capitalized as project costs, including internal compensation costs. In addition, the following costs are capitalized as project costs during periods in which activities necessary to prepare development and redevelopment properties for its intended use are in progress: pre-construction costs essential to the development of the property, interest, real estate taxes and insurance.
	•	For development and redevelopment properties that are pre-leased, we cease capitalization when revenue recognition commences, which is upon substantial completion of tenant improvements.
	•	For development and redevelopment properties that are not pre-leased, we may not immediately build out the tenant improvements. Therefore we cease capitalization when revenue recognition commences upon substantial completion of the tenant improvements, but in any event, no later than one year after the cessation of major construction activities. We also cease capitalization on a development or redevelopment property when activities necessary to prepare the property for its intended use have been suspended.
	•	For development or redevelopment properties with multiple tenants and staged leasing, we cease capitalization and begin depreciation on the portion of the development or redevelopment property for which revenue recognition has commenced.
	Once major construction activity has ceased and the development or redevelopment property is in the lease-up phase, the costs capitalized to construction in progress are transferred to land and improvements, buildings and improvements, and deferred leasing costs and acquisition-related intangible assets, net on our consolidated balance sheets as the historical cost of the property.
	Depreciation and Amortization of Buildings and Improvements
	The cost of buildings and improvements and tenant improvements are depreciated using the straight-line method of accounting over the estimated useful lives set forth in the table below. Depreciation expense for buildings and improvements, including discontinued operations, for the three years ended December 31, 2014, 2013, and 2012 was $153.8 million, $145.3 million and $125.9 million, respectively.
	Asset Description		Depreciable Lives
	Buildings and improvements		25 – 40 years
	Tenant improvements		1 – 20 years (1)
	________________________
	-1	Tenant improvements are amortized over the shorter of the lease term or the estimated useful life.
	Real Estate Assets Held for Sale, Discontinued Operations, and Land Dispositions
	A real estate asset is classified as held for sale when certain criteria are met, including but not limited to the availability of the asset for immediate sale, the existence of an active program to locate a buyer and the probable sale or transfer of the asset within one year. If such criteria are met, we present the applicable assets and liabilities related to the real estate asset held for sale, if material, separately on the balance sheet and we would cease to record depreciation and amortization expense. Real estate assets held for sale are reported at the lower of their carrying value or their estimated fair value less the estimated costs to sell. As of December 31, 2014, we had one undeveloped land parcel classified as held for sale. As of December 31, 2013, we had 12 operating properties classified as held for sale.
	The revenues and expenses of operating properties that have been sold, if material, and the revenues and expenses of operating properties that have been classified as held for sale, if material, are reported in the consolidated statements of operations as discontinued operations for all periods presented through the date of the applicable disposition. The net gains (losses) on disposition of operating properties are reported in the consolidated statements of operations as discontinued operations in the period the properties are sold. In determining whether the revenues, expenses, and net gains (losses) on dispositions of operating properties are reported as discontinued operations, we evaluate whether we have any significant continuing involvement in the operations, leasing, or management of the sold property. If we were to determine that we had any significant continuing involvement, the revenues, expenses and net gain (loss) on dispositions of the operating property would not be recorded in discontinued operations.
	The net gains (losses) on dispositions of non-depreciable real estate property, including land, are reported in the consolidated statements of operations as gains (losses) on sale of land within continuing operations in the period the land is sold.
	Revenue Recognition
	We recognize revenue from rent, tenant reimbursements, parking and other revenue once all of the following criteria are met: (i) the agreement has been fully executed and delivered, (ii) services have been rendered, (iii) the amount is fixed or determinable, and (iv) the collectability of the amount is reasonably assured.
	Minimum annual rental revenues are recognized in rental revenues on a straight-line basis over the term of the related lease. Rental revenue recognition commences when the tenant takes possession or controls the physical use of the leased space. In order for the tenant to take possession, the leased space must be substantially ready for its intended use. To determine whether the leased space is substantially ready for its intended use, we evaluate whether the Company owns or the tenant owns the tenant improvements. When we conclude that the Company is the owner of tenant improvements, rental revenue recognition begins when the tenant takes possession of the finished space, which is when such tenant improvements are substantially complete. In certain instances, when we conclude that the Company is not the owner (the tenant is the owner) of tenant improvements, rental revenue recognition begins when the tenant takes possession of or controls the space.
	When we conclude that the Company is the owner of tenant improvements, we record the cost to construct the tenant improvements, including costs paid for or reimbursed by the tenants, as a capital asset. For these tenant improvements, we record the amount funded by or reimbursed by the tenants as deferred revenue, which is amortized on a straight-line basis as additional rental income over the term of the related lease.
	When we conclude that the tenant is the owner of tenant improvements for accounting purposes, we record our contribution towards those improvements as a lease incentive, which is included in deferred leasing costs and acquisition-related intangible assets, net on our consolidated balance sheets and amortized as a reduction to rental income on a straight-line basis over the term of the lease.
	Tenant Reimbursements
	Reimbursements from tenants, consisting of amounts due from tenants for common area maintenance, real estate taxes and other recoverable costs, are recognized as revenue in the period the recoverable costs are incurred. Tenant reimbursements are recognized and recorded on a gross basis, as we are generally the primary obligor with respect to purchasing goods and services from third-party suppliers, have discretion in selecting the supplier, and have credit risk.
	Other Property Income
	Other property income primarily includes amounts recorded in connection with lease terminations and tenant bankruptcy settlement payments. Lease termination fees are amortized over the remaining lease term, if applicable. If there is no remaining lease term, they are recognized when received and realized. Other property income also includes miscellaneous income from tenants, such as fees related to the restoration of leased premises to their original condition and fees for late rental payments.
	Allowances for Uncollectible Tenant and Deferred Rent Receivables
	We carry our current and deferred rent receivables net of allowances for uncollectible amounts. Our determination of the adequacy of these allowances is based primarily upon evaluations of individual receivables, current economic conditions, historical loss experience, and other relevant factors. The allowances are increased or decreased through the provision for bad debts on our consolidated statements of operations.
	Cash and Cash Equivalents
	We consider all highly-liquid investments with original maturities of three months or less to be cash equivalents.
	Restricted Cash
	Restricted cash consists of cash proceeds from dispositions that are temporarily held at qualified intermediaries for purposes of facilitating potential Section 1031 Exchanges and cash held in escrow related to acquisition holdbacks. Restricted cash also includes cash held as collateral to provide credit enhancement for the Operating Partnership’s mortgage debt, including cash reserves for capital expenditures, tenant improvements and property taxes.
	Marketable Securities / Deferred Compensation Plan
	Marketable securities reported in our consolidated balance sheets represent the assets held in connection with the Kilroy Realty Corporation 2007 Deferred Compensation Plan (the “Deferred Compensation Plan”) (see Note 13 “Employee Benefit Plans” for additional information). The Deferred Compensation Plan assets are held in a limited rabbi trust and invested in various mutual and money market funds. As a result, the marketable securities are treated as trading securities for financial reporting purposes and are adjusted to fair value at the end of each accounting period, with the corresponding gains and losses recorded in interest income and other net investment gains.
	At the time eligible management employees (“Participants”) defer compensation or earn mandatory Company contributions, or if we were to make a discretionary contribution, we record compensation cost and a corresponding deferred compensation plan liability, which is included in accounts payable, accrued expenses, and other liabilities on our consolidated balance sheets. This liability is adjusted to fair value at the end of each accounting period based on the performance of the benchmark funds selected by each Participant, and the impact of adjusting the liability to fair value is recorded as an increase or decrease to compensation cost. The impact of adjusting the deferred compensation plan liability to fair value and the changes in the value of the marketable securities held in connection with the Deferred Compensation Plan generally offset and therefore does not significantly impact net income.
	Deferred Leasing Costs
	Costs incurred in connection with successful property leasing are capitalized as deferred leasing costs and classified as investment activities in the statement of cash flows. Deferred leasing costs consist primarily of leasing commissions and also include certain internal payroll costs and lease incentives, which are amortized using the straight-line method of accounting over the lives of the leases which generally range from one to 20 years. We reevaluate the remaining useful lives of leasing costs as the creditworthiness of our tenants and economic and market conditions change. If we determine that the estimated remaining life of a lease has changed, we adjust the amortization period accordingly. Fully amortized deferred leasing costs are written off each quarter.
	Deferred Financing Costs
	Financing costs related to the origination or assumption of long-term debt are deferred and generally amortized using the straight-line method of accounting, which approximates the effective interest method, over the contractual terms of the applicable financings. Fully amortized deferred financing costs are written off when the corresponding financing is repaid. As of December 31, 2014 and 2013, deferred financing costs were reported net of accumulated amortization of $12.2 million and $13.2 million, respectively.
	Debt Discounts and Premiums
	Original issuance debt discounts and discounts/premiums related to recording debt acquired in connection with operating property acquisitions at fair value are generally amortized and accreted on a straight-line basis, which approximates the effective interest method. Discounts are recorded as additional interest expense from date of issuance or acquisition through the contractual maturity date of the related debt. Premiums are recorded as a reduction to interest expense from the date of issuance or acquisition through the contractual maturity date of the related debt. Our secured debt is presented including unamortized premiums of $10.3 million and $14.6 million as of December 31, 2014 and 2013, respectively. Our unsecured senior notes are presented net of unamortized discounts of $5.9 million and $1.9 million, as of December 31, 2014 and 2013, respectively.
	Exchangeable Debt Instruments
	The initial proceeds from exchangeable debt that may be settled in cash, including partial cash settlements, are bifurcated between a liability component and an equity component associated with the embedded conversion option. The liability and equity components of exchangeable debt are separately accounted for in a manner such that the interest expense on the exchangeable debt is not recorded at the stated rate of interest but rather at an effective rate that reflects the issuer’s conventional debt borrowing rate at the date of issuance.
	We calculate the liability component of exchangeable debt based on the present value of the contractual cash flows discounted at a comparable market conventional debt borrowing rate at the date of issuance. The difference between the principal amount and the fair value of the liability component is reported as a discount on the exchangeable debt that is accreted as additional interest expense from the issuance date through the contractual maturity date using the effective interest method. A portion of this additional interest expense is capitalized to the development and redevelopment balances qualifying for interest capitalization each period. The liability component of the exchangeable debt is reported net of discounts on our consolidated balance sheets.
We calculate the equity component of exchangeable debt based on the difference between the initial proceeds received from the issuance of the exchangeable debt and the fair value of the liability component at the issuance date. The equity component is included in additional paid-in-capital, net of issuance costs, on our consolidated balance sheets. We allocate issuance costs for exchangeable debt between the liability and the equity components based on their relative values.
Our exchangeable debt instruments matured in November 2014. As of December 31, 2014, we had no outstanding exchangeable debt instruments (see Note 7 “Secured and Unsecured Debt of the Operating Partnership” for additional information).
Noncontrolling Interests in the Company’s Consolidated Financial Statements
Noncontrolling interests in the Company’s consolidated financial statements represent the common limited partnership interests in the Operating Partnership not held by the Company (“noncontrolling common units”) and our interest in a consolidated subsidiary, Redwood LLC, formed during 2013 (see Note 3 “Acquisitions” for additional information).
Noncontrolling common units are presented in the equity section of the Company’s consolidated balance sheets and reported at their proportionate share of the net assets of the Operating Partnership. Noncontrolling interests with redemption provisions that permit the issuer to settle in either cash or shares of common stock must be further evaluated to determine whether equity or temporary equity classification on the balance sheet is appropriate. Since the common units contain such a provision, we evaluated the accounting guidance and determined that the common units qualify for equity presentation in the Company’s consolidated financial statements (see Note 9 “Noncontrolling Interests on the Company’s Consolidated Financial Statements”).
Net income attributable to noncontrolling common units is allocated based on their relative ownership percentage of the Operating Partnership during the reported period. The noncontrolling interest ownership percentage is determined by dividing the number of noncontrolling common units by the total number of common units outstanding. The issuance or redemption of additional shares of common stock or common units results in changes to the noncontrolling interest percentage as well as the total net assets of the Company. As a result, all equity transactions result in an allocation between equity and the noncontrolling interest in the Company’s consolidated balance sheets and statements of equity to account for the changes in the noncontrolling interest ownership percentage as well as the change in total net assets of the Company.
Preferred Partnership Interests on the Operating Partnership’s Consolidated Balance Sheets
Preferred partnership interests of the Operating Partnership represent the issued and outstanding 4,000,000 6.875% Series G Cumulative Redeemable Preferred Units (“Series G Preferred Units”) and the 4,000,000 6.375% Series H Cumulative Redeemable Preferred Units (“Series H Preferred Units”) which were outstanding as of December 31, 2014 and 2013.
The Series G and Series H Preferred Units are presented in the permanent equity section of the Operating Partnership’s consolidated balance sheets given that the Series G and Series H Preferred Units may only be redeemed at our option (see Note 11 “Preferred and Common Units of the Operating Partnership”). The Company is the holder of both the Series G and Series H Preferred Units and for each Series G and Series H Preferred Unit the Company has an equivalent number of shares of the Company’s 6.875% Series G Cumulative Redeemable Preferred Stock and shares of the Company’s 6.375% Series H Cumulative Redeemable Preferred Stock publicly issued and outstanding.
Common Partnership Interests on the Operating Partnership’s Consolidated Balance Sheets
The common units held by the Company and the noncontrolling common units held by the common limited partners are both presented in the permanent equity section of the Operating Partnership’s consolidated balance sheets in partners’ capital. The redemption rights of the noncontrolling common units permit us to settle the redemption obligation in either cash or shares of the Company’s common stock at our option (see Note 9 “Noncontrolling Interests on the Company’s Consolidated Financial Statements” for additional information).
Noncontrolling Interests on the Operating Partnership’s Consolidated Balance Sheets
Noncontrolling interests of the Operating Partnership represent the Company’s 1.0% general partnership interest in the Finance Partnership and the Operating Partnership‘s interest in Redwood LLC (see Note 3 “Acquisitions” for additional information). The 1.0% general partnership interest in the Finance Partnership noncontrolling interest is presented in the permanent equity section of the Operating Partnership’s consolidated balance sheets given that these interests are not convertible or redeemable into any other ownership interest of the Company or the Operating Partnership.
Equity Offerings
Underwriting commissions and offering costs incurred in connection with common equity offerings and our at-the-market stock offering program (see Note 10 “Stockholders’ Equity of the Company”) are reflected as a reduction of additional paid-in capital. Issuance costs incurred in connection with preferred equity offerings are reflected as a reduction of the carrying value of the preferred equity.
The Company records preferred stock issuance costs as a noncash preferred equity distribution at the time we notify the holders of preferred stock or units of our intent to redeem such shares or units.
The net proceeds from any equity offering of the Company are generally contributed to the Operating Partnership in exchange for a number of common or preferred units equivalent to the number of shares of common or preferred stock issued and are reflected in the Operating Partnership’s consolidated financial statements as an increase in partners’ capital.
Share-based Incentive Compensation Accounting
Compensation cost for all share-based awards, including options, requires measurement at estimated fair value on the grant date. Compensation cost is recognized over the service vesting period, which represents the requisite service period, on a straight-line basis. The grant date fair value of market measure-based share-based compensation plans are calculated using a Monte Carlo simulation pricing model. The grant date fair value of stock option grants is calculated using the Black-Scholes valuation model. Equity awards settled in cash are valued at the fair value of our common stock on the period end date through the settlement date. Equity awards settled in cash are remeasured at each reporting period and are recognized as a liability in the consolidated balance sheet during the vesting period until settlement.
For share-based awards in which the performance period precedes the grant date, we recognize compensation cost over the requisite service period, which includes both the performance and service vesting periods, using the accelerated attribution expense method. The requisite service period begins on the date the Executive Compensation Committee authorizes the award and adopts any relevant performance measures.
For programs with performance-based measures, the total estimated compensation cost is based on our most recent estimate of the probable achievement of the pre-established specific corporate performance measures. These estimates are based on our latest internal forecasts for each performance measure. For programs with market measures, the total estimated compensation cost is based on the fair value of the award at the grant date.
In accordance with the provisions of our share-based incentive compensation plans, we accept the return of shares of Company common stock, at the current quoted market price, from employees to satisfy minimum statutory tax-withholding requirements related to shares that vested during the period.
For share based awards granted by the Company, the Operating Partnership issues a number of common units equal to the number of shares of common stock ultimately granted by the Company in respect of such awards.
Basic and Diluted Net Income (Loss) Available to Common Stockholders per Share
Basic net income (loss) available to common stockholders per share is computed by dividing net income (loss) available to common stockholders, after preferred distributions and the allocation of income to participating securities, by the weighted-average number of shares of common stock outstanding for the period. Diluted net income (loss) available to common stockholders per share is computed by dividing net income (loss) available for common stockholders, after preferred distributions and the allocation of income to participating securities, by the sum of the weighted-average number of shares of common stock outstanding for the period plus the assumed exercise of all dilutive securities. The impact of the outstanding common units is considered in the calculation of diluted net income (loss) available to common stockholders per share. The common units are not reflected in the diluted net income (loss) available to common stockholders per share calculation because the exchange of common units into common stock is on a one for one basis, and the common units are allocated net income on a per share basis equal to the common stock (see Note 19 “Net Income Available to Common Stockholders Per Share of the Company”). Accordingly, any exchange would not have any effect on diluted net income (loss) available to common stockholders per share.
Nonvested share-based payment awards (including nonvested restricted stock units (“RSUs”), vested market-measure RSUs and vested dividend equivalents issued to holders of RSUs) containing nonforfeitable rights to dividends or dividend equivalents are accounted for as participating securities and included in the computation of basic and diluted net income (loss) available to common stockholders per share pursuant to the two-class method. The dilutive effect of stock options are reflected in the weighted average diluted outstanding shares calculation by application of the treasury stock method. For the period in which they were outstanding, the dilutive effect of the exchangeable debt instruments was reflected in the weighted average diluted outstanding shares calculation when the average quoted trading price of the Company’s common stock on the NYSE for the periods exchangeable was above the exchangeable debt exchange prices. The dilutive effect of the outstanding nonvested shares of common stock (“nonvested shares”) and RSUs that have not yet been granted but are contingently issuable under the share-based compensation programs is reflected in the weighted average diluted shares calculation by application of the treasury stock method at the beginning of the quarterly period in which all necessary conditions have been satisfied.
Basic and Diluted Net Income (Loss) Available to Common Unitholders per Unit
Basic net income (loss) available to common unitholders per unit is computed by dividing net income (loss) available to common unitholders, after preferred distributions and the allocation of income to participating securities, by the weighted-average number of vested common units outstanding for the period. Diluted net income (loss) available to common unitholders per unit is computed by dividing net income (loss) available to common unitholders, after preferred distributions and the allocation of income to participating securities, by the sum of the weighted-average number of common units outstanding for the period plus the assumed exercise of all dilutive securities.
During the periods exchangeable debt instruments were outstanding, the dilutive effect of the exchangeable debt instruments was reflected in the same manner as noted above for net income (loss) available to common stockholders per share. The dilutive effect of stock options, outstanding nonvested shares, RSUs, and awards containing nonforfeitable rights to dividend equivalents are reflected in diluted net income (loss) available to common unitholders per unit in the same manner as noted above for net income (loss) available to common stockholders per share.
Fair Value Measurements
The fair value of our financial assets and liabilities are disclosed in Note 16, "Fair Value Measurements and Disclosures," to our consolidated financial statements. The only financial assets recorded at fair value on a recurring basis in our consolidated financial statements are our marketable securities. We elected not to apply the fair value option for any of our eligible financial instruments or other items.
We determine the estimated fair value of financial assets and liabilities utilizing a hierarchy of valuation techniques based on whether the inputs to a fair value measurement are considered to be observable or unobservable in a marketplace. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect our market assumptions. This hierarchy requires the use of observable market data when available. The following is the fair value hierarchy:
•	Level 1 – quoted prices for identical instruments in active markets;
•	Level 2 – quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active and model-derived valuations in which significant inputs and significant value drivers are observable in active markets; and
•	Level 3 – fair value measurements derived from valuation techniques in which one or more significant inputs or significant value drivers are unobservable.
We determine the fair value for the marketable securities using quoted prices in active markets for identical assets. Our other financial instruments, which are only disclosed at fair value, are comprised of secured debt, unsecured senior notes, unsecured line of credit, unsecured term loan facility and Exchangeable Notes.
We generally determine the fair value of our secured debt, unsecured debt, and unsecured line of credit by performing discounted cash flow analyses using an appropriate market discount rate. We calculate the market rate by obtaining period-end treasury rates for maturities that correspond to the maturities of our fixed-rate debt and then adding an appropriate credit spread based on information obtained from third-party financial institutions. These credit spreads take into account factors, including but not limited to, our credit profile, the tenure of the debt, amortization period, whether the debt is secured or unsecured, and the loan-to-value ratio of the debt to the collateral. These calculations are significantly affected by the assumptions used, including the discount rate, credit spreads and estimates of future cash flow. We calculate the market rate of our unsecured line of credit, unsecured term loan facility, and unsecured term loan by obtaining the period-end London Interbank Offered Rate (“LIBOR”) rate and then adding an appropriate credit spread based on our credit ratings, and the amended terms of our unsecured line of credit, unsecured term loan facility, and unsecured term loan agreement. We determine the fair value of the liability component of our Exchangeable Notes by performing discounted cash flow analyses using an appropriate market interest rate based upon spreads for our publicly traded debt. We determine the fair value of each of our publicly traded unsecured senior notes based on their quoted trading price at the end of the reporting period, if such prices are available.
Carrying amounts of our cash and cash equivalents, restricted cash and accounts payable approximate fair value due to their short-term maturities.
Income Taxes
We have elected to be taxed as a REIT under Sections 856 through 860 of the Code. To qualify as a REIT, we must distribute annually at least 90% of our adjusted taxable income, as defined in the Code, to our stockholders and satisfy certain other organizational and operating requirements. For distributions with respect to taxable years ended on or before December 31, 2011, Internal Revenue Service (“IRS”) guidance allows REITs to satisfy up to 90% of this requirement through the distribution of shares of common stock if certain conditions are met. We generally will not be subject to federal income taxes if we distribute 100% of our taxable income for each year to our stockholders. If we fail to qualify as a REIT in any taxable year, we will be subject to federal income taxes (including any applicable alternative minimum tax) on our taxable income at regular corporate rates and we may not be able to qualify as a REIT for four subsequent taxable years. Even if we qualify for taxation as a REIT, we may be subject to certain state and local taxes on our income and property and to federal income taxes and excise taxes on our undistributed taxable income. We believe that we have met all of the REIT distribution and technical requirements for the years ended December 31, 2014, 2013 and 2012, and we were not subject to any federal income taxes (see Note 21 “Tax Treatment of Distributions” for additional information). We intend to continue to adhere to these requirements and maintain the Company’s REIT status. Accordingly, no provision for income taxes has been made in the accompanying financial statements.
In addition, any taxable income from our taxable REIT subsidiary, which was formed in 2002, is subject to federal, state, and local income taxes. For the years ended December 31, 2014, 2013 and 2012 the taxable REIT subsidiary had de minimis taxable income.
Uncertain Tax Positions
We include favorable tax positions in the calculation of tax liabilities if it is more likely than not that our adopted tax position will prevail if challenged by tax authorities.
As a result of our REIT status, we are able to claim a dividends-paid deduction on our tax return to deduct the full amount of common and preferred dividends paid to stockholders when computing our annual taxable income. Since this dividends-paid deduction has historically exceeded our taxable income, the Company has historically had significant return of capital to its stockholders. In order for us to be required to record any unrecognized tax benefits or additional tax liabilities, any adjustment for potential uncertain tax positions would need to exceed the return of capital.
We evaluated the potential impact of identified uncertain tax positions for all tax years still subject to audit under state and federal income tax law and concluded that our return of capital would not be materially affected for any of the years still subject to audit. As of December 31, 2014, the years still subject to audit are 2010 through 2013 under the California state income tax law and 2011 through 2013 under the federal income tax law. We concluded that we did not have any unrecognized tax benefits or any additional tax liabilities as of December 31, 2014 and 2013.
Use of Estimates
The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reported periods. Actual results could differ from those estimates.
Segment
We currently operate in one operating segment, our office properties segment.
Concentration of Credit Risk
All of our properties and development and redevelopment projects are owned and all of our business is currently conducted in the state of California with the exception of the ownership and operation of thirteen office properties located in the state of Washington. The ability of tenants to honor the terms of their leases is dependent upon the economic, regulatory, and social factors affecting the communities in which our tenants operate.
As of December 31, 2014, our 15 largest tenants represented approximately 35.3% of total annualized base rental revenues.
We have deposited cash with financial institutions that is insured by the Federal Deposit Insurance Corporation (“FDIC”) up to $250,000 per institution. As of December 31, 2014 and 2013, we had cash accounts in excess of FDIC insured limits.
New Accounting Pronouncements
On January 9, 2015 the Financial Accounting Standards Board (“FASB”) issued final guidance on its initiative of simplifying income statement presentation by the eliminating the concept of extraordinary items (Accounting Standards Update (“ASU”) No. 2015-01). Under the guidance an entity will no longer be able to segregate an extraordinary item from the results of operations, separately present an extraordinary item on the income statement, or disclose income taxes or earnings-per-share data applicable to an extraordinary item.  The ASU is effective for all entities for reporting periods (including interim periods) beginning after December 15, 2015, and early adoption is permitted. The Company will adopt the guidance effective January 1, 2016 and the guidance is not anticipated to have a material impact on our consolidated financial statements or notes to our consolidated financial statements.
On June 19, 2014, the FASB issued their final standard to amend the accounting guidance for stock compensation tied to performance targets (ASU No. 2014-12). The issue is the result of a consensus of the FASB Emerging Issues Task Force (Issue No. 13-D). The standard requires that a performance target that could be achieved after the requisite service period be treated as a performance condition, and as a result, this type of performance condition may delay expense recognition until achievement of the performance target is probable. The ASU is effective for all entities for reporting periods (including interim periods) beginning after December 15, 2015, and early adoption is permitted. The Company will adopt the guidance effective January 1, 2016 and the guidance is not anticipated to have a material impact on our consolidated financial statements or notes to our consolidated financial statements.
On May 28, 2014, the FASB issued their final standard on revenue from contracts with customers. The guidance specifically notes that lease contracts with customers are a scope exception. The standard (ASU No. 2014-09) outlines a single comprehensive model for entities to use in accounting for revenues arising from contracts with customers. The ASU is effective for annual reporting periods (including interim periods), beginning after December 15, 2016, and early adoption is not permitted. The Company will adopt the guidance effective January 1, 2017 and is currently assessing the impact on our consolidated financial statements and notes to our consolidated financial statements.
On April 10, 2014, the FASB issued final guidance to change the criteria for reporting discontinued operations while enhancing disclosures in this area (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 adopted the guidance effective January 1, 2015 and the guidance is not expected to have a material impact to our consolidated net income or our statement of financial position.

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
Acquisitions	Acquisitions
	Operating Properties
	During the years ended December 31, 2014 and 2013, we acquired the nine operating office properties, listed below, from unrelated third parties. Unless otherwise noted, we funded these acquisitions with proceeds from the Company’s public offerings of common stock and the Company's at-the-market stock offering program (see Note 10 “Stockholders’ Equity of the Company”), borrowings under the unsecured line of credit (see Note 7 “Secured and Unsecured Debt of the Operating Partnership”), disposition proceeds (see Note 18 “Discontinued Operations”), the assumption of existing debt and/or the issuance of common units of the Operating Partnership.
	Property		Date of Acquisition	Number of Buildings		Rentable Square Feet (unaudited)		Occupancy as of December 31, 2014 (unaudited)		Purchase Price (in millions) (1)
	2014 Acquisitions
	401 Terry Ave. N., Seattle, WA		March 13, 2014	1		140,605		100.00%		$	106.1
	1310, 1315, 1320-1324, 1325-1327 Chesapeake Terrace, Sunnyvale, CA (2)		November 5, 2014	4		266,982		86.00%		100.5
	Total (3)			5		407,587				$	206.6
	2013 Acquisitions
	320 Westlake Ave. N. and 321 Terry Ave. N.,		January 16, 2013	2		320,398		100.00%		$	170
	Seattle, WA (4)(5)
	12780 and 12790 El Camino Real, San Diego,		September 19, 2013	2		218,940		100.00%		126.4
	CA (6)
	Total (7)			4		539,338				$	296.4
	________________________
	-1	Excludes acquisition-related costs and non-lease related accrued liabilities assumed. Includes assumed unpaid leasing commissions and tenant improvements.
	-2	As of December 31, 2014, these properties, together the "Chesapeake Commons" project, were temporarily being held in a separate VIE to facilitate potential Section 1031 Exchanges (see Note 2 "Basis of Presentation and Significant Accounting Policies"). During January 2015, the Company closed out the Section 1031 Exchange related to this VIE.
	-3	The results of operations for the properties acquired during 2014 contributed $7.7 million and $2.8 million to revenues and net income from continuing operations, respectively, for the year ended December 31, 2014.
	-4	We acquired these properties through a special purpose entity wholly owned by the Finance Partnership.
	-5	In connection with this acquisition, we assumed secured debt with an outstanding principal balance of $83.9 million that was recorded at fair value on the acquisition date, resulting in a premium of approximately $11.6 million (see Note 7 “Secured and Unsecured Debt of the Operating Partnership” for additional information).
	-6	As of December 31, 2013, these properties, together the "Heights of Del Mar" project, were temporarily being held in a separate VIE to facilitate potential Section 1031 Exchanges (see Note 2 "Basis of Presentation and Significant Accounting Policies"). The $126.4 million purchase price includes $9.4 million for 4.2 acres of undeveloped land the Company acquired in connection with this acquisition.
	-7	The results of operations for the properties acquired during 2013 contributed $17.5 million and $0.9 million to revenues and net income from continuing operations, respectively, for the year ended December 31, 2013.
	The related assets, liabilities and results of operations of the acquired properties 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 at the respective acquisition dates for our 2014 and 2013 acquisitions:
	Acquisitions	Total 2014		Total 2013
		Acquisitions (1)		Acquisitions (1)
		(in thousands)
	Assets
	Land and improvements	$	81,430	$	53,790
	Buildings and improvements (2)	114,876		218,211
	Undeveloped land and construction in progress (3)	—		9,360
	Deferred leasing costs and acquisition-related intangible assets (4)	17,259		30,789
	Total assets acquired	213,565		312,150
	Liabilities
	Deferred revenue and acquisition-related intangible liabilities (5)	6,990		4,190
	Secured debt, net (6)	—		95,496
	Accounts payable, accrued expenses and other liabilities	2,029		422
	Total liabilities assumed	9,019		100,108
	Net assets and liabilities acquired (7)	$	204,546	$	212,042
	_______________
	-1	The purchase price of the two acquisitions completed during the year ended December 31, 2014, and the two acquisitions completed during the year ended December 31, 2013 were individually less than 5% and in aggregate less than 10% of the Company’s total assets as of December 31, 2014 and December 31, 2013, respectively.
	-2	Represents buildings, building improvements and tenant improvements.
	-3	In connection with one of the 2013 acquisitions, we acquired undeveloped land of approximately 4.2 acres that was added to the Company's future development pipeline upon acquisition.
	-4	Represents in-place leases (approximately $12.3 million with a weighted average amortization period of 7.0 years) and leasing commissions (approximately $4.9 million with a weighted average amortization period of 7.0 years) for the year ended December 31, 2014. Represents in-place leases (approximately $19.6 million with a weighted average amortization period of 4.7 years), above-market leases (approximately $3.2 million with a weighted average amortization period of 6.1 years) and leasing commissions (approximately $7.9 million with a weighted average amortization period of 5.9 years) for the year ended December 31, 2013.
	-5	Represents below-market leases (approximately $7.0 million and $4.2 million with a weighted average amortization period of 6.1 years and 7.7 years) for the years ended December 31, 2014 and December 31, 2013, respectively.
	-6	Represents the mortgage loan, which includes an unamortized premium balance of approximately $11.6 million at the date of acquisition, assumed in connection with the properties acquired in January 2013 (see Note 7 “Secured and Unsecured Debt of the Operating Partnership” for additional information).
	-7	Reflects the purchase price net of assumed secured debt and other lease-related obligations.
	Development and Redevelopment Project Sites
	During the year ended December 31, 2014, we acquired the following undeveloped land sites listed below from unrelated third parties. The acquisitions were funded with proceeds from the Company’s at-the-market stock offering program (see Note 10 “Stockholders’ Equity of the Company” for additional information), borrowings under the unsecured line of credit (see Note 7 “Secured and Unsecured Debt of the Operating Partnership” for additional information), disposition proceeds (see Note 18 “Discontinued Operations” for additional information), and issuance of common stock.
	Project		Date of	Type		Purchase Price
			Acquisition			(in millions)
	The Exchange on 16th, San Francisco, CA (1)		23-May-14	Development		$	95
	Flower Mart, San Francisco, CA (2)		October 23, 2014, December 19, 2014	Development		71
	Total					$	166
	_______________
	-1	In connection with this acquisition, we also assumed $2.3 million in accrued liabilities, which are not included in the purchase price above. As of December 31, 2014, the purchase price and assumed liabilities are included in undeveloped land and construction in progress and the assumed liabilities are included in accounts payable, accrued expenses and other liabilities on our consolidated balance sheets.
	-2	In the fourth quarter of 2014, the Company closed on two adjacent land sites for a total purchase price of $71.0 million and approximately $13.4 million in transaction costs and accrued liabilities, net (see Note 15 “Commitments and Contingencies” for additional information on a portion of accrued liabilities for this transaction). The acquisitions, which were completed through the execution of two merger transactions, were partially funded through the issuance of 351,476 shares of the Company’s common stock valued at approximately $21.6 million and the remainder was paid in cash.
	During the year ended December 31, 2013, we acquired the following land site and land previously subject to a ground lease listed below from unrelated third parties. The acquisitions were funded with proceeds from the Company’s at-the-market stock offering program (see Note 10 “Stockholders’ Equity of the Company”), borrowings under the unsecured line of credit (see Note 7 “Secured and Unsecured Debt of the Operating Partnership”), and disposition proceeds (see Note 18 “Discontinued Operations”).
	Project		Date of	Type		Purchase Price
			Acquisition			(in millions)
	Academy Project, Hollywood, CA (1)		15-Nov-13	Development		$	45
	360 Third Street, San Francisco, CA (2)		29-Oct-13	Land		27.5
	Total					$	72.5
	_______________
	-1	In connection with this acquisition, we also assumed $0.7 million in accrued liabilities, which are not included in the purchase price above. As of December 31, 2014 and 2013, the project is included in our future development pipeline and, as a result, the underlying assets were included as undeveloped land and construction in progress in our consolidated financial statements.
-2	In November 2012, we exercised an option to purchase the land underlying the ground leases at this wholly owned property. This transaction closed in October 2013 and as of December 31, 2014 and 2013, the land was included as land and improvements in our consolidated financial statements.
Additionally, on June 27, 2013, the Company entered into an agreement with an unaffiliated third party and formed Redwood LLC, a new consolidated subsidiary. In connection with this transaction, the Company acquired a 0.35 acre land site, completing the first phase of the land assemblage for its plans to develop an approximate 300,000 square foot office project (the “Crossing/900” project) in Redwood City, California. In October 2013, the Company acquired a 2.0 acre undeveloped land parcel for $17.0 million, completing the final phase of the land assemblage for this project. The related assets, liabilities, and noncontrolling interest acquired in connection with this transaction are included in our consolidated financial statements as of the date of acquisition. The following table summarizes the allocation of the assets acquired and liabilities assumed at the acquisition dates (in thousands):
	Phase I			Phase II			Total
Assets
Undeveloped land and construction in progress	$	11,222		$	17,000		$	28,222
Total assets	11,222			17,000			28,222
Liabilities
Secured debt (1)	1,750			—			1,750
Accounts payable, accrued expenses and other liabilities	1,952			1,475			3,427
Total liabilities	3,702			1,475			5,177
Noncontrolling interest in consolidated subsidiary	4,885			—			4,885
Net assets and liabilities acquired	$	2,635		$	15,525		$	18,160
________________________
-1	This note was repaid as of December 31, 2013.

Deferred_Leasing_Costs_and_Acq

Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, net	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, net	Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, net
	The following table summarizes our deferred leasing costs and acquisition-related intangible assets (acquired value of leasing costs, above-market operating leases, 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 December 31, 2014 and 2013:
		December 31, 2014			December 31, 2013
		(in thousands)
	Deferred Leasing Costs and Acquisition-related Intangible Assets, net:
	Deferred leasing costs	$	216,102		$	178,720
	Accumulated amortization	(74,904		)	(63,246		)
	Deferred leasing costs, net	141,198			115,474
	Above-market operating leases	20,734			27,635
	Accumulated amortization	(13,952		)	(14,283		)
	Above-market operating leases, net	6,782			13,352
	In-place leases	97,250			100,318
	Accumulated amortization	(43,773		)	(42,999		)
	In-place leases, net	53,477			57,319
	Below-market ground lease obligation	490			490
	Accumulated amortization	(21		)	(13		)
	Below-market ground lease obligation, net	469			477
	Total deferred leasing costs and acquisition-related intangible assets, net	$	201,926		$	186,622
	Acquisition-related Intangible Liabilities, net: (1)
	Below-market operating leases	$	68,051		$	69,385
	Accumulated amortization	(30,620		)	(25,706		)
	Below-market operating leases, net	37,431			43,679
	Above-market ground lease obligation	6,320			6,320
	Accumulated amortization	(324		)	(223		)
	Above-market ground lease obligation, net	5,996			6,097
	Total acquisition-related intangible liabilities, net	$	43,427		$	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 intangible liabilities, including amounts attributable to discontinued operations, for years ended December 31, 2014, 2013 and 2012:
		Year Ended December 31,
		2014			2013			2012
		(in thousands)
	Deferred leasing costs (1)	$	27,555		$	25,902		$	20,804
	Above-market operating leases (2)	5,303			5,664			5,695
	In-place leases (1)	21,628			29,363			21,976
	Below-market ground lease obligation (3)	8			8			205
	Below-market operating leases (4)	(13,238		)	(13,441		)	(12,393		)
	Above-market ground lease obligation (5)	(101		)	(101		)	(85		)
	Total	$	41,155		$	47,395		$	36,202
	_______________
	-1	The amortization of 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 intangible assets as of December 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)
	2015	$	27,848		$	2,530		$	13,896		$	8	$	(9,886	)	$	(101	)
	2016	25,051			1,503			10,922			8		(8,403		)	(101		)
	2017	22,128			1,241			9,281			8		(7,337		)	(101		)
	2018	18,580			831			6,373			8		(5,735		)	(101		)
	2019	14,227			643			4,714			8		(3,597		)	(101		)
	Thereafter	33,364			34			8,291			429		(2,473		)	(5,491		)
	Total	$	141,198		$	6,782		$	53,477		$	469	$	(37,431	)	$	(5,996	)
	_______________
	-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	12 Months Ended
	Dec. 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 December 31, 2014 and 2013:
		31-Dec-14			31-Dec-13
		(in thousands)
	Current receivables (1)	$	9,228		$	12,866
	Allowance for uncollectible tenant receivables (1)	(1,999		)	(2,123		)
	Current receivables, net (1)	$	7,229		$	10,743
	______________
	-1	Excludes current receivables, net related to real estate held for sale.
	Deferred Rent Receivables, net
	Deferred rent receivables, net consisted of the following as of December 31, 2014 and 2013:
		31-Dec-14			December 31, 2013
		(in thousands)
	Deferred rent receivables	$	158,405		$	129,198
	Allowance for deferred rent receivables	(1,989		)	(2,075		)
	Deferred rent receivables, net	$	156,416		$	127,123

Secured_and_Unsecured_Debt_of_

Secured and Unsecured Debt of the Company	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Secured and Unsecured Debt of the Company	Secured and Unsecured Debt of the Company
	In this Note 6, the “Company” refers solely to Kilroy Realty Corporation and not to any of our subsidiaries. The Company itself does not hold any indebtedness. All of our secured and unsecured debt is held directly by the Operating Partnership.
	The Company generally guarantees all the Operating Partnership’s unsecured debt obligations including the unsecured revolving credit facility, the $150.0 million unsecured term loan facility, the $39.0 million unsecured term loan, the 5.00% unsecured senior notes due 2015, the 4.80% unsecured senior notes due 2018, the 6.625% unsecured senior notes due 2020, the 3.80% unsecured senior notes due in 2023, and the 4.25% unsecured senior notes due in 2029. As of December 31, 2014 and 2013, the Operating Partnership had $1.9 billion and $1.6 billion, respectively, outstanding in total under these unsecured debt obligations.
	In addition, although the remaining $0.5 billion of the Operating Partnership’s debt as of December 31, 2014, and $0.6 billion as of December 31, 2013 is secured and non-recourse to the Company, the Company provides limited customary secured debt guarantees for items such as voluntary bankruptcy, fraud, misapplication of payments and environmental liabilities.
	Debt Covenants and Restrictions
	One of the covenants contained within the unsecured revolving credit facility, the unsecured term loan facility, and the unsecured term loan as discussed further below in Note 7 prohibits the Company from paying dividends in excess of 95% of funds from operations (“FFO”).

Secured_and_Unsecured_Debt_of_1

Secured and Unsecured Debt of the Operating Partnership	12 Months Ended
	Dec. 31, 2014
Debt Instrument [Line Items]
Secured and Unsecured Debt of the Operating Partnership	Secured and Unsecured Debt of the Company
	In this Note 6, the “Company” refers solely to Kilroy Realty Corporation and not to any of our subsidiaries. The Company itself does not hold any indebtedness. All of our secured and unsecured debt is held directly by the Operating Partnership.
	The Company generally guarantees all the Operating Partnership’s unsecured debt obligations including the unsecured revolving credit facility, the $150.0 million unsecured term loan facility, the $39.0 million unsecured term loan, the 5.00% unsecured senior notes due 2015, the 4.80% unsecured senior notes due 2018, the 6.625% unsecured senior notes due 2020, the 3.80% unsecured senior notes due in 2023, and the 4.25% unsecured senior notes due in 2029. As of December 31, 2014 and 2013, the Operating Partnership had $1.9 billion and $1.6 billion, respectively, outstanding in total under these unsecured debt obligations.
	In addition, although the remaining $0.5 billion of the Operating Partnership’s debt as of December 31, 2014, and $0.6 billion as of December 31, 2013 is secured and non-recourse to the Company, the Company provides limited customary secured debt guarantees for items such as voluntary bankruptcy, fraud, misapplication of payments and environmental liabilities.
	Debt Covenants and Restrictions
	One of the covenants contained within the unsecured revolving credit facility, the unsecured term loan facility, and the unsecured term loan as discussed further below in Note 7 prohibits the Company from paying dividends in excess of 95% of funds from operations (“FFO”).
Kilroy Realty, L.P. [Member]
Debt Instrument [Line Items]
Secured and Unsecured Debt of the Operating Partnership	Secured Debt
	The following table sets forth the composition of our secured debt as of December 31, 2014 and 2013:
		Annual Stated Interest Rate (1)		GAAP	Maturity Date		December 31,
	Type of Debt			Effective Rate (1)(2)			2014 (3)				2013 (3)
							(in thousands)
	Mortgage note payable	4.27%		4.27%	Feb-18		$	130,767			$	133,117
	Mortgage note payable	4.48%		4.48%	Jul-27		97,000				97,000
	Mortgage note payable (4)	6.05%		3.50%	Jun-19		89,242				92,502
	Mortgage note payable	6.51%		6.51%	Feb-17		66,647				67,663
	Mortgage note payable	5.23%		3.50%	Jan-16		52,793				54,570
	Mortgage note payable	5.57%		3.25%	Feb-16		40,258				41,654
	Mortgage note payable	5.09%		3.50%	Aug-15		34,311				34,845
	Mortgage note payable	4.94%		4.00%	Apr-15		26,285				27,641
	Mortgage note payable	7.15%		7.15%	May-17		6,568				8,972
	Other	Various		Various	Various		2,421				2,470
	Total						$	546,292			$	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 of $10.3 million and $14.6 million as of December 31, 2014 and 2013, respectively.
	-4	In January 2013, in connection with the acquisition of two office buildings in Seattle, Washington, we assumed a mortgage loan that is secured by the project. The loan requires monthly principal and interest payments based on a 6.4 year amortization period. As of December 31, 2014 and 2013, the mortgage loan had unamortized debt premiums of $8.0 million and $9.9 million, respectively.
	The Operating Partnership’s secured debt was collateralized by 31 and 21 operating properties as of December 31, 2014 and 2013, respectively, with a combined net book value of approximately $1.6 billion and $1.0 billion as of December 31, 2014 and 2013, respectively.
	Although our mortgage loans are secured and non-recourse to the Company and the Operating Partnership, the Company provides limited customary secured debt guarantees for items such as voluntary bankruptcy, fraud, misapplication of payments and environmental liabilities.
	As of December 31, 2014, nine of the Operating Partnership’s ten secured loans contained restrictions that would require the payment of prepayment penalties for the acceleration of outstanding debt. The mortgage notes payable are secured by deeds of trust on certain of our properties and the assignment of certain rents and leases associated with those properties.
	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”) as of December 31, 2014 and 2013. The Company repaid the 4.25% Exchangeable Notes in November 2014 upon maturity.
	4.25% Exchangeable Notes	December 31,
		2014			2013
		(in thousands)
	Principal amount	$	—		$	172,500
	Unamortized discount	—			(4,128		)
	Net carrying amount of liability component	$	—		$	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 (3)				4,800,796
	_______________
	-1	Interest on the 4.25% Exchangeable Notes was 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 conversation were subject to adjustment under certain circumstances including increases in our common dividends as of December 31, 2013.
	Prior to their maturity on November 15, 2014, the 4.25% Exchangeable Notes were exchangeable for shares of the Company's common stock only upon occurrence of certain events as follows: (i) during any calendar quarter, if 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 a specified period, (ii) during the five consecutive trading-day period following any five consecutive trading days in which the trading price per $1,000 principal amount of the Exchangeable Notes was less than 98% of the product of the closing sale price per share of the Company's common stock multiplied by the applicable exchange rate, (iii) if the Exchangeable Notes had been called for redemption, (iv) upon the occurrence of specified corporate transactions, (v) if the Company's common stock ceased to be listed or approved for quotation for 30 consecutive trading days, or (vi) on or after August 15, 2014. At any time prior to August 15, 2014, the Operating Partnership may have irrevocably elected, in its sole discretion without the consent of the holders of the 4.25% Exchangeable Notes, to settle all of the future exchange obligations of the 4.25% Exchangeable Notes in shares of common stock. Any shares of common stock delivered for settlement were based on a daily exchange value calculated on a proportionate basis for each day of a 30 day trading-day observation period.
	Upon exchange of the 4.25% Exchangeable Notes, the holders received (i) cash up to the principal amount of the 4.25% Exchangeable Notes and (ii) to the extent the exchange value exceeded the principal amount of the 4.25% Exchangeable Notes, shares of the Company’s common stock.
	In connection with the offerings of the 4.25% Exchangeable Notes, the Company entered into capped call option transactions (“capped calls”) to mitigate the dilutive impact of the potential conversion of the 4.25% Exchangeable Notes. The capped calls, as amended, were separate transactions entered into by us with the relevant financial institutions, were not part of the terms of the 4.25% Exchangeable Notes, and did not affect the holders’ rights under the 4.25% Exchangeable Notes. The strike prices of the capped calls, which were subject to customary anti-dilution adjustments, corresponded to the exchange prices of the applicable 4.25% Exchangeable Notes. The capped calls mitigated the dilutive impact to the Company of the potential exchange of all of the 4.25% Exchangeable Notes into shares of common stock. The capped calls for the 4.25% Exchangeable Notes were terminated when the notes were repaid in November 2014. As of December 31, 2013, the referenced shares of common stock under this transaction was 4,800,796 shares and the exchange price, including effect of capped calls was $42.81. The initial costs of capped calls were recorded as a reduction to additional paid-in capital.
	In the third quarter of 2014, we settled early exchanges of the 4.25% Exchangeable Notes with an aggregate principal amount of $37.0 million. For the exchange settlements, the Company paid the noteholders a total of $37.0 million in cash for the principal amount and issued to the noteholders a total of 431,270 shares of our common stock for the excess exchange value. As a result of the exchanges, the Company exercised the equivalent proportionate amount of its capped call options and, in connection received 111,206 shares of our common stock from the counterparties. This reduced the shares of common stock issued in connection with the exchanges to 320,064 shares.
	In November 2014, we repaid the remaining balance of the outstanding 4.25% Exchangeable Notes with an aggregate principal balance of $135.5 million. For the repayment settlement, the Company paid the noteholders a total of $135.5 million in cash for the principal amount and issued to the noteholders a total of 1,660,053 shares of our common stock for the excess exchange value. As a result of the exchanges, the Company exercised the equivalent proportionate amount of its capped call options and received 404,136 shares of our common stock from the counterparties thereby reducing the shares of common stock issued upon maturity to 1,255,917 shares. This reduced the shares of common stock issued in connection with the exchanges to 1,575,981 shares.
	For the 2014 period preceding maturity of the 4.25% Exchangeable Notes on November 15, 2014, and during the year ended December 31, 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 in the table below.
		Period Ended November 15, 2014(1)			Year Ended December 31, 2013
	Per share average trading price of the Company's common stock	$	60.04		$	52.12
	(1) Represents the maturity date of the 4.25% Exchangeable Notes.
	During the year ended December 31, 2013, the closing sales 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, the 4.25% Exchangeable Notes were changeable at the exchange rate stated above. No noteholders exchanged any of the 4.25% Exchangeable Notes in 2013.
	The approximate fair value of the shares exchangeable at December 31, 2013 using the per share average trading price of $52.12, would have been as follows
			Year Ended December 31, 2013
	Approximate fair value of shares upon conversion		$	247,000
	Principal amount of the 4.25% Exchangeable Notes		172,500
	Approximate fair value in excess amount of principal amount		$	74,500
	See Note 18 “Net Income Available to Common Stockholders Per Share of the Company” and Note 19 “Net Income Available to Common Unitholders Per Unit of the Operating Partnership” 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 4.25% Exchangeable Notes
	The unamortized discount on the 4.25% Exchangeable Notes, due in November 2014 and repaid upon maturity, and the 3.25% Exchangeable Notes, due in April 2012 and repaid upon maturity (together the “Exchangeable Notes”), were 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 Exchangeable Notes, in each case based on the respective effective interest rates, before the effect of capitalized interest, for the years ended December 31, 2014, 2013 and 2012:
		Year Ended December 31,
		2014			2013				2012
	(in thousands)
Contractual interest payments (1)	$	5,608		$	7,331			$	8,721
Amortization of discount (1)	3,769			4,427				5,052
Interest expense attributable to the Exchangeable Notes (1)	$	9,377		$	11,758			$	13,773
_______________
-1	The Company repaid the 3.25% Exchangeable Notes in April 2012. Interest payments and discount amortization for the years ended December 31, 2014 and 2013 were solely attributable to the 4.25% Exchangeable Notes.
Unsecured Senior Notes
In July 2014, the Operating Partnership issued $400.0 million aggregate principal amount of unsecured senior notes in a registered public offering. The outstanding balance of the unsecured senior notes is included in unsecured debt, net of issuance discount of $4.3 million, on our consolidated balance sheets. The unsecured senior notes, which are scheduled to mature on August 15, 2029, require semi-annual interest payments each February and August based on a stated annual interest rate of 4.250%. The Company used a portion of the net proceeds for general corporate purposes, including the repayment of borrowings under the Operating Partnership’s unsecured revolving credit facility.
The following table summarizes the balance and significant terms of the registered unsecured senior notes issued by the Operating Partnership as of December 31, 2014 and 2013:
								Principal Amount
								as of December 31,
	Issuance date		Maturity date	Stated		Effective interest rate (1)		2014				2013
				coupon rate
								(in thousands)
4.250% Unsecured Senior Notes (2)	Jul-14		Aug-29	4.25%		4.35%		$	400,000			$	—
Unamortized discount								(4,348		)		—
Net carrying amount								$	395,652			$	—
3.800% Unsecured Senior Notes (3)	Jan-13		Jan-23	3.80%		3.80%		$	300,000			$	300,000
Unamortized discount								(79		)		(90		)
Net carrying amount								$	299,921			$	299,910
4.800% Unsecured Senior Notes (4)	Jul-11		Jul-18	4.80%		4.83%		$	325,000			$	325,000
Unamortized discount								(265		)		(339		)
Net carrying amount								$	324,735			$	324,661
6.625% Unsecured Senior Notes (5)	May-10		Jun-20	6.63%		6.74%		$	250,000			$	250,000
Unamortized discount								(1,154		)		(1,367		)
Net carrying amount								$	248,846			$	248,633
5.000% Unsecured Senior Notes (6)	Nov-10		Nov-15	5.00%		5.01%		$	325,000			$	325,000
Unamortized discount								(33		)		(73		)
Net carrying amount								$	324,967			$	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 4.250% unsecured senior notes is payable semi-annually in arrears on February 15th and August 15th of each year.
-3	Interest on the 3.800% unsecured senior notes is payable semi-annually in arrears on January 15th and July 15th of each year.
-4	Interest on the 4.800% unsecured senior notes is payable semi-annually in arrears on January 15th and July 15th of each year.
-5	Interest on the 6.625% unsecured senior notes is payable semi-annually in arrears on June 1st and December 1st of each year.
-6	Interest on the 5.000% unsecured senior notes is payable semi-annually in arrears on May 3rd and November 3rd of each year.
In August 2014, upon maturity, we repaid our outstanding Series B unsecured senior notes which had an aggregate principal balance of $83.0 million and effective interest rate of 6.45% as of December 31, 2013.
Unsecured Revolving Credit Facility and Unsecured Term Loan Facility
In the second quarter of 2014, the Company amended the terms of our unsecured revolving credit facility and the Company’s $150.0 million unsecured term loan facility. The amendment increased the size of the Company’s unsecured line of credit to $600.0 million, extended the maturity to July 2019 on both the unsecured revolving credit facility and unsecured term loan facility, reduced the annual interest rate on the unsecured revolving credit facility to LIBOR plus 1.250% and reduced the annual interest rate on the unsecured term loan facility to LIBOR plus 1.40%. The amendment did not affect the outstanding borrowings under the credit facility.
The following table summarizes the balance and terms of our unsecured revolving credit facility as of December 31, 2014 and December 31, 2013:
	December 31, 2014			December 31, 2013
	(in thousands)
Outstanding borrowings	$	140,000		$	45,000
Remaining borrowing capacity	460,000			455,000
Total borrowing capacity (1)	$	600,000		$	500,000
Interest rate (2)(3)	1.41		%	1.62		%
Facility fee-annual rate (4)	0.25%			0.30%
Maturity date	Jul-19			Apr-17
_______________
-1	We may elect to borrow, subject to bank approval and obtaining commitments for any additional borrowing capacity, up to an additional $311.0 million under an accordion feature under the terms of the unsecured revolving credit facility and unsecured term loan facility.
-2	Our unsecured revolving credit facility interest rate was calculated based on an annual rate of LIBOR plus 1.250% as of December 31, 2014.
-3	Our unsecured revolving credit facility interest rate was calculated based on an annual rate of LIBOR plus 1.450% as of December 31, 2013.
-4	Our facility fee is paid on a quarterly basis and is calculated based on the total borrowing capacity. In addition to the facility fee, we incurred debt origination and legal costs. As of December 31, 2014, $5.9 million of deferred financing costs remains to be amortized through the amended maturity date of our unsecured revolving credit facility.
The Company intends to borrow amounts under the unsecured 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.
The following table summarizes the balance and terms of our term loan facility, which is included in our unsecured debt, as of December 31, 2014 and December 31, 2013:
	December 31, 2014			December 31, 2013
	(in thousands)
Outstanding borrowings	$	150,000		$	150,000
Interest rate (1)(2)	1.56		%	1.92		%
Maturity date	Jul-19			Mar-16
_______________
-1	Our unsecured term loan facility interest rate was calculated based on an annual rate of LIBOR plus 1.40% as of December 31, 2014.
-2	Our unsecured term loan facility interest rate was calculated based on an annual rate of LIBOR plus 1.75% as of December 31, 2013.
Additionally, in October 2014, the Company drew down on a $39.0 million unsecured term loan with an annual interest rate of LIBOR plus 1.40% that matures in July 2019.
Debt Covenants and Restrictions
The unsecured revolving credit facility, the unsecured term loan facility, the unsecured term loan, 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 principal balance of the associated debt becoming immediately due and payable. We believe we were in compliance with all of our debt covenants as of December 31, 2014 and 2013.
Debt Maturities
The following table summarizes the stated debt maturities and scheduled amortization payments, excluding debt discounts and premiums, as of December 31, 2014:
Year	(in thousands)
2015	$	395,103
2016	99,431
2017	71,748
2018	451,728
2019	405,369
Thereafter	1,041,643
Total (1)	$	2,465,022
________________________
-1	Includes gross principal balance of outstanding debt before impact of net unamortized premiums totaling approximately $4.4 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 years ended December 31, 2014, 2013 and 2012. The interest expense capitalized was recorded as a cost of development and redevelopment, and increased the carrying value of undeveloped land and construction in progress.
	Year Ended December 31,
	2014			2013				2012
	(in thousands)
Gross interest expense	$	114,661		$	111,238			$	98,906
Capitalized interest	(47,090		)	(35,368		)		(19,792		)
Interest expense	$	67,571		$	75,870			$	79,114

Deferred_Revenue_and_Acquisiti

Deferred Revenue and Acquisition Related Liabilities, net	12 Months Ended
	Dec. 31, 2014
Deferred Revenue Disclosure [Abstract]
Deferred Revenue and Acquisition Related Liabilities, net	Deferred Revenue and Acquisition Related Liabilities, net
	Deferred revenue and acquisition-related liabilities, net consists of the following at December 31, 2014 and 2013:
		December 31,
		2014		2013
		(in thousands)
	Deferred revenue related to tenant-funded tenant improvements (1)	$	85,757	$	48,341
	Other deferred revenue	3,055		3,169
	Acquisition-related intangible liabilities, net (2)	43,427		49,776
	Total	$	132,239	$	101,286
	________________________
	-1	Excludes deferred revenue related to tenant-funded tenant improvements related to properties held for sale at December 31, 2013.
	-2	See Note 2 “Basis of Presentation and Significant Accounting Policies” and Note 4 “Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, net” for additional information.
	Deferred Revenue Related to Tenant-funded Tenant Improvements
	During the years ended December 31, 2014, 2013, and 2012, $11.0 million, $10.7 million and $9.1 million, respectively, of deferred revenue related to tenant-funded tenant improvements (including discontinued operations) was amortized and recognized as rental income. The following is the estimated amortization of deferred revenue related to tenant-funded tenant improvements as of December 31, 2014 for the next five years and thereafter:
	Year Ending	(in thousands)
	2015	$	12,402
	2016	11,955
	2017	10,802
	2018	9,177
	2019	7,780
	Thereafter	33,641
	Total	$	85,757

Noncontrolling_Interests_on_th

Noncontrolling Interests on the Company's Consolidated Financial Statements	12 Months Ended
	Dec. 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 98.0% and 97.8% common general partnership interest in the Operating Partnership as of December 31, 2014 and 2013, respectively. The remaining 2.0% and 2.2% common limited partnership interest as of December 31, 2014 and 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 and 1,805,200 common units outstanding held by these investors, executive officers and directors as of December 31, 2014 and 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 $0.01 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 $126.8 million and $90.8 million as of December 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 Subsidiary
	The noncontrolling interest in consolidated subsidiary represents the third party equity interest in Redwood City Partners, LLC (see Note 3 “Acquisitions”). This noncontrolling interest was $5.9 million and $4.9 million at December 31, 2014 and December 31, 2013, respectively.
	2012 Redemption of 7.45% Series A Cumulative Redeemable Preferred Units of the Operating Partnership
	On August 15, 2012 (the “Series A Redemption Date”), the Operating Partnership redeemed all 1,500,000 outstanding 7.45% Series A Cumulative Redeemable Preferred Units representing preferred limited partnership interests in the Operating Partnership (“Series A Preferred Units”). On the Series A Redemption Date, the Series A Preferred Units were redeemed at a redemption price equal to $50.00 per unit, representing $75.0 million in aggregate, plus all accrued and unpaid distributions to the Series A Redemption Date. During the year ended December 31, 2012, we recognized a non-recurring noncash charge of $2.1 million as a reduction to net income available to common stockholders for the original issuance costs related to the Series A Preferred Units.

Stockholders_Equity_of_the_Com

Stockholders' Equity of the Company	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Stockholders' Equity of the Company	Stockholders’ Equity of the Company
	Common Stock
	Issuance of Common Stock
	In October 2014, the Company issued 351,476 shares of the its common stock valued at approximately $21.6 million to partially fund a development acquisition (see Note 3 “Acquisitions” for additional information).
	In September 2013, the Company completed an underwritten public offering of 6,175,000 shares of its common stock. The net offering proceeds, after deducting sales agent compensation and offering expenses, were approximately $295.9 million. We used a portion of the net proceeds from the offering to fund acquisitions, repay borrowings under the unsecured revolving credit facility, and for general corporate purposes.
	In August 2012, the Company completed an underwritten public offering of 5,750,000 shares of its common stock. The net offering proceeds, after deducting sales agent compensation and offering expenses, were approximately $253.8 million. We used a portion of the net proceeds from the offering to fund acquisitions, repay borrowings under the unsecured revolving credit facility, and for general corporate purposes.
	In February 2012, the Company completed an underwritten public offering of 9,487,500 shares of its common stock. The net offering proceeds, after deducting sales agent compensation and offering expenses, were approximately $382.1 million. We used a portion of the net proceeds from the offering to fund acquisitions, repay borrowings under the unsecured revolving credit facility, and for general corporate purposes.
	At-The-Market Stock Offering Programs
	Under our at-the-market stock offering programs, which commenced in July 2011 and December 2014, we may offer and sell shares of our common stock from time to time in “at-the-market” offerings. During the year ended December 31, 2014, the Company completed it's existing at-the-market stock offering program (the “July 2011 At-The-Market Program”) under which we sold an aggregate of $200.0 million in gross sales of shares, and in December 2014 commenced a new at-the-market stock offering program (the “December 2014 At-The-Market Program”) under which we may offer to sell shares of our common stock with an aggregate gross sales price of up $300.0 million.
	The following table sets forth information regarding sales of our common stock under our at-the-market offering programs for the years ended December 31, 2014, 2013 and 2012:
		Year Ended December 31,
		2014			2013		2012
		(in millions, except share data)
	Shares of common stock sold during the period	1,599,123			1,040,838		787,118
	Aggregate gross proceeds	$	104.7		$	55.3	$	37
	Aggregate net proceeds after sales agent compensation	$	103.1		$	54.4	$	36.3
	The proceeds from sales were used to fund acquisitions, development expenditures and general corporate purposes including repayment of borrowings under the unsecured revolving credit facility. During the year ended December 31, 2014, under the July 2011 At-The-Market Program, we sold 1,457,623 shares of common stock and completed the program. Since commencement of the December 2014 At-The-Market Program, as of December 31, 2014, we sold 141,500 shares of common stock and approximately $290.0 million remains 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 the December 2014 At-The-Market program.
	Share Repurchases
	An aggregate of 988,025 shares currently remain eligible for repurchase under a share-repurchase program approved by the Company’s board of directors in prior periods. The Company did not repurchase shares of common stock under this program during the years ended December 31, 2014, 2013 or 2012.
	Accrued Dividends and Distributions
	The following tables summarize accrued dividends and distributions for the noted outstanding shares of common stock, preferred stock, and noncontrolling units as of December 31, 2014 and 2013:
		December 31,
		2014			2013
		(in thousands)
	Dividends and Distributions payable to:
	Common stockholders	$	30,191		$	28,754
	Noncontrolling common unitholders of the Operating Partnership	631			632
	RSU holders (1)	421			405
	Total accrued dividends and distribution to common stockholders and noncontrolling unitholders	31,243			29,791
	Preferred stockholders	1,656			1,699
	Total accrued dividends and distributions	$	32,899		$	31,490
	______________________
	-1	The amount includes the value of the dividend equivalents that will be paid with additional fully-vested RSUs (see Note 12 “Share-Based Compensation” for additional information).
		December 31,
		2014		2013
	Outstanding Shares and Units:
	Common stock (1)	86,259,684		82,153,944
	Noncontrolling common units	1,804,200		1,805,200
	RSUs (2)	1,248,352		1,158,407
	Series G Preferred stock	4,000,000		4,000,000
	Series H Preferred stock	4,000,000		4,000,000
	______________________
	-1	The amount includes nonvested shares.
	-2	The amount includes nonvested RSUs. Does not include the 247,089 and 143,022 market measure-based RSUs since not all the necessary performance conditions have been met as of December 31, 2014 and 2013, respectively.
	2012 Redemption of 7.80% Series E and 7.50% Series F Cumulative Redeemable Preferred Stock
	On April 16, 2012, the Company redeemed all 1,610,000 outstanding shares of its 7.80% Series E Preferred Stock and all 3,450,000 outstanding shares of its 7.50% Series F Preferred Stock. As a result, for the year ended December 31, 2012, we recognized a non-recurring noncash charge of $4.9 million as a reduction to net income available to common stockholders for the original issuance costs related to the Redeemed Preferred Stock.

Preferred_and_Common_Units_of_

Preferred and Common Units of the Operating Partnership	12 Months Ended
	Dec. 31, 2014
Partners' Capital [Abstract]
Preferred and Common Units of the Operating Partnership	Preferred and Common Units of the Operating Partnership
	Common Units
	Issuance of Common Units
	In October 2014, the Company issued 351,476 shares of its common stock to partially fund $21.6 million of a development acquisition (see Note 10 “Stockholders’ Equity of the Company” for additional information). The development acquisition property was contributed by the Company to the Operation Partnership in exchange for 351,476 common units.
	In September 2013, the Company completed an underwritten public offering of 6,175,000 shares of its common stock (see Note 10 “Stockholders’ Equity of the Company” for additional information). The net offering proceeds of approximately $295.9 million were contributed by the Company to the Operating Partnership in exchange for 6,175,000 common units.
	In August 2012, the Company completed an underwritten public offering of 5,750,000 shares of its common stock (see Note 10 “Stockholders’ Equity of the Company” for additional information). The net offering proceeds of approximately $253.8 million were contributed by the Company to the Operating Partnership in exchange for 5,750,000 common units.
	In July 2012, the Company issued 118,372 common units in connection with an operating property acquisition (see Note 3 “Acquisitions” for additional information). Each unit was valued at $47.34, which was the Company’s closing stock price on the NYSE on the acquisition date.
	In February 2012, the Company completed an underwritten public offering of 9,487,500 shares of its common stock (see Note 10 “Stockholders’ Equity of the Company” for additional information). The net offering proceeds of approximately $382.1 million were contributed by the Company to the Operating Partnership in exchange for 9,487,500 common units.
	At-The-Market Stock Offering Program
	During the years ended December 31, 2014, 2013 and 2012, the Company utilized its at-the-market stock offering programs to issue shares of common stock (see Note 10 “Stockholders’ Equity of the Company” for additional information). The net offering proceeds and property acquired using net offering proceeds were contributed by the Company to the Operating Partnership in exchange for common units for the years ended December 31, 2014, 2013 and 2012 are as follows:
		Year Ended December 31,
		2014			2013		2012
		(in millions, except share and per share data)
	Shares of common stock contributed by the Company	1,599,123			1,040,838		787,118
	Common units exchanged for share of common stock by the Company	1,599,123			1,040,838		787,118
	Aggregate gross proceeds	$	104.7		$	55.3	$	37
	Aggregate net proceeds after sales agent compensation	$	103.1		$	54.4	$	36.3
	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:
		December 31, 2014		December 31, 2013
	Company owned common units in the Operating Partnership	86,259,684		82,153,944
	Company owned general partnership interest	98	%	97.8	%
	Noncontrolling common units of the Operating Partnership	1,804,200		1,805,200
	Ownership interest of noncontrolling interest	2	%	2.2	%
	For a further discussion of the noncontrolling common units during the years ended December 31, 2014 and 2013, refer to Note 9 “Noncontrolling Interests on the Company’s Consolidated Financial Statements”.
	Accrued Distributions
	The following tables summarize accrued distributions for the noted common and preferred units as of December 31, 2014 and 2013:
		December 31, 2014			December 31, 2013
		(in thousands)
	Distributions payable to:
	General partner	$	30,191		$	28,754
	Common limited partners	631			632
	RSU holders (1)	421			405
	Total accrued distributions to common unitholders	31,243			29,791
	Preferred unitholders	1,656			1,699
	Total accrued distributions	$	32,899		$	31,490
	______________________
	-1	The amount includes the value of the dividend equivalents that will be paid with additional fully-vested RSUs (see Note 12 “Share-Based Compensation” for additional information).
		December 31, 2014		December 31, 2013
	Outstanding Units:
	Common units held by the general partner	86,259,684		82,153,944
	Common units held by the limited partners	1,804,200		1,805,200
	RSUs (1)	1,248,352		1,158,407
	Series G Preferred units	4,000,000		4,000,000
	Series H Preferred units	4,000,000		4,000,000
	______________________
	-1	Does not include the 247,089 and 143,022 market measure-based RSUs since not all the necessary performance conditions have been met as of December 31, 2014 and 2013, respectively.
	2012 Redemption of 7.80% Series E and 7.50% Series F Cumulative Redeemable Preferred Units
	On April 16, 2012, the Company redeemed all 1,610,000 outstanding units of its 7.80% Series E Cumulative Redeemable Preferred Units and all 3,450,000 outstanding units of its 7.50% Series F Cumulative Redeemable Preferred Units. As a result, for the year ended December 31, 2012, we recognized a non-recurring noncash charge of $4.9 million as a reduction to net income available to common stockholders for the original issuance costs related to the Redeemed Preferred Units.

ShareBased_Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	Share-Based Compensation
	Stockholder Approved Equity Compensation Plans
	As of December 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 new award grants under the 2006 Plan. At our annual meeting of stockholders, on May 22, 2014, stockholders approved an amendment and restatement of the 2006 Plan, which included an increase in the maximum number of shares that may be issued or awarded under the 2006 Plan to 7,120,000 shares. As of December 31, 2014, 681,626 shares were available for grant under the 2006 Plan.
	The Executive Compensation Committee, which is comprised of two independent directors, may grant the following share-based awards as provided under the 2006 Plan: incentive stock options, nonqualified stock options, restricted stock (nonvested shares), stock appreciation rights, performance shares, performance stock units, dividend equivalents, stock payments, deferred stock, restricted stock units (“RSUs”), profit interest units, performance bonus awards, performance-based awards and other incentive awards to eligible individuals. For each award granted under our share-based incentive compensation programs, the Operating Partnership simultaneously issues to the Company a number of common units equal to the number of shares of common stock ultimately paid by the Company in respect of such awards.
	All of our outstanding share-based awards issued prior to 2007 were issued under the 1997 Stock Option and Incentive Plan (the “1997 Plan”), which was terminated by our board of directors in September 2006. Any awards that were outstanding upon the termination of the 1997 Plan continued in effect in accordance with the terms of such plan and the applicable award agreement following termination of the 1997 Plan.
	Stock Award Deferral Program
	We have a Stock Award Deferral Program (the “RSU Program”) under the 2006 Plan. Under the RSU Program, participants may defer receipt of awards of nonvested shares that may be granted by electing to receive an equivalent number of RSUs in lieu of such nonvested shares. Each RSU represents the right to receive one share of our common stock in the future and is subject to the same vesting conditions that would have applied if the award had been issued in nonvested shares. RSUs carry with them the right to receive dividend equivalents such that participants receive additional RSUs at the time dividends are paid equal to the value of the dividend earned on the shares underlying the participant’s RSUs. The dividend equivalents earned vest based on terms specified under the related RSU award agreement. Shares issued upon settlement of vested RSUs including RSUs paid on dividend equivalents are distributed in a single lump sum distribution upon the earlier of (1) the date specified by the participant when the election is made or (2) occurrence of certain other events specified under the RSU program.
	Share-Based Compensation Programs
	The Executive Compensation Committee has historically awarded nonvested shares and RSUs under the following share-based compensation programs. These share-based awards were valued based on the quoted closing share price of the Company’s common stock on the NYSE on the applicable grant date. Prior to 2014, the Executive Compensation Committee awarded annual long-term equity awards based primarily on the prior year’s performance, however, starting in January 2014, such annual awards have been granted as an incentive for the year in which the awards were granted and subsequent years.
	Executive Officer Share-Based Compensation Programs
	The Executive Compensation Committee has annually approved compensation programs that include the potential issuance of share-based awards to our Chief Executive Officer and all other executive officers (the “Executive Officers”) as part of their annual and long-term incentive compensation. The share-based awards are generally issued in the first quarter after the end of our prior fiscal year. The share-based awards generally have a service vesting period, which has historically ranged from one to five years, depending on the type of award.
	2014 Share-Based Compensation Grants
	On January 29, 2014 (the “2014 RSU Grant Date”), the Executive Compensation Committee of the Company’s Board of Directors awarded 236,604 RSUs to certain officers of the Company under the 2006 Plan, which included 119,098 RSUs that are subject to time-based, market and performance-based vesting requirements (each a “2014 Performance-Based RSU” and collectively, the “2014 Performance-Based RSU Grant”) and 117,506 RSUs that are subject to time-based vesting requirements (each a “2014 Time-Based RSU” and collectively, the “2014 Time-Based RSU Grant”). As of the 2014 RSU Grant Date, an insufficient number of shares were available under the 2006 Plan to settle these RSUs in stock and the RSUs were subject to liability accounting. As discussed above, on May 22, 2014 we received stockholder approval for an increase in the maximum number of shares that may be issued or awarded under the 2006 Plan, which resulted in a sufficient number of shares available for issuance to cover settlement of these RSU awards. As a result, as of May 22, 2014 we reclassified these awards as equity awards and re-measured the fair value of the awards as of that date.
	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-defined FFO per share goals (the “performance condition”) for the year ended December 31, 2014 and upon the average annual relative total stockholder return versus the SNL US REIT Office Index (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, subject to the Executive Compensation Committee's determination that the performance conditions and market conditions have been achieved. The number of 2014 Performance-Based RSUs ultimately earned, and therefore the compensation costs for these awards, can fluctuate from the 119,098 RSUs granted based upon the levels of achievement for both the FFO per share and relative total stockholder return metrics. During the 2014 performance period, the estimate of the number of RSUs earned were evaluated quarterly based on our forecasted level of achievement of the FFO per share hurdle. As of December 31, 2014, the FFO per share hurdle performance condition was achieved at 1.5x target. As a result, the number of RSUs earned was adjusted to 178,650 RSUs to reflect the achievement of this metric.
	Each 2014 Performance-Based RSU represents the right to receive one share of our common stock in the future, subject to, and as modified by, the Company's level of achievement of the market condition. As of March 31, 2014, we recorded compensation expense for the award based upon the fair value at period end of $63.44, as we had an insufficient number of shares available for issuance under the 2006 Plan at that time. As discussed above, upon stockholder approval of the amended 2006 Plan on May 22, 2014, we were required to re-measure the fair value of the 2014 Performance-Based RSU Grant and record compensation expense based on the fair value at that date for the cumulative portion of the performance period that had elapsed. The total fair value of the 2014 Performance-Based RSU Grant was $7.7 million at May 22, 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 year ended December 31, 2014, we recorded compensation expense based upon the $65.03 fair value per share at May 22, 2014 multiplied by the 178,650 RSUs banked at December 31, 2014. Compensation expense for the 2014 Performance-Based RSU Grant will be recorded on a straight-line basis over the three-year period. The following table summarizes the assumptions utilized in the Monte Carlo simulation pricing model:
		Fair Value Assumptions
	Fair value per share at May 22, 2014	$65.03
	Expected share price volatility	24.00%
	Risk-free interest rate	0.61%
	Remaining expected life	2.6
	The computation of expected volatility is based on a blend of the historical volatility of our shares of common stock over approximately five years as that is expected to be most consistent with future volatility and equates to a time period twice as long as the approximate two and a half year remaining 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 May 22, 2014. The expected dividend yield is estimated by examining the average of the historical dividend yield levels over the remaining 2.6 year term of the RSUs and our current annualized dividend yield as of May 22, 2014. The expected life of the RSUs is equal to the remaining 2.6 year vesting period at May 22, 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 continued service vesting period. Each 2014 Time-Based RSUs represents the right to receive one share of our common stock in the future, subject to continued employment through the applicable vesting date. As of March 31, 2014, we recorded compensation expense for the award based upon the fair value at period end of $51.64, because at that time an insufficient number of shares were available for issuance under the 2006 Plan. As discussed above, upon stockholder approval of the amended 2006 Plan on May 22, 2014, we were required to re-measure the fair value of the 2014 Time-Based RSU Grant and record compensation expense based on the fair value at that date, for the cumulative portion of the performance period that had elapsed. The total fair value was $7.1 million, which was based on the $60.16 closing share price of the Company’s common stock on the NYSE on May 22, 2014.
	2013 Share-Based Compensation Grants
	On January 10, 2013, the Executive Compensation Committee of the Company’s Board of Directors granted 157,744 RSUs to certain officers of the Company. On April 4, 2013, the terms of 61,327 time-based RSUs were modified to include market and performance-based vesting requirements based on total shareholder return and FFO per share targets. The RSUs will vest in five equal annual installments over the five-years requisite service period and were based on the achievement of the Company's relative total shareholder return and/or FFO performance measured during the period beginning on January 1, 2013 and ending on December 31, 2013. As of December 31, 2013, the Company had achieved the relative total shareholder return market metrics and FFO per share performance metrics, and the RSUs are now only subject to time-based vesting requirements. The Company’s closing stock price on the date of modification was $53.05. The compensation expense related to the modified RSUs will be recognized using the accelerated attribution expense method through the remainder of the five-year requisite service period.
	On April 4, 2013, the Executive Compensation Committee of the Company’s Board of Directors granted 19,084 RSUs to the Company’s Chief Operating Officer as part of his modified employment agreement. Fifty-percent of the RSUs granted are scheduled to vest in six equal annual installments beginning on December 31, 2013 through December 31, 2018. The grant date fair value of these time-based RSUs was $0.5 million, which was based on the $53.05 closing share price of the Company’s common stock on the New York Stock Exchange on the grant date. Compensation expense will be recognized on a straight-line basis over the service vesting period for these time-based RSUs. The remaining 50% of the RSUs granted are scheduled to vest in six equal annual installments for each calendar year during 2013 through 2018 based on the achievement of certain absolute or relative total shareholder return goals measured annually or, if neither of the shareholder return hurdles are achieved for an applicable year during the performance period, those RSUs will remain eligible to vest in a subsequent year (ending in 2018) based on the achievement of a cumulative total shareholder return goal. The grant date fair value of these market measure-based RSUs was $0.4 million and was calculated using a Monte Carlo simulation pricing model based on the assumptions in the table below. The grant date fair value is allocated among each of the six annual vesting tranches for these market measure-based RSUs and compensation expense will be recognized over the service vesting period using the accelerated expense attribution method.
	The computation of expected volatility is based on a blend of the historical volatility of our shares of common stock over 12 years as that is expected to be most consistent with future volatility and equates to a time period twice as long as the six-year term 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 the grant date. The expected dividend yield is estimated by examining the average of the historical dividend yield levels over the six-year term of the RSUs and our current annualized dividend yield as of the grant date. The expected life of the RSUs is equal to the six-year vesting period.
		April 2013 Market-Measure based RSU Grant
	Grant date fair value per share	$44.55
	Expected share price volatility	27.00%
	Risk-free interest rate	0.90%
	Dividend yield	3.60%
	Expected life	6 years
	Key Employee Share-Based Compensation Program
	The Executive Compensation Committee has historically awarded nonvested shares or nonvested RSUs to other key employees on an annual basis as part of their long-term incentive compensation. The share-based awards are generally issued in the first quarter, and the individual share awards generally vest in equal annual installments over the applicable service vesting period, which has historically ranged from two to five years.
	Non-Employee Board Members Share-Based Compensation Program
	The Board of Directors awards nonvested shares or nonvested RSUs to non-employee board members on an annual basis as part of such board members’ annual compensation and to newly elected non-employee board members in accordance with our board of directors compensation program. The share-based awards are generally issued in the second quarter, and the individual share awards vest in equal annual installments over the applicable service vesting period, which will be one year.
	Summary of Market-Measure Based RSUs
	A summary of our market-measure based RSU activity from January 1, 2014 through December 31, 2014 is presented below:
		Nonvested RSUs				Vested RSUs		Total RSUs
		Amount		Weighted-Average
				Fair Value
				Per Share (1)
	Outstanding at January 1, 2014	143,022		$	46.47	—		143,022
	Granted (2)	183,365		64.86		—		183,365
	Vested (3)	(16,338	)	41.53		16,338		—
	Settled (4)					(16,338	)	(16,338	)
	Transferred to time-based restricted stock units (5)	(31,455	)	53.05		—		(31,455	)
	Transferred to restricted stock (6)	(31,505	)	53.05		—		(31,505	)
	Outstanding as of December 31, 2014	247,089		$	58.77	—		247,089
	_______________
	-1	Represents the grant-date fair value for all awards excluding the 2014 Performance-Based RSU Grant. As discussed above, the 2014 Performance-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.
	-2	Includes dividend equivalents issued in accordance with the award agreements.
	-3	Includes dividend equivalents vested in accordance with the award agreements.
	-4	Represents vested RSUs that were settled in cash or shares of the Company’s common stock. Total shares settled include 8,526 shares that were tendered in accordance with the terms of the 2006 Plan to satisfy minimum statutory tax withholding requirements related to the RSUs settled. We accept the return of RSUs, at the current quoted closing share price of the Company’s common stock to satisfy tax obligations.
	-5	On January 29, 2014, the market-measure requirements related to the RSU awards granted in 2013 were met, and as a result, the shares were transferred to time-based restricted stock units since at that point the awards became subject to only time-based vesting requirements pursuant to the award agreements.
	-6	On January 29, 2014, the market-measure requirements related to the RSU award were met and, as a result, the RSUs were transferred to restricted stock based on the employee’s distribution election and remain subject to time-based vesting requirements pursuant to the award agreement.
	A summary of our market-measure based RSU activity for years ended December 31, 2014, 2013 and 2012 is presented below:
		RSUs Granted				RSUs Vested
	Years ended December 31,	Non-Vested		Weighted-Average		Vested RSUs		Total Vest-Date Fair Value
		RSUs Granted		Fair Value				(in thousands)
				Per Share (1)
	2014	183,365		$	64.86	(16,338	)	$	1,092
2013	9,542		44.55		(16,338	)	811
2012	103,239		41.2		(14,748	)	695
_______________
-1	Represents the grant-date fair value for all awards excluding the 2014 Performance-Based RSU Grant. As discussed above, the 2014 Performance-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.
Summary of Time-Based RSUs
A summary of our time-based RSU activity from January 1, 2014 through December 31, 2014 is presented below:
	Nonvested RSUs				Vested RSUs		Total RSUs
	Amount		Weighted Average Fair Value
			Per Share (1)
Outstanding at January 1, 2014	301,660		$	44.74	856,747		1,158,407
Granted (2)	155,016		59.89		—		155,016
Vested (3)(4)	(116,447	)	47.64		116,447		—
Settled					(61,242	)	(61,242	)
Canceled (5)					(3,992	)	(3,992	)
Transferred from market-measure based (6)	31,455		53.05				31,455
Transferred to restricted stock (7)	(30,687	)	48.88		(605	)	(31,292	)
Outstanding as of December 31, 2014	340,997		$	51.04	907,355		1,248,352
_______________
-1	Represents the grant-date fair value for all awards excluding the 2014 Time-Based RSU Grant. As discussed above, the 2014 Time-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.
-2	Includes dividend equivalents issued in accordance with the award agreements.
-3	Includes dividend equivalents vested in accordance with the award agreements.
-4	Represents vested RSUs that were settled in shares of the Company’s common stock. Total shares settled include 5,694 shares that were tendered in accordance with the terms of the 2006 Plan to satisfy minimum statutory tax withholding requirements related to the RSUs settled. We accept the return of RSUs at the current quoted closing share price of the Company’s common stock to satisfy tax obligations.
-5	For shares vested but not yet settled, we accept the return of RSUs at the current quoted closing share price of the Company’s common stock to satisfy minimum statutory tax-withholding requirements related to either the issuance or vesting of RSUs in accordance with the terms of the 2006 Plan.
-6	On January 29, 2014, the market-measure requirements related to the RSU awards granted in 2013 were met. As of December 31, 2014 the awards are only subject to time-based vesting requirements.
-7	During January 2014, RSUs were transferred to restricted stock based on the elected distribution date.
A summary of our time-based RSU activity for the years ended December 31, 2014, 2013 and 2012 is presented below:
	RSUs Granted				RSUs Vested
Year ended December 31,	Non-Vested		Weighted-Average Grant Date		Vested RSUs		Total Vest-Date Fair Value (1)
	RSUs Issued		Fair Value				(in thousands)
			Per Share
2014	155,016		$	59.89	(116,447	)	$	6,675
2013	173,758		49.45		(89,873	)	4,495
2012	204,829		44.34		(73,688	)	3,118
_______________
-1	Total fair value of RSUs vested was calculated based on the quoted closing share price of the Company’s common stock on the NYSE on the day of vesting.
Summary of Nonvested Restricted Stock
A summary of our nonvested restricted stock activity from January 1, 2014 through December 31, 2014 is presented below:
	Non-Vested		Weighted-Average
	Restricted Stock		Grant Date
			Fair Value
			Per Share
Outstanding at January 1, 2014	47,950		$	41.71
Granted (1)	213		51.35
Vested (2)(3)	(25,899	)	45.56
Transferred from market-measure and time-based RSUs	62,797		50.97
Outstanding as of December 31, 2014	85,061		$	47.05
_______________
-1	Includes dividend equivalents issued in accordance with the award agreements.
-2	Includes dividend equivalents vested in accordance with the award agreements.
-3	The total shares vested include 11,020 shares that were tendered in accordance with the terms of the 2006 Plan to satisfy minimum statutory tax withholding requirements related to the restricted shares that have vested. We accept the return of shares at the current quoted closing share price of the Company’s common stock to satisfy tax obligations.
A summary of our nonvested and vested restricted stock activity for years ended December 31, 2014, 2013 and 2012 is presented below:
	Shares Granted				Shares Vested
Years ended December 31,	Non-Vested		Weighted-Average Grant Date		Vested Shares		Total Fair Value at Vest Date(1)
	Shares Issued		Fair Value				(in thousands)
			Per Share
2014	213		$	51.35	(25,899	)	$	1,323
2013	—		—		(47,291	)	2,290
2012	62,137		41.84		(50,862	)	2,110
_______________
-1	Total fair value of shares vested was calculated based on the quoted closing share price of the Company’s common stock on the NYSE on the date of vesting.
Summary of Stock Options
On February 22, 2012, the Executive Compensation Committee of the Company granted non-qualified stock options to certain key members of our senior management team, including our Executive Officers, to purchase an aggregate 1,550,000 shares of the Company’s common stock (the “February 2012” grant) at an exercise price per share equal to $42.61, the closing price of the Company’s common stock on the grant date. The options will vest ratably in annual installments over a five year period, subject to continued employment through the applicable vesting date. The term of each option is ten years from the date of the grant. Dividends will not be paid on vested or unvested options. The options were granted pursuant to the 2006 Plan.
The fair value of each stock option granted is estimated on the date of grant using the Black-Scholes option pricing model based on the following assumptions for the February 2012 grant.
	February 2012 Option Grant
Fair value of options granted per share	$9.20
Expected stock price volatility	33.00%
Risk-free interest rate	1.35%
Dividend yield	3.80%
Expected life of option	6.5 years
The computation of expected volatility is based on a blend of the historical volatility of our shares of common stock over a time period longer than the expected life of the option 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 the grant date. The expected dividend yield is estimated by examining the average of the historical dividend yield levels over the expected life of the option and the current dividend yield as of the grant date. The expected life of the options is calculated as the average of the vesting term and the contractual term. During the year ended December 31, 2014, 304,000 stock options vested with a total fair value of $2.8 million. During the year ended December 31, 2013, 308,000 stock options vested with a total fair value of $2.8 million. No stock options related to the February 2012 grant vested during the year ended December 31, 2012.
A summary of our stock option activity related the February 2012 grant through December 31, 2014 is presented below:
	Number of Options		Exercise Price		Intrinsic Value
					(in millions) (1)
Outstanding at December 31, 2013	1,525,000		$	42.61	$	11.5
Exercised	(495,000	)	42.61		9.6
Forfeited	(22,000	)	42.61		0.4
Outstanding at December 31, 2014 (2)	1,008,000		$	42.61	$	26.7
Options exercisable at December 31, 2014 (3)	114,000				$	3
_______________
-1	The intrinsic value of a stock option is the amount by which the fair value of the underlying stock exceeds the exercise price of an option.
-2	As of December 31, 2014, the average remaining life of stock options outstanding was 7.2 years
-3	As of December 31, 2014, the average remaining life of stock options exercisable was approximately 7.2 years.
In accordance with the provisions of the 2006 Plan, we allow shares of our common stock to be withheld to satisfy the payment of exercise price and/or minimum statutory tax withholding obligations due upon the exercise of stock options. The value of the shares withheld is calculated based on the closing market price of our common stock on the NYSE on the exercise date. During the year ended December 31, 2014, 23,664 shares were withheld on stock option exercises with an aggregate value of $1.5 million. The number of shares withheld for taxes during the years ended December 31, 2013 and 2012 were immaterial to the consolidated financial statements.
Share-Based Compensation Cost Recorded During the Period
The total compensation cost for all share-based compensation programs was $14.5 million, $9.6 million and $8.5 million for the years ended December 31, 2014, 2013 and 2012, respectively. Of the total share-based compensation costs, $2.3 million, $0.9 million and $0.9 million was capitalized as part of real estate assets for the years ended December 31, 2014, 2013 and 2012, respectively. As of December 31, 2014, there was approximately $30.3 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 2.5 years. The remaining compensation cost related to these nonvested incentive awards had been recognized in periods prior to December 31, 2014. The $30.3 million of unrecognized compensation costs does not reflect the future compensation cost related to share-based awards that were granted subsequent to December 31, 2014.

Employee_Benefit_Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Employee Benefit Plans	Employee Benefit Plans
	401(k) Plan
	We have a retirement savings plan designed to qualify under Section 401(k) of the Code (the “401(k) Plan”). Our employees are eligible to participate in the 401(k) Plan on the first day of the month after three months of service. The 401(k) Plan allows eligible employees (“401(k) Participants”) to defer up to 60% of their eligible compensation on a pre-tax basis, subject to certain maximum amounts allowed by the Code. The 401(k) Plan provides for a matching contribution by the Company in an amount equal to 50 cents of each one dollar of participant contributions up to a maximum of 10% of the 401(k) Participant’s annual salary. 401(k) Participants vest immediately in the amounts contributed by us. For each of the years ended December 31, 2014, 2013, and 2012, we contributed $1.0 million, $0.9 million and $0.7 million, respectively, to the 401(k) Plan.
	Deferred Compensation Plan
	In 2007, we adopted the Deferred Compensation Plan, under which directors and certain management employees may defer receipt of their compensation, including up to 70% of their salaries and up to 100% of their director fees and bonuses, as applicable. In addition, employee participants will receive mandatory Company contributions to their Deferred Compensation Plan accounts equal to 10% of their gross monthly salaries, without regard to whether such employees elect to defer salary or bonus compensation under the Deferred Compensation Plan. Our board of directors may, but has no obligation to, approve additional discretionary contributions by the Company to Participant accounts. We hold the Deferred Compensation Plan assets in a limited rabbi trust, which is subject to the claims of our creditors in the event of bankruptcy or insolvency.
	See Note 16 “Fair Value Measurements and Disclosures” for further discussion of our Deferred Compensation Plan assets as of December 31, 2014 and 2013. Our liability of $11.9 million and $9.9 million under the Deferred Compensation Plan was fully funded as of December 31, 2014 and 2013, respectively.

Future_Minimum_Rent

Future Minimum Rent	12 Months Ended
	Dec. 31, 2014
Leases [Abstract]
Future Minimum Rent	Future Minimum Rent
	We have operating leases with tenants that expire at various dates through 2037 and are either subject to scheduled fixed increases or adjustments in rent based on the Consumer Price Index. Generally, the leases grant tenants renewal options. Leases also provide for additional rents based on certain operating expenses. Future contractual minimum rent under operating leases as of December 31, 2014 for future periods is summarized as follows:
	Year Ending	(in thousands)
	2015	$	428,302
	2016	447,163
	2017	414,397
	2018	367,745
	2019	306,878
	Thereafter	1,217,370
	Total	$	3,181,855

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies
	General
	As of December 31, 2014, we had commitments of approximately $552.5 million, excluding our ground lease commitments, for contracts and executed leases directly related to our operating and development properties.
	Ground Leases
	The following table summarizes our properties that are held subject to long-term noncancellable ground lease obligations and the respective contractual expiration dates:
	Property	Contractual Expiration Date (1)
	601 108th Ave NE, Bellevue, WA	Nov-93
	701, 801 and 837 N. 34th Street, Seattle, WA (2)	Dec-41
	Kilroy Airport Center Phases I, II, and III, Long Beach, CA	Jul-84
	____________________
	-1	Reflects the contractual expiration date prior to the impact of any extension or purchase options held by the Company.
	-2	The Company has three 10 year and one 45 year extension option for this ground lease, which if exercised would extend the expiration date to December 2116.
	The minimum commitment under our ground leases as of December 31, 2014 for five years and thereafter is as follows:
	Year Ending	(in thousands)
	2015	$	3,120
	2016	3,120
	2017	3,120
	2018	3,120
	2019	3,120
	Thereafter	154,358
	Total (1)(2)(3)(4)	$	169,958
	________________________
	-1	Reflects the minimum ground lease obligations before the impact of ground lease extension options.
	-2	One of our ground lease obligations is subject to a fair market value adjustment every five years; however, the lease includes ground rent subprotection and infrastructure rent credits which currently limit our annual rental obligations to $1.0 million. The contractual obligations for that ground lease included above assumes the lesser of $1.0 million or annual lease rental obligation in effect as of December 31, 2014.
	-3	One of our ground lease obligations includes a component which is based on the percentage of gross income that exceeds the minimum ground rent. The minimum rent is subject to increases every five years based on 50% of the average annual percentage rent for the previous five years. Currently, gross income does not exceed the threshold requiring us to pay percentage rent. The contractual obligations for that ground lease included above assume the annual lease rental obligation in effect as of December 31, 2014.
	-4	One of our ground lease obligations is subject to a fair market value adjustment every five years based on a combination of CPI adjustments and third-party appraisals limited to maximum increases annually. The contractual obligations included above assume the annual lease rental obligation in effect as of December 31, 2014.
	Litigation
	We and our properties are subject to litigation arising in the ordinary course of business. To our knowledge, neither we nor any of our properties are presently subject to any litigation or threat of litigation which, if determined unfavorably to us, would have a material adverse effect on our cash flow, financial condition, or results of operations.
	Property Damage Settlement
	During the year ended December 31, 2013, we settled an outstanding matter related to property damage at one of our properties. In connection with this settlement, we received cash payments of $5.2 million and $0.9 million, during the years ended December 31, 2013 and December 31, 2012, respectively, and recognized this amount in other property income.
	Settlements with Prior Tenants
	During the year ended December 31, 2013, we settled an outstanding matter with a prior tenant at one of the properties disposed of in December 2012. In connection with this settlement, we received a net cash payment of $3.7 million, which is included in income from discontinued operations in our consolidated statements of operations in 2013.
	Insurance
	We maintain commercial general liability, auto liability, employers liability, umbrella/excess liability, special form property, difference in conditions including earthquake and flood, environmental, rental loss, and terrorism insurance covering all of our properties. Management believes the policy specifications and insured limits are reasonable given the relative risk of loss, the cost of the coverage, and industry practice. We do not carry insurance for generally uninsurable losses such as loss from governmental action, nuclear hazard, and war and military action. Policies are subject to various terms, conditions, and exclusions and some policies may involve large deductibles or co-payments.
	Environmental Matters
	We follow the policy of monitoring all of our properties, both acquisition and existing properties, for the presence of hazardous or toxic substances. As of December 31, 2014, we had accrued environmental remediation liabilities of approximately $15.5 million recorded on our consolidated balance sheets in connection with certain of our recent development acquisitions and related development activities. The accrued environmental remediation liabilities represent the costs we estimate we will incur when we commence development at various development acquisition sites. These estimates, which we developed with the assistance of a third party expert, consist primarily of the removal of contaminated soil and other related costs since we are required to dispose of any existing contaminated soil when we develop new office properties at these sites.
	We record estimated environmental remediation obligations for acquisitions at the acquisition date when we are aware of such costs and when such costs are probable and reasonably estimable. Costs incurred in connection with development related environmental remediation liabilities are recorded as an increase to the cost of the development project. These accruals are adjusted as an increase or decrease to the development project costs and as an increase or decrease to the accrued environmental remediation liability if we obtain further information or circumstances change. The environmental remediation obligations recorded at December 31, 2014 were not discounted to their present value since we expect to complete the remediation activities in the next 1-5 years in connection with development activities at the various sites. It is possible that we could incur additional environmental remediation costs in connection with these recent development acquisitions.  However, given we are in the very early stages of development, possible additional environmental costs are not reasonably estimable at this time.
	Other than the accrued environmental liabilities recorded in connection with certain of our recent development acquisitions and related development activities, we are not aware of any unasserted claims and assessments with respect to an environmental liability that we believe would require additional disclosure or the recording of an additional loss contingency.

Fair_Value_Measurements_and_Di

Fair Value Measurements and Disclosures	12 Months Ended
	Dec. 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 our consolidated financial statements are the marketable securities related to our Deferred Compensation Plan (see Note 13 “Employee Benefit Plans” for additional information). The following table sets forth the fair value of our marketable securities as of December 31, 2014 and 2013:
		Fair Value (Level 1) (1)
		2014		2013
	Description	(in thousands)
	Marketable securities (2)	$	11,971	$	10,008
	_______________
	-1	Fair value calculated using Level 1 inputs 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 also 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 years ended December 31, 2014, 2013 and 2012:
		December 31,
		2014		2013		2012
	Description	(in thousands)
	Net gain on marketable securities	$	397	$	1,489	$	723
	Financial Instruments Disclosed at Fair Value
	The following table sets forth the carrying value and the fair value of our other financial instruments as of December 31, 2014 and 2013:
		December 31,
		2014				2013
		Carrying Value		Fair Value		Carrying Value		Fair Value
		(in thousands)
	Liabilities
	Secured debt (1)	$	546,292	$	559,483	$	560,434	$	568,760
	Exchangeable senior notes, net (1)(2)	—		—		168,372		178,190
	Unsecured debt, net (3)	1,783,121		1,858,492		1,431,132		1,523,052
	Unsecured line of credit (1)	140,000		140,051		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	During the year ended December 31, 2014, we repaid the 4.25% Exchangeable Notes. As of December 31, 2014, there were no exchangeable debt instruments (see Note 7 “Secured and Unsecured Debt of the Operating Partnership” for additional information).
	-3	Fair value calculated primarily using Level I inputs, which are based on quoted prices for identical instruments in active markets. The carrying value and fair value of the Level I instruments was $1,269.4 million and $1,322.2 million, respectively, as of December 31, 2014. The carrying value and fair value of the Level I instruments at December 31, 2013, was $873.5 million and $929.3 million, respectively. The carrying value and fair value of the Level II instruments was $513.7 million and $536.3 million, respectively, as of December 31, 2014. The carrying value and fair value of the Level II instruments at December 31, 2013, was $557.7 million and $593.7 million, respectively.

Other_Significant_Events

Other Significant Events	12 Months Ended
	Dec. 31, 2014
Other Income and Expenses [Abstract]
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, terminated during the year ended December 31, 2014. The total lease termination fee of $5.7 million was recorded as other property income on a straight line basis through the early lease termination date. The Company received the cash payment of the lease termination fee of $5.7 million in September 2014. During the year ended December 31, 2014, the Company also recognized approximately $1.3 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	12 Months Ended
	Dec. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	Discontinued Operations and Land Held for Sale
	Operating Property Dispositions
	The following table summarizes the properties sold during the years ended December 31, 2014, 2013 and 2012:
	Location		Property Type		Month of Disposition		Number of Buildings	Rentable			Sales Price
								Square Feet (unaudited)			(in millions) (1)
	2014 Dispositions
	San Diego Properties, San Diego, CA (2)		Office		January		12	1,049,035			$	294.7
	9785 & 9791 Towne Centre Drive, San Diego, CA		Office		June		2	126,000			29.5
	111 Pacifica, Irvine, CA		Office		September		1	67,496			15.1
	4040 Civic Center Drive, San Rafael, CA		Office		October		1	130,237			34.9
	999 Town & Country Road, Orange, CA		Office		December		1	98,551			25.3
	Total 2014 dispositions						17	1,471,319			$	399.5
	2013 Dispositions
	26541 Agoura Road, Calabasas, CA		Office		June		1	90,156			$	14.7
	8101 Kaiser Boulevard, Anaheim, CA		Office		October		1	59,790			9.6
	4910 Directors Place, San Diego CA		Office		December		1	50,360			32.6
	Total 2013 dispositions						3	200,306			$	56.9
	2012 Dispositions
	15004 Innovation Drive and 10243 Genetic Center Drive,		Office		January		2	253,676			$	146.1
	San Diego, CA
	Industrial Portfolio (3)		Industrial		November/December		39	3,413,354
	5151, 5153 & 5155 Camino Ruiz, Camarillo, CA		Office		December		4	265,372
	4175 E. La Palma Avenue, Anaheim, CA		Office		December		1	43,263
	Subtotal industrial portfolio						44	3,721,989			354.2
	Total 2012 dispositions						46	3,975,665			$	500.3
	__________________
	-1	Represents gross sales price before the impact of broker commissions and closing costs.
	-2	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. These properties were held for sale as of December 31, 2013.
	-3	The industrial portfolio was sold in two tranches in November and December 2012 to two separate third party buyers.
	The major classes of assets and liabilities of the properties held for sale as of December 31, 2013 were as follows:
	Real estate assets and other assets held for sale	(in thousands)
	Land and improvements	$	49,656
	Buildings and improvements	209,594
	Total real estate held for sale	259,250
	Accumulated depreciation and amortization	(63,110		)
	Total real estate held for sale, net	196,140
	Current receivables, net	269
	Deferred rent receivables, net	8,978
	Deferred leasing costs and acquisition-related intangible assets, net	5,791
	Prepaid expenses and other assets, net	1,922
	Real estate and other assets held for sale, net	$	213,100
	Liabilities and deferred revenue of real estate assets held for sale
	Accounts payable, accrued expenses and other liabilities	$	1,153
	Deferred revenue and acquisition-related intangible liabilities, net	10,723
	Rents received in advance and tenant security deposits	2,571
	Liabilities and deferred revenue of real estate assets held for sale	$	14,447
	Discontinued Operations
	For the year ended December 31, 2014, discontinued operations includes the income and net gain on all the properties sold in 2014, except for the operations deemed immaterial related to a June 2014 office property disposition. For the years ended December 31, 2013 and 2012, discontinued operations included the results of all properties sold in 2014, 2013 and 2012 and classified as held for sale at December 31, 2013. The following table summarizes the revenue and expense components that comprise income from discontinued operations for the years ended December 31, 2014, 2013 and 2012:
		Year Ended December 31,
		2014				2013			2012
		(in thousands)
	Revenues:
	Rental income	$	7,206			$	31,984		$	49,689
	Tenant reimbursements	278				3,546			6,544
	Other property income	13				5,178			1,923
	Total revenues	7,497				40,708			58,156
	Expenses:
	Property expenses	2,171				7,207			9,945
	Real estate taxes	692				3,523			5,696
	Provision for bad debts	—				—			(195		)
	Depreciation and amortization	2,061				12,600			19,379
	Total expenses	4,924				23,330			34,825
	Income from discontinued operations before net gain on dispositions of discontinued operations	2,573				17,378			23,331
	Net gain on dispositions of discontinued operations	121,922				12,252			259,245
Total income from discontinued operations	$	124,495			$	29,630		$	282,576
Real Estate Held for Sale
As of December 31, 2014, the Company had one land parcel located at 17150 Von Karman in Irvine, California, classified as held for sale. In January 2015, the Company completed this sale for a gross sales price of $26.0 million (see Note 24 “Subsequent Events” for additional information). The land parcel did not meet the criteria for classification as discontinued operations as of December 31, 2014 because it did not have any significant operations prior to disposal.
Land Disposition
During the year ended December 31, 2014, the Company sold a land parcel located at 10850 Via Frontera in the Rancho Bernardo submarket of San Diego, California for a gross sales price of $33.1 million, resulting in a gain on sale of $3.5 million. The gain on sale is included on our consolidated statements of operations as gain on sale of land within continuing operations.
Restricted Cash Related to Dispositions
As of December 31, 2014 and 2013, approximately $59.2 million and $32.2 million, respectively, of net proceeds related to the land and office property dispositions during the years ended December 31, 2014 and 2013, were temporarily being held at qualified intermediaries, 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 December 31, 2014 and 2013. In January 2015 and February 2014, we successfully completed Section 1031 Exchanges and the $59.2 million and $32.2 million of cash proceeds comprising the balances as of December 31, 2014 and 2013, respectively, were released from the qualified intermediary.

Net_Income_Available_to_Common

Net Income Available to Common Stockholders Per Share of the Company	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Net Income Available to Common Stockholders Per Share of the Company	Net Income Available to Common Stockholders Per Share of the Company
	The following table reconciles the numerator and denominator in computing the Company’s basic and diluted per-share computations for net income available to common stockholders for the years ended December 31, 2014, 2013 and 2012:
		Year Ended December 31,
		2014			2013			2012
		(in thousands, except unit and per unit amounts)
	Numerator:
	Income (loss) from continuing operations	$	59,313		$	14,935		$	(5,475	)
	(Income) loss from continuing operations attributable to noncontrolling common units of the Operating Partnership	(966		)	(36		)	656
	Preferred distributions and dividends	(13,250		)	(13,250		)	(21,088		)
	Allocation to participating securities (1)	(1,699		)	(1,689		)	(1,602		)
	Numerator for basic and diluted income (loss) from continuing operations available to common stockholders	43,398			(40		)	(27,509		)
	Income from discontinued operations	124,495			29,630			282,576
	Income from discontinued operations attributable to noncontrolling common units of the Operating Partnership	(2,623		)	(649		)	(6,843		)
	Numerator for basic and diluted net income available to common stockholders	$	165,270		$	28,941		$	248,224
	Denominator:
	Basic weighted average vested shares outstanding	83,090,235			77,343,853			69,639,623
	Effect of dilutive securities – contingently issuable shares and stock options	1,877,485			—			—
	Diluted weighted average vested shares and common stock equivalents outstanding	84,967,720			77,343,853			69,639,623
	Basic earnings per share:
	Income (loss) from continuing operations available to common stockholders per share	$	0.52		$	0		$	(0.40	)
	Income from discontinued operations per share of common stock	1.47			0.37			3.96
	Net income available to common stockholders per share	$	1.99		$	0.37		$	3.56
	Diluted earnings per share:
	Income (loss) from continuing operations available to common stockholders per share	$	0.51		$	0		$	(0.40	)
	Income from discontinued operations per share of common stock	1.44			0.37			3.96
	Net income available to common stockholders per share	$	1.95		$	0.37		$	3.56
	________________________
	-1	Participating securities include nonvested shares, certain time-based RSUs and vested market measure-based RSUs.
	For the year ended December 31, 2014, contingently issuable shares were considered in our diluted earnings per share calculation because we reported income from continuing operations attributable to common stockholders in the respective periods and the effect was dilutive. For the years ended December 31, 2013 and 2012, contingently issuable shares were not considered in our diluted earnings per share calculation because we reported losses from continuing operations attributable to common stockholders in the respective periods and the effect was anti dilutive. Contingently issuable shares consist of stock options and the impact of the 4.25% Exchangeable Notes prior to their maturity and settlement in November 2014.
	The 2014 Performance-Based RSUs and our other nonvested market measure-based RSUs are not included in dilutive securities as of December 31, 2014 because they are not considered contingently issuable until 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 December 31, 2013 because they were not considered contingently issuable shares as not all the necessary performance conditions were met.
	See Note 7 “Secured and Unsecured Debt of the Operating Partnership” for additional information regarding the 4.25% Exchangeable Notes and Note 12 “Share-Based Compensation” for additional information regarding the stock options and other share-based compensation.

Net_Income_Available_to_Common1

Net Income Available to Common Unitholders Per Unit of the Operating Partnership (Kilroy Realty, L.P. [Member])	12 Months Ended
	Dec. 31, 2014
Kilroy Realty, L.P. [Member]
Net Income Available To Common Unitholders [Line Items]
Net Income Available to Common Unitholders per Unit of the Operating Partnership	Net Income Available to Common Unitholders Per Unit of the Operating Partnership
	The following table reconciles the numerator and denominator in computing the Operating Partnership’s basic and diluted per-unit computations for net income available to common unitholders for the years ended December 31, 2014, 2013 and 2012:
		Year Ended December 31,
		2014			2013			2012
		(in thousands, except unit and per unit amounts)
	Numerator:
	Income (loss) from continuing operations	$	59,313		$	14,935		$	(5,475	)
	Income from continuing operations attributable to noncontrolling interests in consolidated subsidiaries	(247		)	(225		)	(176		)
	Preferred distributions	(13,250		)	(13,250		)	(21,088		)
	Allocation to participating securities (1)	(1,699		)	(1,689		)	(1,602		)
	Numerator for basic and diluted income (loss) from continuing operations available to common unitholders	44,117			(229		)	(28,341		)
	Income from discontinued operations	124,495			29,630			282,576
	(Income) loss from discontinued operations attributable to noncontrolling interests in consolidated subsidiaries	(13		)	1			(462		)
	Numerator for basic and diluted net income available to common unitholders	$	168,599		$	29,402		$	253,773
	Denominator:
	Basic weighted average vested units outstanding	84,894,498			79,166,260			71,403,258
	Effect of dilutive securities - contingently issuable shares and stock options	1,877,485			—			—
	Diluted weighted average vested units and common unit equivalents outstanding	86,771,983			79,166,260			71,403,258
	Basic earnings per unit:
	Income (loss) from continuing operations available to common unitholders per unit	$	0.52		$	0		$	(0.40	)
	Income from discontinued operations per common unit	1.47			0.37			3.96
	Net income available to common unitholders per unit	$	1.99		$	0.37		$	3.56
	Diluted earnings per unit:
	Income (loss) from continuing operations available to common unitholders per unit	$	0.51		$	0		$	(0.40	)
	Income from discontinued operations per common unit	1.43			0.37			3.96
	Net income available to common unitholders per unit	$	1.94		$	0.37		$	3.56
	________________________
	-1	Participating securities include nonvested shares, certain time-based RSUs and vested market measure-based RSUs.
	For the year ended December 31, 2014, contingently issuable shares were considered in our diluted earnings per share calculation because we reported income from continuing operations attributable to common unitholders in the respective periods and the effect was dilutive. For the years ended December 31, 2013 and 2012, contingently issuable shares were not considered in our diluted earnings per share calculation because we reported losses from continuing operations attributable to common unitholders in the respective periods and the effect was anti dilutive. Contingently issuable shares consist of stock options and the impact of the 4.25% Exchangeable Notes prior to their maturity and settlement in November 2014.
	The 2014 Performance-Based RSUs and our other nonvested market measure-based RSUs are not included in dilutive securities as of December 31, 2014 because they are not considered contingently issuable until 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 December 31, 2013 because they were not considered contingently issuable shares as not all the necessary performance conditions were met.
	See Note 7 “Secured and Unsecured Debt of the Operating Partnership” for additional information regarding the 4.25% Exchangeable Notes and Note 12 “Share-Based Compensation” for additional information regarding the stock options and other share-based compensation.

Tax_Treatment_of_Distributions

Tax Treatment of Distributions	12 Months Ended
	Dec. 31, 2014
Tax Treatment of Distributions [Abstract]
Tax Treatment of Distributions	Tax Treatment of Distributions
	The following table reconciles the dividends declared per share of common stock to the dividends paid per share of common stock during the years ended December 31, 2014, 2013 and 2012 as follows:
		Year Ended December 31,
	Dividends	2014		2013			2012
	Dividends declared per share of common stock	1.4		1.4			1.4
	Less: Dividends declared in the current year and paid in the following year	(0.350	)	(0.350	)		(0.350	)
	Add: Dividends declared in the prior year and paid in the current year	0.35		0.35			0.35
	Dividends paid per share of common stock	1.4		1.4			1.4
	The unaudited income tax treatment for the dividends to common stockholders reportable for the years ended December 31, 2014, 2013 and 2012 as identified in the table above was as follows:
		Year Ended December 31,
	Shares of Common Stock	2014						2013				2012
	Ordinary income	$	0.998		71.29	%		$	0.756	54	%	$	0.577	41.21	%
	Qualified dividend	0.002			0.14			0.003		0.21		—		—
	Return of capital	0.398			28.43			0.62		44.29		0.823		58.79
	Capital gains (1)	0.002			0.14			—		—		—		—
	Unrecaptured section 1250 gains	—			—			0.021		1.5		—		—
		$	1.4		100	%		$	1.4	100	%	$	1.4	100	%
	_________________
	-1	Capital gains are comprised entirely of 20% rate gains for 2014 and 2013 and 15% rate gains for 2012.
	The 6.875% Series G Cumulative Redeemable Preferred Stock was issued in March 2012. The unaudited income tax treatment for the dividends to Series G preferred stockholders reportable for the years ended December 31, 2014, 2013, and 2012 was as follows:
		Year Ended December 31,
	Preferred Shares	2014						2013				2012
	Ordinary income	$	1.711		99.54	%		$	1.668	97.03	%	$	1.089	100	%
	Qualified dividend	0.003			0.17			0.006		0.35		—		—
	Capital gains (1)	0.005			0.29			—		—		—		—
	Unrecaptured section 1250 gains	—			—			0.045		2.62		—		—
		$	1.719		100	%		$	1.719	100	%	$	1.089	100	%
	__________________
	-1	Capital gains are comprised entirely of 20% rate gains for 2014 and 2013 and 15% rate gains for 2012.
	The 6.375% Series H Cumulative Redeemable Preferred Stock was issued in August 2012. The unaudited income tax treatment for the dividends to Series H preferred stockholders reportable for the years ended December 31, 2014, 2013, and 2012 was as follows:
		Year Ended December 31,
	Preferred Shares	2014						2013				2012
	Ordinary income	$	1.587		99.56	%		$	1.546	96.99	%	$	0.398	100	%
	Qualified dividend	0.003			0.19			0.006		0.38		—		—
	Capital gains (1)	0.004			0.25			—		—		—		—
	Unrecaptured section 1250 gains	—			—			0.042		2.63		—		—
		$	1.594		100	%		$	1.594	100	%	$	0.398	100	%
	__________________
	-1	Capital gains are comprised entirely of 20% rate gains for 2014 and 2013 and 15% rate gains for 2012.
	The 7.80% Series E Cumulative Redeemable Preferred Stock was redeemed on April 16, 2012. The unaudited income tax treatment for the dividends to Series E preferred stockholders reportable for the year ended December 31, 2012 is seen in the table below.
	Preferred Shares	Year Ended December 31, 2012
	Ordinary income	$	0.818		100	%
	Capital gains (1)	—			—
	Unrecaptured section 1250 gains	—			—
		$	0.818		100	%
	__________________
	-1	Capital gains are comprised entirely of 15% rate gains.
	The 7.50% Series F Cumulative Redeemable Preferred Stock was redeemed on April 16, 2012. The unaudited income tax treatment for the dividends to Series F preferred stockholders reportable for the year ended December 31, 2012 is seen in the table below.
	Preferred Shares	Year Ended December 31, 2012
	Ordinary income	$	0.786		100	%
	Capital gains (1)	—			—
	Unrecaptured section 1250 gains	—			—
		$	0.786		100	%
	_________________
	-1	Capital gains are comprised entirely of 15% rate gains.

Quarterly_Financial_Informatio

Quarterly Financial Information of the Company (Unaudited)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information of the Company	Quarterly Financial Information of the Company (Unaudited)
	Summarized quarterly financial data for the years ended December 31, 2014 and 2013 was as follows:
		2014 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per share amounts)
	Revenues from continuing operations (2)	$	123,758		$	127,178		$	129,024		$	141,765
	Income from continuing operations (2)	10,874			15,854			13,168			19,417
	Income from discontinued operations (2)	91,058			15,289			6,135			12,013
	Net income	101,932			31,143			19,303			31,430
	Net income attributable to Kilroy Realty Corporation	99,845			30,540			18,982			30,852
	Preferred dividends and distributions	(3,313		)	(3,312		)	(3,313		)	(3,312		)
	Net income available to common stockholders	96,532			27,228			15,669			27,540
	Net income available to common stockholders per share – basic	1.17			0.33			0.18			0.32
	Net income available to common stockholders per share – diluted	1.14			0.32			0.18			0.32
		2013 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per share amounts)
	Revenues from continuing operations (2)	$	109,107		$	115,855		$	113,545		$	118,604
	(Loss) income from continuing operations (2)	(225		)	6,942			3,180			5,038
	Income from discontinued operations (2)	2,613			3,161			5,847			18,009
	Net income	2,388			10,103			9,027			23,047
	Net income attributable to Kilroy Realty Corporation	2,410			9,946			8,896			22,628
	Preferred dividends and distributions	(3,313		)	(3,313		)	(3,312		)	(3,312		)
	Net (loss) income available to common stockholders	(903		)	6,633			5,584			19,316
	Net (loss) income available to common stockholders per share – basic	(0.02		)	0.08			0.07			0.23
	Net (loss) income available to common stockholders per share – diluted	(0.02		)	0.08			0.07			0.23
	____________________
	-1	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common stockholders per share does not equal the annual number reported on the consolidated statements of operations due to the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended December 31, 2014 and 2013.
	-2	All periods have been adjusted from amounts previously disclosed in our quarterly filings on Form 10-Q to reclassify amounts related to discontinued operations (see Note 18 “Discontinued Operations” for additional information).

Quarterly_Financial_Informatio1

Quarterly Financial Information of the Operating Partnership (Unaudited)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information of the Operating Partnership	Quarterly Financial Information of the Company (Unaudited)
	Summarized quarterly financial data for the years ended December 31, 2014 and 2013 was as follows:
		2014 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per share amounts)
	Revenues from continuing operations (2)	$	123,758		$	127,178		$	129,024		$	141,765
	Income from continuing operations (2)	10,874			15,854			13,168			19,417
	Income from discontinued operations (2)	91,058			15,289			6,135			12,013
	Net income	101,932			31,143			19,303			31,430
	Net income attributable to Kilroy Realty Corporation	99,845			30,540			18,982			30,852
	Preferred dividends and distributions	(3,313		)	(3,312		)	(3,313		)	(3,312		)
	Net income available to common stockholders	96,532			27,228			15,669			27,540
	Net income available to common stockholders per share – basic	1.17			0.33			0.18			0.32
	Net income available to common stockholders per share – diluted	1.14			0.32			0.18			0.32
		2013 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per share amounts)
	Revenues from continuing operations (2)	$	109,107		$	115,855		$	113,545		$	118,604
	(Loss) income from continuing operations (2)	(225		)	6,942			3,180			5,038
	Income from discontinued operations (2)	2,613			3,161			5,847			18,009
	Net income	2,388			10,103			9,027			23,047
	Net income attributable to Kilroy Realty Corporation	2,410			9,946			8,896			22,628
	Preferred dividends and distributions	(3,313		)	(3,313		)	(3,312		)	(3,312		)
	Net (loss) income available to common stockholders	(903		)	6,633			5,584			19,316
	Net (loss) income available to common stockholders per share – basic	(0.02		)	0.08			0.07			0.23
	Net (loss) income available to common stockholders per share – diluted	(0.02		)	0.08			0.07			0.23
	____________________
	-1	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common stockholders per share does not equal the annual number reported on the consolidated statements of operations due to the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended December 31, 2014 and 2013.
	-2	All periods have been adjusted from amounts previously disclosed in our quarterly filings on Form 10-Q to reclassify amounts related to discontinued operations (see Note 18 “Discontinued Operations” for additional information).
Kilroy Realty, L.P. [Member]
Quarterly Financial Information of the Operating Partnership	Quarterly Financial Information of the Operating Partnership (Unaudited)
	Summarized quarterly financial data for the years ended December 31, 2014 and 2013 was as follows:
		2014 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per unit amounts)
	Revenues from continuing operations (2)	$	123,758		$	127,178		$	129,024		$	141,765
	Income from continuing operations (2)	10,874			15,854			13,168			19,417
	Income from discontinued operations (2)	91,058			15,289			6,135			12,013
	Net income	101,932			31,143			19,303			31,430
	Net income attributable to the Operating Partnership	101,867			31,066			19,244			31,371
	Preferred distributions	(3,313		)	(3,312		)	(3,313		)	(3,312		)
	Net income available to common unitholders	98,554			27,754			15,931			28,059
	Net income available to common unitholders per unit – basic	1.17			0.33			0.18			0.32
	Net income available to common unitholders per unit – diluted	1.14			0.32			0.18			0.31
		2013 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per unit amounts)
	Revenues from continuing operations (2)	$	109,107		$	115,855		$	113,545		$	118,604
	(Loss) income from continuing operations (2)	(225		)	6,942			3,180			5,038
	Income from discontinued operations (2)	2,613			3,161			5,847			18,009
	Net income	2,388			10,103			9,027			23,047
	Net income attributable to the Operating Partnership	2,319			10,041			8,980			23,001
	Preferred distributions	(3,313		)	(3,313		)	(3,312		)	(3,312		)
	Net (loss) income available to common unitholders	(994		)	6,728			5,668			19,689
	Net (loss) income available to common unitholders per unit – basic	(0.02		)	0.08			0.07			0.23
	Net (loss) income available to common unitholders per unit – diluted	(0.02		)	0.08			0.07			0.23
	___________________
	-1	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common unitholders per unit does not equal the annual number reported on the consolidated statements of operations due to the impact of the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended December 31, 2014 and 2013.
	-2	All periods have been adjusted from amounts previously disclosed in our quarterly filings on Form 10-Q to reclassify amounts related to discontinued operations (see Note 18 “Discontinued Operations”).

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2014
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events
	On January 14, 2015, aggregate dividends, distributions and dividend equivalents of $31.3 million were paid to common stockholders, common unitholders and RSU holders of record on December 31, 2014.
	At December 31, 2014, the Company had one land parcel located at 17150 Von Karman in Irvine, California that was classified as held for sale. On January 15, 2015, the Company completed this transaction for a gross sales price of $26.0 million.
	On January 27, 2015, the Executive Compensation Committee granted 212,468 RSUs to Executive Officers and other key employees under the 2006 Plan. 127,657 of these RSUs are subject to market and performance-based vesting requirements, which could cause the final vested amount of RSUs to increase or decrease. The compensation cost related to both time-based and performance-based RSUs is expected to be recognized over a period of three years.

Schedule_II_Valuation_and_Qual

Schedule II Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2014
Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts
		Balance at		Charged to			Recoveries			Balance
		Beginning		Costs and			(Deductions)			at End
		of Period		Expenses (1)						of Period (2)
	Allowance for Uncollectible Tenant Receivables for the year ended
	December 31,
	2014 – Allowance for uncollectible tenant receivables	$	2,134	$	58		$	(193	)	$	1,999
	2013 – Allowance for uncollectible tenant receivables	2,581		396			(843		)	2,134
	2012 – Allowance for uncollectible tenant receivables	2,590		(42		)	33			2,581
	Allowance for Unbilled Deferred Rent for the year ended
	December 31,
	2014 – Allowance for deferred rent	$	2,075	$	—		$	(86	)	$	1,989
	2013 – Allowance for deferred rent	2,607		—			(532		)	2,075
	2012 – Allowance for deferred rent	3,406		—			(799		)	2,607
	_______________
	-1	Includes amounts reported in Discontinued Operations (see Note 18 “Discontinued Operations”).
	(2) For the year ended December 31, 2013, includes amounts reported for properties classified as held for sale (see Note 18 "Discontinued Operations").

Schedule_III_Real_Estate_and_A

Schedule III - Real Estate and Accumulated Depreciation	12 Months Ended
	Dec. 31, 2014
SEC Schedule III, Real Estate and Accumulated Depreciation Disclosure [Abstract]
Schedule III - Real Estate and Accumulated Depreciation	The aggregate gross cost of property included above for federal income tax purposes approximated $5.2 billion as of December 31, 2014.
	The following table reconciles the historical cost of total real estate held for investment from January 1, 2012 to December 31, 2014:
		Year Ended December 31,
		2014			2013			2012
		(in thousands)
	Total real estate held for investment, beginning of year	$	5,264,947		$	4,757,394		$	3,798,690
	Additions during period:
	Acquisitions	340,296			384,650			1,023,384
	Improvements, etc.	588,166			452,331			207,345
	Total additions during period	928,462			836,981			1,230,729
	Deductions during period:
	Cost of real estate sold	(113,416		)	(56,993		)	(264,533		)
	Properties held for sale	(14,700		)	(259,251		)	—
	Other	(7,361		)	(13,184		)	(7,492		)
	Total deductions during period	(135,477		)	(329,428		)	(272,025		)
	Total real estate held for investment, end of year	$	6,057,932		$	5,264,947		$	4,757,394
	The following table reconciles the accumulated depreciation from January 1, 2012 to December 31, 2014:
		Year Ended December 31,
		2014			2013			2012
		(in thousands)
	Accumulated depreciation, beginning of year	$	818,957		$	756,515		$	742,503
	Additions during period:
	Depreciation of real estate	153,841			145,325			125,906
	Total additions during period	153,841			145,325			125,906
	Deductions during period:
	Write-offs due to sale	(18,111		)	(17,144		)	(109,797		)
	Properties held for sale	(7,007		)	(63,110		)	—
	Other	(16		)	(2,629		)	(2,097		)
	Total deductions during period	(25,134		)	(82,883		)	(111,894		)
	Accumulated depreciation, end of year	$	947,664		$	818,957		$	756,515

Basis_of_Presentation_and_Sign1

Basis of Presentation and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Basis of presentation and significant accounting policies [Line Items]
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 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 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.
	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 December 31, 2014, the consolidated financial statements of the Company and the Operating Partnership included two variable interest entities (“VIEs”), in which we were deemed to be the primary beneficiary. One VIE, Redwood LLC, was established in the second quarter of 2013 in connection with an undeveloped land acquisition (see Note 3 “Acquisitions” for additional information regarding the Redwood City, California acquisition). The other VIE was established during the fourth quarter of 2014 to facilitate potential future Section 1031 Exchanges to defer taxable gains on dispositions for federal and state income tax purposes. The impact of consolidating the VIEs increased the Company’s total assets, liabilities and noncontrolling interests by approximately $219.6 million (of which $211.8 million related to real estate held for investment on our consolidated balance sheet), approximately $23.4 million and approximately $5.9 million, respectively, as of December 31, 2014. During January 2015, the Company successfully completed the Section 1031 Exchange and the related VIE was terminated. As a result, $59.2 million of our restricted cash balance at December 31, 2014, which related to prior period disposition proceeds that were set aside to facilitate the Section 1031 Exchanges, was released from escrow.
	At 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 LLC and the remaining three were established during the third and fourth quarter of 2013 to facilitate potential Section 1031 Exchanges. During the three months ended March 31, 2014, these three Section 1031 Exchanges were successfully completed and the three VIEs, excluding Redwood LLC, 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.
	Our accounting policy is to consolidate entities in which we have a controlling financial interest and significant decision making control over the entity's operations. In determining whether we have a controlling financial interest in a partially owned entity and the requirement to consolidate the accounts of that entity, we consider factors such as ownership interest, board representation, management representation, size of our investment (including loans), authority to control decisions, and contractual and substantive participating rights of the members. In addition to evaluating control rights, we consolidate entities in which the other members have no substantive kick-out rights to remove the Company as the managing member.
	We also evaluate whether the entity is a variable interest entity (“VIE”) and whether we are the primary beneficiary. VIEs are entities in which the equity investors do not have sufficient equity at risk to finance their endeavors without additional financial support or the holders of the equity investment at risk do not have a controlling financial interest. We are deemed to be the primary beneficiary of a VIE when we have the power to direct the activities of the VIE that most significantly impact the VIEs’ economic performance and the obligation to absorb losses or receive benefits that could potentially be significant to the VIE.
	If the requirements for consolidation are not met, the Company would account for investments under the equity method of accounting if we have the ability to exercise significant influence over the entity. Equity method investments would be initially recorded at cost and subsequently adjusted for our share of net income or loss and cash contributions and distributions each period. The Company did not have any equity method investments at December 31, 2014 or December 31, 2013.
Acquisitions	Acquisitions
	We record the acquired tangible and intangible assets and assumed liabilities of acquisitions of operating properties and development and redevelopment opportunities that meet the accounting criteria to be accounted for as business combinations at fair value at the acquisition date. The acquired assets and assumed liabilities for an acquisition generally include but are not limited to (i) land and improvements, buildings and improvements, undeveloped land and construction in progress and (ii) identified tangible and intangible assets and liabilities associated with in-place leases, including tenant improvements, leasing costs, value of above-market and below-market operating leases and ground leases, acquired in-place lease values and tenant relationships, if any. Any debt assumed and equity (including common units of the Operating Partnership) issued in connection with a property acquisition is recorded at fair value on the date of acquisition.
	The fair value of land and improvements is derived from comparable sales of land and improvements within the same submarket and/or region. The fair value of buildings and improvements, tenant improvements and leasing costs considers the value of the property as if it was vacant as well as current replacement costs and other relevant market rate information.
	The fair value of the above-market or below-market component of an acquired in-place operating lease is based upon the present value (calculated using a market discount rate) of the difference between (i) the contractual rents to be paid pursuant to the lease over its remaining non-cancellable lease term and (ii) our estimate of the rents that would be paid using fair market rental rates and rent escalations at the date of acquisition measured over the remaining non-cancellable term of the lease for above-market operating leases and the initial non-cancellable term plus the term of any below-market fixed rate renewal options, if applicable, for below-market operating leases. Our below-market operating leases generally do not include fixed rate or below-market renewal options. The amounts recorded for above-market operating leases are included in deferred leasing costs and acquisition-related intangible assets, net on the balance sheet and are amortized on a straight-line basis as a reduction of rental income over the remaining term of the applicable leases. The amounts recorded for below-market operating leases are included in deferred revenue and acquisition-related intangible liabilities, net on the balance sheet and are amortized on a straight-line basis as an increase to rental income over the remaining term of the applicable leases plus the term of any below-market fixed rate renewal options, if applicable.
	The fair value of acquired in-place leases is derived based on our assessment of lost revenue and costs incurred for the period required to lease the “assumed vacant” property to the occupancy level when purchased. The amount recorded for acquired in-place leases is included in deferred leasing costs and acquisition-related intangible assets, net on the balance sheet and amortized as an increase to depreciation and amortization expense over the remaining term of the applicable leases. Fully amortized intangible assets are written off each quarter.
	We record the acquisition of undeveloped land that does not meet the accounting criteria to be accounted for as business combinations and the subsequent acquisition of the fee interest in land and improvements underlying our properties at the purchase price paid and capitalize the associated acquisition costs. During the years ended December 31, 2014, 2013 and 2012 we capitalized $4.5 million, $2.3 million and $0.7 million, respectively, in acquisition costs associated with the development acquisitions.
Operating Properties, Cost Capitalization, and Depreciations and Amortization of Buildings and IMprovements	Operating Properties
	Operating properties are generally carried at historical cost less accumulated depreciation. Properties held for sale are reported at the lower of the carrying value or the fair value less estimated cost to sell. The cost of operating properties includes the purchase price or development costs of the properties. Costs incurred for the renovation and betterment of the operating properties are capitalized to our investment in that property. Maintenance and repairs are charged to expense as incurred.
	When evaluating properties to be held and used for potential impairment, we first evaluate whether there are any indicators of impairment for any of our properties. If any impairment indicators are present for a specific property, we then perform an undiscounted cash flow analysis and compare the net carrying amount of the property to the property’s estimated undiscounted future cash flow over the anticipated holding period. If the estimated undiscounted future cash flow is less than the net carrying amount of the property, we then perform an impairment loss calculation to determine if the fair value of the property is less than the net carrying value of the property. Our impairment loss calculation compares the net carrying amount of the property to the property’s estimated fair value, which may be based on estimated discounted future cash flow calculations or third-party valuations or appraisals. We would recognize an impairment loss if the asset’s net carrying amount exceeds the asset’s estimated fair value. If we were to recognize an impairment loss, the estimated fair value of the asset (less costs to sell for assets held for sale) would become its new cost basis. For a depreciable long-lived asset, the new cost basis would be depreciated (amortized) over the remaining useful life of that asset. We did not record any impairment losses for the periods presented.
	Cost Capitalization
	All costs clearly associated with the development, redevelopment and construction of a property are capitalized as project costs, including internal compensation costs. In addition, the following costs are capitalized as project costs during periods in which activities necessary to prepare development and redevelopment properties for its intended use are in progress: pre-construction costs essential to the development of the property, interest, real estate taxes and insurance.
	•	For development and redevelopment properties that are pre-leased, we cease capitalization when revenue recognition commences, which is upon substantial completion of tenant improvements.
	•	For development and redevelopment properties that are not pre-leased, we may not immediately build out the tenant improvements. Therefore we cease capitalization when revenue recognition commences upon substantial completion of the tenant improvements, but in any event, no later than one year after the cessation of major construction activities. We also cease capitalization on a development or redevelopment property when activities necessary to prepare the property for its intended use have been suspended.
	•	For development or redevelopment properties with multiple tenants and staged leasing, we cease capitalization and begin depreciation on the portion of the development or redevelopment property for which revenue recognition has commenced.
	Once major construction activity has ceased and the development or redevelopment property is in the lease-up phase, the costs capitalized to construction in progress are transferred to land and improvements, buildings and improvements, and deferred leasing costs and acquisition-related intangible assets, net on our consolidated balance sheets as the historical cost of the property.
	Depreciation and Amortization of Buildings and Improvements
	The cost of buildings and improvements and tenant improvements are depreciated using the straight-line method of accounting over the estimated useful lives set forth in the table below. Depreciation expense for buildings and improvements, including discontinued operations, for the three years ended December 31, 2014, 2013, and 2012 was $153.8 million, $145.3 million and $125.9 million, respectively.
	Asset Description		Depreciable Lives
	Buildings and improvements		25 – 40 years
	Tenant improvements		1 – 20 years (1)
	________________________
	-1	Tenant improvements are amortized over the shorter of the lease term or the estimated useful life.
Discontinued Operations and Properties Held for Sale	Real Estate Assets Held for Sale, Discontinued Operations, and Land Dispositions
	A real estate asset is classified as held for sale when certain criteria are met, including but not limited to the availability of the asset for immediate sale, the existence of an active program to locate a buyer and the probable sale or transfer of the asset within one year. If such criteria are met, we present the applicable assets and liabilities related to the real estate asset held for sale, if material, separately on the balance sheet and we would cease to record depreciation and amortization expense. Real estate assets held for sale are reported at the lower of their carrying value or their estimated fair value less the estimated costs to sell. As of December 31, 2014, we had one undeveloped land parcel classified as held for sale. As of December 31, 2013, we had 12 operating properties classified as held for sale.
	The revenues and expenses of operating properties that have been sold, if material, and the revenues and expenses of operating properties that have been classified as held for sale, if material, are reported in the consolidated statements of operations as discontinued operations for all periods presented through the date of the applicable disposition. The net gains (losses) on disposition of operating properties are reported in the consolidated statements of operations as discontinued operations in the period the properties are sold. In determining whether the revenues, expenses, and net gains (losses) on dispositions of operating properties are reported as discontinued operations, we evaluate whether we have any significant continuing involvement in the operations, leasing, or management of the sold property. If we were to determine that we had any significant continuing involvement, the revenues, expenses and net gain (loss) on dispositions of the operating property would not be recorded in discontinued operations.
	The net gains (losses) on dispositions of non-depreciable real estate property, including land, are reported in the consolidated statements of operations as gains (losses) on sale of land within continuing operations in the period the land is sold.
Revenue Recognition, Tenant Reimbursements and Other Property Income	Revenue Recognition
	We recognize revenue from rent, tenant reimbursements, parking and other revenue once all of the following criteria are met: (i) the agreement has been fully executed and delivered, (ii) services have been rendered, (iii) the amount is fixed or determinable, and (iv) the collectability of the amount is reasonably assured.
	Minimum annual rental revenues are recognized in rental revenues on a straight-line basis over the term of the related lease. Rental revenue recognition commences when the tenant takes possession or controls the physical use of the leased space. In order for the tenant to take possession, the leased space must be substantially ready for its intended use. To determine whether the leased space is substantially ready for its intended use, we evaluate whether the Company owns or the tenant owns the tenant improvements. When we conclude that the Company is the owner of tenant improvements, rental revenue recognition begins when the tenant takes possession of the finished space, which is when such tenant improvements are substantially complete. In certain instances, when we conclude that the Company is not the owner (the tenant is the owner) of tenant improvements, rental revenue recognition begins when the tenant takes possession of or controls the space.
	When we conclude that the Company is the owner of tenant improvements, we record the cost to construct the tenant improvements, including costs paid for or reimbursed by the tenants, as a capital asset. For these tenant improvements, we record the amount funded by or reimbursed by the tenants as deferred revenue, which is amortized on a straight-line basis as additional rental income over the term of the related lease.
	When we conclude that the tenant is the owner of tenant improvements for accounting purposes, we record our contribution towards those improvements as a lease incentive, which is included in deferred leasing costs and acquisition-related intangible assets, net on our consolidated balance sheets and amortized as a reduction to rental income on a straight-line basis over the term of the lease.
	Tenant Reimbursements
	Reimbursements from tenants, consisting of amounts due from tenants for common area maintenance, real estate taxes and other recoverable costs, are recognized as revenue in the period the recoverable costs are incurred. Tenant reimbursements are recognized and recorded on a gross basis, as we are generally the primary obligor with respect to purchasing goods and services from third-party suppliers, have discretion in selecting the supplier, and have credit risk.
	Other Property Income
	Other property income primarily includes amounts recorded in connection with lease terminations and tenant bankruptcy settlement payments. Lease termination fees are amortized over the remaining lease term, if applicable. If there is no remaining lease term, they are recognized when received and realized. Other property income also includes miscellaneous income from tenants, such as fees related to the restoration of leased premises to their original condition and fees for late rental payments.
Allowances for Uncollectible Tenant and Deferred Rent Receivables	Allowances for Uncollectible Tenant and Deferred Rent Receivables
	We carry our current and deferred rent receivables net of allowances for uncollectible amounts. Our determination of the adequacy of these allowances is based primarily upon evaluations of individual receivables, current economic conditions, historical loss experience, and other relevant factors. The allowances are increased or decreased through the provision for bad debts on our consolidated statements of operations.
Cash and Cash Equivalents	Cash and Cash Equivalents
	We consider all highly-liquid investments with original maturities of three months or less to be cash equivalents
Restricted Cash	Restricted Cash
	Restricted cash consists of cash proceeds from dispositions that are temporarily held at qualified intermediaries for purposes of facilitating potential Section 1031 Exchanges and cash held in escrow related to acquisition holdbacks. Restricted cash also includes cash held as collateral to provide credit enhancement for the Operating Partnership’s mortgage debt, including cash reserves for capital expenditures, tenant improvements and property taxes.
Marketable Securities	Marketable Securities / Deferred Compensation Plan
	Marketable securities reported in our consolidated balance sheets represent the assets held in connection with the Kilroy Realty Corporation 2007 Deferred Compensation Plan (the “Deferred Compensation Plan”) (see Note 13 “Employee Benefit Plans” for additional information). The Deferred Compensation Plan assets are held in a limited rabbi trust and invested in various mutual and money market funds. As a result, the marketable securities are treated as trading securities for financial reporting purposes and are adjusted to fair value at the end of each accounting period, with the corresponding gains and losses recorded in interest income and other net investment gains.
Deferred Compensation Plan	At the time eligible management employees (“Participants”) defer compensation or earn mandatory Company contributions, or if we were to make a discretionary contribution, we record compensation cost and a corresponding deferred compensation plan liability, which is included in accounts payable, accrued expenses, and other liabilities on our consolidated balance sheets. This liability is adjusted to fair value at the end of each accounting period based on the performance of the benchmark funds selected by each Participant, and the impact of adjusting the liability to fair value is recorded as an increase or decrease to compensation cost. The impact of adjusting the deferred compensation plan liability to fair value and the changes in the value of the marketable securities held in connection with the Deferred Compensation Plan generally offset and therefore does not significantly impact net income.
Deferred Leasing Costs	Deferred Leasing Costs
	Costs incurred in connection with successful property leasing are capitalized as deferred leasing costs and classified as investment activities in the statement of cash flows. Deferred leasing costs consist primarily of leasing commissions and also include certain internal payroll costs and lease incentives, which are amortized using the straight-line method of accounting over the lives of the leases which generally range from one to 20 years. We reevaluate the remaining useful lives of leasing costs as the creditworthiness of our tenants and economic and market conditions change. If we determine that the estimated remaining life of a lease has changed, we adjust the amortization period accordingly. Fully amortized deferred leasing costs are written off each quarter.
Deferred Financing Costs, Debt Discounts and Premiums, Exchangeable Debt Instruments, and Gain and Losses on Early Extinguishment of Debt	Deferred Financing Costs
	Financing costs related to the origination or assumption of long-term debt are deferred and generally amortized using the straight-line method of accounting, which approximates the effective interest method, over the contractual terms of the applicable financings. Fully amortized deferred financing costs are written off when the corresponding financing is repaid. As of December 31, 2014 and 2013, deferred financing costs were reported net of accumulated amortization of $12.2 million and $13.2 million, respectively.
	Debt Discounts and Premiums
	Original issuance debt discounts and discounts/premiums related to recording debt acquired in connection with operating property acquisitions at fair value are generally amortized and accreted on a straight-line basis, which approximates the effective interest method. Discounts are recorded as additional interest expense from date of issuance or acquisition through the contractual maturity date of the related debt. Premiums are recorded as a reduction to interest expense from the date of issuance or acquisition through the contractual maturity date of the related debt. Our secured debt is presented including unamortized premiums of $10.3 million and $14.6 million as of December 31, 2014 and 2013, respectively. Our unsecured senior notes are presented net of unamortized discounts of $5.9 million and $1.9 million, as of December 31, 2014 and 2013, respectively.
	Exchangeable Debt Instruments
	The initial proceeds from exchangeable debt that may be settled in cash, including partial cash settlements, are bifurcated between a liability component and an equity component associated with the embedded conversion option. The liability and equity components of exchangeable debt are separately accounted for in a manner such that the interest expense on the exchangeable debt is not recorded at the stated rate of interest but rather at an effective rate that reflects the issuer’s conventional debt borrowing rate at the date of issuance.
	We calculate the liability component of exchangeable debt based on the present value of the contractual cash flows discounted at a comparable market conventional debt borrowing rate at the date of issuance. The difference between the principal amount and the fair value of the liability component is reported as a discount on the exchangeable debt that is accreted as additional interest expense from the issuance date through the contractual maturity date using the effective interest method. A portion of this additional interest expense is capitalized to the development and redevelopment balances qualifying for interest capitalization each period. The liability component of the exchangeable debt is reported net of discounts on our consolidated balance sheets.
	We calculate the equity component of exchangeable debt based on the difference between the initial proceeds received from the issuance of the exchangeable debt and the fair value of the liability component at the issuance date. The equity component is included in additional paid-in-capital, net of issuance costs, on our consolidated balance sheets. We allocate issuance costs for exchangeable debt between the liability and the equity components based on their relative values.
Noncontrolling Interest and Partnership Interests	Noncontrolling Interests in the Company’s Consolidated Financial Statements
	Noncontrolling interests in the Company’s consolidated financial statements represent the common limited partnership interests in the Operating Partnership not held by the Company (“noncontrolling common units”) and our interest in a consolidated subsidiary, Redwood LLC, formed during 2013 (see Note 3 “Acquisitions” for additional information).
	Noncontrolling common units are presented in the equity section of the Company’s consolidated balance sheets and reported at their proportionate share of the net assets of the Operating Partnership. Noncontrolling interests with redemption provisions that permit the issuer to settle in either cash or shares of common stock must be further evaluated to determine whether equity or temporary equity classification on the balance sheet is appropriate. Since the common units contain such a provision, we evaluated the accounting guidance and determined that the common units qualify for equity presentation in the Company’s consolidated financial statements (see Note 9 “Noncontrolling Interests on the Company’s Consolidated Financial Statements”).
	Net income attributable to noncontrolling common units is allocated based on their relative ownership percentage of the Operating Partnership during the reported period. The noncontrolling interest ownership percentage is determined by dividing the number of noncontrolling common units by the total number of common units outstanding. The issuance or redemption of additional shares of common stock or common units results in changes to the noncontrolling interest percentage as well as the total net assets of the Company. As a result, all equity transactions result in an allocation between equity and the noncontrolling interest in the Company’s consolidated balance sheets and statements of equity to account for the changes in the noncontrolling interest ownership percentage as well as the change in total net assets of the Company.
	Preferred Partnership Interests on the Operating Partnership’s Consolidated Balance Sheets
	Preferred partnership interests of the Operating Partnership represent the issued and outstanding 4,000,000 6.875% Series G Cumulative Redeemable Preferred Units (“Series G Preferred Units”) and the 4,000,000 6.375% Series H Cumulative Redeemable Preferred Units (“Series H Preferred Units”) which were outstanding as of December 31, 2014 and 2013.
	The Series G and Series H Preferred Units are presented in the permanent equity section of the Operating Partnership’s consolidated balance sheets given that the Series G and Series H Preferred Units may only be redeemed at our option (see Note 11 “Preferred and Common Units of the Operating Partnership”). The Company is the holder of both the Series G and Series H Preferred Units and for each Series G and Series H Preferred Unit the Company has an equivalent number of shares of the Company’s 6.875% Series G Cumulative Redeemable Preferred Stock and shares of the Company’s 6.375% Series H Cumulative Redeemable Preferred Stock publicly issued and outstanding.
Equity Offerings	Equity Offerings
	Underwriting commissions and offering costs incurred in connection with common equity offerings and our at-the-market stock offering program (see Note 10 “Stockholders’ Equity of the Company”) are reflected as a reduction of additional paid-in capital. Issuance costs incurred in connection with preferred equity offerings are reflected as a reduction of the carrying value of the preferred equity.
	The Company records preferred stock issuance costs as a noncash preferred equity distribution at the time we notify the holders of preferred stock or units of our intent to redeem such shares or units.
	The net proceeds from any equity offering of the Company are generally contributed to the Operating Partnership in exchange for a number of common or preferred units equivalent to the number of shares of common or preferred stock issued and are reflected in the Operating Partnership’s consolidated financial statements as an increase in partners’ capital.
Share-based Incentive Compensation Accounting	Share-based Incentive Compensation Accounting
	Compensation cost for all share-based awards, including options, requires measurement at estimated fair value on the grant date. Compensation cost is recognized over the service vesting period, which represents the requisite service period, on a straight-line basis. The grant date fair value of market measure-based share-based compensation plans are calculated using a Monte Carlo simulation pricing model. The grant date fair value of stock option grants is calculated using the Black-Scholes valuation model. Equity awards settled in cash are valued at the fair value of our common stock on the period end date through the settlement date. Equity awards settled in cash are remeasured at each reporting period and are recognized as a liability in the consolidated balance sheet during the vesting period until settlement.
	For share-based awards in which the performance period precedes the grant date, we recognize compensation cost over the requisite service period, which includes both the performance and service vesting periods, using the accelerated attribution expense method. The requisite service period begins on the date the Executive Compensation Committee authorizes the award and adopts any relevant performance measures.
	For programs with performance-based measures, the total estimated compensation cost is based on our most recent estimate of the probable achievement of the pre-established specific corporate performance measures. These estimates are based on our latest internal forecasts for each performance measure. For programs with market measures, the total estimated compensation cost is based on the fair value of the award at the grant date.
	In accordance with the provisions of our share-based incentive compensation plans, we accept the return of shares of Company common stock, at the current quoted market price, from employees to satisfy minimum statutory tax-withholding requirements related to shares that vested during the period.
	For share based awards granted by the Company, the Operating Partnership issues a number of common units equal to the number of shares of common stock ultimately granted by the Company in respect of such awards.
Basic and Diluted Net Income (Loss)	Basic and Diluted Net Income (Loss) Available to Common Stockholders per Share
	Basic net income (loss) available to common stockholders per share is computed by dividing net income (loss) available to common stockholders, after preferred distributions and the allocation of income to participating securities, by the weighted-average number of shares of common stock outstanding for the period. Diluted net income (loss) available to common stockholders per share is computed by dividing net income (loss) available for common stockholders, after preferred distributions and the allocation of income to participating securities, by the sum of the weighted-average number of shares of common stock outstanding for the period plus the assumed exercise of all dilutive securities. The impact of the outstanding common units is considered in the calculation of diluted net income (loss) available to common stockholders per share. The common units are not reflected in the diluted net income (loss) available to common stockholders per share calculation because the exchange of common units into common stock is on a one for one basis, and the common units are allocated net income on a per share basis equal to the common stock (see Note 19 “Net Income Available to Common Stockholders Per Share of the Company”). Accordingly, any exchange would not have any effect on diluted net income (loss) available to common stockholders per share.
	Nonvested share-based payment awards (including nonvested restricted stock units (“RSUs”), vested market-measure RSUs and vested dividend equivalents issued to holders of RSUs) containing nonforfeitable rights to dividends or dividend equivalents are accounted for as participating securities and included in the computation of basic and diluted net income (loss) available to common stockholders per share pursuant to the two-class method. The dilutive effect of stock options are reflected in the weighted average diluted outstanding shares calculation by application of the treasury stock method. For the period in which they were outstanding, the dilutive effect of the exchangeable debt instruments was reflected in the weighted average diluted outstanding shares calculation when the average quoted trading price of the Company’s common stock on the NYSE for the periods exchangeable was above the exchangeable debt exchange prices. The dilutive effect of the outstanding nonvested shares of common stock (“nonvested shares”) and RSUs that have not yet been granted but are contingently issuable under the share-based compensation programs is reflected in the weighted average diluted shares calculation by application of the treasury stock method at the beginning of the quarterly period in which all necessary conditions have been satisfied.
Fair Value Measurements	Fair Value Measurements
	The fair value of our financial assets and liabilities are disclosed in Note 16, "Fair Value Measurements and Disclosures," to our consolidated financial statements. The only financial assets recorded at fair value on a recurring basis in our consolidated financial statements are our marketable securities. We elected not to apply the fair value option for any of our eligible financial instruments or other items.
	We determine the estimated fair value of financial assets and liabilities utilizing a hierarchy of valuation techniques based on whether the inputs to a fair value measurement are considered to be observable or unobservable in a marketplace. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect our market assumptions. This hierarchy requires the use of observable market data when available. The following is the fair value hierarchy:
	•	Level 1 – quoted prices for identical instruments in active markets;
	•	Level 2 – quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active and model-derived valuations in which significant inputs and significant value drivers are observable in active markets; and
	•	Level 3 – fair value measurements derived from valuation techniques in which one or more significant inputs or significant value drivers are unobservable.
	We determine the fair value for the marketable securities using quoted prices in active markets for identical assets. Our other financial instruments, which are only disclosed at fair value, are comprised of secured debt, unsecured senior notes, unsecured line of credit, unsecured term loan facility and Exchangeable Notes.
	We generally determine the fair value of our secured debt, unsecured debt, and unsecured line of credit by performing discounted cash flow analyses using an appropriate market discount rate. We calculate the market rate by obtaining period-end treasury rates for maturities that correspond to the maturities of our fixed-rate debt and then adding an appropriate credit spread based on information obtained from third-party financial institutions. These credit spreads take into account factors, including but not limited to, our credit profile, the tenure of the debt, amortization period, whether the debt is secured or unsecured, and the loan-to-value ratio of the debt to the collateral. These calculations are significantly affected by the assumptions used, including the discount rate, credit spreads and estimates of future cash flow. We calculate the market rate of our unsecured line of credit, unsecured term loan facility, and unsecured term loan by obtaining the period-end London Interbank Offered Rate (“LIBOR”) rate and then adding an appropriate credit spread based on our credit ratings, and the amended terms of our unsecured line of credit, unsecured term loan facility, and unsecured term loan agreement. We determine the fair value of the liability component of our Exchangeable Notes by performing discounted cash flow analyses using an appropriate market interest rate based upon spreads for our publicly traded debt. We determine the fair value of each of our publicly traded unsecured senior notes based on their quoted trading price at the end of the reporting period, if such prices are available.
	Carrying amounts of our cash and cash equivalents, restricted cash and accounts payable approximate fair value due to their short-term maturities.
Income Taxes	Income Taxes
	We have elected to be taxed as a REIT under Sections 856 through 860 of the Code. To qualify as a REIT, we must distribute annually at least 90% of our adjusted taxable income, as defined in the Code, to our stockholders and satisfy certain other organizational and operating requirements. For distributions with respect to taxable years ended on or before December 31, 2011, Internal Revenue Service (“IRS”) guidance allows REITs to satisfy up to 90% of this requirement through the distribution of shares of common stock if certain conditions are met. We generally will not be subject to federal income taxes if we distribute 100% of our taxable income for each year to our stockholders. If we fail to qualify as a REIT in any taxable year, we will be subject to federal income taxes (including any applicable alternative minimum tax) on our taxable income at regular corporate rates and we may not be able to qualify as a REIT for four subsequent taxable years. Even if we qualify for taxation as a REIT, we may be subject to certain state and local taxes on our income and property and to federal income taxes and excise taxes on our undistributed taxable income. We believe that we have met all of the REIT distribution and technical requirements for the years ended December 31, 2014, 2013 and 2012, and we were not subject to any federal income taxes (see Note 21 “Tax Treatment of Distributions” for additional information). We intend to continue to adhere to these requirements and maintain the Company’s REIT status. Accordingly, no provision for income taxes has been made in the accompanying financial statements.
	In addition, any taxable income from our taxable REIT subsidiary, which was formed in 2002, is subject to federal, state, and local income taxes. For the years ended December 31, 2014, 2013 and 2012 the taxable REIT subsidiary had de minimis taxable income.
Uncertain Tax Positions	Uncertain Tax Positions
	We include favorable tax positions in the calculation of tax liabilities if it is more likely than not that our adopted tax position will prevail if challenged by tax authorities.
	As a result of our REIT status, we are able to claim a dividends-paid deduction on our tax return to deduct the full amount of common and preferred dividends paid to stockholders when computing our annual taxable income. Since this dividends-paid deduction has historically exceeded our taxable income, the Company has historically had significant return of capital to its stockholders. In order for us to be required to record any unrecognized tax benefits or additional tax liabilities, any adjustment for potential uncertain tax positions would need to exceed the return of capital.
	We evaluated the potential impact of identified uncertain tax positions for all tax years still subject to audit under state and federal income tax law and concluded that our return of capital would not be materially affected for any of the years still subject to audit. As of December 31, 2014, the years still subject to audit are 2010 through 2013 under the California state income tax law and 2011 through 2013 under the federal income tax law. We concluded that we did not have any unrecognized tax benefits or any additional tax liabilities as of December 31, 2014 and 2013.
Use of Estimates	Use of Estimates
	The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reported periods. Actual results could differ from those estimates.
Concentration of Credit Risk	Concentration of Credit Risk
	All of our properties and development and redevelopment projects are owned and all of our business is currently conducted in the state of California with the exception of the ownership and operation of thirteen office properties located in the state of Washington. The ability of tenants to honor the terms of their leases is dependent upon the economic, regulatory, and social factors affecting the communities in which our tenants operate.
	As of December 31, 2014, our 15 largest tenants represented approximately 35.3% of total annualized base rental revenues.
	We have deposited cash with financial institutions that is insured by the Federal Deposit Insurance Corporation (“FDIC”) up to $250,000 per institution. As of December 31, 2014 and 2013, we had cash accounts in excess of FDIC insured limits.
Recent Accounting Pronouncements	Accounting Pronouncements
	On January 9, 2015 the Financial Accounting Standards Board (“FASB”) issued final guidance on its initiative of simplifying income statement presentation by the eliminating the concept of extraordinary items (Accounting Standards Update (“ASU”) No. 2015-01). Under the guidance an entity will no longer be able to segregate an extraordinary item from the results of operations, separately present an extraordinary item on the income statement, or disclose income taxes or earnings-per-share data applicable to an extraordinary item.  The ASU is effective for all entities for reporting periods (including interim periods) beginning after December 15, 2015, and early adoption is permitted. The Company will adopt the guidance effective January 1, 2016 and the guidance is not anticipated to have a material impact on our consolidated financial statements or notes to our consolidated financial statements.
	On June 19, 2014, the FASB issued their final standard to amend the accounting guidance for stock compensation tied to performance targets (ASU No. 2014-12). The issue is the result of a consensus of the FASB Emerging Issues Task Force (Issue No. 13-D). The standard requires that a performance target that could be achieved after the requisite service period be treated as a performance condition, and as a result, this type of performance condition may delay expense recognition until achievement of the performance target is probable. The ASU is effective for all entities for reporting periods (including interim periods) beginning after December 15, 2015, and early adoption is permitted. The Company will adopt the guidance effective January 1, 2016 and the guidance is not anticipated to have a material impact on our consolidated financial statements or notes to our consolidated financial statements.
	On May 28, 2014, the FASB issued their final standard on revenue from contracts with customers. The guidance specifically notes that lease contracts with customers are a scope exception. The standard (ASU No. 2014-09) outlines a single comprehensive model for entities to use in accounting for revenues arising from contracts with customers. The ASU is effective for annual reporting periods (including interim periods), beginning after December 15, 2016, and early adoption is not permitted. The Company will adopt the guidance effective January 1, 2017 and is currently assessing the impact on our consolidated financial statements and notes to our consolidated financial statements.
	On April 10, 2014, the FASB issued final guidance to change the criteria for reporting discontinued operations while enhancing disclosures in this area (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 adopted the guidance effective January 1, 2015 and the guidance is not expected to have a material impact to our consolidated net income or our statement of financial position.
Kilroy Realty, L.P. [Member]
Basis of presentation and significant accounting policies [Line Items]
Noncontrolling Interest and Partnership Interests	Common Partnership Interests on the Operating Partnership’s Consolidated Balance Sheets
	The common units held by the Company and the noncontrolling common units held by the common limited partners are both presented in the permanent equity section of the Operating Partnership’s consolidated balance sheets in partners’ capital. The redemption rights of the noncontrolling common units permit us to settle the redemption obligation in either cash or shares of the Company’s common stock at our option (see Note 9 “Noncontrolling Interests on the Company’s Consolidated Financial Statements” for additional information).
	Noncontrolling Interests on the Operating Partnership’s Consolidated Balance Sheets
	Noncontrolling interests of the Operating Partnership represent the Company’s 1.0% general partnership interest in the Finance Partnership and the Operating Partnership‘s interest in Redwood LLC (see Note 3 “Acquisitions” for additional information). The 1.0% general partnership interest in the Finance Partnership noncontrolling interest is presented in the permanent equity section of the Operating Partnership’s consolidated balance sheets given that these interests are not convertible or redeemable into any other ownership interest of the Company or the Operating Partnership.
Basic and Diluted Net Income (Loss)	Basic and Diluted Net Income (Loss) Available to Common Unitholders per Unit
	Basic net income (loss) available to common unitholders per unit is computed by dividing net income (loss) available to common unitholders, after preferred distributions and the allocation of income to participating securities, by the weighted-average number of vested common units outstanding for the period. Diluted net income (loss) available to common unitholders per unit is computed by dividing net income (loss) available to common unitholders, after preferred distributions and the allocation of income to participating securities, by the sum of the weighted-average number of common units outstanding for the period plus the assumed exercise of all dilutive securities.
	During the periods exchangeable debt instruments were outstanding, the dilutive effect of the exchangeable debt instruments was reflected in the same manner as noted above for net income (loss) available to common stockholders per share. The dilutive effect of stock options, outstanding nonvested shares, RSUs, and awards containing nonforfeitable rights to dividend equivalents are reflected in diluted net income (loss) available to common unitholders per unit in the same manner as noted above for net income (loss) available to common stockholders per share.

Basis_of_Presentation_and_Sign2

Basis of Presentation and Significant Accounting Policies Segment Reporting (Policies)	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Segment Reporting Disclosure [Text Block]	Segment
	We currently operate in one operating segment, our office properties segment.

Organization_and_Ownership_Tab

Organization and Ownership (Tables)	12 Months Ended
	Dec. 31, 2014							Dec. 31, 2013
Real Estate Properties [Line Items]
Schedule of Real Estate Properties [Table Text Block]	Our stabilized portfolio of operating properties was comprised of the following office properties at December 31, 2014:							The major classes of assets and liabilities of the properties held for sale as of December 31, 2013 were as follows:
		Number of		Rentable	Number of	Percentage		Real estate assets and other assets held for sale	(in thousands)
		Buildings		Square Feet	Tenants	Occupied		Land and improvements	$	49,656
				(unaudited)
	Stabilized Office Properties	111		14,096,617	526	94.4	%	Buildings and improvements	209,594
	As of December 31, 2014, the following properties were excluded from our stabilized portfolio:							Total real estate held for sale	259,250
								Accumulated depreciation and amortization	(63,110		)
								Total real estate held for sale, net	196,140
		Number of	Estimated Rentable
		Properties/Projects	Square Feet (unaudited) (1)					Current receivables, net	269
	Development projects under construction	6	1,732,000
								Deferred rent receivables, net	8,978
	_______________
								Deferred leasing costs and acquisition-related intangible assets, net	5,791
	-1	Estimated rentable square feet upon completion.
								Prepaid expenses and other assets, net	1,922
								Real estate and other assets held for sale, net	$	213,100
								Liabilities and deferred revenue of real estate assets held for sale
								Accounts payable, accrued expenses and other liabilities	$	1,153
								Deferred revenue and acquisition-related intangible liabilities, net	10,723
								Rents received in advance and tenant security deposits	2,571
								Liabilities and deferred revenue of real estate assets held for sale	$	14,447

Basis_of_Presentation_and_Sign3

Basis of Presentation and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2014
Basis of Presentation and Significant Accounting Policies [Abstract]
Schedule of BUildings and Tenant Improvement Depreciable Lives
	Asset Description		Depreciable Lives
	Buildings and improvements		25 – 40 years
	Tenant improvements		1 – 20 years (1)
	________________________
	-1	Tenant improvements are amortized over the shorter of the lease term or the estimated useful life.

Acquisitions_Tables

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2014										Dec. 31, 2013
Office Properties Acquisitions
Business Acquisition [Line Items]
Acquired operating properties from unrelated third parties	During the years ended December 31, 2014 and 2013, we acquired the nine operating office properties, listed below, from unrelated third parties. Unless otherwise noted, we funded these acquisitions with proceeds from the Company’s public offerings of common stock and the Company's at-the-market stock offering program (see Note 10 “Stockholders’ Equity of the Company”), borrowings under the unsecured line of credit (see Note 7 “Secured and Unsecured Debt of the Operating Partnership”), disposition proceeds (see Note 18 “Discontinued Operations”), the assumption of existing debt and/or the issuance of common units of the Operating Partnership.
	Property		Date of Acquisition	Number of Buildings		Rentable Square Feet (unaudited)		Occupancy as of December 31, 2014 (unaudited)	Purchase Price (in millions) (1)
	2014 Acquisitions
	401 Terry Ave. N., Seattle, WA		March 13, 2014	1		140,605		100.00%	$	106.1
	1310, 1315, 1320-1324, 1325-1327 Chesapeake Terrace, Sunnyvale, CA (2)		November 5, 2014	4		266,982		86.00%	100.5
	Total (3)			5		407,587			$	206.6
	2013 Acquisitions
	320 Westlake Ave. N. and 321 Terry Ave. N.,		January 16, 2013	2		320,398		100.00%	$	170
	Seattle, WA (4)(5)
	12780 and 12790 El Camino Real, San Diego,		September 19, 2013	2		218,940		100.00%	126.4
	CA (6)
	Total (7)			4		539,338			$	296.4
	________________________
	-1	Excludes acquisition-related costs and non-lease related accrued liabilities assumed. Includes assumed unpaid leasing commissions and tenant improvements.
	-2	As of December 31, 2014, these properties, together the "Chesapeake Commons" project, were temporarily being held in a separate VIE to facilitate potential Section 1031 Exchanges (see Note 2 "Basis of Presentation and Significant Accounting Policies"). During January 2015, the Company closed out the Section 1031 Exchange related to this VIE.
	-3	The results of operations for the properties acquired during 2014 contributed $7.7 million and $2.8 million to revenues and net income from continuing operations, respectively, for the year ended December 31, 2014.
	-4	We acquired these properties through a special purpose entity wholly owned by the Finance Partnership.
	-5	In connection with this acquisition, we assumed secured debt with an outstanding principal balance of $83.9 million that was recorded at fair value on the acquisition date, resulting in a premium of approximately $11.6 million (see Note 7 “Secured and Unsecured Debt of the Operating Partnership” for additional information).
	-6	As of December 31, 2013, these properties, together the "Heights of Del Mar" project, were temporarily being held in a separate VIE to facilitate potential Section 1031 Exchanges (see Note 2 "Basis of Presentation and Significant Accounting Policies"). The $126.4 million purchase price includes $9.4 million for 4.2 acres of undeveloped land the Company acquired in connection with this acquisition.
	-7	The results of operations for the properties acquired during 2013 contributed $17.5 million and $0.9 million to revenues and net income from continuing operations, respectively, for the year ended December 31, 2013.
	The related assets, liabilities and results of operations of the acquired properties 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 at the respective acquisition dates for our 2014 and 2013 acquisitions:
	Acquisitions	Total 2014		Total 2013
		Acquisitions (1)		Acquisitions (1)
		(in thousands)
	Assets
	Land and improvements	$	81,430	$	53,790
	Buildings and improvements (2)	114,876		218,211
	Undeveloped land and construction in progress (3)	—		9,360
	Deferred leasing costs and acquisition-related intangible assets (4)	17,259		30,789
	Total assets acquired	213,565		312,150
	Liabilities
	Deferred revenue and acquisition-related intangible liabilities (5)	6,990		4,190
	Secured debt, net (6)	—		95,496
	Accounts payable, accrued expenses and other liabilities	2,029		422
	Total liabilities assumed	9,019		100,108
	Net assets and liabilities acquired (7)	$	204,546	$	212,042
	_______________
	-1	The purchase price of the two acquisitions completed during the year ended December 31, 2014, and the two acquisitions completed during the year ended December 31, 2013 were individually less than 5% and in aggregate less than 10% of the Company’s total assets as of December 31, 2014 and December 31, 2013, respectively.
	-2	Represents buildings, building improvements and tenant improvements.
	-3	In connection with one of the 2013 acquisitions, we acquired undeveloped land of approximately 4.2 acres that was added to the Company's future development pipeline upon acquisition.
	-4	Represents in-place leases (approximately $12.3 million with a weighted average amortization period of 7.0 years) and leasing commissions (approximately $4.9 million with a weighted average amortization period of 7.0 years) for the year ended December 31, 2014. Represents in-place leases (approximately $19.6 million with a weighted average amortization period of 4.7 years), above-market leases (approximately $3.2 million with a weighted average amortization period of 6.1 years) and leasing commissions (approximately $7.9 million with a weighted average amortization period of 5.9 years) for the year ended December 31, 2013.
	-5	Represents below-market leases (approximately $7.0 million and $4.2 million with a weighted average amortization period of 6.1 years and 7.7 years) for the years ended December 31, 2014 and December 31, 2013, respectively.
	-6	Represents the mortgage loan, which includes an unamortized premium balance of approximately $11.6 million at the date of acquisition, assumed in connection with the properties acquired in January 2013 (see Note 7 “Secured and Unsecured Debt of the Operating Partnership” for additional information).
	-7	Reflects the purchase price net of assumed secured debt and other lease-related obligations.
Fair values of assets acquired and liabilities assumed
Development Properties [Member]
Business Acquisition [Line Items]
Property, Plant and Equipment, Schedule of Significant Acquisitions and Disposals [Table Text Block]	During the year ended December 31, 2014, we acquired the following undeveloped land sites listed below from unrelated third parties. The acquisitions were funded with proceeds from the Company’s at-the-market stock offering program (see Note 10 “Stockholders’ Equity of the Company” for additional information), borrowings under the unsecured line of credit (see Note 7 “Secured and Unsecured Debt of the Operating Partnership” for additional information), disposition proceeds (see Note 18 “Discontinued Operations” for additional information), and issuance of common stock.										During the year ended December 31, 2013, we acquired the following land site and land previously subject to a ground lease listed below from unrelated third parties. The acquisitions were funded with proceeds from the Company’s at-the-market stock offering program (see Note 10 “Stockholders’ Equity of the Company”), borrowings under the unsecured line of credit (see Note 7 “Secured and Unsecured Debt of the Operating Partnership”), and disposition proceeds (see Note 18 “Discontinued Operations”).
	Project		Date of	Type		Purchase Price					Project		Date of	Type		Purchase Price
			Acquisition			(in millions)							Acquisition			(in millions)
	The Exchange on 16th, San Francisco, CA (1)		23-May-14	Development		$	95				Academy Project, Hollywood, CA (1)		15-Nov-13	Development		$	45
	Flower Mart, San Francisco, CA (2)		October 23, 2014, December 19, 2014	Development		71					360 Third Street, San Francisco, CA (2)		29-Oct-13	Land		27.5
	Total					$	166				Total					$	72.5
	_______________										_______________
	-1	In connection with this acquisition, we also assumed $2.3 million in accrued liabilities, which are not included in the purchase price above. As of December 31, 2014, the purchase price and assumed liabilities are included in undeveloped land and construction in progress and the assumed liabilities are included in accounts payable, accrued expenses and other liabilities on our consolidated balance sheets.									-1	In connection with this acquisition, we also assumed $0.7 million in accrued liabilities, which are not included in the purchase price above. As of December 31, 2014 and 2013, the project is included in our future development pipeline and, as a result, the underlying assets were included as undeveloped land and construction in progress in our consolidated financial statements.
	-2	In the fourth quarter of 2014, the Company closed on two adjacent land sites for a total purchase price of $71.0 million and approximately $13.4 million in transaction costs and accrued liabilities, net (see Note 15 “Commitments and Contingencies” for additional information on a portion of accrued liabilities for this transaction). The acquisitions, which were completed through the execution of two merger transactions, were partially funded through the issuance of 351,476 shares of the Company’s common stock valued at approximately $21.6 million and the remainder was paid in cash.									-2	In November 2012, we exercised an option to purchase the land underlying the ground leases at this wholly owned property. This transaction closed in October 2013 and as of December 31, 2014 and 2013, the land was included as land and improvements in our consolidated financial statements.
Fair values of assets acquired and liabilities assumed											Additionally, on June 27, 2013, the Company entered into an agreement with an unaffiliated third party and formed Redwood LLC, a new consolidated subsidiary. In connection with this transaction, the Company acquired a 0.35 acre land site, completing the first phase of the land assemblage for its plans to develop an approximate 300,000 square foot office project (the “Crossing/900” project) in Redwood City, California. In October 2013, the Company acquired a 2.0 acre undeveloped land parcel for $17.0 million, completing the final phase of the land assemblage for this project. The related assets, liabilities, and noncontrolling interest acquired in connection with this transaction are included in our consolidated financial statements as of the date of acquisition. The following table summarizes the allocation of the assets acquired and liabilities assumed at the acquisition dates (in thousands):
												Phase I			Phase II			Total
											Assets
											Undeveloped land and construction in progress	$	11,222		$	17,000		$	28,222
											Total assets	11,222			17,000			28,222
											Liabilities
											Secured debt (1)	1,750			—			1,750
											Accounts payable, accrued expenses and other liabilities	1,952			1,475			3,427
											Total liabilities	3,702			1,475			5,177
											Noncontrolling interest in consolidated subsidiary	4,885			—			4,885
											Net assets and liabilities acquired	$	2,635		$	15,525		$	18,160
											________________________
											-1	This note was repaid as of December 31, 2013.

Deferred_Leasing_Costs_and_Acq1

Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, net (Tables)	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of identified deferred leasing costs and acquisition-related intangible assets	The following table summarizes our deferred leasing costs and acquisition-related intangible assets (acquired value of leasing costs, above-market operating leases, 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 December 31, 2014 and 2013:
		December 31, 2014			December 31, 2013
		(in thousands)
	Deferred Leasing Costs and Acquisition-related Intangible Assets, net:
	Deferred leasing costs	$	216,102		$	178,720
	Accumulated amortization	(74,904		)	(63,246		)
	Deferred leasing costs, net	141,198			115,474
	Above-market operating leases	20,734			27,635
	Accumulated amortization	(13,952		)	(14,283		)
	Above-market operating leases, net	6,782			13,352
	In-place leases	97,250			100,318
	Accumulated amortization	(43,773		)	(42,999		)
	In-place leases, net	53,477			57,319
	Below-market ground lease obligation	490			490
	Accumulated amortization	(21		)	(13		)
	Below-market ground lease obligation, net	469			477
	Total deferred leasing costs and acquisition-related intangible assets, net	$	201,926		$	186,622
	Acquisition-related Intangible Liabilities, net: (1)
	Below-market operating leases	$	68,051		$	69,385
	Accumulated amortization	(30,620		)	(25,706		)
	Below-market operating leases, net	37,431			43,679
	Above-market ground lease obligation	6,320			6,320
	Accumulated amortization	(324		)	(223		)
	Above-market ground lease obligation, net	5,996			6,097
	Total acquisition-related intangible liabilities, net	$	43,427		$	49,776
	_______________
	-1	Included in deferred revenue and acquisition-related intangible liabilities, net in the consolidated balance sheets.
Amortization for the period related to deferred leasing costs and acquisition-related intangibles	The following table sets forth amortization related to deferred leasing costs and acquisition-related intangible liabilities, including amounts attributable to discontinued operations, for years ended December 31, 2014, 2013 and 2012:
		Year Ended December 31,
		2014			2013			2012
		(in thousands)
	Deferred leasing costs (1)	$	27,555		$	25,902		$	20,804
	Above-market operating leases (2)	5,303			5,664			5,695
	In-place leases (1)	21,628			29,363			21,976
	Below-market ground lease obligation (3)	8			8			205
	Below-market operating leases (4)	(13,238		)	(13,441		)	(12,393		)
	Above-market ground lease obligation (5)	(101		)	(101		)	(85		)
	Total	$	41,155		$	47,395		$	36,202
	_______________
	-1	The amortization of 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.
Estimated annual amortization related to deferred leasing costs and acquisition-related intangibles	The following table sets forth the estimated annual amortization expense related to deferred leasing costs and acquisition-related intangible assets as of December 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)
	2015	$	27,848		$	2,530		$	13,896		$	8	$	(9,886	)	$	(101	)
	2016	25,051			1,503			10,922			8		(8,403		)	(101		)
	2017	22,128			1,241			9,281			8		(7,337		)	(101		)
	2018	18,580			831			6,373			8		(5,735		)	(101		)
	2019	14,227			643			4,714			8		(3,597		)	(101		)
	Thereafter	33,364			34			8,291			429		(2,473		)	(5,491		)
	Total	$	141,198		$	6,782		$	53,477		$	469	$	(37,431	)	$	(5,996	)
	_______________
	-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)	12 Months Ended
	Dec. 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 December 31, 2014 and 2013:
		31-Dec-14			31-Dec-13
		(in thousands)
	Current receivables (1)	$	9,228		$	12,866
	Allowance for uncollectible tenant receivables (1)	(1,999		)	(2,123		)
	Current receivables, net (1)	$	7,229		$	10,743
	______________
	-1	Excludes current receivables, net related to real estate held for sale.
Deferred Rent Receivables, net	Deferred rent receivables, net consisted of the following as of December 31, 2014 and 2013:
		31-Dec-14			December 31, 2013
		(in thousands)
	Deferred rent receivables	$	158,405		$	129,198
	Allowance for deferred rent receivables	(1,989		)	(2,075		)
	Deferred rent receivables, net	$	156,416		$	127,123

Secured_and_Unsecured_Debt_of_2

Secured and Unsecured Debt of the Operating Partnership (Tables) (Kilroy Realty, L.P. [Member])	12 Months Ended
	Dec. 31, 2014
Debt Instrument [Line Items]
Schedule of Line of Credit Facilities [Table Text Block]	In the second quarter of 2014, the Company amended the terms of our unsecured revolving credit facility and the Company’s $150.0 million unsecured term loan facility. The amendment increased the size of the Company’s unsecured line of credit to $600.0 million, extended the maturity to July 2019 on both the unsecured revolving credit facility and unsecured term loan facility, reduced the annual interest rate on the unsecured revolving credit facility to LIBOR plus 1.250% and reduced the annual interest rate on the unsecured term loan facility to LIBOR plus 1.40%. The amendment did not affect the outstanding borrowings under the credit facility.
	The following table summarizes the balance and terms of our unsecured revolving credit facility as of December 31, 2014 and December 31, 2013:
		December 31, 2014			December 31, 2013
		(in thousands)
	Outstanding borrowings	$	140,000		$	45,000
	Remaining borrowing capacity	460,000			455,000
	Total borrowing capacity (1)	$	600,000		$	500,000
	Interest rate (2)(3)	1.41		%	1.62		%
	Facility fee-annual rate (4)	0.25%			0.30%
	Maturity date	Jul-19			Apr-17
	_______________
	-1	We may elect to borrow, subject to bank approval and obtaining commitments for any additional borrowing capacity, up to an additional $311.0 million under an accordion feature under the terms of the unsecured revolving credit facility and unsecured term loan facility.
	-2	Our unsecured revolving credit facility interest rate was calculated based on an annual rate of LIBOR plus 1.250% as of December 31, 2014.
	-3	Our unsecured revolving credit facility interest rate was calculated based on an annual rate of LIBOR plus 1.450% as of December 31, 2013.
	-4	Our facility fee is paid on a quarterly basis and is calculated based on the total borrowing capacity. In addition to the facility fee, we incurred debt origination and legal costs. As of December 31, 2014, $5.9 million of deferred financing costs remains to be amortized through the amended maturity date of our unsecured revolving credit facility.
	The Company intends to borrow amounts under the unsecured 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.
Schedule of Term Loan Facilities [Table Text Block]	The following table summarizes the balance and terms of our term loan facility, which is included in our unsecured debt, as of December 31, 2014 and December 31, 2013:
		December 31, 2014			December 31, 2013
		(in thousands)
	Outstanding borrowings	$	150,000		$	150,000
	Interest rate (1)(2)	1.56		%	1.92		%
	Maturity date	Jul-19			Mar-16
	_______________
	-1	Our unsecured term loan facility interest rate was calculated based on an annual rate of LIBOR plus 1.40% as of December 31, 2014.
	-2	Our unsecured term loan facility interest rate was calculated based on an annual rate of LIBOR plus 1.75% as of December 31, 2013.
	Additionally, in October 2014, the Company drew down on a $39.0 million unsecured term loan with an annual interest rate of LIBOR plus 1.40% that matures in July 2019.
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 December 31, 2014:
	Year	(in thousands)
	2015	$	395,103
	2016	99,431
	2017	71,748
	2018	451,728
	2019	405,369
	Thereafter	1,041,643
	Total (1)	$	2,465,022
	________________________
	-1	Includes gross principal balance of outstanding debt before impact of net unamortized premiums totaling approximately $4.4 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 years ended December 31, 2014, 2013 and 2012. The interest expense capitalized was recorded as a cost of development and redevelopment, and increased the carrying value of undeveloped land and construction in progress.
		Year Ended December 31,
		2014			2013				2012
		(in thousands)
	Gross interest expense	$	114,661		$	111,238			$	98,906
	Capitalized interest	(47,090		)	(35,368		)		(19,792		)
	Interest expense	$	67,571		$	75,870			$	79,114
Secured Debt [Member]
Debt Instrument [Line Items]
Debt balance and significant terms	The following table sets forth the composition of our secured debt as of December 31, 2014 and 2013:
		Annual Stated Interest Rate (1)		GAAP	Maturity Date		December 31,
	Type of Debt			Effective Rate (1)(2)			2014 (3)				2013 (3)
							(in thousands)
	Mortgage note payable	4.27%		4.27%	Feb-18		$	130,767			$	133,117
	Mortgage note payable	4.48%		4.48%	Jul-27		97,000				97,000
	Mortgage note payable (4)	6.05%		3.50%	Jun-19		89,242				92,502
	Mortgage note payable	6.51%		6.51%	Feb-17		66,647				67,663
	Mortgage note payable	5.23%		3.50%	Jan-16		52,793				54,570
	Mortgage note payable	5.57%		3.25%	Feb-16		40,258				41,654
	Mortgage note payable	5.09%		3.50%	Aug-15		34,311				34,845
	Mortgage note payable	4.94%		4.00%	Apr-15		26,285				27,641
	Mortgage note payable	7.15%		7.15%	May-17		6,568				8,972
	Other	Various		Various	Various		2,421				2,470
	Total						$	546,292			$	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 of $10.3 million and $14.6 million as of December 31, 2014 and 2013, respectively.
	-4	In January 2013, in connection with the acquisition of two office buildings in Seattle, Washington, we assumed a mortgage loan that is secured by the project. The loan requires monthly principal and interest payments based on a 6.4 year amortization period. As of December 31, 2014 and 2013, the mortgage loan had unamortized debt premiums of $8.0 million and $9.9 million, respectively.
	The Operating Partnership’s secured debt was collateralized by 31 and 21 operating properties as of December 31, 2014 and 2013, respectively, with a combined net book value of approximately $1.6 billion and $1.0 billion as of December 31, 2014 and 2013, respectively.
	Although our mortgage loans are secured and non-recourse to the Company and the Operating Partnership, the Company provides limited customary secured debt guarantees for items such as voluntary bankruptcy, fraud, misapplication of payments and environmental liabilities.
	As of December 31, 2014, nine of the Operating Partnership’s ten secured loans contained restrictions that would require the payment of prepayment penalties for the acceleration of outstanding debt. The mortgage notes payable are secured by deeds of trust on certain of our properties and the assignment of certain rents and leases associated with those properties.
Exchangeable Notes [Member]
Debt Instrument [Line Items]
Debt balance and significant terms	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”) as of December 31, 2014 and 2013. The Company repaid the 4.25% Exchangeable Notes in November 2014 upon maturity.
	4.25% Exchangeable Notes	December 31,
		2014			2013
		(in thousands)
	Principal amount	$	—		$	172,500
	Unamortized discount	—			(4,128		)
	Net carrying amount of liability component	$	—		$	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 (3)				4,800,796
	_______________
	-1	Interest on the 4.25% Exchangeable Notes was 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 conversation were subject to adjustment under certain circumstances including increases in our common dividends as of December 31, 2013.
	Prior to their maturity on November 15, 2014, the 4.25% Exchangeable Notes were exchangeable for shares of the Company's common stock only upon occurrence of certain events as follows: (i) during any calendar quarter, if 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 a specified period, (ii) during the five consecutive trading-day period following any five consecutive trading days in which the trading price per $1,000 principal amount of the Exchangeable Notes was less than 98% of the product of the closing sale price per share of the Company's common stock multiplied by the applicable exchange rate, (iii) if the Exchangeable Notes had been called for redemption, (iv) upon the occurrence of specified corporate transactions, (v) if the Company's common stock ceased to be listed or approved for quotation for 30 consecutive trading days, or (vi) on or after August 15, 2014. At any time prior to August 15, 2014, the Operating Partnership may have irrevocably elected, in its sole discretion without the consent of the holders of the 4.25% Exchangeable Notes, to settle all of the future exchange obligations of the 4.25% Exchangeable Notes in shares of common stock. Any shares of common stock delivered for settlement were based on a daily exchange value calculated on a proportionate basis for each day of a 30 day trading-day observation period.
	Upon exchange of the 4.25% Exchangeable Notes, the holders received (i) cash up to the principal amount of the 4.25% Exchangeable Notes and (ii) to the extent the exchange value exceeded the principal amount of the 4.25% Exchangeable Notes, shares of the Company’s common stock.
	In connection with the offerings of the 4.25% Exchangeable Notes, the Company entered into capped call option transactions (“capped calls”) to mitigate the dilutive impact of the potential conversion of the 4.25% Exchangeable Notes. The capped calls, as amended, were separate transactions entered into by us with the relevant financial institutions, were not part of the terms of the 4.25% Exchangeable Notes, and did not affect the holders’ rights under the 4.25% Exchangeable Notes. The strike prices of the capped calls, which were subject to customary anti-dilution adjustments, corresponded to the exchange prices of the applicable 4.25% Exchangeable Notes. The capped calls mitigated the dilutive impact to the Company of the potential exchange of all of the 4.25% Exchangeable Notes into shares of common stock. The capped calls for the 4.25% Exchangeable Notes were terminated when the notes were repaid in November 2014. As of December 31, 2013, the referenced shares of common stock under this transaction was 4,800,796 shares and the exchange price, including effect of capped calls was $42.81. The initial costs of capped calls were recorded as a reduction to additional paid-in capital.
	In the third quarter of 2014, we settled early exchanges of the 4.25% Exchangeable Notes with an aggregate principal amount of $37.0 million. For the exchange settlements, the Company paid the noteholders a total of $37.0 million in cash for the principal amount and issued to the noteholders a total of 431,270 shares of our common stock for the excess exchange value. As a result of the exchanges, the Company exercised the equivalent proportionate amount of its capped call options and, in connection received 111,206 shares of our common stock from the counterparties. This reduced the shares of common stock issued in connection with the exchanges to 320,064 shares.
	In November 2014, we repaid the remaining balance of the outstanding 4.25% Exchangeable Notes with an aggregate principal balance of $135.5 million. For the repayment settlement, the Company paid the noteholders a total of $135.5 million in cash for the principal amount and issued to the noteholders a total of 1,660,053 shares of our common stock for the excess exchange value. As a result of the exchanges, the Company exercised the equivalent proportionate amount of its capped call options and received 404,136 shares of our common stock from the counterparties thereby reducing the shares of common stock issued upon maturity to 1,255,917 shares. This reduced the shares of common stock issued in connection with the exchanges to 1,575,981 shares.
	For the 2014 period preceding maturity of the 4.25% Exchangeable Notes on November 15, 2014, and during the year ended December 31, 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 in the table below.
		Period Ended November 15, 2014(1)			Year Ended December 31, 2013
	Per share average trading price of the Company's common stock	$	60.04		$	52.12
	(1) Represents the maturity date of the 4.25% Exchangeable Notes.
	During the year ended December 31, 2013, the closing sales 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, the 4.25% Exchangeable Notes were changeable at the exchange rate stated above. No noteholders exchanged any of the 4.25% Exchangeable Notes in 2013.
	The approximate fair value of the shares exchangeable at December 31, 2013 using the per share average trading price of $52.12, would have been as follows
			Year Ended December 31, 2013
	Approximate fair value of shares upon conversion		$	247,000
	Principal amount of the 4.25% Exchangeable Notes		172,500
	Approximate fair value in excess amount of principal amount		$	74,500
	See Note 18 “Net Income Available to Common Stockholders Per Share of the Company” and Note 19 “Net Income Available to Common Unitholders Per Unit of the Operating Partnership” 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 4.25% Exchangeable Notes
	The unamortized discount on the 4.25% Exchangeable Notes, due in November 2014 and repaid upon maturity, and the 3.25% Exchangeable Notes, due in April 2012 and repaid upon maturity (together the “Exchangeable Notes”), were 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 Exchangeable Notes, in each case based on the respective effective interest rates, before the effect of capitalized interest, for the years ended December 31, 2014, 2013 and 2012:
		Year Ended December 31,
		2014			2013				2012
		(in thousands)
	Contractual interest payments (1)	$	5,608		$	7,331			$	8,721
	Amortization of discount (1)	3,769			4,427				5,052
	Interest expense attributable to the Exchangeable Notes (1)	$	9,377		$	11,758			$	13,773
	_______________
	-1	The Company repaid the 3.25% Exchangeable Notes in April 2012. Interest payments and discount amortization for the years ended December 31, 2014 and 2013 were solely attributable to the 4.25% Exchangeable Notes.
	Uns
Unsecured Senior Notes [Member]
Debt Instrument [Line Items]
Debt balance and significant terms	In July 2014, the Operating Partnership issued $400.0 million aggregate principal amount of unsecured senior notes in a registered public offering. The outstanding balance of the unsecured senior notes is included in unsecured debt, net of issuance discount of $4.3 million, on our consolidated balance sheets. The unsecured senior notes, which are scheduled to mature on August 15, 2029, require semi-annual interest payments each February and August based on a stated annual interest rate of 4.250%. The Company used a portion of the net proceeds for general corporate purposes, including the repayment of borrowings under the Operating Partnership’s unsecured revolving credit facility.
	The following table summarizes the balance and significant terms of the registered unsecured senior notes issued by the Operating Partnership as of December 31, 2014 and 2013:
									Principal Amount
									as of December 31,
		Issuance date		Maturity date	Stated		Effective interest rate (1)		2014				2013
					coupon rate
									(in thousands)
	4.250% Unsecured Senior Notes (2)	Jul-14		Aug-29	4.25%		4.35%		$	400,000			$	—
	Unamortized discount								(4,348		)		—
	Net carrying amount								$	395,652			$	—
	3.800% Unsecured Senior Notes (3)	Jan-13		Jan-23	3.80%		3.80%		$	300,000			$	300,000
	Unamortized discount								(79		)		(90		)
	Net carrying amount								$	299,921			$	299,910
	4.800% Unsecured Senior Notes (4)	Jul-11		Jul-18	4.80%		4.83%		$	325,000			$	325,000
	Unamortized discount								(265		)		(339		)
	Net carrying amount								$	324,735			$	324,661
	6.625% Unsecured Senior Notes (5)	May-10		Jun-20	6.63%		6.74%		$	250,000			$	250,000
	Unamortized discount								(1,154		)		(1,367		)
	Net carrying amount								$	248,846			$	248,633
	5.000% Unsecured Senior Notes (6)	Nov-10		Nov-15	5.00%		5.01%		$	325,000			$	325,000
	Unamortized discount								(33		)		(73		)
	Net carrying amount								$	324,967			$	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 4.250% unsecured senior notes is payable semi-annually in arrears on February 15th and August 15th of each year.
	-3	Interest on the 3.800% unsecured senior notes is payable semi-annually in arrears on January 15th and July 15th of each year.
	-4	Interest on the 4.800% unsecured senior notes is payable semi-annually in arrears on January 15th and July 15th of each year.
	-5	Interest on the 6.625% unsecured senior notes is payable semi-annually in arrears on June 1st and December 1st of each year.
	-6	Interest on the 5.000% unsecured senior notes is payable semi-annually in arrears on May 3rd and November 3rd of each year.
	In August 2014, upon maturity, we repaid our outstanding Series B unsecured senior notes which had an aggregate principal balance of $83.0 million and effective interest rate of 6.45% as of December 31, 2013.

Deferred_Revenue_and_Acquisiti1

Deferred Revenue and Acquisition Related Liabilities, net (Tables)	12 Months Ended
	Dec. 31, 2014
Deferred Revenue Disclosure [Abstract]
Deferred Revenue and Acquisition-related Liabilities	Deferred revenue and acquisition-related liabilities, net consists of the following at December 31, 2014 and 2013:
		December 31,
		2014		2013
		(in thousands)
	Deferred revenue related to tenant-funded tenant improvements (1)	$	85,757	$	48,341
	Other deferred revenue	3,055		3,169
	Acquisition-related intangible liabilities, net (2)	43,427		49,776
	Total	$	132,239	$	101,286
	________________________
	-1	Excludes deferred revenue related to tenant-funded tenant improvements related to properties held for sale at December 31, 2013.
	-2	See Note 2 “Basis of Presentation and Significant Accounting Policies” and Note 4 “Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, net” for additional information.
Estimated Amortization of Deferred Revenue Related to Tenant-funded Improvements	During the years ended December 31, 2014, 2013, and 2012, $11.0 million, $10.7 million and $9.1 million, respectively, of deferred revenue related to tenant-funded tenant improvements (including discontinued operations) was amortized and recognized as rental income. The following is the estimated amortization of deferred revenue related to tenant-funded tenant improvements as of December 31, 2014 for the next five years and thereafter:
	Year Ending	(in thousands)
	2015	$	12,402
	2016	11,955
	2017	10,802
	2018	9,177
	2019	7,780
	Thereafter	33,641
	Total	$	85,757

Stockholders_Equity_of_the_Com1

Stockholders' Equity of the Company Stockholders' Equity of the Company (Tables)	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Schedule of Common Stock Sales Under the At-the-Market Offering	Under our at-the-market stock offering programs, which commenced in July 2011 and December 2014, we may offer and sell shares of our common stock from time to time in “at-the-market” offerings. During the year ended December 31, 2014, the Company completed it's existing at-the-market stock offering program (the “July 2011 At-The-Market Program”) under which we sold an aggregate of $200.0 million in gross sales of shares, and in December 2014 commenced a new at-the-market stock offering program (the “December 2014 At-The-Market Program”) under which we may offer to sell shares of our common stock with an aggregate gross sales price of up $300.0 million.
	The following table sets forth information regarding sales of our common stock under our at-the-market offering programs for the years ended December 31, 2014, 2013 and 2012:
		Year Ended December 31,
		2014			2013		2012
		(in millions, except share data)
	Shares of common stock sold during the period	1,599,123			1,040,838		787,118
	Aggregate gross proceeds	$	104.7		$	55.3	$	37
	Aggregate net proceeds after sales agent compensation	$	103.1		$	54.4	$	36.3
	The proceeds from sales were used to fund acquisitions, development expenditures and general corporate purposes including repayment of borrowings under the unsecured revolving credit facility. During the year ended December 31, 2014, under the July 2011 At-The-Market Program, we sold 1,457,623 shares of common stock and completed the program. Since commencement of the December 2014 At-The-Market Program, as of December 31, 2014, we sold 141,500 shares of common stock and approximately $290.0 million remains 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 the December 2014 At-The-Market program.
Schedule of Accrued Dividends and Distributions	The following tables summarize accrued dividends and distributions for the noted outstanding shares of common stock, preferred stock, and noncontrolling units as of December 31, 2014 and 2013:
		December 31,
		2014			2013
		(in thousands)
	Dividends and Distributions payable to:
	Common stockholders	$	30,191		$	28,754
	Noncontrolling common unitholders of the Operating Partnership	631			632
	RSU holders (1)	421			405
	Total accrued dividends and distribution to common stockholders and noncontrolling unitholders	31,243			29,791
	Preferred stockholders	1,656			1,699
	Total accrued dividends and distributions	$	32,899		$	31,490
	______________________
	-1	The amount includes the value of the dividend equivalents that will be paid with additional fully-vested RSUs (see Note 12 “Share-Based Compensation” for additional information)
Schedule of Outstanding Shares of Common Stock, Preferred Stock and Noncontrolling Units
		December 31,
		2014		2013
	Outstanding Shares and Units:
	Common stock (1)	86,259,684		82,153,944
	Noncontrolling common units	1,804,200		1,805,200
	RSUs (2)	1,248,352		1,158,407
	Series G Preferred stock	4,000,000		4,000,000
	Series H Preferred stock	4,000,000		4,000,000
	______________________
	-1	The amount includes nonvested shares.
	-2	The amount includes nonvested RSUs. Does not include the 247,089 and 143,022 market measure-based RSUs since not all the necessary performance conditions have been met as of December 31, 2014 and 2013, respectively.

Preferred_and_Common_Units_of_1

Preferred and Common Units of the Operating Partnership (Tables)	12 Months Ended
	Dec. 31, 2014
Class of Stock [Line Items]
Schedule of Common Stock Sales Under the At-the-Market Offering	Under our at-the-market stock offering programs, which commenced in July 2011 and December 2014, we may offer and sell shares of our common stock from time to time in “at-the-market” offerings. During the year ended December 31, 2014, the Company completed it's existing at-the-market stock offering program (the “July 2011 At-The-Market Program”) under which we sold an aggregate of $200.0 million in gross sales of shares, and in December 2014 commenced a new at-the-market stock offering program (the “December 2014 At-The-Market Program”) under which we may offer to sell shares of our common stock with an aggregate gross sales price of up $300.0 million.
	The following table sets forth information regarding sales of our common stock under our at-the-market offering programs for the years ended December 31, 2014, 2013 and 2012:
		Year Ended December 31,
		2014			2013		2012
		(in millions, except share data)
	Shares of common stock sold during the period	1,599,123			1,040,838		787,118
	Aggregate gross proceeds	$	104.7		$	55.3	$	37
	Aggregate net proceeds after sales agent compensation	$	103.1		$	54.4	$	36.3
	The proceeds from sales were used to fund acquisitions, development expenditures and general corporate purposes including repayment of borrowings under the unsecured revolving credit facility. During the year ended December 31, 2014, under the July 2011 At-The-Market Program, we sold 1,457,623 shares of common stock and completed the program. Since commencement of the December 2014 At-The-Market Program, as of December 31, 2014, we sold 141,500 shares of common stock and approximately $290.0 million remains 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 the December 2014 At-The-Market program.
Redeemable Noncontrolling Interest [Table Text Block]	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:
		December 31, 2014		December 31, 2013
	Company owned common units in the Operating Partnership	86,259,684		82,153,944
	Company owned general partnership interest	98	%	97.8	%
	Noncontrolling common units of the Operating Partnership	1,804,200		1,805,200
	Ownership interest of noncontrolling interest	2	%	2.2	%
	For a further discussion of the noncontrolling common units during the years ended December 31, 2014 and 2013, refer to Note 9 “Noncontrolling Interests on the Company’s Consolidated Financial Statements”.
Schedule of Accrued Dividends and Distributions	The following tables summarize accrued dividends and distributions for the noted outstanding shares of common stock, preferred stock, and noncontrolling units as of December 31, 2014 and 2013:
		December 31,
		2014			2013
		(in thousands)
	Dividends and Distributions payable to:
	Common stockholders	$	30,191		$	28,754
	Noncontrolling common unitholders of the Operating Partnership	631			632
	RSU holders (1)	421			405
	Total accrued dividends and distribution to common stockholders and noncontrolling unitholders	31,243			29,791
	Preferred stockholders	1,656			1,699
	Total accrued dividends and distributions	$	32,899		$	31,490
	______________________
	-1	The amount includes the value of the dividend equivalents that will be paid with additional fully-vested RSUs (see Note 12 “Share-Based Compensation” for additional information)
Schedule of Outstanding Shares of Common Stock, Preferred Stock and Noncontrolling Units
		December 31,
		2014		2013
	Outstanding Shares and Units:
	Common stock (1)	86,259,684		82,153,944
	Noncontrolling common units	1,804,200		1,805,200
	RSUs (2)	1,248,352		1,158,407
	Series G Preferred stock	4,000,000		4,000,000
	Series H Preferred stock	4,000,000		4,000,000
	______________________
	-1	The amount includes nonvested shares.
	-2	The amount includes nonvested RSUs. Does not include the 247,089 and 143,022 market measure-based RSUs since not all the necessary performance conditions have been met as of December 31, 2014 and 2013, respectively.
Kilroy Realty, L.P. [Member]
Class of Stock [Line Items]
Schedule of Common Stock Sales Under the At-the-Market Offering	During the years ended December 31, 2014, 2013 and 2012, the Company utilized its at-the-market stock offering programs to issue shares of common stock (see Note 10 “Stockholders’ Equity of the Company” for additional information). The net offering proceeds and property acquired using net offering proceeds were contributed by the Company to the Operating Partnership in exchange for common units for the years ended December 31, 2014, 2013 and 2012 are as follows:
		Year Ended December 31,
		2014			2013		2012
		(in millions, except share and per share data)
	Shares of common stock contributed by the Company	1,599,123			1,040,838		787,118
	Common units exchanged for share of common stock by the Company	1,599,123			1,040,838		787,118
	Aggregate gross proceeds	$	104.7		$	55.3	$	37
	Aggregate net proceeds after sales agent compensation	$	103.1		$	54.4	$	36.3
Schedule of Accrued Dividends and Distributions	The following tables summarize accrued distributions for the noted common and preferred units as of December 31, 2014 and 2013:
		December 31, 2014			December 31, 2013
		(in thousands)
	Distributions payable to:
	General partner	$	30,191		$	28,754
	Common limited partners	631			632
	RSU holders (1)	421			405
	Total accrued distributions to common unitholders	31,243			29,791
	Preferred unitholders	1,656			1,699
	Total accrued distributions	$	32,899		$	31,490
	______________________
	-1	The amount includes the value of the dividend equivalents that will be paid with additional fully-vested RSUs (see Note 12 “Share-Based Compensation” for additional information).
Schedule of Outstanding Shares of Common Stock, Preferred Stock and Noncontrolling Units
		December 31, 2014		December 31, 2013
	Outstanding Units:
	Common units held by the general partner	86,259,684		82,153,944
	Common units held by the limited partners	1,804,200		1,805,200
	RSUs (1)	1,248,352		1,158,407
	Series G Preferred units	4,000,000		4,000,000
	Series H Preferred units	4,000,000		4,000,000
	______________________
	-1	Does not include the 247,089 and 143,022 market measure-based RSUs since not all the necessary performance conditions have been met as of December 31, 2014 and 2013, respectively.
	2012 Redemption of 7.80% Series E and 7.50% Series F Cumulative Redeemable Preferred Units
	On April 16, 2012, the Company redeemed all 1,610,000 outstanding units of its 7.80% Series E Cumulative Redeemable Preferred Units and all 3,450,000 outstanding units of its 7.50% Series F Cumulative Redeemable Preferred Units. As a result, for the year ended December 31, 2012, we recognized a non-recurring noncash charge of $4.9 million as a reduction to net income available to common stockholders for the original issuance costs related to the Redeemed Preferred Units.

ShareBased_Compensation_Tables

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Restricted Stock Units Valuation Assumptions
		April 2013 Market-Measure based RSU Grant
	Grant date fair value per share	$44.55
	Expected share price volatility	27.00%
	Risk-free interest rate	0.90%
	Dividend yield	3.60%
	Expected life	6 years
Summary of Nonvested Restricted Stock	A summary of our nonvested restricted stock activity from January 1, 2014 through December 31, 2014 is presented below:
		Non-Vested		Weighted-Average
		Restricted Stock		Grant Date
				Fair Value
				Per Share
	Outstanding at January 1, 2014	47,950		$	41.71
	Granted (1)	213		51.35
	Vested (2)(3)	(25,899	)	45.56
	Transferred from market-measure and time-based RSUs	62,797		50.97
	Outstanding as of December 31, 2014	85,061		$	47.05
	_______________
	-1	Includes dividend equivalents issued in accordance with the award agreements.
	-2	Includes dividend equivalents vested in accordance with the award agreements.
	-3	The total shares vested include 11,020 shares that were tendered in accordance with the terms of the 2006 Plan to satisfy minimum statutory tax withholding requirements related to the restricted shares that have vested. We accept the return of shares at the current quoted closing share price of the Company’s common stock to satisfy tax obligations.
Summary of Nonvested and Vested Restricted Stock Activity	A summary of our nonvested and vested restricted stock activity for years ended December 31, 2014, 2013 and 2012 is presented below:
		Shares Granted				Shares Vested
	Years ended December 31,	Non-Vested		Weighted-Average Grant Date		Vested Shares		Total Fair Value at Vest Date(1)
		Shares Issued		Fair Value				(in thousands)
				Per Share
	2014	213		$	51.35	(25,899	)	$	1,323
	2013	—		—		(47,291	)	2,290
	2012	62,137		41.84		(50,862	)	2,110
	_______________
	-1	Total fair value of shares vested was calculated based on the quoted closing share price of the Company’s common stock on the NYSE on the date of vesting.
Schedule of Stock Options Valuation Assumptions	The fair value of each stock option granted is estimated on the date of grant using the Black-Scholes option pricing model based on the following assumptions for the February 2012 grant.
		February 2012 Option Grant
	Fair value of options granted per share	$9.20
	Expected stock price volatility	33.00%
	Risk-free interest rate	1.35%
	Dividend yield	3.80%
	Expected life of option	6.5 years
Summary of Stock Options Activity	A summary of our stock option activity related the February 2012 grant through December 31, 2014 is presented below:
		Number of Options		Exercise Price		Intrinsic Value
						(in millions) (1)
	Outstanding at December 31, 2013	1,525,000		$	42.61	$	11.5
	Exercised	(495,000	)	42.61		9.6
	Forfeited	(22,000	)	42.61		0.4
	Outstanding at December 31, 2014 (2)	1,008,000		$	42.61	$	26.7
	Options exercisable at December 31, 2014 (3)	114,000				$	3
	_______________
	-1	The intrinsic value of a stock option is the amount by which the fair value of the underlying stock exceeds the exercise price of an option.
Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of Restricted Stock Units Award Activity	A summary of our market-measure based RSU activity for years ended December 31, 2014, 2013 and 2012 is presented below:
		RSUs Granted				RSUs Vested
	Years ended December 31,	Non-Vested		Weighted-Average		Vested RSUs		Total Vest-Date Fair Value
		RSUs Granted		Fair Value				(in thousands)
				Per Share (1)
	2014	183,365		$	64.86	(16,338	)	$	1,092
	2013	9,542		44.55		(16,338	)	811
	2012	103,239		41.2		(14,748	)	695
	A summary of our market-measure based RSU activity from January 1, 2014 through December 31, 2014 is presented below:
		Nonvested RSUs				Vested RSUs		Total RSUs
		Amount		Weighted-Average
				Fair Value
				Per Share (1)
	Outstanding at January 1, 2014	143,022		$	46.47	—		143,022
	Granted (2)	183,365		64.86		—		183,365
	Vested (3)	(16,338	)	41.53		16,338		—
	Settled (4)					(16,338	)	(16,338	)
	Transferred to time-based restricted stock units (5)	(31,455	)	53.05		—		(31,455	)
	Transferred to restricted stock (6)	(31,505	)	53.05		—		(31,505	)
	Outstanding as of December 31, 2014	247,089		$	58.77	—		247,089
	_______________
	-1	Represents the grant-date fair value for all awards excluding the 2014 Performance-Based RSU Grant. As discussed above, the 2014 Performance-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.
	-2	Includes dividend equivalents issued in accordance with the award agreements.
	-3	Includes dividend equivalents vested in accordance with the award agreements.
	-4	Represents vested RSUs that were settled in cash or shares of the Company’s common stock. Total shares settled include 8,526 shares that were tendered in accordance with the terms of the 2006 Plan to satisfy minimum statutory tax withholding requirements related to the RSUs settled. We accept the return of RSUs, at the current quoted closing share price of the Company’s common stock to satisfy tax obligations.
	-5	On January 29, 2014, the market-measure requirements related to the RSU awards granted in 2013 were met, and as a result, the shares were transferred to time-based restricted stock units since at that point the awards became subject to only time-based vesting requirements pursuant to the award agreements.
	-6
Time-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of Restricted Stock Units Award Activity	A summary of our time-based RSU activity from January 1, 2014 through December 31, 2014 is presented below:
		Nonvested RSUs				Vested RSUs		Total RSUs
		Amount		Weighted Average Fair Value
				Per Share (1)
	Outstanding at January 1, 2014	301,660		$	44.74	856,747		1,158,407
	Granted (2)	155,016		59.89		—		155,016
	Vested (3)(4)	(116,447	)	47.64		116,447		—
	Settled					(61,242	)	(61,242	)
	Canceled (5)					(3,992	)	(3,992	)
	Transferred from market-measure based (6)	31,455		53.05				31,455
	Transferred to restricted stock (7)	(30,687	)	48.88		(605	)	(31,292	)
	Outstanding as of December 31, 2014	340,997		$	51.04	907,355		1,248,352
	_______________
	-1	Represents the grant-date fair value for all awards excluding the 2014 Time-Based RSU Grant. As discussed above, the 2014 Time-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.
	-2	Includes dividend equivalents issued in accordance with the award agreements.
	-3	Includes dividend equivalents vested in accordance with the award agreements.
	-4	Represents vested RSUs that were settled in shares of the Company’s common stock. Total shares settled include 5,694 shares that were tendered in accordance with the terms of the 2006 Plan to satisfy minimum statutory tax withholding requirements related to the RSUs settled. We accept the return of RSUs at the current quoted closing share price of the Company’s common stock to satisfy tax obligations.
	-5	For shares vested but not yet settled, we accept the return of RSUs at the current quoted closing share price of the Company’s common stock to satisfy minimum statutory tax-withholding requirements related to either the issuance or vesting of RSUs in accordance with the terms of the 2006 Plan.
	-6	On January 29, 2014, the market-measure requirements related to the RSU awards granted in 2013 were met. As of December 31, 2014 the awards are only subject to time-based vesting requirements.
	-7	During January 2014, RSUs were transferred to restricted stock based on the elected distribution date.
	A summary of our time-based RSU activity for the years ended December 31, 2014, 2013 and 2012 is presented below:
		RSUs Granted				RSUs Vested
	Year ended December 31,	Non-Vested		Weighted-Average Grant Date		Vested RSUs		Total Vest-Date Fair Value (1)
		RSUs Issued		Fair Value				(in thousands)
				Per Share
	2014	155,016		$	59.89	(116,447	)	$	6,675
	2013	173,758		49.45		(89,873	)	4,495
	2012	204,829		44.34		(73,688	)	3,118
	_______________
	-1	Total fair value of RSUs vested was calculated based on the quoted closing share price of the Company’s common stock on the NYSE on the day of vesting.

Future_Minimum_Rent_Tables

Future Minimum Rent (Tables)	12 Months Ended
	Dec. 31, 2014
Leases [Abstract]
Future contractual minimum rent under operating lease	Future contractual minimum rent under operating leases as of December 31, 2014 for future periods is summarized as follows:
	Year Ending	(in thousands)
	2015	$	428,302
	2016	447,163
	2017	414,397
	2018	367,745
	2019	306,878
	Thereafter	1,217,370
	Total	$	3,181,855
	The minimum commitment under our ground leases as of December 31, 2014 for five years and thereafter is as follows:
	Year Ending	(in thousands)
	2015	$	3,120
	2016	3,120
	2017	3,120
	2018	3,120
	2019	3,120
	Thereafter	154,358
	Total (1)(2)(3)(4)	$	169,958
	________________________
	-1	Reflects the minimum ground lease obligations before the impact of ground lease extension options.
	-2	One of our ground lease obligations is subject to a fair market value adjustment every five years; however, the lease includes ground rent subprotection and infrastructure rent credits which currently limit our annual rental obligations to $1.0 million. The contractual obligations for that ground lease included above assumes the lesser of $1.0 million or annual lease rental obligation in effect as of December 31, 2014.
	-3	One of our ground lease obligations includes a component which is based on the percentage of gross income that exceeds the minimum ground rent. The minimum rent is subject to increases every five years based on 50% of the average annual percentage rent for the previous five years. Currently, gross income does not exceed the threshold requiring us to pay percentage rent. The contractual obligations for that ground lease included above assume the annual lease rental obligation in effect as of December 31, 2014.
	-4	One of our ground lease obligations is subject to a fair market value adjustment every five years based on a combination of CPI adjustments and third-party appraisals limited to maximum increases annually. The contractual obligations included above assume the annual lease rental obligation in effect as of December 31, 2014.

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Schedule of Contractual Expiration Dates for Ground Leases	The following table summarizes our properties that are held subject to long-term noncancellable ground lease obligations and the respective contractual expiration dates:
	Property	Contractual Expiration Date (1)
	601 108th Ave NE, Bellevue, WA	Nov-93
	701, 801 and 837 N. 34th Street, Seattle, WA (2)	Dec-41
	Kilroy Airport Center Phases I, II, and III, Long Beach, CA	Jul-84
	____________________
	-1	Reflects the contractual expiration date prior to the impact of any extension or purchase options held by the Company.
	-2	The Company has three 10 year and one 45 year extension option for this ground lease, which if exercised would extend the expiration date to December 2116.
Schedule Of Future Minimum Rental Payments For Ground Leases	Future contractual minimum rent under operating leases as of December 31, 2014 for future periods is summarized as follows:
	Year Ending	(in thousands)
	2015	$	428,302
	2016	447,163
	2017	414,397
	2018	367,745
	2019	306,878
	Thereafter	1,217,370
	Total	$	3,181,855
	The minimum commitment under our ground leases as of December 31, 2014 for five years and thereafter is as follows:
	Year Ending	(in thousands)
	2015	$	3,120
	2016	3,120
	2017	3,120
	2018	3,120
	2019	3,120
	Thereafter	154,358
	Total (1)(2)(3)(4)	$	169,958
	________________________
	-1	Reflects the minimum ground lease obligations before the impact of ground lease extension options.
	-2	One of our ground lease obligations is subject to a fair market value adjustment every five years; however, the lease includes ground rent subprotection and infrastructure rent credits which currently limit our annual rental obligations to $1.0 million. The contractual obligations for that ground lease included above assumes the lesser of $1.0 million or annual lease rental obligation in effect as of December 31, 2014.
	-3	One of our ground lease obligations includes a component which is based on the percentage of gross income that exceeds the minimum ground rent. The minimum rent is subject to increases every five years based on 50% of the average annual percentage rent for the previous five years. Currently, gross income does not exceed the threshold requiring us to pay percentage rent. The contractual obligations for that ground lease included above assume the annual lease rental obligation in effect as of December 31, 2014.
	-4	One of our ground lease obligations is subject to a fair market value adjustment every five years based on a combination of CPI adjustments and third-party appraisals limited to maximum increases annually. The contractual obligations included above assume the annual lease rental obligation in effect as of December 31, 2014.

Fair_Value_Measurements_and_Di1

Fair Value Measurements and Disclosures (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair value of the company's marketable securities	The only assets we record at fair value on our consolidated financial statements are the marketable securities related to our Deferred Compensation Plan (see Note 13 “Employee Benefit Plans” for additional information). The following table sets forth the fair value of our marketable securities as of December 31, 2014 and 2013:
		Fair Value (Level 1) (1)
		2014		2013
	Description	(in thousands)
	Marketable securities (2)	$	11,971	$	10,008
	_______________
	-1	Fair value calculated using Level 1 inputs 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 also 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.
Fair Value Adjustment Of Marketable Securities And Deferred Compensation Plan Liability [Table Text Block]	The following table sets forth the net gain on marketable securities recorded during the years ended December 31, 2014, 2013 and 2012:
		December 31,
		2014		2013		2012
	Description	(in thousands)
	Net gain on marketable securities	$	397	$	1,489	$	723
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 December 31, 2014 and 2013:
		December 31,
		2014				2013
		Carrying Value		Fair Value		Carrying Value		Fair Value
		(in thousands)
	Liabilities
	Secured debt (1)	$	546,292	$	559,483	$	560,434	$	568,760
	Exchangeable senior notes, net (1)(2)	—		—		168,372		178,190
	Unsecured debt, net (3)	1,783,121		1,858,492		1,431,132		1,523,052
	Unsecured line of credit (1)	140,000		140,051		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	During the year ended December 31, 2014, we repaid the 4.25% Exchangeable Notes. As of December 31, 2014, there were no exchangeable debt instruments (see Note 7 “Secured and Unsecured Debt of the Operating Partnership” for additional information).
	-3	Fair value calculated primarily using Level I inputs, which are based on quoted prices for identical instruments in active markets. The carrying value and fair value of the Level I instruments was $1,269.4 million and $1,322.2 million, respectively, as of December 31, 2014. The carrying value and fair value of the Level I instruments at December 31, 2013, was $873.5 million and $929.3 million, respectively. The carrying value and fair value of the Level II instruments was $513.7 million and $536.3 million, respectively, as of December 31, 2014. The carrying value and fair value of the Level II instruments at December 31, 2013, was $557.7 million and $593.7 million, respectively.

Discontinued_Operations_Tables

Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2014													Dec. 31, 2013
Discontinued Operations and Disposal Groups [Abstract]
Schedule of Properties Sold	The following table summarizes the properties sold during the years ended December 31, 2014, 2013 and 2012:
	Location		Property Type		Month of Disposition		Number of Buildings		Rentable			Sales Price
									Square Feet (unaudited)			(in millions) (1)
	2014 Dispositions
	San Diego Properties, San Diego, CA (2)		Office		January		12		1,049,035			$	294.7
	9785 & 9791 Towne Centre Drive, San Diego, CA		Office		June		2		126,000			29.5
	111 Pacifica, Irvine, CA		Office		September		1		67,496			15.1
	4040 Civic Center Drive, San Rafael, CA		Office		October		1		130,237			34.9
	999 Town & Country Road, Orange, CA		Office		December		1		98,551			25.3
	Total 2014 dispositions						17		1,471,319			$	399.5
	2013 Dispositions
	26541 Agoura Road, Calabasas, CA		Office		June		1		90,156			$	14.7
	8101 Kaiser Boulevard, Anaheim, CA		Office		October		1		59,790			9.6
	4910 Directors Place, San Diego CA		Office		December		1		50,360			32.6
	Total 2013 dispositions						3		200,306			$	56.9
	2012 Dispositions
	15004 Innovation Drive and 10243 Genetic Center Drive,		Office		January		2		253,676			$	146.1
	San Diego, CA
	Industrial Portfolio (3)		Industrial		November/December		39		3,413,354
	5151, 5153 & 5155 Camino Ruiz, Camarillo, CA		Office		December		4		265,372
	4175 E. La Palma Avenue, Anaheim, CA		Office		December		1		43,263
	Subtotal industrial portfolio						44		3,721,989			354.2
	Total 2012 dispositions						46		3,975,665			$	500.3
	__________________
	-1	Represents gross sales price before the impact of broker commissions and closing costs.
	-2	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. These properties were held for sale as of December 31, 2013.
	-3	The industrial portfolio was sold in two tranches in November and December 2012 to two separate third party buyers.
Schedule of Real Estate Properties [Table Text Block]	Our stabilized portfolio of operating properties was comprised of the following office properties at December 31, 2014:													The major classes of assets and liabilities of the properties held for sale as of December 31, 2013 were as follows:
		Number of			Rentable			Number of			Percentage			Real estate assets and other assets held for sale	(in thousands)
		Buildings			Square Feet			Tenants			Occupied			Land and improvements	$	49,656
					(unaudited)
	Stabilized Office Properties	111			14,096,617			526			94.4	%		Buildings and improvements	209,594
	As of December 31, 2014, the following properties were excluded from our stabilized portfolio:													Total real estate held for sale	259,250
														Accumulated depreciation and amortization	(63,110		)
														Total real estate held for sale, net	196,140
		Number of		Estimated Rentable
		Properties/Projects		Square Feet (unaudited) (1)										Current receivables, net	269
	Development projects under construction	6		1,732,000
														Deferred rent receivables, net	8,978
	_______________
														Deferred leasing costs and acquisition-related intangible assets, net	5,791
	-1	Estimated rentable square feet upon completion.
														Prepaid expenses and other assets, net	1,922
														Real estate and other assets held for sale, net	$	213,100
														Liabilities and deferred revenue of real estate assets held for sale
														Accounts payable, accrued expenses and other liabilities	$	1,153
														Deferred revenue and acquisition-related intangible liabilities, net	10,723
														Rents received in advance and tenant security deposits	2,571
														Liabilities and deferred revenue of real estate assets held for sale	$	14,447
Revenue and Expense Components Comprising Income from Discontinued Operations	For the year ended December 31, 2014, discontinued operations includes the income and net gain on all the properties sold in 2014, except for the operations deemed immaterial related to a June 2014 office property disposition. For the years ended December 31, 2013 and 2012, discontinued operations included the results of all properties sold in 2014, 2013 and 2012 and classified as held for sale at December 31, 2013. The following table summarizes the revenue and expense components that comprise income from discontinued operations for the years ended December 31, 2014, 2013 and 2012:
		Year Ended December 31,
		2014				2013				2012
		(in thousands)
	Revenues:
	Rental income	$	7,206			$	31,984			$	49,689
	Tenant reimbursements	278				3,546				6,544
	Other property income	13				5,178				1,923
	Total revenues	7,497				40,708				58,156
	Expenses:
	Property expenses	2,171				7,207				9,945
	Real estate taxes	692				3,523				5,696
	Provision for bad debts	—				—				(195		)
	Depreciation and amortization	2,061				12,600				19,379
	Total expenses	4,924				23,330				34,825
	Income from discontinued operations before net gain on dispositions of discontinued operations	2,573				17,378				23,331
	Net gain on dispositions of discontinued operations	121,922				12,252				259,245
	Total income from discontinued operations	$	124,495			$	29,630			$	282,576

Net_Income_Available_to_Common2

Net Income Available to Common Stockholders Per Share of the Company (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Net income available to common stockholders	The following table reconciles the numerator and denominator in computing the Company’s basic and diluted per-share computations for net income available to common stockholders for the years ended December 31, 2014, 2013 and 2012:
		Year Ended December 31,
		2014			2013			2012
		(in thousands, except unit and per unit amounts)
	Numerator:
	Income (loss) from continuing operations	$	59,313		$	14,935		$	(5,475	)
	(Income) loss from continuing operations attributable to noncontrolling common units of the Operating Partnership	(966		)	(36		)	656
	Preferred distributions and dividends	(13,250		)	(13,250		)	(21,088		)
	Allocation to participating securities (1)	(1,699		)	(1,689		)	(1,602		)
	Numerator for basic and diluted income (loss) from continuing operations available to common stockholders	43,398			(40		)	(27,509		)
	Income from discontinued operations	124,495			29,630			282,576
	Income from discontinued operations attributable to noncontrolling common units of the Operating Partnership	(2,623		)	(649		)	(6,843		)
	Numerator for basic and diluted net income available to common stockholders	$	165,270		$	28,941		$	248,224
	Denominator:
	Basic weighted average vested shares outstanding	83,090,235			77,343,853			69,639,623
	Effect of dilutive securities – contingently issuable shares and stock options	1,877,485			—			—
	Diluted weighted average vested shares and common stock equivalents outstanding	84,967,720			77,343,853			69,639,623
	Basic earnings per share:
	Income (loss) from continuing operations available to common stockholders per share	$	0.52		$	0		$	(0.40	)
	Income from discontinued operations per share of common stock	1.47			0.37			3.96
	Net income available to common stockholders per share	$	1.99		$	0.37		$	3.56
	Diluted earnings per share:
	Income (loss) from continuing operations available to common stockholders per share	$	0.51		$	0		$	(0.40	)
	Income from discontinued operations per share of common stock	1.44			0.37			3.96
	Net income available to common stockholders per share	$	1.95		$	0.37		$	3.56
	________________________
	-1	Participating securities include nonvested shares, certain time-based RSUs and vested market measure-based RSUs.

Net_Income_Available_to_Common3

Net Income Available to Common Unitholders Per Unit of the Operating Partnership (Tables)	12 Months Ended
	Dec. 31, 2014
Net Income Available To Common Unitholders [Line Items]
Net income available to common unitholders	The following table reconciles the numerator and denominator in computing the Company’s basic and diluted per-share computations for net income available to common stockholders for the years ended December 31, 2014, 2013 and 2012:
		Year Ended December 31,
		2014			2013			2012
		(in thousands, except unit and per unit amounts)
	Numerator:
	Income (loss) from continuing operations	$	59,313		$	14,935		$	(5,475	)
	(Income) loss from continuing operations attributable to noncontrolling common units of the Operating Partnership	(966		)	(36		)	656
	Preferred distributions and dividends	(13,250		)	(13,250		)	(21,088		)
	Allocation to participating securities (1)	(1,699		)	(1,689		)	(1,602		)
	Numerator for basic and diluted income (loss) from continuing operations available to common stockholders	43,398			(40		)	(27,509		)
	Income from discontinued operations	124,495			29,630			282,576
	Income from discontinued operations attributable to noncontrolling common units of the Operating Partnership	(2,623		)	(649		)	(6,843		)
	Numerator for basic and diluted net income available to common stockholders	$	165,270		$	28,941		$	248,224
	Denominator:
	Basic weighted average vested shares outstanding	83,090,235			77,343,853			69,639,623
	Effect of dilutive securities – contingently issuable shares and stock options	1,877,485			—			—
	Diluted weighted average vested shares and common stock equivalents outstanding	84,967,720			77,343,853			69,639,623
	Basic earnings per share:
	Income (loss) from continuing operations available to common stockholders per share	$	0.52		$	0		$	(0.40	)
	Income from discontinued operations per share of common stock	1.47			0.37			3.96
	Net income available to common stockholders per share	$	1.99		$	0.37		$	3.56
	Diluted earnings per share:
	Income (loss) from continuing operations available to common stockholders per share	$	0.51		$	0		$	(0.40	)
	Income from discontinued operations per share of common stock	1.44			0.37			3.96
	Net income available to common stockholders per share	$	1.95		$	0.37		$	3.56
	________________________
	-1	Participating securities include nonvested shares, certain time-based RSUs and vested market measure-based RSUs.
Kilroy Realty, L.P. [Member]
Net Income Available To Common Unitholders [Line Items]
Net income available to common unitholders	The following table reconciles the numerator and denominator in computing the Operating Partnership’s basic and diluted per-unit computations for net income available to common unitholders for the years ended December 31, 2014, 2013 and 2012:
		Year Ended December 31,
		2014			2013			2012
		(in thousands, except unit and per unit amounts)
	Numerator:
	Income (loss) from continuing operations	$	59,313		$	14,935		$	(5,475	)
	Income from continuing operations attributable to noncontrolling interests in consolidated subsidiaries	(247		)	(225		)	(176		)
	Preferred distributions	(13,250		)	(13,250		)	(21,088		)
	Allocation to participating securities (1)	(1,699		)	(1,689		)	(1,602		)
	Numerator for basic and diluted income (loss) from continuing operations available to common unitholders	44,117			(229		)	(28,341		)
	Income from discontinued operations	124,495			29,630			282,576
	(Income) loss from discontinued operations attributable to noncontrolling interests in consolidated subsidiaries	(13		)	1			(462		)
	Numerator for basic and diluted net income available to common unitholders	$	168,599		$	29,402		$	253,773
	Denominator:
	Basic weighted average vested units outstanding	84,894,498			79,166,260			71,403,258
	Effect of dilutive securities - contingently issuable shares and stock options	1,877,485			—			—
	Diluted weighted average vested units and common unit equivalents outstanding	86,771,983			79,166,260			71,403,258
	Basic earnings per unit:
	Income (loss) from continuing operations available to common unitholders per unit	$	0.52		$	0		$	(0.40	)
	Income from discontinued operations per common unit	1.47			0.37			3.96
	Net income available to common unitholders per unit	$	1.99		$	0.37		$	3.56
	Diluted earnings per unit:
	Income (loss) from continuing operations available to common unitholders per unit	$	0.51		$	0		$	(0.40	)
	Income from discontinued operations per common unit	1.43			0.37			3.96
	Net income available to common unitholders per unit	$	1.94		$	0.37		$	3.56
	________________________
	-1	Participating securities include nonvested shares, certain time-based RSUs and vested market measure-based RSUs.

Tax_Treatment_of_Distributions1

Tax Treatment of Distributions (Tables)	12 Months Ended
	Dec. 31, 2014
Class of Stock [Line Items]
Reconciliation of Dividends Declared to Dividends Paid [Table Text Block]	The following table reconciles the dividends declared per share of common stock to the dividends paid per share of common stock during the years ended December 31, 2014, 2013 and 2012 as follows:
		Year Ended December 31,
	Dividends	2014		2013			2012
	Dividends declared per share of common stock	1.4		1.4			1.4
	Less: Dividends declared in the current year and paid in the following year	(0.350	)	(0.350	)		(0.350	)
	Add: Dividends declared in the prior year and paid in the current year	0.35		0.35			0.35
	Dividends paid per share of common stock	1.4		1.4			1.4
Common Stock
Class of Stock [Line Items]
Reconciliation of Dividends Declared to Dividends Paid [Table Text Block]	The unaudited income tax treatment for the dividends to common stockholders reportable for the years ended December 31, 2014, 2013 and 2012 as identified in the table above was as follows:
		Year Ended December 31,
	Shares of Common Stock	2014						2013				2012
	Ordinary income	$	0.998		71.29	%		$	0.756	54	%	$	0.577	41.21	%
	Qualified dividend	0.002			0.14			0.003		0.21		—		—
	Return of capital	0.398			28.43			0.62		44.29		0.823		58.79
	Capital gains (1)	0.002			0.14			—		—		—		—
	Unrecaptured section 1250 gains	—			—			0.021		1.5		—		—
		$	1.4		100	%		$	1.4	100	%	$	1.4	100	%
	_________________
	-1	Capital gains are comprised entirely of 20% rate gains for 2014 and 2013 and 15% rate gains for 2012.
Series G Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Reconciliation of Dividends Declared to Dividends Paid [Table Text Block]	The 6.875% Series G Cumulative Redeemable Preferred Stock was issued in March 2012. The unaudited income tax treatment for the dividends to Series G preferred stockholders reportable for the years ended December 31, 2014, 2013, and 2012 was as follows:
		Year Ended December 31,
	Preferred Shares	2014						2013				2012
	Ordinary income	$	1.711		99.54	%		$	1.668	97.03	%	$	1.089	100	%
	Qualified dividend	0.003			0.17			0.006		0.35		—		—
	Capital gains (1)	0.005			0.29			—		—		—		—
	Unrecaptured section 1250 gains	—			—			0.045		2.62		—		—
		$	1.719		100	%		$	1.719	100	%	$	1.089	100	%
	__________________
	-1	Capital gains are comprised entirely of 20% rate gains for 2014 and 2013 and 15% rate gains for 2012.
Series H Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Reconciliation of Dividends Declared to Dividends Paid [Table Text Block]	The 6.375% Series H Cumulative Redeemable Preferred Stock was issued in August 2012. The unaudited income tax treatment for the dividends to Series H preferred stockholders reportable for the years ended December 31, 2014, 2013, and 2012 was as follows:
		Year Ended December 31,
	Preferred Shares	2014						2013				2012
	Ordinary income	$	1.587		99.56	%		$	1.546	96.99	%	$	0.398	100	%
	Qualified dividend	0.003			0.19			0.006		0.38		—		—
	Capital gains (1)	0.004			0.25			—		—		—		—
	Unrecaptured section 1250 gains	—			—			0.042		2.63		—		—
		$	1.594		100	%		$	1.594	100	%	$	0.398	100	%
	__________________
	-1	Capital gains are comprised entirely of 20% rate gains for 2014 and 2013 and 15% rate gains for 2012.
Series E Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Reconciliation of Dividends Declared to Dividends Paid [Table Text Block]	The 7.80% Series E Cumulative Redeemable Preferred Stock was redeemed on April 16, 2012. The unaudited income tax treatment for the dividends to Series E preferred stockholders reportable for the year ended December 31, 2012 is seen in the table below.
	Preferred Shares	Year Ended December 31, 2012
	Ordinary income	$	0.818		100	%
	Capital gains (1)	—			—
	Unrecaptured section 1250 gains	—			—
		$	0.818		100	%
	__________________
	-1	Capital gains are comprised entirely of 15% rate gains.
Series F Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Reconciliation of Dividends Declared to Dividends Paid [Table Text Block]	The 7.50% Series F Cumulative Redeemable Preferred Stock was redeemed on April 16, 2012. The unaudited income tax treatment for the dividends to Series F preferred stockholders reportable for the year ended December 31, 2012 is seen in the table below.
	Preferred Shares	Year Ended December 31, 2012
	Ordinary income	$	0.786		100	%
	Capital gains (1)	—			—
	Unrecaptured section 1250 gains	—			—
		$	0.786		100	%
	_________________
	-1	Capital gains are comprised entirely of 15% rate gains.

Quarterly_Financial_Informatio2

Quarterly Financial Information of the Company (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Schedule of Summarized Quarterly Financial Data	Summarized quarterly financial data for the years ended December 31, 2014 and 2013 was as follows:
		2014 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per share amounts)
	Revenues from continuing operations (2)	$	123,758		$	127,178		$	129,024		$	141,765
	Income from continuing operations (2)	10,874			15,854			13,168			19,417
	Income from discontinued operations (2)	91,058			15,289			6,135			12,013
	Net income	101,932			31,143			19,303			31,430
	Net income attributable to Kilroy Realty Corporation	99,845			30,540			18,982			30,852
	Preferred dividends and distributions	(3,313		)	(3,312		)	(3,313		)	(3,312		)
	Net income available to common stockholders	96,532			27,228			15,669			27,540
	Net income available to common stockholders per share – basic	1.17			0.33			0.18			0.32
	Net income available to common stockholders per share – diluted	1.14			0.32			0.18			0.32
		2013 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per share amounts)
	Revenues from continuing operations (2)	$	109,107		$	115,855		$	113,545		$	118,604
	(Loss) income from continuing operations (2)	(225		)	6,942			3,180			5,038
	Income from discontinued operations (2)	2,613			3,161			5,847			18,009
	Net income	2,388			10,103			9,027			23,047
	Net income attributable to Kilroy Realty Corporation	2,410			9,946			8,896			22,628
	Preferred dividends and distributions	(3,313		)	(3,313		)	(3,312		)	(3,312		)
	Net (loss) income available to common stockholders	(903		)	6,633			5,584			19,316
	Net (loss) income available to common stockholders per share – basic	(0.02		)	0.08			0.07			0.23
	Net (loss) income available to common stockholders per share – diluted	(0.02		)	0.08			0.07			0.23
	____________________
	-1	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common stockholders per share does not equal the annual number reported on the consolidated statements of operations due to the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended December 31, 2014 and 2013.
	-2	All periods have been adjusted from amounts previously disclosed in our quarterly filings on Form 10-Q to reclassify amounts related to discontinued operations (see Note 18 “Discontinued Operations” for additional information).

Quarterly_Financial_Informatio3

Quarterly Financial Information of the Operating Partnership (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2014
Schedule of Summarized Quarterly Financial Data	Summarized quarterly financial data for the years ended December 31, 2014 and 2013 was as follows:
		2014 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per share amounts)
	Revenues from continuing operations (2)	$	123,758		$	127,178		$	129,024		$	141,765
	Income from continuing operations (2)	10,874			15,854			13,168			19,417
	Income from discontinued operations (2)	91,058			15,289			6,135			12,013
	Net income	101,932			31,143			19,303			31,430
	Net income attributable to Kilroy Realty Corporation	99,845			30,540			18,982			30,852
	Preferred dividends and distributions	(3,313		)	(3,312		)	(3,313		)	(3,312		)
	Net income available to common stockholders	96,532			27,228			15,669			27,540
	Net income available to common stockholders per share – basic	1.17			0.33			0.18			0.32
	Net income available to common stockholders per share – diluted	1.14			0.32			0.18			0.32
		2013 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per share amounts)
	Revenues from continuing operations (2)	$	109,107		$	115,855		$	113,545		$	118,604
	(Loss) income from continuing operations (2)	(225		)	6,942			3,180			5,038
	Income from discontinued operations (2)	2,613			3,161			5,847			18,009
	Net income	2,388			10,103			9,027			23,047
	Net income attributable to Kilroy Realty Corporation	2,410			9,946			8,896			22,628
	Preferred dividends and distributions	(3,313		)	(3,313		)	(3,312		)	(3,312		)
	Net (loss) income available to common stockholders	(903		)	6,633			5,584			19,316
	Net (loss) income available to common stockholders per share – basic	(0.02		)	0.08			0.07			0.23
	Net (loss) income available to common stockholders per share – diluted	(0.02		)	0.08			0.07			0.23
	____________________
	-1	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common stockholders per share does not equal the annual number reported on the consolidated statements of operations due to the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended December 31, 2014 and 2013.
	-2	All periods have been adjusted from amounts previously disclosed in our quarterly filings on Form 10-Q to reclassify amounts related to discontinued operations (see Note 18 “Discontinued Operations” for additional information).
Kilroy Realty, L.P. [Member]
Schedule of Summarized Quarterly Financial Data	Summarized quarterly financial data for the years ended December 31, 2014 and 2013 was as follows:
		2014 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per unit amounts)
	Revenues from continuing operations (2)	$	123,758		$	127,178		$	129,024		$	141,765
	Income from continuing operations (2)	10,874			15,854			13,168			19,417
	Income from discontinued operations (2)	91,058			15,289			6,135			12,013
	Net income	101,932			31,143			19,303			31,430
	Net income attributable to the Operating Partnership	101,867			31,066			19,244			31,371
	Preferred distributions	(3,313		)	(3,312		)	(3,313		)	(3,312		)
	Net income available to common unitholders	98,554			27,754			15,931			28,059
	Net income available to common unitholders per unit – basic	1.17			0.33			0.18			0.32
	Net income available to common unitholders per unit – diluted	1.14			0.32			0.18			0.31
		2013 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per unit amounts)
	Revenues from continuing operations (2)	$	109,107		$	115,855		$	113,545		$	118,604
	(Loss) income from continuing operations (2)	(225		)	6,942			3,180			5,038
	Income from discontinued operations (2)	2,613			3,161			5,847			18,009
	Net income	2,388			10,103			9,027			23,047
	Net income attributable to the Operating Partnership	2,319			10,041			8,980			23,001
	Preferred distributions	(3,313		)	(3,313		)	(3,312		)	(3,312		)
	Net (loss) income available to common unitholders	(994		)	6,728			5,668			19,689
	Net (loss) income available to common unitholders per unit – basic	(0.02		)	0.08			0.07			0.23
	Net (loss) income available to common unitholders per unit – diluted	(0.02		)	0.08			0.07			0.23
	___________________
	-1	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common unitholders per unit does not equal the annual number reported on the consolidated statements of operations due to the impact of the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended December 31, 2014 and 2013.
	-2	All periods have been adjusted from amounts previously disclosed in our quarterly filings on Form 10-Q to reclassify amounts related to discontinued operations (see Note 18 “Discontinued Operations”).

Organization_and_Ownership_Det

Organization and Ownership (Details)	Dec. 31, 2014		Jan. 31, 2014
	property		sqft
	sqft
Real Estate Properties [Line Items]
Number of real estate properties	9
Net Rentable Area	14,096,617		79,000
Middlefield, Mountain View, CA [Member]
Real Estate Properties [Line Items]
Net Rentable Area	340,913
Stabilized Office Properties [Member]
Real Estate Properties [Line Items]
Number of real estate properties	111
Net Rentable Area	14,096,617
Number of Tenants	526
Percentage Occupied (unaudited)	94.40%
Development Properties [Member]
Real Estate Properties [Line Items]
Number of real estate properties	6	[1]
Net Rentable Area	1,732,000	[1]
Land [Member]
Real Estate Properties [Line Items]
Area of Land	103.8
[1]	Estimated rentable square feet upon completion.

Organization_and_Ownership_Det1

Organization and Ownership (Details Textuals) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012	Jan. 31, 2014
	property				sqft
	sqft
Real Estate Properties [Line Items]
Proceeds from Sale of Real Estate Held-for-investment	$427,544		$21,178	$263,572
Stabilized occupancy	95.00%
Number of real estate properties	9
Percentage of general partnership interest owned by the company in the Operating Partnership	98.00%		97.80%
Ownership interest of noncontrolling interest	2.00%		2.20%
Net Rentable Area	14,096,617				79,000
Kilroy Realty, L.P. [Member]
Real Estate Properties [Line Items]
Proceeds from Sale of Real Estate Held-for-investment	$427,544		$21,178	$263,572
Percentage of limited partnership interest owned by Operating Partnership	99.00%
Kilroy Realty Finance, Inc. [Member]
Real Estate Properties [Line Items]
Percentage of General partnership interest owned by wholly-owned subsidiary of the Company	1.00%
Washington
Real Estate Properties [Line Items]
Number of real estate properties	13
505, 555 and 605 N. Mathilda Avenue [Member]
Real Estate Properties [Line Items]
Area of Real Estate Property	587,429
Development Properties [Member]
Real Estate Properties [Line Items]
Number of real estate properties	6	[1]
Net Rentable Area	1,732,000	[1]
Middlefield, Mountain View, CA [Member]
Real Estate Properties [Line Items]
Net Rentable Area	340,913
[1]	Estimated rentable square feet upon completion.

Basis_of_Presentation_and_Sign4

Basis of Presentation and Significant Accounting Policies (Partially Owned Entities and Variable Interest Entities (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	property
Variable Interest Entity [Line Items]
Number of real estate properties	9
VIE Asset Amount	$219,600,000	$251,800,000
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	23,400,000	12,100,000
Noncontrolling interest in consolidated subsidiary	5,862,000	4,885,000
Proceeds from Sale of Real Estate Held-for-investment	427,544,000	21,178,000	263,572,000
Real Estate Investment [Member]
Variable Interest Entity [Line Items]
VIE Asset Amount	211,800,000	234,500,000
Washington
Variable Interest Entity [Line Items]
Number of real estate properties	13
Restricted cash [Member]
Variable Interest Entity [Line Items]
Proceeds from Sale of Real Estate Held-for-investment	59,200,000	32,200,000
Undeveloped Land [Member]
Variable Interest Entity [Line Items]
Business acquisition costs capitalized	$4,500,000	$2,300,000	$700,000

Basis_of_Presentation_and_Sign5

Basis of Presentation and Significant Accounting Policies (Acquisitions and Building Properties) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
	property
Property, Plant and Equipment [Line Items]
Depreciation of real estate	($153,841,000)		($145,325,000)	($125,906,000)
Number of real estate properties	9
Undeveloped Land [Member]
Property, Plant and Equipment [Line Items]
Business acquisition costs capitalized	$4,500,000		$2,300,000	$700,000
Building and Building Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property depreciable lives	25 years
Building and Building Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property depreciable lives	40 years
Leasehold Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property depreciable lives	1 year
Leasehold Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property depreciable lives	20 years
Lease Agreements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Deferred lease costs amortization period	1 year
Lease Agreements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Deferred lease costs amortization period	20 years
San Diego Properties, San Diego, CA [Member]
Property, Plant and Equipment [Line Items]
Number of real estate properties	12	[1]
San Diego Properties, San Diego, CA [Member] | Properties Held for Sale [Member]
Property, Plant and Equipment [Line Items]
Disclosure of Long Lived Assets Held-for-sale [Table Text Block]			12
[1]	Represents gross sales price before the impact of broker commissions and closing costs.

Basis_of_Presentation_and_Sign6

Basis of Presentation and Significant Accounting Policies (Deferred Finance Costs and Debt) (Details) (USD $)	12 Months Ended		1 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Mar. 31, 2012	Aug. 31, 2012
Debt Instrument [Line Items]
Amortization of Financing Costs	$12.20	$13.20
Debt premium	10.3
Secured Debt [Member]
Debt Instrument [Line Items]
Debt premium	10.3	14.6
Unamortized discount (premium), Net		-14.6
Unsecured Debt [Member]
Debt Instrument [Line Items]
Unamortized discount (premium), Net	$5.90	$1.90
Series G Cumulative Redeemable Preferred Stock
Debt Instrument [Line Items]
Preferred Units, Issued		4,000,000
Preferred stock dividend rate (percentage)	6.88%	6.88%	6.88%
Series H Cumulative Redeemable Preferred Stock
Debt Instrument [Line Items]
Preferred Units, Issued		4,000,000
Preferred stock dividend rate (percentage)	6.38%	6.38%		6.38%
Series G Cumulative Redeemable Preferred Unit [Member] | Series G Cumulative Redeemable Preferred Stock
Debt Instrument [Line Items]
Preferred Units, Issued	4,000,000
Series H Cumulative Redeemable Preferred Unit [Member] | Series H Cumulative Redeemable Preferred Stock
Debt Instrument [Line Items]
Preferred Units, Issued	4,000,000
Minimum [Member] | Lease Agreements [Member]
Debt Instrument [Line Items]
Finite-Lived Intangible Asset, Useful Life	1 year
Maximum [Member] | Lease Agreements [Member]
Debt Instrument [Line Items]
Finite-Lived Intangible Asset, Useful Life	20 years

Basis_of_Presentation_and_Sign7

Basis of Presentation and Significant Accounting Policies (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2011
	property
Basis of presentation and significant accounting policies [Line Items]
Number of real estate properties	9
REIT annual taxable income distribution requirement percentage	90.00%	90.00%
Company annual taxable income distribution	100.00%
Concentration Risk of Significant Tenants, Percentage	35.30%
Cash, FDIC Insured Amount	$250,000
Kilroy Realty Finance, Inc. [Member]
Basis of presentation and significant accounting policies [Line Items]
Percentage of General partnership interest owned by wholly-owned subsidiary of the Company	1.00%

Acquisitions_Details

Acquisitions (Details) (USD $)	1 Months Ended	12 Months Ended
	Oct. 31, 2013	Dec. 31, 2014		Dec. 31, 2013		Jan. 31, 2014	Jun. 27, 2013
				building		sqft
				sqft
Business Acquisition [Line Items]
Number of buildings		9
Net Rentable Area		14,096,617				79,000
Liabilities
Accounts Payable		$225,830,000		$198,467,000
The Crossing / 900 Project [Member]
Assets
Undeveloped land and construction in progress				28,222,000
Total assets				28,222,000
Liabilities
Secured debt				1,750,000	[1]
Accounts payable, accrued expenses and other liabilities				3,427,000
Total liabilities assumed				5,177,000
Noncontrolling interest in consolidated subsidiary				4,885,000
Net assets and liabilities acquired				18,160,000
Crossing / 900 Project, Phase I [Member]
Assets
Undeveloped land and construction in progress							11,222,000
Total assets							11,222,000
Liabilities
Secured debt							1,750,000	[1]
Accounts payable, accrued expenses and other liabilities							1,952,000
Total liabilities assumed							3,702,000
Noncontrolling interest in consolidated subsidiary							4,885,000
Net assets and liabilities acquired							2,635,000
Crossing / 900 Project, Phase II [Member]
Assets
Undeveloped land and construction in progress	17,000,000
Total assets	17,000,000
Liabilities
Secured debt	0
Accounts payable, accrued expenses and other liabilities	1,475,000
Total liabilities assumed	1,475,000
Noncontrolling interest in consolidated subsidiary	0
Net assets and liabilities acquired	15,525,000
Payments to Acquire Land	17,000,000
Kilroy Mission Bay [Member]
Liabilities
Accounts Payable		2,300,000
Payments to Acquire Land		95,000,000	[2]
SFFGA [Member]
Liabilities
Accounts Payable		0
Payments to Acquire Land		71,000,000	[2]
Office Properties Acquisitions [Member]
Business Acquisition [Line Items]
Number of buildings		5	[3],[4]	4	[3]
Net Rentable Area		407,587	[3],[4]	539,338	[3]
Purchase Price		206,600,000	[4],[5]	296,400,000	[3],[5]
Assets
Land and improvements		81,430,000		53,790,000
Buildings and improvements		114,876,000	[6]	218,211,000	[6]
Undeveloped land and construction in progress				9,360,000
Deferred leasing costs and acquisition-related intangible assets		17,259,000	[7]	30,789,000	[7]
Total assets		213,565,000	[8]	312,150,000	[8]
Liabilities
Deferred revenue and acquisition-related intangible liabilities		6,990,000	[9]	4,190,000	[9]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable		2,029,000	[8]	422,000	[8]
Secured debt				95,496,000	[8]
Total liabilities assumed		9,019,000	[8]	100,108,000	[8]
Net assets and liabilities acquired		204,546,000	[8]	212,042,000	[8]
320 & 321 Westlake Terry, Seattle WA [Member]
Business Acquisition [Line Items]
Date of Acquisition		13-Mar-14
Number of buildings				2	[10],[11]
Net Rentable Area				320,398	[10],[11]
Occupancy as of December 31, 2013				100.00%	[10],[11]
Purchase Price				170,000,000	[5]
401 Terry Avenue North, Seattle, WA [Member]
Business Acquisition [Line Items]
Number of buildings		1
Net Rentable Area		140,605
Occupancy as of December 31, 2013		100.00%
Purchase Price		106,100,000	[5]
12780 and 12790 El Camino Real, Sandiego, CA [Member]
Business Acquisition [Line Items]
Date of Acquisition		5-Nov-14
Number of buildings				2	[12]
Net Rentable Area				218,940	[12]
Occupancy as of December 31, 2013				100.00%
Purchase Price				126,400,000	[5]
1310, 1315, 1320-1324, 1325-1327 Chesapeake Terrace, Sunnyvale, CA [Domain]
Business Acquisition [Line Items]
Number of buildings		4
Net Rentable Area		266,982
Occupancy as of December 31, 2013		86.00%
Purchase Price		100,500,000	[5]
4100 - 4700 Bohannon Dr, Menlo Park, CA [Member]
Business Acquisition [Line Items]
Date of Acquisition				16-Jan-13
701 and 801 N. 34th St, Seattle, WA [Member]
Business Acquisition [Line Items]
Date of Acquisition				19-Sep-13
Middlefield, Mountain View, CA [Member]
Liabilities
Accounts Payable		$700,000
Purchase Price Of Business Combination [Member] | Assets, Total [Member] | Office Properties Acquisitions [Member]
Business Acquisition [Line Items]
Purchase price of aggregated acquisitions as percentage of Company's assets (percentage		10.00%
Purchase Price Of Business Combination [Member] | Assets, Total [Member] | 320 & 321 Westlake Terry, Seattle WA [Member]
Business Acquisition [Line Items]
Purchase price of individual acquisition as percentage of Company's assets (percentage)		5.00%
[1]	(1)This note was repaid as of DecemberB 31,B 2013.
[2]	In connection with this acquisition, we also assumed $2.3B million in accrued liabilities, which are not included in the purchase price above. As of DecemberB 31,B 2014, the purchase price and assumed liabilities are included in undeveloped land and construction in progress and the assumed liabilities are included in accounts payable, accrued expenses and other liabilities on our consolidated balance sheets.
[3]	The results of operations for the properties acquired during 2013 contributed $17.5 million and $0.9 million to revenues and net income from continuing operations, respectively, for the year ended DecemberB 31,B 2013.
[4]	The results of operations for the properties acquired during 2014 contributed $7.7B million and $2.8B million to revenues and net income from continuing operations, respectively, for the year ended DecemberB 31,B 2014.
[5]	Excludes acquisition-related costs and non-lease related accrued liabilities assumed. Includes assumed unpaid leasing commissions and tenant improvements.
[6]	Represents buildings, building improvements and tenant improvements.
[7]	Represents in-place leases (approximately $12.3B million with a weighted average amortization period of 7.0B years) and leasing commissions (approximately $4.9B million with a weighted average amortization period of 7.0B years) for the yearB ended DecemberB 31,B 2014.
[8]	The purchase price of the two acquisitions completed during the yearB ended DecemberB 31,B 2014, and the two acquisitions completed during the year ended DecemberB 31,B 2013 were individually less than 5% and in aggregate less than 10% of the Companybs total assets as of DecemberB 31,B 2014 and DecemberB 31,B 2013, respectively.
[9]	Represents below-market leases (approximately $7.0B million and $4.2B million with a weighted average amortization period of 6.1B years and 7.7 years) for the years ended DecemberB 31,B 2014 and DecemberB 31,B 2013, respectively.
[10]	We acquired these properties through a special purpose entity wholly owned by the Finance Partnership.
[11]	In connection with this acquisition, we assumed secured debt with an outstanding principal balance of $83.9B million that was recorded at fair value on the acquisition date, resulting in a premium of approximately $11.6B million (see NoteB 7 bSecured and Unsecured Debt of the Operating Partnershipb for additional information).
[12]	As of DecemberB 31,B 2013, these properties, together the "Heights of Del Mar" project, were temporarily being held in a separate VIE to facilitate potential Section 1031 Exchanges (see Note 2 "Basis of Presentation and Significant Accounting Policies"). The $126.4 million purchase price includes $9.4 million for 4.2 acres of undeveloped land the Company acquired in connection with this acquisition.

Acquisitions_Details_Textuals

Acquisitions (Details Textuals) (USD $)	12 Months Ended				1 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Oct. 23, 2014	Oct. 31, 2013	Jun. 27, 2013
	property					acre	sqft
Business Acquisition [Line Items]
Number of buildings	9
Initial premium on outstanding amount of secured debt	$10,300,000
Revenues	7,700,000		17,500,000
Net income	2,800,000		900,000
Below-market leases acquired	7,000,000
Weighted average amortization period of below-market leases	6 years 1 month 0 days
Accounts Payable and Accrued Liabilities	225,830,000		198,467,000
Kilroy Mission Bay [Member]
Business Acquisition [Line Items]
Payments to acquire land	95,000,000	[1]
Accounts Payable and Accrued Liabilities	2,300,000
Office Properties Acquisitions [Member]
Business Acquisition [Line Items]
Number of buildings	5	[2],[3]	4	[2]
Purchase price	206,600,000	[3],[4]	296,400,000	[2],[4]
In-place leases, above-market leases, and leasing commissions acquired	17,259,000	[5]	30,789,000	[5]
Deferred revenue and acquisition-related intangible liabilities	6,990,000	[6]	4,190,000	[6]
320 & 321 Westlake Terry, Seattle WA [Member]
Business Acquisition [Line Items]
Number of buildings			2	[7],[8]
Purchase price			170,000,000	[4]
12780 and 12790 El Camino Real, Sandiego, CA [Member]
Business Acquisition [Line Items]
Number of buildings			2	[9]
Purchase price			126,400,000	[4]
Area of Land			4.2
Land			9,400,000
Middlefield, Mountain View, CA [Member]
Business Acquisition [Line Items]
Purchase price			45,000,000	[10]
6121 Sunset Boulevard, Los Angeles, CA [Member]
Business Acquisition [Line Items]
Purchase price			27,500,000	[11]
SFFGA [Member]
Business Acquisition [Line Items]
Payments to acquire land	71,000,000	[1]
Accounts Payable and Accrued Liabilities	0
Common stock, shares issued					351,476
purchase price, value of shares issued to acquire land					21,600,000
Secured Debt [Member]
Business Acquisition [Line Items]
Initial premium on outstanding amount of secured debt	10,300,000		14,600,000
In-Place Leases [Member]
Business Acquisition [Line Items]
In-place leases, above-market leases, and leasing commissions acquired	12,300,000		19,600,000
Weighted average amortization period of above-market leases in years	7 years 0 months 0 days		4 years 8 months 0 days
Above Market Leases [Member]
Business Acquisition [Line Items]
In-place leases, above-market leases, and leasing commissions acquired			3,200,000
Weighted average amortization period of above-market leases in years			6 years 1 month 0 days
Deferred Leasing Costs [Member]
Business Acquisition [Line Items]
In-place leases, above-market leases, and leasing commissions acquired	4,900,000		7,900,000
Weighted average amortization period of above-market leases in years	7 years 0 months 0 days		5 years 11 months 0 days
Below-Market Leases [Member]
Business Acquisition [Line Items]
Below-market leases acquired			4,200,000
Weighted average amortization period of below-market leases			7 years 8 months 0 days
The Crossing / 900 Project [Member]
Business Acquisition [Line Items]
Area of Real Estate Property							300,000
Crossing / 900 Project, Phase I [Member]
Business Acquisition [Line Items]
Area of Land							0.35
Crossing / 900 Project, Phase II [Member]
Business Acquisition [Line Items]
Payments to acquire land						17,000,000
Area of Land						2
Kilroy Realty, L.P. [Member]
Business Acquisition [Line Items]
Accounts Payable and Accrued Liabilities	225,830,000		198,467,000
Kilroy Realty, L.P. [Member] | Secured Debt [Member]
Business Acquisition [Line Items]
Initial premium on outstanding amount of secured debt			11,600,000
Kilroy Realty, L.P. [Member] | 6.05% Mortgage Payable Due June 1, 2019 [Member] | Secured Debt [Member]
Business Acquisition [Line Items]
Initial premium on outstanding amount of secured debt	8,000,000		9,900,000
Kilroy Realty, L.P. [Member] | 6.05% Mortgage Payable Due June 1, 2019 [Member] | Secured Debt [Member] | Bohannon Drive Menlo Park, CA [Member]
Business Acquisition [Line Items]
Outstanding principal balance	83,900,000
Initial premium on outstanding amount of secured debt	$11,600,000
[1]	In connection with this acquisition, we also assumed $2.3B million in accrued liabilities, which are not included in the purchase price above. As of DecemberB 31,B 2014, the purchase price and assumed liabilities are included in undeveloped land and construction in progress and the assumed liabilities are included in accounts payable, accrued expenses and other liabilities on our consolidated balance sheets.
[2]	The results of operations for the properties acquired during 2013 contributed $17.5 million and $0.9 million to revenues and net income from continuing operations, respectively, for the year ended DecemberB 31,B 2013.
[3]	The results of operations for the properties acquired during 2014 contributed $7.7B million and $2.8B million to revenues and net income from continuing operations, respectively, for the year ended DecemberB 31,B 2014.
[4]	Excludes acquisition-related costs and non-lease related accrued liabilities assumed. Includes assumed unpaid leasing commissions and tenant improvements.
[5]	Represents in-place leases (approximately $12.3B million with a weighted average amortization period of 7.0B years) and leasing commissions (approximately $4.9B million with a weighted average amortization period of 7.0B years) for the yearB ended DecemberB 31,B 2014.
[6]	Represents below-market leases (approximately $7.0B million and $4.2B million with a weighted average amortization period of 6.1B years and 7.7 years) for the years ended DecemberB 31,B 2014 and DecemberB 31,B 2013, respectively.
[7]	We acquired these properties through a special purpose entity wholly owned by the Finance Partnership.
[8]	In connection with this acquisition, we assumed secured debt with an outstanding principal balance of $83.9B million that was recorded at fair value on the acquisition date, resulting in a premium of approximately $11.6B million (see NoteB 7 bSecured and Unsecured Debt of the Operating Partnershipb for additional information).
[9]	As of DecemberB 31,B 2013, these properties, together the "Heights of Del Mar" project, were temporarily being held in a separate VIE to facilitate potential Section 1031 Exchanges (see Note 2 "Basis of Presentation and Significant Accounting Policies"). The $126.4 million purchase price includes $9.4 million for 4.2 acres of undeveloped land the Company acquired in connection with this acquisition.
[10]	In connection with this acquisition, we also assumed $0.7 million in accrued liabilities, which are not included in the purchase price above. As of DecemberB 31,B 2014 and 2013, the project is included in our future development pipeline and, as a result, the underlying assets were included as undeveloped land and construction in progress in our consolidated financial statements.
[11]	In NovemberB 2012, we exercised an option to purchase the land underlying the ground leases at this wholly owned property. This transaction closed in October 2013 and as of DecemberB 31,B 2014 and 2013, the land was included as land and improvements in our consolidated financial statements.

Deferred_Leasing_Costs_and_Acq2

Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, net (Details) (USD $)	Dec. 31, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, Net
Total deferred leasing costs and acquisition-related intangible assets, net	$201,926		$186,622
Acquisition-related Intangible Liabilities, Net [Abstract]
Total acquisitions-related intangible liabilities, net	43,427	[1],[2]	49,776	[1],[2]
Deferred Leasing Costs [Member]
Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, Net
Finite-lived intangible assets/liabilities, gross	216,102		178,720
Accumulated amortization	-74,904		-63,246
Finite-lived intangible assets/liabilities, net	141,198		115,474
Above Market Operating Leases [Member]
Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, Net
Finite-lived intangible assets/liabilities, gross	20,734		27,635
Accumulated amortization	-13,952		-14,283
Finite-lived intangible assets/liabilities, net	6,782	[3]	13,352
Leases, Acquired-in-Place [Member]
Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, Net
Finite-lived intangible assets/liabilities, gross	97,250		100,318
Accumulated amortization	-43,773		-42,999
Finite-lived intangible assets/liabilities, net	53,477		57,319
Below-Market Ground Lease Obligation [Member]
Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, Net
Finite-lived intangible assets/liabilities, gross	490		490
Accumulated amortization	-21		-13
Finite-lived intangible assets/liabilities, net	469	[4]	477
Below Market Operating Lease [Member]
Acquisition-related Intangible Liabilities, Net [Abstract]
Acquisition-related intangible liabilities, gross	68,051		69,385
Accumulated amortization	-30,620		-25,706
Acquisition-related intangible liabilities, net	37,431	[5]	43,679
Above-Market Ground Lease Obligation [Member]
Acquisition-related Intangible Liabilities, Net [Abstract]
Acquisition-related intangible liabilities, gross	6,320		6,320
Accumulated amortization	-324		-223
Acquisition-related intangible liabilities, net	$5,996	[6]	$6,097
[1]	Included in deferred revenue and acquisition-related intangible liabilities, net in the consolidated balance sheets
[2]	See Note 2 bBasis of Presentation and Significant Accounting Policiesb and Note 4 bDeferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, netb for additional information.
[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]	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
[5]	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.
[6]	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 $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Amortization for the period related to deferred leasing costs and acquisition-related intangibles
Amortization for the period related to deferred leasing costs and acquisition-related intangibles	$41,155		$47,395		$36,202
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 intangibles	27,555	[1]	25,902	[1]	20,804	[1]
Estimated annual amortization related to acquisition-related intangibles
2015	27,848
2016	25,051
2017	22,128
2018	18,580
2019	14,227
Thereafter	33,364
Finite-lived intangible assets/liabilities, net	141,198		115,474
Above Market Operating 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 intangibles	5,303	[2]	5,664	[2]	5,695	[2]
Estimated annual amortization related to acquisition-related intangibles
2015	2,530	[3]
2016	1,503	[3]
2017	1,241	[3]
2018	831	[3]
2019	643	[3]
Thereafter	34	[3]
Finite-lived intangible assets/liabilities, net	6,782	[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 intangibles	21,628	[1]	29,363	[1]	21,976	[1]
Estimated annual amortization related to acquisition-related intangibles
2015	13,896
2016	10,922
2017	9,281
2018	6,373
2019	4,714
Thereafter	8,291
Finite-lived intangible assets/liabilities, net	53,477		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 intangibles	8	[4]	8	[4]	205	[4]
Estimated annual amortization related to acquisition-related intangibles
2015	8	[5]
2016	8	[5]
2017	8	[5]
2018	8	[5]
2019	8	[5]
Thereafter	429	[5]
Finite-lived intangible assets/liabilities, net	469	[5]	477
Below Market Operating Lease [Member]
Amortization for the period related to deferred leasing costs and acquisition-related intangibles
Amortization Of Intangible Liabilities	-13,238	[6]	-13,441	[6]	-12,393	[6]
Estimated annual amortization related to acquisition-related intangibles
2015	-9,886	[7]
2016	-8,403	[7]
2017	-7,337	[7]
2018	-5,735	[7]
2019	-3,597	[7]
Thereafter	-2,473	[7]
Total	-37,431	[7]	-43,679
Above-Market Ground Lease Obligation [Member]
Amortization for the period related to deferred leasing costs and acquisition-related intangibles
Amortization Of Intangible Liabilities	-101	[8]	-101	[8]	-85	[8]
Estimated annual amortization related to acquisition-related intangibles
2015	-101	[9]
2016	-101	[9]
2017	-101	[9]
2018	-101	[9]
2019	-101	[9]
Thereafter	-5,491	[9]
Total	($5,996)	[9]	($6,097)
[1]	The amortization of 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]	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.
[9]	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 $)	Dec. 31, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
Current Receivables, net
Current receivables	$9,228	[1]	$12,866
Allowance for uncollectible tenant receivables	-1,999	[1]	-2,123
Current receivables, net	7,229	[1]	10,743
Deferred Rent Receivables, net
Deferred rent receivables	158,405		129,198
Allowance for deferred rent receivables	-1,989		-2,075
Deferred rent receivables, net	$156,416		$127,123
[1]	Excludes current receivables, net related to real estate held for sale.

Secured_and_Unsecured_Debt_of_3

Secured and Unsecured Debt of the Company Secured and Unsecured Debt of the Company (Details) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013
Debt Instrument [Line Items]
Unsecured Debt	$1,783,121,000		$1,431,132,000
Secured debt (Notes 3, 6, 7 and 16)	546,292,000		560,434,000
Maximum dividend payment as percentage of funds from operations	95.00%
Line of Credit [Member] | $150.0 Term Loan Facility [Member]
Debt Instrument [Line Items]
Unsecured Debt	150,000,000
Unsecured Debt [Member]
Debt Instrument [Line Items]
Long-term Debt	1,900,000,000		1,600,000,000
Unsecured Debt [Member] | Thirty Nine Million Unsecured Term Loan Due July 2019 [Member]
Debt Instrument [Line Items]
Unsecured Debt	39,000,000
Unsecured Senior Notes [Member] | 6.625% Unsecured Senior Notes due June 1, 2020 [Member]
Debt Instrument [Line Items]
Stated interest rate	6.63%
Unsecured Senior Notes [Member] | 4.80% Unsecured Senior Notes due July 15, 2018 [Member]
Debt Instrument [Line Items]
Stated interest rate	4.80%
Unsecured Senior Notes [Member] | 5.00% Unsecured Senior Notes due Nov 3, 2015 [Member]
Debt Instrument [Line Items]
Stated interest rate	5.00%
Unsecured Senior Notes [Member] | 3.800% Unsecured Senior Notes [Member]
Debt Instrument [Line Items]
Stated interest rate	3.80%	[1]
Unsecured Senior Notes [Member] | Four Point Two Five Zero Percent Unsecured Senior Notes [Member] [Domain]
Debt Instrument [Line Items]
Stated interest rate	4.25%
Subsidiaries [Member]
Debt Instrument [Line Items]
Unsecured Debt	1,783,121,000		1,431,132,000
Secured debt (Notes 3, 6, 7 and 16)	546,292,000		560,434,000
Subsidiaries [Member] | Line of Credit [Member] | $150.0 Term Loan Facility [Member]
Debt Instrument [Line Items]
Unsecured Debt	150,000,000		150,000,000
Subsidiaries [Member] | Unsecured Senior Notes [Member] | 6.45% Unsecured Senior Notes due Aug 4 2014 [Member]
Debt Instrument [Line Items]
Unsecured Debt			83,000,000
Subsidiaries [Member] | Unsecured Senior Notes [Member] | 6.625% Unsecured Senior Notes due June 1, 2020 [Member]
Debt Instrument [Line Items]
Unsecured Debt	248,846,000		248,633,000
Stated interest rate	6.63%
Subsidiaries [Member] | Unsecured Senior Notes [Member] | 4.80% Unsecured Senior Notes due July 15, 2018 [Member]
Debt Instrument [Line Items]
Unsecured Debt	324,735,000		324,661,000
Stated interest rate	4.80%
Subsidiaries [Member] | Unsecured Senior Notes [Member] | 5.00% Unsecured Senior Notes due Nov 3, 2015 [Member]
Debt Instrument [Line Items]
Unsecured Debt	324,967,000		324,927,000
Stated interest rate	5.00%
Subsidiaries [Member] | Unsecured Senior Notes [Member] | 3.800% Unsecured Senior Notes [Member]
Debt Instrument [Line Items]
Unsecured Debt	299,921,000		299,910,000
Stated interest rate	3.80%
Subsidiaries [Member] | Unsecured Senior Notes [Member] | Four Point Two Five Zero Percent Unsecured Senior Notes [Member] [Domain]
Debt Instrument [Line Items]
Unsecured Debt	$395,652,000		$0
Stated interest rate	4.25%
[1]	Interest on the 3.800%B unsecured senior notes is payable semi-annually in arrears on January 15th and July 15th of each year.

Secured_and_Unsecured_Debt_of_4

Secured and Unsecured Debt of the Operating Partnership Secured and Unsecured Debt of the Operating Partnership - Secured Debt (Details) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013
Secured Debt
Secured debt (Notes 3, 6, 7 and 16)	$546,292,000		$560,434,000
Debt premium	10,300,000
Secured Debt [Member]
Secured Debt
Debt premium	10,300,000		14,600,000
Secured Debt [Member] | 4.27% Mortgage Payable due Feb 1, 2018 [Member]
Secured Debt
Secured debt (Notes 3, 6, 7 and 16)	130,800,000
Secured Debt [Member] | 4.48% Mortgage Payable due July 2027
Secured Debt
Secured debt (Notes 3, 6, 7 and 16)	97,000,000
Secured Debt [Member] | 6.05% Mortgage Payable Due June 1, 2019 [Member]
Secured Debt
Secured debt (Notes 3, 6, 7 and 16)	81,200,000
Secured Debt [Member] | 6.51% Mortgage Payable due February 1, 2017 [Member]
Secured Debt
Secured debt (Notes 3, 6, 7 and 16)	66,600,000
Secured Debt [Member] | 5.23% Mortgage Payable due January 2016 [Member]
Secured Debt
Secured debt (Notes 3, 6, 7 and 16)	51,900,000
Secured Debt [Member] | 5.57% Mortgage Note Payable due February 2016 [Member]
Secured Debt
Secured debt (Notes 3, 6, 7 and 16)	39,300,000
Secured Debt [Member] | 5.09% Mortgage Payable due August 2015 [Member] [Member]
Secured Debt
Secured debt (Notes 3, 6, 7 and 16)	34,000,000
Secured Debt [Member] | 4.94% Mortgage Payable due April 15, 2015 [Member]
Secured Debt
Secured debt (Notes 3, 6, 7 and 16)	26,200,000
Secured Debt [Member] | 7.15% Mortgage Payable due May 1, 2017 [Member]
Secured Debt
Secured debt (Notes 3, 6, 7 and 16)	6,600,000
Kilroy Realty, L.P. [Member]
Secured Debt
Secured debt (Notes 3, 6, 7 and 16)	546,292,000		560,434,000
Kilroy Realty, L.P. [Member] | Secured Debt [Member]
Secured Debt
Secured debt (Notes 3, 6, 7 and 16)	546,292,000	[1]	560,434,000	[1]
Debt premium			11,600,000
Number of properties used as collateral for secured debbt	31		21
Net book value of properties pledged as collateral for secured debt	1,600,000,000		1,000,000,000
Number of secured loans with restrictions	9
Number of secured debt	10
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 4.27% Mortgage Payable due Feb 1, 2018 [Member]
Secured Debt
Stated interest rate	4.27%	[2]
Effective interest rate	4.27%	[2],[3]
Maturity date	1-Feb-18
Secured debt (Notes 3, 6, 7 and 16)	130,767,000		133,117,000
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 4.48% Mortgage Payable due July 2027
Secured Debt
Stated interest rate	4.48%	[2]
Effective interest rate	4.48%	[2],[3]
Maturity date	1-Jul-27
Secured debt (Notes 3, 6, 7 and 16)	97,000,000	[4]	97,000,000	[4]
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 6.05% Mortgage Payable Due June 1, 2019 [Member]
Secured Debt
Stated interest rate	6.05%	[2]
Effective interest rate	3.50%	[2],[3]
Maturity date	1-Jun-19
Secured debt (Notes 3, 6, 7 and 16)	89,242,000	[1]	92,502,000	[1]
Debt premium	8,000,000		9,900,000
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 6.51% Mortgage Payable due February 1, 2017 [Member]
Secured Debt
Stated interest rate	6.51%	[2]
Effective interest rate	6.51%	[2],[3]
Maturity date	1-Feb-17
Secured debt (Notes 3, 6, 7 and 16)	66,647,000	[1]	67,663,000	[1]
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 5.23% Mortgage Payable due January 2016 [Member]
Secured Debt
Stated interest rate	5.23%	[2]
Effective interest rate	3.50%	[2],[3]
Maturity date	1-Jan-16
Secured debt (Notes 3, 6, 7 and 16)	52,793,000	[1]	54,570,000	[1]
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 5.57% Mortgage Note Payable due February 2016 [Member]
Secured Debt
Stated interest rate	5.57%	[2]
Effective interest rate	3.25%	[2],[3]
Maturity date	11-Feb-16
Secured debt (Notes 3, 6, 7 and 16)	40,258,000	[1]	41,654,000	[1]
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 5.09% Mortgage Payable due August 2015 [Member] [Member]
Secured Debt
Stated interest rate	5.09%	[2]
Effective interest rate	3.50%	[2],[3]
Maturity date	7-Aug-15
Secured debt (Notes 3, 6, 7 and 16)	34,311,000	[1]	34,845,000	[1]
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 4.94% Mortgage Payable due April 15, 2015 [Member]
Secured Debt
Stated interest rate	4.94%	[2]
Effective interest rate	4.00%	[2],[3]
Maturity date	15-Apr-15
Secured debt (Notes 3, 6, 7 and 16)	26,285,000	[1]	27,641,000	[1]
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 7.15% Mortgage Payable due May 1, 2017 [Member]
Secured Debt
Stated interest rate	7.15%	[2]
Effective interest rate	7.15%	[2],[3]
Maturity date	1-May-17
Secured debt (Notes 3, 6, 7 and 16)	6,568,000	[1]	8,972,000	[1]
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | Other [Member]
Secured Debt
Secured debt (Notes 3, 6, 7 and 16)	$2,421,000	[1]	$2,470,000	[1]
[1]	Amounts reported include the amounts of unamortized debt premiums of $10.3B million and $14.6 million as of DecemberB 31,B 2014 and 2013, respectively.
[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]	In January 2013, in connection with the acquisition of two office buildings in Seattle, Washington, we assumed a mortgage loan that is secured by the project. The loan requires monthly principal and interest payments based on a 6.4 year amortization period. As of DecemberB 31,B 2014 and 2013, the mortgage loan had unamortized debt premiums of $8.0 million and $9.9 million, respectively.

Secured_and_Unsecured_Debt_of_5

Secured and Unsecured Debt of the Operating Partnership - Exchangeable Senior Notes (Details) (USD $)	12 Months Ended			3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Sep. 30, 2014	Nov. 13, 2014
Debt Instrument [Line Items]
Debt Instrument, Unamortized Premium	$10,300,000			10,300,000
Balance and significant terms of the Exchangeable Notes outstanding
Net carrying amount of liability component	0	168,372,000		0
Kilroy Realty, L.P. [Member]
Balance and significant terms of the Exchangeable Notes outstanding
Net carrying amount of liability component	0	168,372,000		0
Kilroy Realty, L.P. [Member] | Exchangeable Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Convertible, If-converted Fair Value		247,000,000
Average Trading Price Of The Companys Stock	$60.04	$52.12
Balance and significant terms of the Exchangeable Notes outstanding
Long-term Debt, Gross	0	172,500,000		0		135,500,000
Unamortized discount	0	-4,128,000		0
Carrying amount of equity component		19,835,000
Interest expense for the Exchangeable Notes
Contractual interest payments	5,608,000	7,331,000	8,721,000
Amortization of discount	3,769,000	4,427,000	5,052,000
Interest expense attributable to the Exchangeable Notes	9,377,000	11,758,000	13,773,000
Capped call transactions
Referenced shares of common stock		4,800,796
Exchange price including effect of capped calls		42.81
Debt Instrument, Convertible, Stock Price Trigger	$35.93
Debt Instrument, Convertible, If-converted Value in Excess of Principal		74,500,000
Debt Instrument, Convertible, Number of Equity Instruments		4,800,796
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	$0	$168,372,000		0
Maturity date	15-Nov-14
Stated interest rate	4.25%			4.25%
Effective interest rate	7.13%			7.13%
Debt Instrument, Exchange Rate, Per $1,000 of Principal Value	2783.07%			2783.07%
Common Stock
Debt Disclosure [Abstract]
Stock issued during period, shares, conversion of convertible securities, net of adjustments	1,255,917
Debt Instrument [Line Items]
Stock Issued During Period, Shares, Conversion of Convertible Securities	2,091,323			1,660,053	431,270
Common Stock, Issued, Net of Capped Calls	1,575,981				320,064

Secured_and_Unsecured_Debt_of_6

Secured and Unsecured Debt of the Operating Partnership - Exchangeable Senior Notes (Details Textuals) (USD $)	3 Months Ended			9 Months Ended	12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014	Dec. 31, 2014	Nov. 13, 2014
Kilroy Realty, L.P. [Member] | Exchangeable Notes [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	0		172,500,000		0	$135,500,000
Kilroy Realty, L.P. [Member] | Exchangeable Notes [Member] | Exchangeable Note Two [Member]
Debt Instrument [Line Items]
Stated interest rate	4.25%				4.25%
Exchangeable note repurchased prinicipal amount	0		0		0
Kilroy Realty, L.P. [Member] | Exchangeable Notes [Member] | Notes exchanged during 2014 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	37,000,000				37,000,000
Common Stock
Debt Instrument [Line Items]
Stock Issued During Period, Shares, Conversion of Convertible Securities	1,660,053	431,270			2,091,323
Shares of Common stock exercised in the capped call option			404,136	111,206	515,342
Stock issued during period, shares, conversion of convertible securities, net of adjustments					1,255,917
Common Stock, Issued, Net of Capped Calls		320,064			1,575,981

Secured_and_Unsecured_Debt_of_7

Secured and Unsecured Debt of the Operating Partnership - Unsecured Senior Notes and Term Loan Facility (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Net carrying amount	$1,783,121		$1,431,132
Unsecured Debt [Member] | Thirty Nine Million Unsecured Term Loan Due July 2019 [Member]
Debt Instrument [Line Items]
Net carrying amount	39,000
Unsecured Senior Notes [Member] | Four Point Two Five Zero Percent Unsecured Senior Notes [Member] [Domain]
Debt Instrument [Line Items]
Stated interest rate	4.25%
Unsecured Senior Notes [Member] | 3.800% Unsecured Senior Notes [Member]
Debt Instrument [Line Items]
Stated interest rate	3.80%	[1]
Unsecured Senior Notes [Member] | 4.80% Unsecured Senior Notes due July 15, 2018 [Member]
Debt Instrument [Line Items]
Stated interest rate	4.80%
Unsecured Senior Notes [Member] | 6.625% Unsecured Senior Notes due June 1, 2020 [Member]
Debt Instrument [Line Items]
Stated interest rate	6.63%
Unsecured Senior Notes [Member] | 5.00% Unsecured Senior Notes due Nov 3, 2015 [Member]
Debt Instrument [Line Items]
Stated interest rate	5.00%
Line of Credit [Member] | $150.0 Term Loan Facility [Member]
Debt Instrument [Line Items]
Net carrying amount	150,000
Kilroy Realty, L.P. [Member]
Debt Instrument [Line Items]
Net carrying amount	1,783,121		1,431,132
Kilroy Realty, L.P. [Member] | Unsecured Senior Notes [Member] | Four Point Two Five Zero Percent Unsecured Senior Notes [Member] [Domain]
Debt Instrument [Line Items]
Stated interest rate	4.25%
Effective interest rate	4.35%
Principal amount	400,000		0
Unamortized discount	-4,348		0
Net carrying amount	395,652		0
Kilroy Realty, L.P. [Member] | Unsecured Senior Notes [Member] | 3.800% Unsecured Senior Notes [Member]
Debt Instrument [Line Items]
Stated interest rate	3.80%
Effective interest rate	3.80%
Principal amount	300,000		300,000
Unamortized discount	-79		-90
Net carrying amount	299,921		299,910
Kilroy Realty, L.P. [Member] | Unsecured Senior Notes [Member] | 4.80% Unsecured Senior Notes due July 15, 2018 [Member]
Debt Instrument [Line Items]
Stated interest rate	4.80%
Effective interest rate	4.83%
Principal amount	325,000		325,000
Unamortized discount	-265		-339
Net carrying amount	324,735		324,661
Kilroy Realty, L.P. [Member] | Unsecured Senior Notes [Member] | 6.625% Unsecured Senior Notes due June 1, 2020 [Member]
Debt Instrument [Line Items]
Stated interest rate	6.63%
Effective interest rate	6.74%
Principal amount	250,000		250,000
Unamortized discount	-1,154		-1,367
Net carrying amount	248,846		248,633
Kilroy Realty, L.P. [Member] | Unsecured Senior Notes [Member] | 5.00% Unsecured Senior Notes due Nov 3, 2015 [Member]
Debt Instrument [Line Items]
Stated interest rate	5.00%
Effective interest rate	5.01%
Principal amount	325,000		325,000
Unamortized discount	-33		-73
Net carrying amount	324,967		324,927
Kilroy Realty, L.P. [Member] | Unsecured Senior Notes [Member] | 6.45% Unsecured Senior Notes due Aug 4 2014 [Member]
Debt Instrument [Line Items]
Effective interest rate			6.45%	6.45%
Net carrying amount			83,000
Kilroy Realty, L.P. [Member] | Line of Credit [Member] | $150.0 Term Loan Facility [Member]
Debt Instrument [Line Items]
Maturity date	1-Jul-19		29-Mar-16
Net carrying amount	$150,000		$150,000
Spread on variable rate	1.56%		1.92%
Kilroy Realty, L.P. [Member] | Line of Credit [Member] | Thirty Nine Million Unsecured Term Loan Due July 2019 [Member]
Debt Instrument [Line Items]
Spread on variable rate	1.40%
[1]	Interest on the 3.800%B unsecured senior notes is payable semi-annually in arrears on January 15th and July 15th of each year.

Secured_and_Unsecured_Debt_of_8

Secured and Unsecured Debt of the Operating Partnership - Unsecured Revolving Credit Facility (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Line of Credit Facility [Line Items]
Unsecured Debt	$1,783,121,000	$1,431,132,000
Terms of the Credit Facility
Outstanding borrowings	140,000,000	45,000,000
Kilroy Realty, L.P. [Member]
Line of Credit Facility [Line Items]
Unsecured Debt	1,783,121,000	1,431,132,000
Terms of the Credit Facility
Outstanding borrowings	140,000,000	45,000,000
Revolving Credit Facility [Member] | Kilroy Realty, L.P. [Member]
Terms of the Credit Facility
Outstanding borrowings	140,000,000	45,000,000
Remaining borrowing capacity	460,000,000	455,000,000
Total borrowing capacity	600,000,000	500,000,000
Interest rate	1.41%	1.62%
Facility fee - annual rate	0.25%	0.30%
Maturity date	1-Jul-19	3-Apr-17
Unsecured debt additional borrowing amount	311,000,000
Spread on variable rate	1.25%	1.45%
Debt Issuance Cost	5,900,000
$150.0 Term Loan Facility [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Unsecured Debt	150,000,000
$150.0 Term Loan Facility [Member] | Line of Credit [Member] | Kilroy Realty, L.P. [Member]
Line of Credit Facility [Line Items]
Unsecured Debt	$150,000,000	$150,000,000
Terms of the Credit Facility
Spread on variable rate	1.56%	1.92%
Debt Instrument, Maturity Date	1-Jul-19	29-Mar-16
London Interbank Offered Rate (LIBOR) [Member] | $150.0 Term Loan Facility [Member] | Line of Credit [Member] | Kilroy Realty, L.P. [Member]
Terms of the Credit Facility
Spread on variable rate	1.40%	1.75%

Secured_and_Unsecured_Debt_of_9

Secured and Unsecured Debt of the Operating Partnership - Debt Maturities (Details) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Capitalized interest and loan fees
Interest expense	$67,571,000		$75,870,000	$79,114,000
Kilroy Realty, L.P. [Member]
Capitalized interest and loan fees
Gross interest expense	114,661,000		111,238,000	98,906,000
Capitalized interest	47,090,000		35,368,000	19,792,000
Interest expense	67,571,000		75,870,000	79,114,000
Debt [Member] | Kilroy Realty, L.P. [Member]
Stated debt maturities and scheduled amortization payments, excluding debt discounts
2015	395,103,000
2016	99,431,000
2017	71,748,000
2018	451,728,000
2019	405,369,000
Thereafter	1,041,643,000
Total	2,465,022,000	[1]
Unamortized discount (premium), Net	($4,400,000)
[1]	Includes gross principal balance of outstanding debt before impact of net unamortized premiums totaling approximately $4.4 million.

Deferred_Revenue_and_Acquisiti2

Deferred Revenue and Acquisition Related Liabilities, net (Details) (USD $)	Dec. 31, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred Revenue Arrangement [Line Items]
Acquisition-related intangible liabilities, net	$43,427	[1],[2]	$49,776	[1],[2]
Deferred revenue and acquisition-related intangible liabilities, net	132,239		101,286
Tenant Funded Tenant Improvements [Member]
Deferred Revenue Arrangement [Line Items]
Deferred Revenue	85,757	[3]	48,341	[3]
Other Deferred Revenue [Member]
Deferred Revenue Arrangement [Line Items]
Deferred Revenue	$3,055		$3,169
[1]	Included in deferred revenue and acquisition-related intangible liabilities, net in the consolidated balance sheets
[2]	See Note 2 bBasis of Presentation and Significant Accounting Policiesb and Note 4 bDeferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, netb for additional information.
[3]	Excludes deferred revenue related to tenant-funded tenant improvements related to properties held for sale at

Deferred_Revenue_and_Acquisiti3

Deferred Revenue and Acquisition Related Liabilities, net (Textuals) (Details) (Tenant Funded Tenant Improvements [Member], USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Tenant Funded Tenant Improvements [Member]
Deferred Revenue Arrangement [Line Items]
Deferred revenues amortized and recognized as rental income	$11,000,000		$10,700,000		$9,100,000
2015	12,402,000
2016	11,955,000
2017	10,802,000
2018	9,177,000
2019	7,780,000
Thereafter	33,641,000
Deferred revenue	$85,757,000	[1]	$48,341,000	[1]
[1]	Excludes deferred revenue related to tenant-funded tenant improvements related to properties held for sale at

Noncontrolling_Interests_on_th1

Noncontrolling Interests on the Company's Consolidated Financial Statements (Details) (USD $)	12 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Aug. 15, 2012
Noncontrolling Interest [Line Items]
Percentage of general partnership interest owned by the company in the Operating Partnership	98.00%	97.80%
Ownership interest of noncontrolling interest	2.00%	2.20%
Noncontrolling common units	1,804,200	1,805,200
Common stock, par value	$0.01
Aggregate value upon redemption of outstanding noncontrolling common units	$126,800,000	$90,800,000
Noncontrolling Interest	5,862,000	4,885,000
Redemption value			2,062,000
Original issuance costs of redeemed preferred stock and preferred units (Notes 9 and 11)	0	0	-6,980,000
Series A Cummulative Redeemable Preferred Unit [Member]
Noncontrolling Interest [Line Items]
Preferred units outstanding				1,500,000
Preferred Units, Percentage				7.45%
Preferred units redemption value per unit				$50
Redemption value				75,000,000
Original issuance costs of redeemed preferred stock and preferred units (Notes 9 and 11)			($2,100,000)

Stockholders_Equity_of_the_Com2

Stockholders' Equity of the Company (Details Textuals) (USD $)	12 Months Ended				0 Months Ended	1 Months Ended				0 Months Ended	1 Months Ended
	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012	Apr. 16, 2012	Mar. 31, 2012	Aug. 31, 2012	Feb. 28, 2012	Sep. 30, 2013	Sep. 18, 2013	Oct. 23, 2014
Class of Stock [Line Items]
Stock redeemed during period, value				$2,062,000
Preferred stock redemption premium	0		0	6,980,000
Aggregate gross proceeds	102,229,000		349,951,000	672,102,000
Share Repurchase, remaining number of shares authorized to be repurchased	988,025
Series E Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Preferred stock, dividend rate					7.80%
Preferred stock (in shares)					1,610,000
Series F Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Preferred stock, dividend rate					7.50%
Preferred stock (in shares)					3,450,000
Series G Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Preferred stock, dividend rate	6.88%		6.88%			6.88%
Preferred stock (in shares)	4,000,000		4,000,000
Series H Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Preferred stock, dividend rate	6.38%		6.38%				6.38%
Preferred stock (in shares)	4,000,000		4,000,000
Series E and Series F Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Stock redeemed during period, value				126,500,000
Common Stock
Class of Stock [Line Items]
Common stock, shares issued	86,259,684		82,153,944
July 2011 At-The-Market Program [Member]
Class of Stock [Line Items]
At Market Stock Offering Program Aggregate Value Of Common Stock	200,000,000
Common stock, shares issued	1,457,623
December 2014 At-The-Market Program [Member]
Class of Stock [Line Items]
At Market Stock Offering Program Aggregate Value Of Common Stock	300,000,000
Common stock, shares issued	141,500
Issuance of Equity under ATM Program [Member] | Common Stock
Class of Stock [Line Items]
Share of common stock sold during the period	1,599,123		1,040,838	787,118
Aggregate net proceeds after sales agent compensation	103,100,000		54,400,000	36,300,000
Aggregate gross proceeds	104,700,000		55,300,000	37,000,000
At Market Stock Offering Program Remained Available For Issuance	290,000,000
Issuance of Equity - equity offering [Domain]
Class of Stock [Line Items]
Aggregate gross proceeds							253,800,000	382,100,000
Issuance of Equity - equity offering [Domain] | Common Stock
Class of Stock [Line Items]
Share of common stock sold during the period							5,750,000	9,487,500	6,175,000
Kilroy Realty, L.P. [Member]
Class of Stock [Line Items]
Stock redeemed during period, value				2,062,000
Preferred stock redemption premium	0		0	6,980,000
Kilroy Realty, L.P. [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]
Class of Stock [Line Items]
Number of RSUs outstanding	247,089	[1]	143,022
Issuance of Equity - equity offering [Domain] | Issuance of Equity - equity offering [Domain] | Common Stock
Class of Stock [Line Items]
Aggregate gross proceeds										295,900,000
SFFGA [Member]
Class of Stock [Line Items]
Common stock, shares issued											351,476
purchase price, value of shares issued to acquire land											$21,600,000
[1]	The amount includes nonvested RSUs. Does not include the 247,089B and 143,022 market measure-based RSUs since not all the necessary performance conditions have been met as of DecemberB 31,B 2014 and 2013, respectively.

Stockholders_Equity_of_the_Com3

Stockholders' Equity of the Company Stockholders' Equity of the Company (Details) (USD $)	12 Months Ended					1 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012	Oct. 23, 2014
Dividends Payable [Line Items]
Aggregate gross proceeds	$102,229,000		$349,951,000		$672,102,000
Accrued dividend and distributions
Accrued dividends and distributions	32,899,000		31,490,000
Common Stockholders And Unitholders Dividends And Distributions Declared But Not Paid	-31,243,000		-29,378,000		-26,863,000
Summary of shares and units
Common stock	86,259,684	[1]	82,153,944	[1]
Noncontrolling common units	1,804,200		1,805,200
Common stockholders and noncontrolling unitholders [Member]
Accrued dividend and distributions
Accrued dividends and distributions			29,791,000
Common Stock
Dividends Payable [Line Items]
Common Stock, Shares, Issued	86,259,684		82,153,944
Accrued dividend and distributions
Accrued dividends and distributions	30,191,000		28,754,000
Summary of shares and units
Common stock	86,259,684		82,153,944
Capital Units [Member]
Accrued dividend and distributions
Accrued dividends and distributions	631,000		632,000
Preferred Stock [Member]
Accrued dividend and distributions
Accrued dividends and distributions	1,656,000		1,699,000
Series G Cumulative Redeemable Preferred Stock
Summary of shares and units
Preferred stock (in shares)	4,000,000		4,000,000
Series H Cumulative Redeemable Preferred Stock
Summary of shares and units
Preferred stock (in shares)	4,000,000		4,000,000
Restricted Stock Units (RSUs) [Member]
Accrued dividend and distributions
Accrued dividends and distributions	421,000	[2]	405,000	[3]
Time-Based Restricted Stock Units (RSUs) [Member]
Summary of shares and units
RSUs	1,248,352	[4]	1,158,407	[4]
Issuance of Equity under ATM Program [Member] | Common Stock
Dividends Payable [Line Items]
Share of common stock sold during the period	1,599,123		1,040,838		787,118
Aggregate gross proceeds	104,700,000		55,300,000		37,000,000
Aggregate net proceeds after sales agent compensation	103,100,000		54,400,000		36,300,000
SFFGA [Member]
Dividends Payable [Line Items]
Common Stock, Shares, Issued						351,476
purchase price, value of shares issued to acquire land						$21,600,000
[1]	The amount includes nonvested shares.
[2]	The amount includes the value of the dividend equivalents that will be paid with additional fully-vested RSUs (see Note 12 bShare-Based Compensationb for additional information).
[3]	The amount includes the value of the dividend equivalents that will be paid with additional fully-vested RSUs (see Note 12 bShare-Based Compensationb for additional information)
[4]	The amount includes nonvested RSUs. Does not include the 247,089B and 143,022 market measure-based RSUs since not all the necessary performance conditions have been met as of DecemberB 31,B 2014 and 2013, respectively.

Preferred_and_Common_Units_of_2

Preferred and Common Units of the Operating Partnership (Details Textuals) (USD $)

12 Months Ended

1 Months Ended

0 Months Ended

1 Months Ended

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Aug. 31, 2012

Mar. 31, 2012

Sep. 30, 2013

Feb. 28, 2012

Sep. 18, 2013

Oct. 23, 2014

Jul. 31, 2012

22-May-14

Mar. 31, 2014

Aug. 15, 2012

Class of Stock [Line Items]

Net proceeds from issuance of common stock

$102,229,000

$349,951,000

$672,102,000

Share price per unit of common units issued (dollars per unit)

$60.16

$51.64

Series A Preferred Units [Member]

Class of Stock [Line Items]

Preferred units outstanding

1,500,000

Series H Cumulative Redeemable Preferred Stock

Class of Stock [Line Items]

Preferred units issued

4,000,000

Preferred stock, dividend rate

6.38%

6.38%

6.38%

Preferred Stock, Shares Outstanding

4,000,000

4,000,000

Series H Cumulative Redeemable Preferred Stock | Series H Cumulative Redeemable Preferred Unit [Member]

Class of Stock [Line Items]

Preferred units issued

4,000,000

Series G Cumulative Redeemable Preferred Stock

Class of Stock [Line Items]

Preferred units issued

4,000,000

Preferred stock, dividend rate

6.88%

6.88%

6.88%

Preferred Stock, Shares Outstanding

4,000,000

4,000,000

Series G Cumulative Redeemable Preferred Stock | Series G Cumulative Redeemable Preferred Unit [Member]

Class of Stock [Line Items]

Preferred units issued

4,000,000

Common Stock

Class of Stock [Line Items]

Common Stock, Shares, Issued

86,259,684

82,153,944

Kilroy Realty, L.P. [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]

Class of Stock [Line Items]

Number of RSUs outstanding

247,089

[1]

143,022

Kilroy Realty, L.P. [Member] | Series H Cumulative Redeemable Preferred Unit [Member]

Class of Stock [Line Items]

Preferred units issued

4,000,000

4,000,000

Preferred units outstanding

4,000,000

4,000,000

Preferred stock, dividend rate

6.38%

6.38%

Kilroy Realty, L.P. [Member] | Series G Cumulative Redeemable Preferred Unit [Member]

Class of Stock [Line Items]

Preferred units issued

4,000,000

4,000,000

Preferred units outstanding

4,000,000

4,000,000

Preferred stock, dividend rate

6.88%

6.88%

Kilroy Realty, L.P. [Member] | Partners Capital Common Unit [Member]

Class of Stock [Line Items]

Issuance of common units, units

16,024,618

5,750,000

6,175,000

9,487,500

Issuance of Equity - equity offering [Domain]

Class of Stock [Line Items]

Net proceeds from issuance of common stock

253,800,000

382,100,000

Issuance of Equity - equity offering [Domain] | Common Stock

Class of Stock [Line Items]

Share of common stock sold during the period

5,750,000

6,175,000

9,487,500

Issuance of Equity - equity offering [Domain] | Common Stock | Issuance of Equity - equity offering [Domain]

Class of Stock [Line Items]

Net proceeds from issuance of common stock

295,900,000

SFFGA [Member]

Class of Stock [Line Items]

Common Stock, Shares, Issued

351,476

purchase price, value of shares issued to acquire land

$21,600,000

6255 Sunset Boulevard, Los Angeles, CA [Member] | Kilroy Realty, L.P. [Member] | Partners Capital Common Unit [Member]

Class of Stock [Line Items]

Issuance of common units in connection with an operating property acquisition

118,372

Share price per unit of common units issued (dollars per unit)

$47.34

[1]

The amount includes nonvested RSUs. Does not include the 247,089B and 143,022 market measure-based RSUs since not all the necessary performance conditions have been met as of DecemberB 31,B 2014 and 2013, respectively.

Preferred_and_Common_Units_of_3

Preferred and Common Units of the Operating Partnership (Details) (USD $)	12 Months Ended					1 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012	Sep. 30, 2013	Aug. 31, 2012	Feb. 28, 2012
Class of Stock [Line Items]
Aggregate gross proceeds	$102,229,000		$349,951,000		$672,102,000
Accrued distributions
Accrued dividends and distributions	32,899,000		31,490,000
Summary of units
Company owned general partnership interest	98.00%		97.80%
Noncontrolling common units of the Operating Partnership	1,804,200		1,805,200
Ownership interest of noncontrolling interest	2.00%		2.20%
Restricted Stock Units (RSUs) [Member]
Accrued distributions
Accrued dividends and distributions	421,000	[1]	405,000	[2]
Issuance of Equity under ATM Program [Member] | Partners Capital Common Unit [Member]
Class of Stock [Line Items]
Common units exchanged for share of common stock by the Company	1,599,123		1,040,838		787,118
Capital Units [Member]
Accrued distributions
Accrued dividends and distributions	631,000		632,000
Common Stock
Accrued distributions
Accrued dividends and distributions	30,191,000		28,754,000
Common Stock | Issuance of Equity under ATM Program [Member]
Class of Stock [Line Items]
Share of common stock sold during the period	1,599,123		1,040,838		787,118
Aggregate gross proceeds	104,700,000		55,300,000		37,000,000
Aggregate net proceeds after sales agent compensation	103,100,000		54,400,000		36,300,000
Kilroy Realty, L.P. [Member]
Accrued distributions
Accrued dividends and distributions	32,899,000		31,490,000
Kilroy Realty, L.P. [Member] | Restricted Stock Units (RSUs) [Member]
Accrued distributions
Accrued dividends and distributions			405,000	[1]
Summary of units
RSUs	1,248,352	[3]	1,158,407	[3]
Kilroy Realty, L.P. [Member] | Partners Capital Common Unit [Member]
Class of Stock [Line Items]
Common units exchanged for share of common stock by the Company					16,024,618	6,175,000	5,750,000	9,487,500
Accrued distributions
Accrued dividends and distributions	31,243,000		29,791,000
Kilroy Realty, L.P. [Member] | Partners Capital General Partner [Member]
Accrued distributions
Accrued dividends and distributions	30,191,000		28,754,000
Kilroy Realty, L.P. [Member] | Partners Capital Limited Partner [Member]
Accrued distributions
Accrued dividends and distributions	631,000		632,000
Kilroy Realty, L.P. [Member] | Partners Capital Preferred Units [Member]
Accrued distributions
Accrued dividends and distributions	$1,656,000		$1,699,000
Kilroy Realty, L.P. [Member] | Series G Cumulative Redeemable Preferred Unit [Member]
Summary of units
Preferred units outstanding	4,000,000		4,000,000
Kilroy Realty, L.P. [Member] | Series H Cumulative Redeemable Preferred Unit [Member]
Summary of units
Preferred units outstanding	4,000,000		4,000,000
Kilroy Realty, L.P. [Member] | Capital Units [Member]
Summary of units
Company owned common units in the Operating Partnership	86,259,684		82,153,944
[1]	The amount includes the value of the dividend equivalents that will be paid with additional fully-vested RSUs (see Note 12 bShare-Based Compensationb for additional information).
[2]	The amount includes the value of the dividend equivalents that will be paid with additional fully-vested RSUs (see Note 12 bShare-Based Compensationb for additional information)
[3]	Does not include the 247,089B and 143,022 market measure-based RSUs since not all the necessary performance conditions have been met as of DecemberB 31,B 2014 and 2013, respectively.

ShareBased_Compensation_Detail

Share-Based Compensation (Details Textuals) (USD $)	12 Months Ended				0 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012	Apr. 04, 2013		Jan. 10, 2013	Feb. 22, 2012	22-May-14	Mar. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	236,604
Trading price of the company's stock									$60.16	$51.64
Allocated Share-based Compensation Expense	$14.50		$9.60	$8.50
Share-based compensation cost capitalized as part of real estate assets	2.3		0.9	0.9
Total unrecognized compensation cost weighted-average period	2 years 6 months
Total unrecognized compensation cost related to nonvested incentive awards granted	30.3
Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	119,098
Share-based Compensation Arrangement by Share-based Payment Award, Options, Other Increases (Decreases) in Period	178,650		61,327
Grants in period, grant date fair value	7.7
Grant date fair value per share	$64.86	[1]	$44.55	$41.20
Expected share price volatility	24.00%
Risk-free interest rate	0.61%
Expected life	2 years 7 months
Time-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	117,506
Modified from time based, Weighted Average Grant Date Fair Value (in dollars per share)					$48.88	[2]
Grants in period, grant date fair value	7.1
Grant date fair value per share	$59.89	[2]	$49.45	$44.34
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)			0	62,137
Grant date fair value per share	$51.35		$0	$41.84
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected share price volatility			33.00%
Risk-free interest rate			1.35%
Expected life			6 years 6 months
Kilroy Realty 2006 Incentive Award Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Available for Grant	681,626
Kilroy Realty 2006 Incentive Award Plan [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options, Withheld in Period	23,664
Options, Withheld in Period, Intrinsic Value	1.5
Executive Officer Share-Based Compensation Programs [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Modified from time based, Weighted Average Grant Date Fair Value (in dollars per share)					$53.05	[1],[2]
Minimum [Member] | Executive Officer Share-Based Compensation Programs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service Vesting Period	1 year
Minimum [Member] | Key Employee Share-Based Compensation Program [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service Vesting Period	2 years
Maximum [Member] | Executive Officer Share-Based Compensation Programs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service Vesting Period	5 years
Maximum [Member] | Key Employee Share-Based Compensation Program [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service Vesting Period	5 years
Executive Officer [Member] | Executive Officer Share-Based Compensation Programs [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)							157,744
Chief Executive Officer [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value per share					$44.55
Expected share price volatility					27.00%
Risk-free interest rate					0.90%
Expected life					6 years
Chief Executive Officer [Member] | Executive Officer Share-Based Compensation Programs [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service Vesting Period					6 years
Granted (in shares)					19,084
Award vesting period					6 years
Chief Executive Officer [Member] | Executive Officer Share-Based Compensation Programs [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period					6 years
Historical volatility, period					12 years
Grants in period, grant date fair value					0.4
Chief Executive Officer [Member] | Executive Officer Share-Based Compensation Programs [Member] | Time-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period					6 years
Exercise Price					$53.05
Grants in period, grant date fair value					$0.50
Management [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period								5 years
Options granted in period								1,550,000
Trading price of the company's stock								$42.61
Expiration period								10 years
Nonvested Restricted Stock Units R S U [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	183,365	[3]	9,542	103,239
Nonvested Restricted Stock Units R S U [Member] | Time-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	155,016	[4]	173,758	204,829
Number of shares that were tendered to satisfy minimum statutory tax withholding requirements	3,992	[5]
Nonvested Restricted Stock Units R S U [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	213
Modified from time based (in shares)	62,797	[6]
Modified from time based, Weighted Average Grant Date Fair Value (in dollars per share)	$50.97	[6]
Nonvested Restricted Stock Units R S U [Member] | Executive Officer Share-Based Compensation Programs [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Modified from time based (in shares)					-31,455	[7],[8]
Vested Restricted Stock Units R S U [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	0
Modified from time based (in shares)	0
Number of shares that were tendered to satisfy minimum statutory tax withholding requirements	8,526
Vested Restricted Stock Units R S U [Member] | Time-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	0
Number of shares that were tendered to satisfy minimum statutory tax withholding requirements	5,694
Vested Restricted Stock Units R S U [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares that were tendered to satisfy minimum statutory tax withholding requirements	11,020
Shareholder Meeting Date May 22, 2014 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares Requested	7,120,000
Shareholder Meeting Date May 22, 2014 [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value per share	$65.03
At the End of March [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value per share	$63.44
[1]	Represents the grant-date fair value for all awards excluding the 2014 Performance-Based RSU Grant. As discussed above, the 2014 Performance-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.
[2]	Represents the grant-date fair value for all awards excluding the 2014 Time-Based RSU Grant. As discussed above, the 2014 Time-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.
[3]	Includes dividend equivalents issued in accordance with the award agreements.
[4]	(2)Includes dividend equivalents issued in accordance with the award agreements.
[5]	(5)For shares vested but not yet settled, we accept the return of RSUs at the current quoted closing share price of the Companybs common stock to satisfy minimum statutory tax-withholding requirements related to either the issuance or vesting of RSUs in accordance with the terms of the 2006 Plan.
[6]	The total shares vested include 11,020 shares that were tendered in accordance with the terms of the 2006B Plan to satisfy minimum statutory tax withholding requirements related to the restricted shares that have vested. We accept the return of shares at the current quoted closing share price of the Companybs common stock to satisfy tax obligations.
[7]	(6)On January 29, 2014, the market-measure requirements related to the RSU awards granted in 2013 were met. As of DecemberB 31,B 2014 the awards are only subject to time-based vesting requirements.
[8]	On January 29, 2014, the market-measure requirements related to the RSU awards granted in 2013 were met, and as a result, the shares were transferred to time-based restricted stock units since at that point the awards became subject to only time-based vesting requirements pursuant to the award agreements.

ShareBased_Compensation_Detail1

Share-Based Compensation (Details) (Market Measure-Based Restricted Stock Units (RSUs) [Member], USD $)	12 Months Ended				0 Months Ended
	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012	Apr. 04, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value per share	$64.86	[1]	$44.55	$41.20
Expected share price volatility	24.00%
Risk-free interest rate	0.61%
Expected life	2 years 7 months
Chief Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value per share					$44.55
Expected share price volatility					27.00%
Risk-free interest rate					0.90%
Dividend yield					3.60%
Expected life					6 years
Vested Restricted Stock Units R S U [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, Vested in Period	16,338	[2]	16,338	14,748
[1]	Represents the grant-date fair value for all awards excluding the 2014 Performance-Based RSU Grant. As discussed above, the 2014 Performance-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.
[2]	Includes dividend equivalents vested in accordance with the award agreements.

ShareBased_Compensation_Detail2

Share-Based Compensation (Details 1) (USD $)	0 Months Ended		12 Months Ended
In Millions, except Share data, unless otherwise specified	Apr. 04, 2013		Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense			$14.50		$9.60		$8.50
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Granted (in shares)			236,604
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of year, Weighted Average Grant Date Fair Value (in dollars per share)			$41.71
Granted (in shares)					0		62,137
Grant date fair value per share			$51.35		$0		$41.84
Vested (in shares)					-47,291		-50,862
Outstanding at end of year, Weighted Average Grant Date Fair Value (in dollars per share)			$47.05		$41.71
Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of year, Weighted Average Grant Date Fair Value (in dollars per share)			$46.47	[1]
Granted (in shares)			119,098
Grant date fair value per share			$64.86	[1]	$44.55		$41.20
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value			$41.53	[1]
Outstanding at end of year, Weighted Average Grant Date Fair Value (in dollars per share)			$58.77	[1]	$46.47	[1]
Time-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of year, Weighted Average Grant Date Fair Value (in dollars per share)			$44.74	[2]
Outstanding at beginning of year, Vested RSUs			1,158,407	[3]
Granted (in shares)			117,506
Grant date fair value per share			$59.89	[2]	$49.45		$44.34
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value			$47.64	[2]
Modified from time based, Weighted Average Grant Date Fair Value (in dollars per share)	$48.88	[2]
Outstanding at end of year, Weighted Average Grant Date Fair Value (in dollars per share)			$51.04		$44.74	[2]
Outstanding at end of year, Vested RSUs			1,248,352	[3]	1,158,407	[3]
Restricted Stock Units (RSUs) [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of year, Total RSUs			143,022
Granted (in shares)			183,365
Vested (in shares)			0
Settled (in shares)			-16,338
Modified from time based (in shares)			31,455
Outstanding at beginning of year, Total RSUs			247,089
Restricted Stock Units (RSUs) [Member] | Time-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of year, Total RSUs			1,158,407
Granted (in shares)			155,016
Vested (in shares)			0	[4],[5]
Outstanding at beginning of year, Total RSUs			1,248,352
Nonvested Restricted Stock Units R S U [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of year (in shares)			47,950
Granted (in shares)			213
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value			$45.56	[6]
Modified from time based (in shares)			-62,797	[6]
Modified from time based, Weighted Average Grant Date Fair Value (in dollars per share)			$50.97	[6]
Outstanding at end of year (in shares)			85,061
Nonvested Restricted Stock Units R S U [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Granted (in shares)			183,365	[7]	9,542		103,239
Outstanding at end of year (in shares)			247,089
Nonvested Restricted Stock Units R S U [Member] | Time-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of year (in shares)			301,660
Granted (in shares)			155,016	[8]	173,758		204,829
Cancelled (in shares)			-3,992	[9]
Outstanding at end of year (in shares)			340,997		301,660
Vested Restricted Stock Units R S U [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Vested (in shares)			-25,899	[6]
Cancelled (in shares)			-11,020
Vested Restricted Stock Units R S U [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of year, Vested RSUs			0
Granted (in shares)			0
Vested (in shares)			-16,338	[10]	-16,338		-14,748
Settled (in shares)			-16,338	[11]
Modified from time based (in shares)			0
Cancelled (in shares)			-8,526
Outstanding at end of year, Vested RSUs			0		0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Period Increase (Decrease)			0
Vested Restricted Stock Units R S U [Member] | Time-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of year, Vested RSUs			856,747
Granted (in shares)			0
Vested (in shares)			-116,447	[4],[5]	-89,873		-73,688
Settled (in shares)			-61,242
Cancelled (in shares)			-5,694
Outstanding at end of year, Vested RSUs			907,355		856,747
Executive Officer Share-Based Compensation Programs [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Modified from time based, Weighted Average Grant Date Fair Value (in dollars per share)	$53.05	[1],[2]
Executive Officer Share-Based Compensation Programs [Member] | Restricted Stock Units (RSUs) [Member] | Time-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Period Increase (Decrease)	-31,292	[12]
Executive Officer Share-Based Compensation Programs [Member] | Nonvested Restricted Stock Units R S U [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Modified from time based (in shares)	31,455	[13],[14]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Period Increase (Decrease)	-31,505	[15]
Executive Officer Share-Based Compensation Programs [Member] | Nonvested Restricted Stock Units R S U [Member] | Time-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Period Increase (Decrease)	-30,687	[12]
Executive Officer Share-Based Compensation Programs [Member] | Vested Restricted Stock Units R S U [Member] | Time-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Period Increase (Decrease)	-605	[15]
[1]	Represents the grant-date fair value for all awards excluding the 2014 Performance-Based RSU Grant. As discussed above, the 2014 Performance-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.
[2]	Represents the grant-date fair value for all awards excluding the 2014 Time-Based RSU Grant. As discussed above, the 2014 Time-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.
[3]	The amount includes nonvested RSUs. Does not include the 247,089B and 143,022 market measure-based RSUs since not all the necessary performance conditions have been met as of DecemberB 31,B 2014 and 2013, respectively.
[4]	(3)Includes dividend equivalents vested in accordance with the award agreements.
[5]	(4)Represents vested RSUs that were settled in shares of the Companybs common stock. Total shares settled include 5,694 shares that were tendered in accordance with the terms of the 2006B Plan to satisfy minimum statutory tax withholding requirements related to the RSUs settled. We accept the return of RSUs at the current quoted closing share price of the Companybs common stock to satisfy tax obligations.
[6]	The total shares vested include 11,020 shares that were tendered in accordance with the terms of the 2006B Plan to satisfy minimum statutory tax withholding requirements related to the restricted shares that have vested. We accept the return of shares at the current quoted closing share price of the Companybs common stock to satisfy tax obligations.
[7]	Includes dividend equivalents issued in accordance with the award agreements.
[8]	(2)Includes dividend equivalents issued in accordance with the award agreements.
[9]	(5)For shares vested but not yet settled, we accept the return of RSUs at the current quoted closing share price of the Companybs common stock to satisfy minimum statutory tax-withholding requirements related to either the issuance or vesting of RSUs in accordance with the terms of the 2006 Plan.
[10]	Includes dividend equivalents vested in accordance with the award agreements.
[11]	Represents vested RSUs that were settled in cash or shares of the Companybs common stock. Total shares settled include 8,526 shares that were tendered in accordance with the terms of the 2006B Plan to satisfy minimum statutory tax withholding requirements related to the RSUs settled. We accept the return of RSUs, at the current quoted closing share price of the Companybs common stock to satisfy tax obligations.
[12]	(7)During January 2014, RSUs were transferred to restricted stock based on the elected distribution date.
[13]	(6)On January 29, 2014, the market-measure requirements related to the RSU awards granted in 2013 were met. As of DecemberB 31,B 2014 the awards are only subject to time-based vesting requirements.
[14]	On January 29, 2014, the market-measure requirements related to the RSU awards granted in 2013 were met, and as a result, the shares were transferred to time-based restricted stock units since at that point the awards became subject to only time-based vesting requirements pursuant to the award agreements.
[15]	On January 29, 2014, the market-measure requirements related to the RSU award were met and, as a result, the RSUs were transferred to restricted stock based on the employeebs distribution election and remain subject to time-based vesting requirements pursuant to the award agreement.

ShareBased_Compensation_Detail3

Share-Based Compensation (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	236,604
Time-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	117,506
Granted, Weighted Average Grant Date Fair Value (in dollars per share)	$59.89	[1]	$49.45		$44.34
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	$47.64	[1]
Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	119,098
Granted, Weighted Average Grant Date Fair Value (in dollars per share)	$64.86	[2]	$44.55		$41.20
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	$41.53	[2]
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)			0		62,137
Granted, Weighted Average Grant Date Fair Value (in dollars per share)	$51.35		$0		$41.84
Vested (in shares)			-47,291		-50,862
Vested, Total Vest-Date Fair Value	$1,323,000	[3]	$2,290,000	[3]	$2,110,000	[3]
Vested Restricted Stock Units R S U [Member] | Time-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	0
Vested (in shares)	-116,447	[4],[5]	-89,873		-73,688
Vested, Total Vest-Date Fair Value	6,675,000	[6]	4,495,000	[6]	3,118,000	[6]
Vested Restricted Stock Units R S U [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	0
Vested (in shares)	-16,338	[7]	-16,338		-14,748
Vested, Total Vest-Date Fair Value	$1,092,000		$811,000		$695
Vested Restricted Stock Units R S U [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested (in shares)	-25,899	[8]
Nonvested Restricted Stock Units R S U [Member] | Time-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	155,016	[9]	173,758		204,829
Nonvested Restricted Stock Units R S U [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	183,365	[10]	9,542		103,239
Nonvested Restricted Stock Units R S U [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	213
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	$45.56	[8]
[1]	Represents the grant-date fair value for all awards excluding the 2014 Time-Based RSU Grant. As discussed above, the 2014 Time-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.
[2]	Represents the grant-date fair value for all awards excluding the 2014 Performance-Based RSU Grant. As discussed above, the 2014 Performance-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.
[3]	Total fair value of shares vested was calculated based on the quoted closing share price of the Companybs common stock on the NYSE on the date of vesting.
[4]	(3)Includes dividend equivalents vested in accordance with the award agreements.
[5]	(4)Represents vested RSUs that were settled in shares of the Companybs common stock. Total shares settled include 5,694 shares that were tendered in accordance with the terms of the 2006B Plan to satisfy minimum statutory tax withholding requirements related to the RSUs settled. We accept the return of RSUs at the current quoted closing share price of the Companybs common stock to satisfy tax obligations.
[6]	Total fair value of RSUs vested was calculated based on the quoted closing share price of the Companybs common stock on the NYSE on the day of vesting
[7]	Includes dividend equivalents vested in accordance with the award agreements.
[8]	The total shares vested include 11,020 shares that were tendered in accordance with the terms of the 2006B Plan to satisfy minimum statutory tax withholding requirements related to the restricted shares that have vested. We accept the return of shares at the current quoted closing share price of the Companybs common stock to satisfy tax obligations.
[9]	(2)Includes dividend equivalents issued in accordance with the award agreements.
[10]	Includes dividend equivalents issued in accordance with the award agreements.

ShareBased_Compensation_Stock_

Share-Based Compensation (Stock Options Activity) (Details) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Options, Intrinsic Value [Roll Forward]
Options, outstanding, weighted average remaining contractual term	7 years 2 months
Options, exercisable, weighted average remaining contractual term	7 years 2 months
Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected share price volatility	24.00%
Risk-free interest rate	0.61%
Expected life	2 years 7 months
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Fair value of options granted per share			$9.20
Expected share price volatility			33.00%
Risk-free interest rate			1.35%
Dividend yield			3.80%
Expected life			6 years 6 months
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding, Number of Options, Beginning of Year	1,525,000
Exercised (in shares)	-495,000
Forfeited (in shares)	-22,000
Outstanding, Number of Options, End of Year	1,008,000	[1]	1,525,000
Exercisable	114,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Outstanding, Exercise Price, Beginning of Year (in dollars per share)	$42.61
Exercised, Exercise Price (in dollars per share)	$42.61
Forfeited, Exercise Price (in dollars per share)	$42.61
Outstanding, Exercise Price, End of Year (in dollars per share)	$42.61	[1]	$42.61
Share-based Compensation Arrangement by Share-based Payment Award, Options, Intrinsic Value [Roll Forward]
Outstanding at December 31, 2013	$11.50
Exercised	26.7		11.5
Forfeited	0.4
Outstanding at December 31, 2014	9.6
Options Exercisable at December 31, 2014	$3
[1]	.

Employee_Benefit_Plans_Employe

Employee Benefit Plans Employee Benefit Plans (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2007
Compensation and Retirement Disclosure [Abstract]
Eligibility period for 401K savings plan, number of months	3 months
Defined Contribution Plan - maximum participant deferral percent	60.00%
Defined Contribution Plan - employer match per dollar of participant contribution	$0.50
Defined Contribution Plan - maximum employer match percentage	10.00%
Defined Contribution Plan - contributions made	1,000,000	900,000	700,000
Deferred Compensation - maximum participant deferral percent				70.00%
Deferred Compensation - maximum director fees and bonuses that may be deferred (percent)				100.00%
Deferred Compensation - mandatory Company contributions as percentage of gross monthly salary (percent)				10.00%
Deferred Compensation - liability under Plan	$11,900,000	$9,900,000

Future_Minimum_Rent_Details

Future Minimum Rent (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Future contractual minimum rent under operating lease
2015	$428,302
2016	447,163
2017	414,397
2018	367,745
2019	306,878
Thereafter	1,217,370
Total	$3,181,855

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Summary of minimum commitment
2015	$3,120
2016	3,120
2017	3,120
2018	3,120
2019	3,120
Thereafter	154,358
Total	$169,958	[1],[2],[3],[4]
[1]	One of our ground lease obligations includes a component which is based on the percentage of gross income that exceeds the minimum ground rent. The minimum rent is subject to increases every five years based on 50% of the average annual percentage rent for the previous five years. Currently, gross income does not exceed the threshold requiring us to pay percentage rent. The contractual obligations for that ground lease included above assume the annual lease rental obligation in effect as of DecemberB 31,B 2014.
[2]	One of our ground lease obligations is subject to a fair market value adjustment every five years; however, the lease includes ground rent subprotection and infrastructure rent credits which currently limit our annual rental obligations to $1.0B million. The contractual obligations for that ground lease included above assumes the lesser of $1.0B million or annual lease rental obligation in effect as of DecemberB 31,B 2014.
[3]	One of our ground lease obligations is subject to a fair market value adjustment every five years based on a combination of CPI adjustments and third-party appraisals limited to maximum increases annually. The contractual obligations included above assume the annual lease rental obligation in effect as of DecemberB 31,B 2014.
[4]	Reflects the minimum ground lease obligations before the impact of ground lease extension options.

Commitments_and_Contingencies_2

Commitments and Contingencies (Details 1) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Long-term Purchase Commitment [Line Items]
Commitments for contracts and executed leases, operating and redevelopment and development properties	$552.50
Period after which Ground lease rentals are adjusted based on fair market value and the Consumer Price Index	5 years
Annual ground lease rental obligations limit	1
Duration of ground lease prior to increase	5 years
Average annual precentage rent for previous five years (percent)	50.00%
Accrual for Environmental Loss Contingencies	15.5
Ten Year Ground Lease Extension Option [Member]
Long-term Purchase Commitment [Line Items]
Number of extension options	3
Ground lease extension option term	10 years
Forty-Five Year Ground Lease Extension Option [Member]
Long-term Purchase Commitment [Line Items]
Number of extension options	1
Ground lease extension option term	45 years
Property Damage Litigation Case [Member]
Long-term Purchase Commitment [Line Items]
Proceeds from Legal Settlements	5.2	0.9
Former Tenant Litigation Case [Member]
Long-term Purchase Commitment [Line Items]
Proceeds from Legal Settlements		$3.70

Fair_Value_Measurements_and_Di2

Fair Value Measurements and Disclosures (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Fair value adjustment of marketable securities and deferred compensation plan liability
Net gain on marketable securities	$397		$1,489		$723
Fair Value (Level 1) [Member]
Assets and Liabilities Reported at Fair Value
Marketable securities	$11,971	[1],[2]	$10,008	[1],[2]
[1]	The marketable securities are held in a limited rabbi trust.
[2]	Fair value calculated using Level 1 inputs based on quoted prices in active markets for identical securities.

Fair_Value_Measurements_and_Di3

Fair Value Measurements and Disclosures (Details 1) (USD $)	Dec. 31, 2014		Dec. 31, 2013
Liabilities
Secured debt	$546,292,000		$560,434,000
Exchangeable senior notes, net	0		168,372,000
Unsecured Debt	1,783,121,000		1,431,132,000
Unsecured line of credit	140,000,000		45,000,000
Carrying Value
Liabilities
Secured debt	546,292,000	[1]	560,434,000	[1]
Exchangeable senior notes, net	0	[1],[2]	168,372,000	[1]
Unsecured Debt	1,783,121,000	[3]	1,431,132,000	[3]
Unsecured line of credit	140,000,000	[1]	45,000,000	[1]
Carrying Value | Fair Value (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure	513,700,000
Carrying Value | Unsecured Debt [Member] | Fair Value (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure	1,269,400,000
Liabilities
Unsecured Debt			873,500,000
Carrying Value | Unsecured Debt [Member] | Fair Value (Level 2) [Member]
Liabilities
Unsecured Debt			557,700,000
Fair Value
Liabilities
Secured debt	559,483,000	[1]	568,760,000	[1]
Exchangeable senior notes, net	0	[1],[2]	178,190,000	[1]
Unsecured Debt	1,858,492,000	[3]	1,523,052,000	[3]
Unsecured line of credit	140,051,000	[1]	45,012,000	[1]
Fair Value | Fair Value (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure	536,300,000
Fair Value | Unsecured Debt [Member] | Fair Value (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure	1,322,200,000		929,300,000
Fair Value | Unsecured Debt [Member] | Fair Value (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure			$593,700,000
[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]	During the year ended DecemberB 31,B 2014, we repaid the 4.25% Exchangeable Notes. As of DecemberB 31,B 2014, there were no exchangeable debt instruments (see Note 7 bSecured and Unsecured Debt of the Operating Partnershipb for additional information).
[3]	Fair value calculated primarily using Level I inputs, which are based on quoted prices for identical instruments in active markets. The carrying value and fair value of the Level I instruments was $1,269.4B million and $1,322.2B million, respectively, as of DecemberB 31,B 2014. The carrying value and fair value of the Level I instruments at DecemberB 31,B 2013, was $873.5B million and $929.3B million, respectively. The carrying value and fair value of the Level II instruments was $513.7B million and $536.3B million, respectively, as of DecemberB 31,B 2014. The carrying value and fair value of the Level II instruments at DecemberB 31,B 2013, was $557.7B million and $593.7B million, respectively.

Other_Significant_Events_Detai

Other Significant Events (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jan. 31, 2014
	sqft			sqft
Other Significant Noncash Transactions [Line Items]
Net Rentable Area	14,096,617			79,000
Lease termination fee	$5,700,000
Amortization of Intangible Assets	41,155,000	47,395,000	36,202,000
Contract Termination [Member]
Other Significant Noncash Transactions [Line Items]
Amortization of Intangible Assets	$1,300,000

Discontinued_Operations_Discon

Discontinued Operations Discontinued Operations (Details) (USD $)	12 Months Ended						0 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012		Jan. 15, 2015	Jan. 31, 2014
	sqft		sqft		sqft			sqft
	building		building		building
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties	9
Net Rentable Area	14,096,617							79,000
San Diego Properties, San Diego, CA [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties	12	[1]
Net Rentable Area	1,049,035	[1]
Dispositions Sales Price	$294.70	[1],[2]
9785&9791 Towne Centre Drive, San Diego CA [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties	2
Net Rentable Area	126,000
Dispositions Sales Price	29.5	[1]
111 Pacifica [Member] [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties	1
Net Rentable Area	67,496
Dispositions Sales Price	15.1	[1]
4040 Civic [Member] [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties	1
Net Rentable Area	130,237
Dispositions Sales Price	34.9	[1]
999 Town &Country[Member] [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties	1
Net Rentable Area	98,551
Dispositions Sales Price	25.3	[1]
2014 Dispositions [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties	17
Net Rentable Area	1,471,319
Dispositions Sales Price	399.5	[1]
Agoura Road, 26541, Calabasas, CA [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties			1
Area of Real Estate Property			90,156
Dispositions Sales Price			14.7	[1]
Kaiser Boulevard, Anaheim, California [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties			1
Area of Real Estate Property			59,790
Dispositions Sales Price			9.6	[1]
Directors Place, Sorrento Mesa, California One [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties			1
Area of Real Estate Property			50,360
Dispositions Sales Price			32.6	[1]
2013 Dispositions [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties			3
Area of Real Estate Property			200,306
Dispositions Sales Price			56.9	[1]
Innovation Drive and Genetic Center Drive, San Diego, CA [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties					2
Area of Real Estate Property					253,676
Dispositions Sales Price					146.1	[1]
Industrial Portfolio and Other Properties [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties					44
Area of Real Estate Property					3,721,989
Dispositions Sales Price					354.2	[1]
Industrial Portfolio [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties					39	[3]
Area of Real Estate Property					3,413,354	[3]
Carmino Ruiz CA [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties					4
Area of Real Estate Property					265,372
4175 E. La Palma Avenue, Anaheim, California [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties					1
Area of Real Estate Property					43,263
2012 Dispositions [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties					46
Area of Real Estate Property					3,975,665
Dispositions Sales Price					500.3	[1]
Properties Held for Sale [Member] | Subsequent Event [Member] | Von Karman, Irvine, California [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Dispositions Sales Price							$26
[1]	Represents gross sales price before the impact of broker commissions and closing costs.
[2]	The San Diego Properties included the following: 10020 Pacific Mesa Boulevard, 6055 Lusk Avenue, 5010 and 5005 Wateridge Vista Drive, 15435 and 15445B Innovation Drive, and 15051,B 15073, 15231, 15253, 15333 and 15378 Avenue of Science. These properties were held for sale as of December 31, 2013.
[3]	The industrial portfolio was sold in two tranches in November and December 2012 to two separate third party buyers.

Discontinued_Operations_Detail

Discontinued Operations (Details 1) (USD $)	3 Months Ended																12 Months Ended
	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jan. 31, 2014
	sqft																sqft			sqft
	property																property
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Land And Improvements									$49,656,000									$49,656,000
Disposal Group, Including Discontinued Operation, Buildings and Improvements									209,594,000									209,594,000
Disposal Group, Including Discontinued Operation, Property, Plant and Equipment									259,250,000									259,250,000
Disposal Group, Including Discontinued Operation, Property, Plant, and Equipment, Accumulated Depreciation									63,110,000									63,110,000
Disposal Group, Including Discontinued Operation, Property, Plant and Equipment, Noncurrent									196,140,000									196,140,000
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net									269,000									269,000
Disposal Group, Including Discontinued Operation, Deferred Rent Receivable, Net									8,978,000									8,978,000
Disposal Group, Including Discontinued Operation, Deferred Leasing Costs and Acquisition-related Intangible Assets, Net									5,791,000									5,791,000
Disposal Group, Including Discontinued Operation, Prepaid and Other Assets, Current									1,922,000									1,922,000
Disposal Group, Including Discontinued Operation, Assets	8,211,000								213,100,000								8,211,000	213,100,000
Number of real estate properties	9																9
Net Rentable Area	14,096,617																14,096,617			79,000
Rental income																	7,206,000	31,984,000	49,689,000
Tenant reimbursements																	278,000	3,546,000	6,544,000
Other property income																	13,000	5,178,000	1,923,000
Total revenues																	7,497,000	40,708,000	58,156,000
Property expenses																	2,171,000	7,207,000	9,945,000
Real estate taxes																	692,000	3,523,000	5,696,000
Provision for bad debts																	0	0	-195,000
Depreciation and amortization																	2,061,000	12,600,000	19,379,000
Total expenses																	4,924,000	23,330,000	34,825,000
Income from discontinued operations before net gain on dispositions of discontinued operations																	2,573,000	17,378,000	23,331,000
Net gain on dispositions of discontinued operations (Note 18)																	121,922,000	12,252,000	259,245,000
Total income from discontinued operations	12,013,000	[1],[2]	6,135,000	[1],[2]	15,289,000	[1],[2]	91,058,000	[1],[2]	18,009,000	[1],[2]	5,847,000	[1],[2]	3,161,000	[1],[2]	2,613,000	[1],[2]	124,495,000	29,630,000	282,576,000
Gain (Loss) on Disposition of Property Plant Equipment																	3,490,000
Net proceeds received from dispositions of operating properties and land (Note 18)																	427,544,000	21,178,000	263,572,000
Disposal Group, Including Discontinued Operation, Accounts Payable and Accrued Liabilities									1,153,000									1,153,000
Disposal Group, Including Discontinued Operation, Deferred Revenue and Acquisition-related Intangible Liabilities, Net									10,723,000									10,723,000
Disposal Group, Including Discontinued Operation, Advance Rents and Tenant Security Deposits									2,571,000									2,571,000
Disposal Group, Including Discontinued Operation, Liabilities	56,000								14,447,000								56,000	14,447,000
10850 Via Frontera San Diego CA [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Dispositions Sales Price																	33,100,000
Restricted cash [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net proceeds received from dispositions of operating properties and land (Note 18)																	59,200,000	32,200,000
Restricted cash [Member] | Released from Qualified Intermediary 2015 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net proceeds received from dispositions of operating properties and land (Note 18)																	59,200,000
Restricted cash [Member] | Released July 2014 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net proceeds received from dispositions of operating properties and land (Note 18)																		$32,200,000
[1]	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common stockholders per share does not equal the annual number reported on the consolidated statements of operations due to the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended DecemberB 31,B 2014 and 2013.
[2]	All periods have been adjusted from amounts previously disclosed in our quarterly filings on FormB 10-Q to reclassify amounts related to discontinued operations (see NoteB 18 bDiscontinued Operationsb for additional information).

Net_Income_Available_to_Common4

Net Income Available to Common Stockholders Per Share of the Company (Details) (USD $)	3 Months Ended																12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Numerator:
Income (loss) from continuing operations	$19,417	[1],[2]	$13,168	[1],[2]	$15,854	[1],[2]	$10,874	[1],[2]	$5,038	[1],[2]	$3,180	[1],[2]	$6,942	[1],[2]	($225)	[1],[2]	$59,313		$14,935		($5,475)
(Income) loss from continuing operations attributable to noncontrolling common units of the Operating Partnership																	-966		-36		656
Preferred dividends and distributions	-3,312	[1]	-3,313	[1]	-3,312	[1]	-3,313	[1]	-3,312	[1]	-3,312	[1]	-3,313	[1]	-3,313	[1]	-13,250		-13,250		-21,088
Allocation to participating securities (1)																	-1,699	[3]	-1,689	[3]	-1,602	[3]
Numerator for basic and diluted income (loss) from continuing operations available to common stockholders																	43,398		-40		-27,509
Income from discontinued operations	12,013	[1],[2]	6,135	[1],[2]	15,289	[1],[2]	91,058	[1],[2]	18,009	[1],[2]	5,847	[1],[2]	3,161	[1],[2]	2,613	[1],[2]	124,495		29,630		282,576
Income from discontinued operations attributable to noncontrolling common units of the Operating Partnership																	-2,623		-649		-6,843
Numerator for basic and diluted net income available to common stockholders																	$165,270		$28,941		$248,224
Denominator:
Basic weighted average vested shares outstanding																	83,090,235		77,343,853		69,639,623
Effect of dilutive securities b contingently issuable shares and stock options																	1,877,485		0		0
Diluted weighted average vested shares and common stock equivalents outstanding																	84,967,720		77,343,853		69,639,623
Basic earnings per share:
Income (loss) from continuing operations available to common stockholders per share (dollars per share)																	$0.52		$0		($0.40)
Income from discontinued operations per share of common stock (dollars per share)																	$1.47		$0.37		$3.96
Net income available to common stockholders per share (dollars per share)	$0.32	[1]	$0.18	[1]	$0.33	[1]	$1.17	[1]	$0.23	[1]	$0.07	[1]	$0.08	[1]	($0.02)	[1]	$1.99		$0.37		$3.56
Diluted earnings per share:
Income (loss) from continuing operations available to common stockholders per share (dollars per share)																	$0.51		$0		($0.40)
Income from discontinued operations per share of common stock (dollars per share)																	$1.44		$0.37		$3.96
Net income available to common stockholders per share (dollars per share)	$0.32	[1]	$0.18	[1]	$0.32	[1]	$1.14	[1]	$0.23	[1]	$0.07	[1]	$0.08	[1]	($0.02)	[1]	$1.95		$0.37		$3.56
[1]	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common stockholders per share does not equal the annual number reported on the consolidated statements of operations due to the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended DecemberB 31,B 2014 and 2013.
[2]	All periods have been adjusted from amounts previously disclosed in our quarterly filings on FormB 10-Q to reclassify amounts related to discontinued operations (see NoteB 18 bDiscontinued Operationsb for additional information).
[3]	Participating securities include nonvested shares, certain time-based RSUs and vested market measure-based RSUs.

Net_Income_Available_to_Common5

Net Income Available to Common Unitholders Per Unit of the Operating Partnership (Details) (USD $)	3 Months Ended																12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Numerator:
Income (loss) from continuing operations	$19,417	[1],[2]	$13,168	[1],[2]	$15,854	[1],[2]	$10,874	[1],[2]	$5,038	[1],[2]	$3,180	[1],[2]	$6,942	[1],[2]	($225)	[1],[2]	$59,313		$14,935		($5,475)
Income from continuing operations attributable to noncontrolling interests in consolidated subsidiaries																	-966		-36		656
Preferred dividends and distributions	-3,312	[1]	-3,313	[1]	-3,312	[1]	-3,313	[1]	-3,312	[1]	-3,312	[1]	-3,313	[1]	-3,313	[1]	-13,250		-13,250		-21,088
Allocation to participating securities (1)																	-1,699	[3]	-1,689	[3]	-1,602	[3]
Numerator for basic and diluted income (loss) from continuing operations available to common unitholders																	43,398		-40		-27,509
Income from discontinued operations	12,013	[1],[2]	6,135	[1],[2]	15,289	[1],[2]	91,058	[1],[2]	18,009	[1],[2]	5,847	[1],[2]	3,161	[1],[2]	2,613	[1],[2]	124,495		29,630		282,576
Loss (income) from discontinued operations attributable to noncontrolling interests in consolidated subsidiaries																	-2,623		-649		-6,843
Numerator for basic and diluted net income available to common unitholders																	165,270		28,941		248,224
Denominator:
Basic weighted average vested shares outstanding																	83,090,235		77,343,853		69,639,623
Effect of dilutive securities b contingently issuable shares and stock options																	1,877,485		0		0
Diluted weighted average vested units and common unit equivalents outstanding																	84,967,720		77,343,853		69,639,623
Basic earnings per unit:
Income (loss) from continuing operations available to common stockholders per share (dollars per share)																	$0.52		$0		($0.40)
Income from discontinued operations per common unit (dollars per unit)																	$1.47		$0.37		$3.96
Net income available to common unitholders per unit (dollars per unit)	$0.32	[1]	$0.18	[1]	$0.33	[1]	$1.17	[1]	$0.23	[1]	$0.07	[1]	$0.08	[1]	($0.02)	[1]	$1.99		$0.37		$3.56
Diluted earnings per unit:
Income (loss) from continuing operations available to common unitholders per unit (dollars per unit)																	$0.51		$0		($0.40)
Income from discontinued operations per common unit (dollars per unit)																	$1.44		$0.37		$3.96
Net income available to common unitholders per unit (dollars per unit)	$0.32	[1]	$0.18	[1]	$0.32	[1]	$1.14	[1]	$0.23	[1]	$0.07	[1]	$0.08	[1]	($0.02)	[1]	$1.95		$0.37		$3.56
Kilroy Realty, L.P. [Member]
Numerator:
Income (loss) from continuing operations	19,417	[4],[5]	13,168	[4],[5]	15,854	[4],[5]	10,874	[4],[5]	5,038	[4],[5]	3,180	[4],[5]	6,942	[4],[5]	-225	[4],[5]	59,313		14,935		-5,475
Income from continuing operations attributable to noncontrolling interests in consolidated subsidiaries																	-247		-225		-176
Preferred dividends and distributions	-3,312	[4]	-3,313	[4]	-3,312	[4]	-3,313	[4]	-3,312	[4]	-3,312	[4]	-3,313	[4]	-3,313	[4]	-13,250		-13,250		-21,088
Allocation to participating securities (1)																	-1,699	[3]	-1,689	[3]	-1,602	[3]
Numerator for basic and diluted income (loss) from continuing operations available to common unitholders																	44,117		-229		-28,341
Income from discontinued operations	12,013	[4],[5]	6,135	[4],[5]	15,289	[4],[5]	91,058	[4],[5]	18,009	[4],[5]	5,847	[4],[5]	3,161	[4],[5]	2,613	[4],[5]	124,495		29,630		282,576
Loss (income) from discontinued operations attributable to noncontrolling interests in consolidated subsidiaries																	-13		1		-462
Numerator for basic and diluted net income available to common unitholders																	$168,599		$29,402		$253,773
Denominator:
Basic weighted average vested shares outstanding																	84,894,498		79,166,260		71,403,258
Effect of dilutive securities b contingently issuable shares and stock options																	1,877,485		0		0
Diluted weighted average vested units and common unit equivalents outstanding																	86,771,983		79,166,260		71,403,258
Basic earnings per unit:
Income (loss) from continuing operations available to common stockholders per share (dollars per share)																	$0.52		$0		($0.40)
Income from discontinued operations per common unit (dollars per unit)																	$1.47		$0.37		$3.96
Net income available to common unitholders per unit (dollars per unit)	$0.32	[4]	$0.18	[4]	$0.33	[4]	$1.17	[4]	$0.23	[4]	$0.07	[4]	$0.08	[4]	($0.02)	[4]	$1.99		$0.37		$3.56
Diluted earnings per unit:
Income (loss) from continuing operations available to common unitholders per unit (dollars per unit)																	$0.51		$0		($0.40)
Income from discontinued operations per common unit (dollars per unit)																	$1.43		$0.37		$3.96
Net income available to common unitholders per unit (dollars per unit)	$0.31	[4]	$0.18	[4]	$0.32	[4]	$1.14	[4]	$0.23	[4]	$0.07	[4]	$0.08	[4]	($0.02)	[4]	$1.94		$0.37		$3.56
[1]	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common stockholders per share does not equal the annual number reported on the consolidated statements of operations due to the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended DecemberB 31,B 2014 and 2013.
[2]	All periods have been adjusted from amounts previously disclosed in our quarterly filings on FormB 10-Q to reclassify amounts related to discontinued operations (see NoteB 18 bDiscontinued Operationsb for additional information).
[3]	Participating securities include nonvested shares, certain time-based RSUs and vested market measure-based RSUs.
[4]	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common unitholders per unit does not equal the annual number reported on the consolidated statements of operations due to the impact of the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended DecemberB 31,B 2014 and 2013.
[5]	All periods have been adjusted from amounts previously disclosed in our quarterly filings on Form 10-Q to reclassify amounts related to discontinued operations (see Note 18 bDiscontinued Operationsb).

Tax_Treatment_of_Distributions2

Tax Treatment of Distributions (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2011	Dec. 31, 2012
Class of Stock [Line Items]
Dividends declared per common share	$1.40	$1.40	$1.40
Common Stock
Class of Stock [Line Items]
Dividends declared per common share	$1.40	$1.40		$1.40
Less: Dividends declared in the current year and paid in the following year	($0.35)	($0.35)		($0.35)
Add: Dividends declared in the prior year and paid in the current year	$0.35	$0.35		$0.35
Dividends paid per common share	$1.40	$1.40		$1.40

Tax_Treatment_of_Distributions3

Tax Treatment of Distributions (Details 1) (USD $)	12 Months Ended						1 Months Ended		0 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012		Mar. 31, 2012	Aug. 31, 2012	Apr. 16, 2012
Income Tax Treatment of Dividends Paid [Line Items]
Capital gains, federal statutory tax rate	20.00%		20.00%		15.00%
Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per common share	$1.40		$1.40		$1.40
Common Stock, Dividends, Per Share, Cash Paid, Percentage	100.00%		100.00%		100.00%
Series G Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred stock, dividend rate	6.88%		6.88%				6.88%
Preferred Stock, Dividends, Per Share, Cash Paid	$1.72		$1.72		$1.09
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage	100.00%		100.00%		100.00%
Series H Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred stock, dividend rate	6.38%		6.38%					6.38%
Preferred Stock, Dividends, Per Share, Cash Paid	$1.59		$1.59		$0.40
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage	100.00%		100.00%		100.00%
Series E Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred stock, dividend rate									7.80%
Preferred Stock, Dividends, Per Share, Cash Paid	$0		$0		$0.82
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage	0.00%		0.00%		100.00%
Series F Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred stock, dividend rate									7.50%
Preferred Stock, Dividends, Per Share, Cash Paid	$0		$0		$0.79
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage	0.00%		0.00%		100.00%
Tax Treatment, Ordinary Income | Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per common share	$1.00		$0.76		$0.58
Common Stock, Dividends, Per Share, Cash Paid, Percentage	71.29%		54.00%		41.21%
Tax Treatment, Ordinary Income | Series G Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid	$1.71		$1.67		$1.09
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage	99.54%		97.03%		100.00%
Tax Treatment, Ordinary Income | Series H Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid	$1.59		$1.55		$0.40
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage	99.56%		96.99%		100.00%
Tax Treatment, Ordinary Income | Series E Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid	$0		$0		$0.82
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage	0.00%		0.00%		100.00%
Tax Treatment, Ordinary Income | Series F Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid	$0		$0		$0.79
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage	0.00%		0.00%		100.00%
Tax Treatment, Qualified Dividend | Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per common share	$0.00		$0.00		$0
Common Stock, Dividends, Per Share, Cash Paid, Percentage	0.14%		0.21%		0.00%
Tax Treatment, Qualified Dividend | Series G Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid	$0.00		$0.01		$0
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage	0.17%		0.35%		0.00%
Tax Treatment, Qualified Dividend | Series H Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid	$0.00		$0.01		$0
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage	0.19%		0.38%		0.00%
Tax Treatment, Return of Capital | Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per common share	$0.40		$0.62		$0.82
Common Stock, Dividends, Per Share, Cash Paid, Percentage	28.43%		44.29%		58.79%
Tax Treatment, Capital Gains | Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per common share	$0.00	[1]	$0	[1]	$0	[1]
Common Stock, Dividends, Per Share, Cash Paid, Percentage	0.14%	[1]	0.00%	[1]	0.00%	[1]
Tax Treatment, Capital Gains | Series G Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid	$0.01	[1]	$0	[1]	$0	[1]
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage	0.29%	[1]	0.00%	[1]	0.00%	[1]
Tax Treatment, Capital Gains | Series H Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid	$0.00	[1]	$0	[1]	$0	[1]
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage	0.25%	[1]	0.00%	[1]	0.00%	[1]
Tax Treatment, Capital Gains | Series E Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid	$0	[2]	$0	[2]	$0	[2]
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage	0.00%	[2]	0.00%	[2]	0.00%	[2]
Tax Treatment, Capital Gains | Series F Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid	$0	[2]	$0	[2]	$0	[2]
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage	0.00%	[2]	0.00%	[2]	0.00%	[2]
Tax Treatment, Unrecaptured Section 1250 Gains | Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per common share	$0		$0.02		$0
Common Stock, Dividends, Per Share, Cash Paid, Percentage	0.00%		1.50%		0.00%
Tax Treatment, Unrecaptured Section 1250 Gains | Series G Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid	$0		$0.05		$0
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage	0.00%		2.62%		0.00%
Tax Treatment, Unrecaptured Section 1250 Gains | Series H Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid	$0		$0.04		$0
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage	0.00%		2.63%		0.00%
Tax Treatment, Unrecaptured Section 1250 Gains | Series E Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid	$0		$0		$0
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage	0.00%		0.00%		0.00%
Tax Treatment, Unrecaptured Section 1250 Gains | Series F Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid	$0		$0		$0
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage	0.00%		0.00%		0.00%
[1]	Capital gains are comprised entirely of 20% rate gains for 2014 and 2013 and 15% rate gains for 2012.
[2]	Capital gains are comprised entirely of 15% rate gains.

Quarterly_Financial_Informatio4

Quarterly Financial Information of the Company (Unaudited) (Details) (USD $)	3 Months Ended																12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Revenues from continuing operations	$141,765	[1],[2]	$129,024	[1],[2]	$127,178	[1],[2]	$123,758	[1],[2]	$118,604	[1],[2]	$113,545	[1],[2]	$115,855	[1],[2]	$109,107	[1],[2]	$521,725	$457,111	$373,318
Income (loss) from continuing operations	19,417	[1],[2]	13,168	[1],[2]	15,854	[1],[2]	10,874	[1],[2]	5,038	[1],[2]	3,180	[1],[2]	6,942	[1],[2]	-225	[1],[2]	59,313	14,935	-5,475
Income from discontinued operations	12,013	[1],[2]	6,135	[1],[2]	15,289	[1],[2]	91,058	[1],[2]	18,009	[1],[2]	5,847	[1],[2]	3,161	[1],[2]	2,613	[1],[2]	124,495	29,630	282,576
Net income	31,430	[1]	19,303	[1]	31,143	[1]	101,932	[1]	23,047	[1]	9,027	[1]	10,103	[1]	2,388	[1]	183,808	44,565	277,101
Net income attributable to Kilroy Realty Corporation	30,852	[1]	18,982	[1]	30,540	[1]	99,845	[1]	22,628	[1]	8,896	[1]	9,946	[1]	2,410	[1]	180,219	43,880	270,914
Preferred dividends and distributions	-3,312	[1]	-3,313	[1]	-3,312	[1]	-3,313	[1]	-3,312	[1]	-3,312	[1]	-3,313	[1]	-3,313	[1]	-13,250	-13,250	-21,088
Net income available to common stockholders	$27,540	[1]	$15,669	[1]	$27,228	[1]	$96,532	[1]	$19,316	[1]	$5,584	[1]	$6,633	[1]	($903)	[1]	$166,969	$30,630	$249,826
Net income (loss) available to common stockholders per sharebbasic (dollars per share)	$0.32	[1]	$0.18	[1]	$0.33	[1]	$1.17	[1]	$0.23	[1]	$0.07	[1]	$0.08	[1]	($0.02)	[1]	$1.99	$0.37	$3.56
Net income (loss) available to common stockholders per sharebdiluted (dollars per share)	$0.32	[1]	$0.18	[1]	$0.32	[1]	$1.14	[1]	$0.23	[1]	$0.07	[1]	$0.08	[1]	($0.02)	[1]	$1.95	$0.37	$3.56
[1]	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common stockholders per share does not equal the annual number reported on the consolidated statements of operations due to the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended DecemberB 31,B 2014 and 2013.
[2]	All periods have been adjusted from amounts previously disclosed in our quarterly filings on FormB 10-Q to reclassify amounts related to discontinued operations (see NoteB 18 bDiscontinued Operationsb for additional information).

Quarterly_Financial_Informatio5

Quarterly Financial Information of the Operating Partnership (Unaudited) (Details) (USD $)	3 Months Ended																12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues from continuing operations	$141,765	[1],[2]	$129,024	[1],[2]	$127,178	[1],[2]	$123,758	[1],[2]	$118,604	[1],[2]	$113,545	[1],[2]	$115,855	[1],[2]	$109,107	[1],[2]	$521,725	$457,111	$373,318
Income (loss) from continuing operations	19,417	[1],[2]	13,168	[1],[2]	15,854	[1],[2]	10,874	[1],[2]	5,038	[1],[2]	3,180	[1],[2]	6,942	[1],[2]	-225	[1],[2]	59,313	14,935	-5,475
Income from discontinued operations	12,013	[1],[2]	6,135	[1],[2]	15,289	[1],[2]	91,058	[1],[2]	18,009	[1],[2]	5,847	[1],[2]	3,161	[1],[2]	2,613	[1],[2]	124,495	29,630	282,576
Net income	31,430	[1]	19,303	[1]	31,143	[1]	101,932	[1]	23,047	[1]	9,027	[1]	10,103	[1]	2,388	[1]	183,808	44,565	277,101
Net income attributable to the Operating Partnership	30,852	[1]	18,982	[1]	30,540	[1]	99,845	[1]	22,628	[1]	8,896	[1]	9,946	[1]	2,410	[1]	180,219	43,880	270,914
Preferred distributions	-3,312	[1]	-3,313	[1]	-3,312	[1]	-3,313	[1]	-3,312	[1]	-3,312	[1]	-3,313	[1]	-3,313	[1]	-13,250	-13,250	-21,088
Net income available to common stockholders	27,540	[1]	15,669	[1]	27,228	[1]	96,532	[1]	19,316	[1]	5,584	[1]	6,633	[1]	-903	[1]	166,969	30,630	249,826
Net income (loss) available to common stockholders per sharebbasic (dollars per share)	$0.32	[1]	$0.18	[1]	$0.33	[1]	$1.17	[1]	$0.23	[1]	$0.07	[1]	$0.08	[1]	($0.02)	[1]	$1.99	$0.37	$3.56
Net income (loss) available to common stockholders per sharebdiluted (dollars per share)	$0.32	[1]	$0.18	[1]	$0.32	[1]	$1.14	[1]	$0.23	[1]	$0.07	[1]	$0.08	[1]	($0.02)	[1]	$1.95	$0.37	$3.56
Kilroy Realty, L.P. [Member]
Revenues from continuing operations	141,765	[1],[3]	129,024	[1],[3]	127,178	[1],[3]	123,758	[1],[3]	118,604	[3],[4]	113,545	[3],[4]	115,855	[3],[4]	109,107	[3],[4]	521,725	457,111	373,318
Income (loss) from continuing operations	19,417	[3],[4]	13,168	[3],[4]	15,854	[3],[4]	10,874	[3],[4]	5,038	[3],[4]	3,180	[3],[4]	6,942	[3],[4]	-225	[3],[4]	59,313	14,935	-5,475
Income from discontinued operations	12,013	[3],[4]	6,135	[3],[4]	15,289	[3],[4]	91,058	[3],[4]	18,009	[3],[4]	5,847	[3],[4]	3,161	[3],[4]	2,613	[3],[4]	124,495	29,630	282,576
Net income	31,430	[4]	19,303	[4]	31,143	[4]	101,932	[4]	23,047	[4]	9,027	[4]	10,103	[4]	2,388	[4]	183,808	44,565	277,101
Net income attributable to the Operating Partnership	31,371	[4]	19,244	[4]	31,066	[4]	101,867	[4]	23,001	[4]	8,980	[4]	10,041	[4]	2,319	[4]	183,548	44,341	276,463
Preferred distributions	-3,312	[4]	-3,313	[4]	-3,312	[4]	-3,313	[4]	-3,312	[4]	-3,312	[4]	-3,313	[4]	-3,313	[4]	-13,250	-13,250	-21,088
Net income available to common stockholders	$28,059	[4]	$15,931	[4]	$27,754	[4]	$98,554	[4]	$19,689	[4]	$5,668	[4]	$6,728	[4]	($994)	[4]	$170,298	$31,091	$255,375
Net income (loss) available to common stockholders per sharebbasic (dollars per share)	$0.32	[4]	$0.18	[4]	$0.33	[4]	$1.17	[4]	$0.23	[4]	$0.07	[4]	$0.08	[4]	($0.02)	[4]	$1.99	$0.37	$3.56
Net income (loss) available to common stockholders per sharebdiluted (dollars per share)	$0.31	[4]	$0.18	[4]	$0.32	[4]	$1.14	[4]	$0.23	[4]	$0.07	[4]	$0.08	[4]	($0.02)	[4]	$1.94	$0.37	$3.56
[1]	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common stockholders per share does not equal the annual number reported on the consolidated statements of operations due to the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended DecemberB 31,B 2014 and 2013.
[2]	All periods have been adjusted from amounts previously disclosed in our quarterly filings on FormB 10-Q to reclassify amounts related to discontinued operations (see NoteB 18 bDiscontinued Operationsb for additional information).
[3]	All periods have been adjusted from amounts previously disclosed in our quarterly filings on Form 10-Q to reclassify amounts related to discontinued operations (see Note 18 bDiscontinued Operationsb).
[4]	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common unitholders per unit does not equal the annual number reported on the consolidated statements of operations due to the impact of the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended DecemberB 31,B 2014 and 2013.

Subsequent_Events_Details

Subsequent Events (Details) (USD $)	12 Months Ended				0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Jan. 27, 2015	Jan. 14, 2015	Jan. 15, 2015
Subsequent Event [Line Items]
Payments of Ordinary Dividends, Common Stock	$118,463,000	$111,517,000	$97,386,000
Common Stock, Dividends, Per Share, Declared	$1.40	$1.40		$1.40
Dividends, Preferred Stock	13,250,000	13,250,000	14,108,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	236,604
Subsequent Event [Member]
Subsequent Event [Line Items]
Payments of Ordinary Dividends, Common Stock						31,300,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period					212,468
Von Karman, Irvine, California [Member] | Subsequent Event [Member] | Properties Held for Sale [Member]
Subsequent Event [Line Items]
Dispositions Sales Price							$26,000,000
Market Measure-Based Restricted Stock Units (RSUs) [Member]
Subsequent Event [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	119,098
Market Measure-Based Restricted Stock Units (RSUs) [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period					127,657

Schedule_II_Valuation_and_Qual1

Schedule II Valuation and Qualifying Accounts (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2010
Allowance for Uncollectible Tenant Receivables
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$2,134		$2,581				$2,590
Charged to Costs and Expenses	58	[1]	396	[1]	-42	[1]
Recoveries (Deductions)	-193		-843		33
Balance at End of Period	1,999		2,134		2,581		2,590
Allowance for Unbilled Deferred Rent
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	2,075		2,607				3,406
Charged to Costs and Expenses	0	[1]	0	[1]	0	[1]
Recoveries (Deductions)	-86		-532		-799
Balance at End of Period	$1,989		$2,075		$2,607		$3,406
[1]	Includes amounts reported in Discontinued Operations (see Note 18 bDiscontinued Operationsb).

Schedule_III_Real_Estate_and_A1

Schedule III - Real Estate and Accumulated Depreciation (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Jan. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2010
	sqft	sqft
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	$536,022
Real Estate and Accumulated Depreciation, Initial Cost of Land	1,397,986
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	2,870,399
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,789,547
Real Estate and Accumulated Depreciation, Carrying Amount of Land	1,437,779
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	4,620,153
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	6,057,932
Real Estate and Accumulated Depreciation, Accumulated Depreciation	947,664		818,957	756,515	742,503
Net Rentable Area	14,096,617	79,000
Office Building [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	533,601
Real Estate and Accumulated Depreciation, Initial Cost of Land	837,840
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	2,866,029
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,233,403
Real Estate and Accumulated Depreciation, Carrying Amount of Land	877,633
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	4,059,639
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	4,937,272
Real Estate and Accumulated Depreciation, Accumulated Depreciation	947,664
Net Rentable Area	14,096,617
Office Building [Member] | 801 N. 34th St., Lake Union, WA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	0
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	58,537
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,166
Real Estate and Accumulated Depreciation, Carrying Amount of Land	0
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	59,703
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	59,703
Real Estate and Accumulated Depreciation, Accumulated Depreciation	5,690
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	169,412
Office Building [Member] | Westlake Avenue North [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	81,198
Real Estate and Accumulated Depreciation, Initial Cost of Land	14,710
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	82,018
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,114
Real Estate and Accumulated Depreciation, Carrying Amount of Land	14,710
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	83,132
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	97,842
Real Estate and Accumulated Depreciation, Accumulated Depreciation	5,392
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	184,643
Office Building [Member] | Pacific Center Boulevard, Sorrento Mesa, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	2,693
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	6,280
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	4,220
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,693
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	10,500
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	13,193
Real Estate and Accumulated Depreciation, Accumulated Depreciation	3,325
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	67,995
Office Building [Member] | Executive Drive, UTC, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	1,623
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	7,926
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	2,604
Real Estate and Accumulated Depreciation, Carrying Amount of Land	1,623
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	10,530
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	12,153
Real Estate and Accumulated Depreciation, Accumulated Depreciation	5,688
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	47,212
Office Building [Member] | Valley Centre Drive, Del Mar, California Two [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	4,184
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	19,352
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	18,063
Real Estate and Accumulated Depreciation, Carrying Amount of Land	5,259
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	36,340
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	41,599
Real Estate and Accumulated Depreciation, Accumulated Depreciation	17,821
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	130,349
Office Building [Member] | 23925 Park Sorrento, Calabasas, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	6,568
Real Estate and Accumulated Depreciation, Initial Cost of Land	50
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	2,346
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	495
Real Estate and Accumulated Depreciation, Carrying Amount of Land	50
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	2,841
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	2,891
Real Estate and Accumulated Depreciation, Accumulated Depreciation	1,471
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	11,789
Office Building [Member] | 23975 Park Sorrento, Calabasas, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	765
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	17,720
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	6,348
Real Estate and Accumulated Depreciation, Carrying Amount of Land	765
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	24,068
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	24,833
Real Estate and Accumulated Depreciation, Accumulated Depreciation	12,794
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	104,797
Office Building [Member] | 24025 Park Sorrento, Calabasas, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	845
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	15,896
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	4,755
Real Estate and Accumulated Depreciation, Carrying Amount of Land	845
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	20,651
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	21,496
Real Estate and Accumulated Depreciation, Accumulated Depreciation	11,620
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	108,671
Office Building [Member] | Townsgate Road, Thousand Oaks, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	5,248
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	8,001
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	7,025
Real Estate and Accumulated Depreciation, Carrying Amount of Land	5,248
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	15,026
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	20,274
Real Estate and Accumulated Depreciation, Accumulated Depreciation	8,938
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	81,067
Office Building [Member] | 2240 E. Imperial Highway, El Segundo, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	1,044
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	11,763
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	29,362
Real Estate and Accumulated Depreciation, Carrying Amount of Land	1,047
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	41,122
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	42,169
Real Estate and Accumulated Depreciation, Accumulated Depreciation	20,421
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	122,870
Office Building [Member] | 2250 E. Imperial Highway, El Segundo, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	2,579
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	29,062
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	34,713
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,547
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	63,807
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	66,354
Real Estate and Accumulated Depreciation, Accumulated Depreciation	44,738
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	298,728
Office Building [Member] | 2260 E. Imperial Highway, El Segundo, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	2,518
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	28,370
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	36,381
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,547
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	64,722
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	67,269
Real Estate and Accumulated Depreciation, Accumulated Depreciation	5,081
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	298,728
Office Building [Member] | 909 Sepulveda Boulevard, El Segundo, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	66,647
Real Estate and Accumulated Depreciation, Initial Cost of Land	3,577
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	34,042
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	42,397
Real Estate and Accumulated Depreciation, Carrying Amount of Land	3,577
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	76,439
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	80,016
Real Estate and Accumulated Depreciation, Accumulated Depreciation	26,481
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	241,607
Office Building [Member] | 999 Sepulveda Boulevard, El Segundo, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	1,407
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	34,326
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	11,857
Real Estate and Accumulated Depreciation, Carrying Amount of Land	1,407
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	46,183
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	47,590
Real Estate and Accumulated Depreciation, Accumulated Depreciation	16,648
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	128,592
Office Building [Member] | 3750 Kilroy Airport Way, Long Beach, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	1,941
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	10,455
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	12,396
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	12,396
Real Estate and Accumulated Depreciation, Accumulated Depreciation	8,938
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	10,457
Office Building [Member] | 3760 Kilroy Airport Way, Long Beach, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	17,467
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	9,396
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	26,863
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	26,863
Real Estate and Accumulated Depreciation, Accumulated Depreciation	20,924
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	165,278
Office Building [Member] | 3780 Kilroy Airport Way, Long Beach, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	22,319
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	15,763
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	38,082
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	38,082
Real Estate and Accumulated Depreciation, Accumulated Depreciation	31,437
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	219,822
Office Building [Member] | 3800 Kilroy Airport Way, Long Beach, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	19,408
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	16,899
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	36,307
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	36,307
Real Estate and Accumulated Depreciation, Accumulated Depreciation	19,320
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	192,476
Office Building [Member] | 3840 Kilroy Airport Way, Long Beach, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	13,586
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	9,236
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	22,822
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	22,822
Real Estate and Accumulated Depreciation, Accumulated Depreciation	12,535
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	136,026
Office Building [Member] | 3880 Kilroy Airport Way, Long Beach, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	9,704
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	7,310
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	17,014
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	17,014
Real Estate and Accumulated Depreciation, Accumulated Depreciation	1,114
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	96,035
Office Building [Member] | 3900 Kilroy Airport Way, Long Beach, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	12,615
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	9,055
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	21,670
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	21,670
Real Estate and Accumulated Depreciation, Accumulated Depreciation	12,880
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	126,840
Office Building [Member] | Kilroy Airport Center, Phase IV, Long Beach, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	4,997
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	4,997
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	4,997
Real Estate and Accumulated Depreciation, Accumulated Depreciation	4,980
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Office Building [Member] | 12100 W. Olympic Boulevard, Los Angeles, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	352
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	45,611
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	15,867
Real Estate and Accumulated Depreciation, Carrying Amount of Land	9,633
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	52,197
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	61,830
Real Estate and Accumulated Depreciation, Accumulated Depreciation	19,393
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	150,167
Office Building [Member] | 12200 W. Olympic Boulevard, Los Angeles, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	4,329
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	35,488
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	16,135
Real Estate and Accumulated Depreciation, Carrying Amount of Land	3,977
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	51,975
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	55,952
Real Estate and Accumulated Depreciation, Accumulated Depreciation	29,665
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	150,117
Office Building [Member] | 12233 Olympic Blvd, Los Angeles, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	39,339
Real Estate and Accumulated Depreciation, Initial Cost of Land	22,100
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	53,170
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,243
Real Estate and Accumulated Depreciation, Carrying Amount of Land	22,100
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	54,413
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	76,513
Real Estate and Accumulated Depreciation, Accumulated Depreciation	3,894
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	151,029
Office Building [Member] | 12312 W. Olympic Boulevard, Los Angeles, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	3,325
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	12,202
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	9,008
Real Estate and Accumulated Depreciation, Carrying Amount of Land	3,399
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	21,136
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	24,535
Real Estate and Accumulated Depreciation, Accumulated Depreciation	6,398
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	76,644
Office Building [Member] | 6255 Sunset Boulevard, Los Angeles, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	51,877
Real Estate and Accumulated Depreciation, Initial Cost of Land	18,111
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	60,320
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	27,831
Real Estate and Accumulated Depreciation, Carrying Amount of Land	18,111
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	88,151
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	106,262
Real Estate and Accumulated Depreciation, Accumulated Depreciation	8,173
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	324,617
Office Building [Member] | 1633 26th Street, Santa Monica, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	2,080
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	6,672
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	2,955
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,040
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	9,667
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	11,707
Real Estate and Accumulated Depreciation, Accumulated Depreciation	5,629
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	44,915
Office Building [Member] | 2100 Colorado Avenue, Santa Monica, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	97,000
Real Estate and Accumulated Depreciation, Initial Cost of Land	5,474
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	26,087
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	13,187
Real Estate and Accumulated Depreciation, Carrying Amount of Land	5,476
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	39,272
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	44,748
Real Estate and Accumulated Depreciation, Accumulated Depreciation	17,314
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	102,864
Office Building [Member] | 3130 Wilshire Boulevard, Santa Monica, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	8,921
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	6,579
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	11,440
Real Estate and Accumulated Depreciation, Carrying Amount of Land	9,188
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	17,752
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	26,940
Real Estate and Accumulated Depreciation, Accumulated Depreciation	11,313
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	88,339
Office Building [Member] | 501 Santa Monica Boulevard, Santa Monica, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	4,547
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	12,044
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	7,194
Real Estate and Accumulated Depreciation, Carrying Amount of Land	4,552
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	19,233
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	23,785
Real Estate and Accumulated Depreciation, Accumulated Depreciation	11,011
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	73,115
Office Building [Member] | Michelson Drive Irvine CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	9,319
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	82,836
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	2,682
Real Estate and Accumulated Depreciation, Carrying Amount of Land	9,319
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	85,518
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	94,837
Real Estate and Accumulated Depreciation, Accumulated Depreciation	14,316
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	271,556
Office Building [Member] | 12225 El Camino Real, Del Mar, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	1,700
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	9,633
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	2,969
Real Estate and Accumulated Depreciation, Carrying Amount of Land	1,660
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	12,642
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	14,302
Real Estate and Accumulated Depreciation, Accumulated Depreciation	6,382
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	58,401
Office Building [Member] | 12235 El Camino Real, Del Mar, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	1,507
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	8,543
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	4,659
Real Estate and Accumulated Depreciation, Carrying Amount of Land	1,554
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	13,155
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	14,709
Real Estate and Accumulated Depreciation, Accumulated Depreciation	7,645
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	54,673
Office Building [Member] | 12340 El Camino Real, Del Mar, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	4,201
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	13,896
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	7,587
Real Estate and Accumulated Depreciation, Carrying Amount of Land	4,201
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	21,483
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	25,684
Real Estate and Accumulated Depreciation, Accumulated Depreciation	8,170
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	87,374
Office Building [Member] | 12390 El Camino Real, Del Mar, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	3,453
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	11,981
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,344
Real Estate and Accumulated Depreciation, Carrying Amount of Land	3,453
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	13,325
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	16,778
Real Estate and Accumulated Depreciation, Accumulated Depreciation	7,558
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	72,332
Office Building [Member] | 12348 High Bluff Drive, Del Mar, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	1,629
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	3,096
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	4,395
Real Estate and Accumulated Depreciation, Carrying Amount of Land	1,629
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	7,491
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	9,120
Real Estate and Accumulated Depreciation, Accumulated Depreciation	4,882
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	38,806
Office Building [Member] | 12400 High Bluff Drive, Del Mar, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	15,167
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	40,497
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	12,107
Real Estate and Accumulated Depreciation, Carrying Amount of Land	15,167
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	52,604
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	67,771
Real Estate and Accumulated Depreciation, Accumulated Depreciation	19,934
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	209,220
Office Building [Member] | 3579 Valley Centre Drive, Del Mar, California One [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	2,167
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	6,897
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	7,257
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,858
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	13,463
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	16,321
Real Estate and Accumulated Depreciation, Accumulated Depreciation	7,063
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	50,677
Office Building [Member] | 3661 Valley Centre Drive, Del Mar, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	4,038
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	21,144
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	12,408
Real Estate and Accumulated Depreciation, Carrying Amount of Land	4,725
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	32,865
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	37,590
Real Estate and Accumulated Depreciation, Accumulated Depreciation	15,318
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	129,782
Office Building [Member] | 3721 Valley Centre Drive, Del Mar, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	4,297
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	18,967
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	12,783
Real Estate and Accumulated Depreciation, Carrying Amount of Land	4,253
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	31,794
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	36,047
Real Estate and Accumulated Depreciation, Accumulated Depreciation	9,901
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	114,780
Office Building [Member] | 3811 Valley Centre Drive, Del Mar, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	3,452
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	16,152
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	20,077
Real Estate and Accumulated Depreciation, Carrying Amount of Land	4,457
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	35,224
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	39,681
Real Estate and Accumulated Depreciation, Accumulated Depreciation	16,343
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	112,067
Office Building [Member] | El Camino Real, Del Mar, California Five [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	18,398
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	54,954
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,096
Real Estate and Accumulated Depreciation, Carrying Amount of Land	18,398
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	56,050
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	74,448
Real Estate and Accumulated Depreciation, Accumulated Depreciation	2,738
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	140,591
Office Building [Member] | El Camino Real, Del Mar, California Six [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	10,252
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	21,236
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	611
Real Estate and Accumulated Depreciation, Carrying Amount of Land	10,252
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	21,847
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	32,099
Real Estate and Accumulated Depreciation, Accumulated Depreciation	1,080
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	78,349
Office Building [Member] | 6200 Greenwich Drive, Governor Park, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	1,583
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	5,235
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	7,458
Real Estate and Accumulated Depreciation, Carrying Amount of Land	1,762
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	12,514
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	14,276
Real Estate and Accumulated Depreciation, Accumulated Depreciation	5,115
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	73,507
Office Building [Member] | 6220 Greenwich Drive, Governor Park, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	3,213
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	10,628
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	18,927
Real Estate and Accumulated Depreciation, Carrying Amount of Land	3,386
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	29,382
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	32,768
Real Estate and Accumulated Depreciation, Accumulated Depreciation	9,991
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	141,214
Office Building [Member] | 13280 Evening Creek Drive, South I-15 Corridor, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	3,701
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	8,398
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	3,970
Real Estate and Accumulated Depreciation, Carrying Amount of Land	3,701
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	12,368
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	16,069
Real Estate and Accumulated Depreciation, Accumulated Depreciation	2,712
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	41,196
Office Building [Member] | 13290 Evening Creek Drive, South I-15 Corridor, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	5,229
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	11,871
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	5,919
Real Estate and Accumulated Depreciation, Carrying Amount of Land	5,229
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	17,790
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	23,019
Real Estate and Accumulated Depreciation, Accumulated Depreciation	2,583
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	61,180
Office Building [Member] | 13480 Evening Creek Drive, North I-15 Corridor, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	7,997
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	48,020
Real Estate and Accumulated Depreciation, Carrying Amount of Land	7,997
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	48,020
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	56,017
Real Estate and Accumulated Depreciation, Accumulated Depreciation	11,409
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	149,817
Office Building [Member] | 13500 Evening Creek Drive, North I-15 Corridor, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	7,581
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	35,903
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	8,201
Real Estate and Accumulated Depreciation, Carrying Amount of Land	7,580
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	44,105
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	51,685
Real Estate and Accumulated Depreciation, Accumulated Depreciation	14,251
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	147,533
Office Building [Member] | 13520 Evening Creek Drive, North I-15 Corridor, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	7,581
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	35,903
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	9,541
Real Estate and Accumulated Depreciation, Carrying Amount of Land	7,580
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	45,445
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	53,025
Real Estate and Accumulated Depreciation, Accumulated Depreciation	15,711
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	141,128
Office Building [Member] | 7525 Torrey Santa Fe, 56 Corridor, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	2,348
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	28,035
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	4,061
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,348
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	32,096
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	34,444
Real Estate and Accumulated Depreciation, Accumulated Depreciation	8,882
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	103,979
Office Building [Member] | 7535 Torrey Santa Fe, 56 Corridor, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	2,950
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	33,808
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	5,991
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,949
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	39,800
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	42,749
Real Estate and Accumulated Depreciation, Accumulated Depreciation	11,407
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	130,243
Office Building [Member] | 7545 Torrey Santa Fe, 56 Corridor, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	2,950
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	33,708
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	8,118
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,950
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	41,826
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	44,776
Real Estate and Accumulated Depreciation, Accumulated Depreciation	12,868
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	130,354
Office Building [Member] | 7555 Torrey Santa Fe, 56 Corridor, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	2,287
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	24,916
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	3,714
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,287
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	28,630
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	30,917
Real Estate and Accumulated Depreciation, Accumulated Depreciation	7,909
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	101,236
Office Building [Member] | 2355 Northside Drive, Mission Valley, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	4,066
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	8,332
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,194
Real Estate and Accumulated Depreciation, Carrying Amount of Land	3,344
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	10,248
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	13,592
Real Estate and Accumulated Depreciation, Accumulated Depreciation	2,276
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	53,610
Office Building [Member] | 2365 Northside Drive, Mission Valley, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	7,359
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	15,257
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,711
Real Estate and Accumulated Depreciation, Carrying Amount of Land	6,015
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	18,312
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	24,327
Real Estate and Accumulated Depreciation, Accumulated Depreciation	3,662
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	96,436
Office Building [Member] | 2375 Northside Drive, Mission Valley, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	3,947
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	8,146
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	2,083
Real Estate and Accumulated Depreciation, Carrying Amount of Land	3,213
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	10,963
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	14,176
Real Estate and Accumulated Depreciation, Accumulated Depreciation	2,119
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	51,516
Office Building [Member] | 2385 Northside Drive, Mission Valley, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	2,752
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	14,513
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	5,081
Real Estate and Accumulated Depreciation, Carrying Amount of Land	5,552
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	16,794
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	22,346
Real Estate and Accumulated Depreciation, Accumulated Depreciation	3,522
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	89,023
Office Building [Member] | 2305 Historic Decatur Road, San Diego, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	5,240
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	22,220
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,035
Real Estate and Accumulated Depreciation, Carrying Amount of Land	5,240
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	23,255
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	28,495
Real Estate and Accumulated Depreciation, Accumulated Depreciation	4,086
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	103,900
Office Building [Member] | 4921 Directors Place, Sorrento Mesa, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	3,792
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	11,091
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	4,845
Real Estate and Accumulated Depreciation, Carrying Amount of Land	3,792
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	15,936
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	19,728
Real Estate and Accumulated Depreciation, Accumulated Depreciation	3,353
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	56,136
Office Building [Member] | 4939 Directors Place, Sorrento Mesa, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	2,225
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	12,698
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	4,359
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,198
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	17,084
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	19,282
Real Estate and Accumulated Depreciation, Accumulated Depreciation	8,324
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	60,662
Office Building [Member] | 4955 Directors Place, Sorrento Mesa, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	2,521
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	14,122
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	3,697
Real Estate and Accumulated Depreciation, Carrying Amount of Land	3,179
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	17,161
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	20,340
Real Estate and Accumulated Depreciation, Accumulated Depreciation	12,205
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	76,246
Office Building [Member] | 10770 Wateridge Circle, San Diego, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	4,560
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	26,671
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	236
Real Estate and Accumulated Depreciation, Carrying Amount of Land	4,560
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	26,907
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	31,467
Real Estate and Accumulated Depreciation, Accumulated Depreciation	7,055
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	174,310
Office Building [Member] | 6260 Sequence Drive, Sorrento Mesa, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	3,206
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	9,803
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	11,377
Real Estate and Accumulated Depreciation, Carrying Amount of Land	3,212
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	21,174
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	24,386
Real Estate and Accumulated Depreciation, Accumulated Depreciation	6,794
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	130,536
Office Building [Member] | 6290 Sequence Drive, Sorrento Mesa, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	2,403
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	7,349
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	6,944
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,407
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	14,289
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	16,696
Real Estate and Accumulated Depreciation, Accumulated Depreciation	7,935
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	90,000
Office Building [Member] | 303 Second Street, San Francisco, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	130,767
Real Estate and Accumulated Depreciation, Initial Cost of Land	63,550
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	154,153
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	29,808
Real Estate and Accumulated Depreciation, Carrying Amount of Land	63,550
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	183,961
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	247,511
Real Estate and Accumulated Depreciation, Accumulated Depreciation	33,520
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	740,047
Office Building [Member] | 100 First Street, San Francisco, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	49,150
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	131,238
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	21,180
Real Estate and Accumulated Depreciation, Carrying Amount of Land	49,150
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	152,418
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	201,568
Real Estate and Accumulated Depreciation, Accumulated Depreciation	25,401
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	466,490
Office Building [Member] | 250 Brannan Street, San Francisco, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	7,630
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	22,770
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	4,322
Real Estate and Accumulated Depreciation, Carrying Amount of Land	7,630
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	27,092
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	34,722
Real Estate and Accumulated Depreciation, Accumulated Depreciation	4,747
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	95,008
Office Building [Member] | 201 Third Street, San Francisco, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	19,260
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	84,018
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	21,473
Real Estate and Accumulated Depreciation, Carrying Amount of Land	19,260
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	105,491
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	124,751
Real Estate and Accumulated Depreciation, Accumulated Depreciation	18,065
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	344,551
Office Building [Member] | 301 Brannan Street, San Francisco, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	5,910
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	22,450
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,785
Real Estate and Accumulated Depreciation, Carrying Amount of Land	5,910
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	24,235
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	30,145
Real Estate and Accumulated Depreciation, Accumulated Depreciation	3,135
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	74,430
Office Building [Member] | 360 Third St., San Francisco, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	0
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	88,235
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	108,122
Real Estate and Accumulated Depreciation, Carrying Amount of Land	28,504
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	167,853
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	196,357
Real Estate and Accumulated Depreciation, Accumulated Depreciation	10,834
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	429,996
Office Building [Member] | 1310 Chesapeake Terrace, Sunnyvale, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	16,700
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	11,020
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	0
Real Estate and Accumulated Depreciation, Carrying Amount of Land	16,700
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	11,020
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	27,720
Real Estate and Accumulated Depreciation, Accumulated Depreciation	82
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	76,244
Office Building [Member] | 1315 Chesapeake Terrace, Sunnyvale, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	12,260
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	7,930
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	0
Real Estate and Accumulated Depreciation, Carrying Amount of Land	12,260
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	7,930
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	20,190
Real Estate and Accumulated Depreciation, Accumulated Depreciation	76
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	55,635
Office Building [Member] | 1320-1324 Chesapeake Terrace, Sunnyvale, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	17,360
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	10,720
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	0
Real Estate and Accumulated Depreciation, Carrying Amount of Land	17,360
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	10,720
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	28,080
Real Estate and Accumulated Depreciation, Accumulated Depreciation	62
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	79,720
Office Building [Member] | 1325-1327 Chesapeake Terrace, Sunnyvale, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	12,610
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	8,160
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	0
Real Estate and Accumulated Depreciation, Carrying Amount of Land	12,610
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	8,160
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	20,770
Real Estate and Accumulated Depreciation, Accumulated Depreciation	79
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	55,383
Office Building [Member] | 505 Mathilda Ave., Sunnyvale, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	37,843
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	1,163
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	53,030
Real Estate and Accumulated Depreciation, Carrying Amount of Land	37,872
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	54,164
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	92,036
Real Estate and Accumulated Depreciation, Accumulated Depreciation	492
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	212,322
Office Building [Member] | 555 Mathilda Ave., Sunnyvale, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	37,843
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	1,163
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	53,026
Real Estate and Accumulated Depreciation, Carrying Amount of Land	37,872
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	54,160
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	92,032
Real Estate and Accumulated Depreciation, Accumulated Depreciation	492
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	212,322
Office Building [Member] | 605 Mathilda Ave., Sunnyvale, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	29,014
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	891
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	69,887
Real Estate and Accumulated Depreciation, Carrying Amount of Land	29,036
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	70,756
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	99,792
Real Estate and Accumulated Depreciation, Accumulated Depreciation	1,068
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	162,785
Office Building [Member] | 599 N. Mathilda Avenue, Sunnyvale, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	13,538
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	12,559
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	59
Real Estate and Accumulated Depreciation, Carrying Amount of Land	13,538
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	12,618
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	26,156
Real Estate and Accumulated Depreciation, Accumulated Depreciation	1,181
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	75,810
Office Building [Member] | 601 108th Avenue, Bellevue, Washington [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	0
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	214,095
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	21,988
Real Estate and Accumulated Depreciation, Carrying Amount of Land	0
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	236,083
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	236,083
Real Estate and Accumulated Depreciation, Accumulated Depreciation	32,892
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	488,470
Office Building [Member] | NE 4th Street 10900 Bellevue, Washington [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	25,080
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	150,877
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	19,537
Real Estate and Accumulated Depreciation, Carrying Amount of Land	25,080
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	170,414
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	195,494
Real Estate and Accumulated Depreciation, Accumulated Depreciation	16,265
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	416,755
Office Building [Member] | Sequence Drive, Sorrento Mesa, California Three [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	2,940
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	4,946
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	329
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,941
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	5,274
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	8,215
Real Estate and Accumulated Depreciation, Accumulated Depreciation	3,060
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	62,415
Office Building [Member] | Sequence Drive, Sorrento Mesa, California Four [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	2,434
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	7,302
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	9,965
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,465
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	17,236
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	19,701
Real Estate and Accumulated Depreciation, Accumulated Depreciation	9,571
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	66,400
Office Building [Member] | Sequence Drive, Sorrento Mesa, California Five [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	4,941
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	14,824
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	2,629
Real Estate and Accumulated Depreciation, Carrying Amount of Land	4,922
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	17,472
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	22,394
Real Estate and Accumulated Depreciation, Accumulated Depreciation	6,940
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	132,600
Office Building [Member] | Pacific Center Court, Sorrento Mesa, California One [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	3,267
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	5,779
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	7,501
Real Estate and Accumulated Depreciation, Carrying Amount of Land	3,267
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	13,280
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	16,547
Real Estate and Accumulated Depreciation, Accumulated Depreciation	5,352
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	68,400
Office Building [Member] | Pacific Center Court, Sorrento Mesa, California Two [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	2,696
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	7,134
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	-780
Real Estate and Accumulated Depreciation, Carrying Amount of Land	1,672
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	7,378
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	9,050
Real Estate and Accumulated Depreciation, Accumulated Depreciation	3,788
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	59,630
Office Building [Member] | Pacific Center Court, Sorrento Mesa, California Three [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	1,947
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	5,152
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,316
Real Estate and Accumulated Depreciation, Carrying Amount of Land	1,222
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	7,193
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	8,415
Real Estate and Accumulated Depreciation, Accumulated Depreciation	3,524
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	43,645
Office Building [Member] | Pacific Center Court, Sorrento Mesa, California Four [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	2,926
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	7,979
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	21,865
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,926
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	29,844
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	32,770
Real Estate and Accumulated Depreciation, Accumulated Depreciation	14,998
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	75,899
Office Building [Member] | Pacific Center Court, Sorrento Mesa, California Five [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	2,247
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	5,945
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,832
Real Estate and Accumulated Depreciation, Carrying Amount of Land	1,809
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	8,215
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	10,024
Real Estate and Accumulated Depreciation, Accumulated Depreciation	3,750
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	48,709
Office Building [Member] | Pacific Center Court, Sorrento Mesa, California Six [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	4,044
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	10,701
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	-2,250
Real Estate and Accumulated Depreciation, Carrying Amount of Land	3,780
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	8,715
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	12,495
Real Estate and Accumulated Depreciation, Accumulated Depreciation	4,250
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	90,000
Office Building [Member] | Bohannon Drive 4100, Menlo Park, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	4,835
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	15,526
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	381
Real Estate and Accumulated Depreciation, Carrying Amount of Land	4,835
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	15,907
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	20,742
Real Estate and Accumulated Depreciation, Accumulated Depreciation	1,572
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	47,379
Office Building [Member] | Bohannon Drive 4200, Menlo Park, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	4,798
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	15,406
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,856
Real Estate and Accumulated Depreciation, Carrying Amount of Land	4,798
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	17,262
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	22,060
Real Estate and Accumulated Depreciation, Accumulated Depreciation	1,572
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	45,451
Office Building [Member] | Bohannon Drive 4300, Menlo Park, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	6,527
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	20,958
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	2,760
Real Estate and Accumulated Depreciation, Carrying Amount of Land	6,527
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	23,718
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	30,245
Real Estate and Accumulated Depreciation, Accumulated Depreciation	2,601
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	63,079
Office Building [Member] | Bohannon Drive 4400, Menlo Park, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	4,798
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	15,406
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,818
Real Estate and Accumulated Depreciation, Carrying Amount of Land	4,798
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	17,224
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	22,022
Real Estate and Accumulated Depreciation, Accumulated Depreciation	1,823
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	48,146
Office Building [Member] | Bohannon Drive 4500, Menlo Park, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	6,527
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	20,957
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,568
Real Estate and Accumulated Depreciation, Carrying Amount of Land	6,527
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	22,525
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	29,052
Real Estate and Accumulated Depreciation, Accumulated Depreciation	2,256
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	63,078
Office Building [Member] | Bohannon Drive 4600, Menlo Park, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	4,798
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	15,406
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,922
Real Estate and Accumulated Depreciation, Carrying Amount of Land	4,798
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	17,328
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	22,126
Real Estate and Accumulated Depreciation, Accumulated Depreciation	1,459
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	48,147
Office Building [Member] | Bohannon Drive 4700, Menlo Park, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	6,527
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	20,958
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,344
Real Estate and Accumulated Depreciation, Carrying Amount of Land	6,527
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	22,302
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	28,829
Real Estate and Accumulated Depreciation, Accumulated Depreciation	2,190
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	63,078
Office Building [Member] | Fairchild Drive, 331, Mountain View, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	18,396
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	17,712
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	7,883
Real Estate and Accumulated Depreciation, Carrying Amount of Land	18,396
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	25,595
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	43,991
Real Estate and Accumulated Depreciation, Accumulated Depreciation	1,075
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	87,147
Office Building [Member] | 680 E Middlefield Road, Mountain View, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	34,605
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	0
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	54,311
Real Estate and Accumulated Depreciation, Carrying Amount of Land	34,605
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	54,311
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	88,916
Real Estate and Accumulated Depreciation, Accumulated Depreciation	291
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	170,090
Office Building [Member] | 690 E Middlefield Road, Mountain View, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	34,755
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	0
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	58,036
Real Estate and Accumulated Depreciation, Carrying Amount of Land	34,755
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	58,036
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	92,791
Real Estate and Accumulated Depreciation, Accumulated Depreciation	292
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	170,823
Office Building [Member] | NE Points Drive, Kirkland, Washington One [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	26,205
Real Estate and Accumulated Depreciation, Initial Cost of Land	2,554
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	12,080
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	634
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,554
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	12,714
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	15,268
Real Estate and Accumulated Depreciation, Accumulated Depreciation	1,825
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	49,851
Office Building [Member] | NE Points Drive, Kirkland, Washington Two [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	5,071
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	24,694
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	2,497
Real Estate and Accumulated Depreciation, Carrying Amount of Land	5,070
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	27,192
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	32,262
Real Estate and Accumulated Depreciation, Accumulated Depreciation	3,948
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	98,982
Office Building [Member] | NE Points Drive, Kirkland, Washington Three [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	4,336
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	24,187
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,552
Real Estate and Accumulated Depreciation, Carrying Amount of Land	4,336
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	25,739
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	30,075
Real Estate and Accumulated Depreciation, Accumulated Depreciation	3,769
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	84,641
Office Building [Member] | 3933 Lake WA Blvd. NE, Kirkland, WA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	2,380
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	15,114
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	2,705
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,380
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	17,819
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	20,199
Real Estate and Accumulated Depreciation, Accumulated Depreciation	2,517
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	46,450
Office Building [Member] | Fremont Lake View Seattle WA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	0
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	37,404
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	604
Real Estate and Accumulated Depreciation, Carrying Amount of Land	0
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	38,008
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	38,008
Real Estate and Accumulated Depreciation, Accumulated Depreciation	3,965
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	111,580
Office Building [Member] | Terry Avenue North, Washington Two [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	10,430
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	60,003
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	182
Real Estate and Accumulated Depreciation, Carrying Amount of Land	10,430
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	60,185
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	70,615
Real Estate and Accumulated Depreciation, Accumulated Depreciation	4,124
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	135,755
Office Building [Member] | 701 N. 34th St., Lake Union, WA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	34,000
Real Estate and Accumulated Depreciation, Initial Cost of Land	0
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	48,027
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,601
Real Estate and Accumulated Depreciation, Carrying Amount of Land	0
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	49,628
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	49,628
Real Estate and Accumulated Depreciation, Accumulated Depreciation	5,370
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	138,995
Office Building [Member] | 15050 N.E. 36th St., Redmond, WA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	9,260
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	34,650
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	197
Real Estate and Accumulated Depreciation, Carrying Amount of Land	9,260
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	34,847
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	44,107
Real Estate and Accumulated Depreciation, Accumulated Depreciation	4,644
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	122,103
Office Building [Member] | 401 Terry Avenue North, Lake Union, WA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	22,500
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	77,046
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	0
Real Estate and Accumulated Depreciation, Carrying Amount of Land	22,500
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	77,046
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	99,546
Real Estate and Accumulated Depreciation, Accumulated Depreciation	2,222
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area	140,605
Undeveloped Land and CIP Properties [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	2,421
Real Estate and Accumulated Depreciation, Initial Cost of Land	560,146
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	4,370
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	556,144
Real Estate and Accumulated Depreciation, Carrying Amount of Land	560,146
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	560,514
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	$1,120,660

Schedule_III_Real_Estate_and_A2

Schedule III - Real Estate and Accumulated Depreciation (Details 2) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2010
SEC Schedule III, Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Total real estate held for investment, beginning of year	$5,264,947		$4,757,394				$3,798,690
Acquisitions	340,296		384,650		1,023,384
Improvements, etc.	588,166		452,331		207,345
Total additions during period	928,462		836,981		1,230,729
Cost of real estate sold	-113,416		-56,993		-264,533
Properties held for sale	-14,700		-259,251		0
Other	-7,361	[1]	-13,184	[1]	-7,492	[1]
Total deductions during period	-135,477		-329,428		-272,025
Total real estate held for investment, end of year	$6,057,932		$5,264,947		$4,757,394		$3,798,690
[1]	{F|ahBzfndlYmZpbGluZ3MtaHJkcmoLEgZYTUxEb2MiXlhCUkxEb2NHZW5JbmZvOmUyOWE0ZTIxNmIxZTRhODI5NmIzM2U3NWViZmJjODczfFRleHRTZWxlY3Rpb246MUZBNjVBQUVGMzIyQkEwM0JDQkRGOTkxQzlDMzdBNTEM}

Schedule_III_Real_Estate_and_A3

Schedule III - Real Estate and Accumulated Depreciation (Details 3) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2010
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Accumulated depreciation, beginning of year	$818,957		$756,515				$742,503
Depreciation of real estate	153,841		145,325		125,906
Total additions during period	153,841		145,325		125,906
Write-offs due to sale	-18,111		-17,144		-109,797
Properties held for sale	-7,007		-63,110		0
Other	-16	[1]	-2,629	[1]	-2,097	[1]
Total deductions during period	-25,134		-82,883		-111,894
Accumulated depreciation, end of year	$947,664		$818,957		$756,515		$742,503
[1]	{F|ahBzfndlYmZpbGluZ3MtaHJkcmoLEgZYTUxEb2MiXlhCUkxEb2NHZW5JbmZvOmUyOWE0ZTIxNmIxZTRhODI5NmIzM2U3NWViZmJjODczfFRleHRTZWxlY3Rpb246QzRERkRFRDZEN0REQUQ5QTVGQjJGOTkxQzlDM0NBRjIM}

Schedule_III_Real_Estate_and_A4

Schedule III - Real Estate and Accumulated Depreciation (Details) (Textuals) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Real Estate and Accumulated Depreciation [Line Items]
Secured debt (Notes 3, 6, 7 and 16)	546,292,000	$560,434,000
Debt premium	10,300,000
Aggregate cost of property for federal income tax purposes	5,200,000,000
Secured Debt [Member]
Real Estate and Accumulated Depreciation [Line Items]
Debt premium	10,300,000	14,600,000
Secured Debt [Member] | 7.15% Mortgage Payable due May 1, 2017 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Secured debt (Notes 3, 6, 7 and 16)	6,600,000
Secured Debt [Member] | 6.51% Mortgage Payable due February 1, 2017 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Secured debt (Notes 3, 6, 7 and 16)	66,600,000
Secured Debt [Member] | 5.57% Mortgage Note Payable due February 2016 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Secured debt (Notes 3, 6, 7 and 16)	39,300,000
Secured Debt [Member] | 5.23% Mortgage Payable due January 2016 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Secured debt (Notes 3, 6, 7 and 16)	51,900,000
Secured Debt [Member] | 4.48% Mortgage Payable due July 2027
Real Estate and Accumulated Depreciation [Line Items]
Secured debt (Notes 3, 6, 7 and 16)	97,000,000
Secured Debt [Member] | 4.27% Mortgage Payable due Feb 1, 2018 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Secured debt (Notes 3, 6, 7 and 16)	130,800,000
Secured Debt [Member] | 4.94% Mortgage Payable due April 15, 2015 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Secured debt (Notes 3, 6, 7 and 16)	26,200,000
Secured Debt [Member] | 6.05% Mortgage Payable Due June 1, 2019 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Secured debt (Notes 3, 6, 7 and 16)	81,200,000
Secured Debt [Member] | 5.09% Mortgage Payable due August 2015 [Member] [Member]
Real Estate and Accumulated Depreciation [Line Items]
Secured debt (Notes 3, 6, 7 and 16)	34,000,000
Building [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Tenant Improvements [Member] | Minimum [Member]
Real Estate and Accumulated Depreciation [Line Items]
Property, Plant and Equipment, Useful Life	1 year
Tenant Improvements [Member] | Maximum [Member]
Real Estate and Accumulated Depreciation [Line Items]
Property, Plant and Equipment, Useful Life	20 years