Kilroy Realty (KRC) 10-K/A 6 Jun 14 2013 FY Annual report (amended) Financial data

Document_and_Entity_Informatio

Document and Entity Information Document (USD $)	12 Months Ended
	Dec. 31, 2013	Feb. 05, 2014	Jun. 30, 2013
Entity Information [Line Items]	'	'	'
Entity Registrant Name	'KILROY REALTY CORP	'	'
Entity Central Index Key	'0001025996	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Filer Category	'Large Accelerated Filer	'	'
Document Type	'10-K	'	'
Document Period End Date	31-Dec-13	'	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
Amendment Flag	'false	'	'
Entity Common Stock, Shares Outstanding	'	82,130,022	'
Entity Public Float	'	'	$3,991,944,820
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	'0001493976	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Filer Category	'Non-accelerated Filer	'	'
Document Type	'10-K	'	'
Document Period End Date	31-Dec-13	'	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
Amendment Flag	'false	'	'
Entity Public Float	'	'	$55,100,926
Entity Well-known Seasoned Issuer	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Current Reporting Status	'Yes	'	'

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
REAL ESTATE ASSETS (Notes 3 and 17):	'		'
Land and improvements	$657,491		$612,714
Buildings and improvements	3,590,699		3,335,026
Undeveloped land and construction in progress	1,016,757		809,654
Total real estate held for investment	5,264,947		4,757,394
Accumulated depreciation and amortization	818,957		756,515
Total real estate held for investment, net ($206,319 and $319,770 of VIE, Note 2)	4,445,990		4,000,879
Assets of Disposal Group, Including Discontinued Operation	213,100		0
REAL ESTATE ASSETS AND OTHER ASSETS HELD FOR SALE, NET (Note 17)	213,100		'
CASH AND CASH EQUIVALENTS	35,377		16,700
RESTRICTED CASH (Note 17)	49,780		247,544
MARKETABLE SECURITIES (Notes 13 and 16)	10,008	[1],[2]	7,435	[1],[2]
CURRENT RECEIVABLES, NET (Note 5)	10,743	[3]	9,220
DEFERRED RENT RECEIVABLES, NET (Note 5)	127,123	[4]	115,418
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Notes 3 and 4)	186,622		189,968
DEFERRED FINANCING COSTS, NET (Notes 2 and 7)	16,502		18,971
PREPAID EXPENSES AND OTHER ASSETS, NET	15,783		9,949
TOTAL ASSETS	5,111,028		4,616,084
LIABILITIES:	'		'
Exchangeable senior notes, net	168,372		163,944
Unsecured debt, net	1,431,132		1,130,895
Unsecured line of credit (Notes 6, 7 and 16)	45,000		185,000
Accounts payable, accrued expenses and other liabilities (Note 15)	198,467		154,734
Accrued distributions (Note 10)	31,490		28,924
Deferred revenue and acquisition-related intangible liabilities, net (Notes 3, 4 and 8)	101,286		117,904
Rents received in advance and tenant security deposits	44,240		37,654
Liabilities of Disposal Group, Including Discontinued Operation	14,447		0
Liabilities and deferred revenue of real estate assets held for sale (Note 17)	14,447		'
Total liabilities	2,594,868		2,380,151
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, 74,926,981 and 58,819,717 shares issued and outstanding, respectively	822		749
Additional paid-in capital	2,478,975		2,126,005
Distributions in excess of earnings	210,896		129,535
Total stockholders' equity	2,461,312		2,189,630
Noncontrolling interest:	'		'
Common units of the Operating Partnership	49,963		46,303
Noncontrolling interest in consolidated subsidiary	4,885		0
Total noncontrolling interests	54,848		46,303
Total equity	2,516,160		2,235,933
TOTAL LIABILITIES AND EQUITY	5,111,028		4,616,084
Secured debt	560,434		561,096
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]	The marketable securities are held in a limited rabbi trust.
[2]	Based on quoted prices in active markets for identical securities.
[3]	Excludes current receivables, net related to properties held for sale at December 31, 2013.
[4]	Excludes deferred rent receivables, net related to properties held for sale at December 31, 2013.

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified	Common Stock	Common Stock	Preferred Stock [Member]	Preferred Stock [Member]	Series G Cumulative Redeemable Preferred Stock	Series G Cumulative Redeemable Preferred Stock	Series H Cumulative Redeemable Preferred Stock	Series H Cumulative Redeemable Preferred Stock
Common stock, par value	$0.01	$0.01	'	'	'	'	'	'
Common stock, shares authorized	150,000,000	150,000,000	'	'	'	'	'	'
Common stock, shares issued	82,153,944	74,926,981	'	'	'	'	'	'
Common stock, shares outstanding	82,153,944	74,926,981	'	'	'	'	'	'
Preferred stock, shares authorized	'	'	30,000,000	30,000,000	4,600,000	4,600,000	4,000,000	4,000,000
Preferred stock, par value	'	'	$0.01	$0.01	$0.01	$0.01	$0.01	$0.01
Preferred stock, shares outstanding	'	'	'	'	4,000,000	4,000,000	4,000,000	4,000,000
Preferred stock dividend rate (percentage)	'	'	'	'	6.88%	6.88%	6.38%	6.38%
Preferred stock liquidation preference	'	'	'	'	$100,000	$100,000	$100,000	$100,000

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
REVENUES:	'	'	'
Rental income	$419,189	$349,613	$287,078
Tenant reimbursements	38,313	29,889	20,957
Other property income (Note 15)	7,596	1,498	2,389
Total revenues	465,098	381,000	310,424
EXPENSES:	'	'	'
Property expenses	96,606	76,219	63,722
Real estate taxes	40,156	32,323	26,981
Provision for bad debts	404	153	695
Ground leases (Note 4 and 15)	3,504	3,168	1,565
General and administrative expenses	39,660	36,188	28,148
Acquisition-related expenses	1,962	4,937	4,053
Depreciation and amortization (Notes 2 and 4)	192,734	153,251	115,630
Total expenses	375,026	306,239	240,794
OTHER (EXPENSES) INCOME:	'	'	'
Interest income and other net investment gains (Note 16)	1,635	848	571
Interest expense (Note 7)	-75,870	-79,114	-85,785
Total other (expenses) income	-74,235	-78,266	-85,214
INCOME (LOSS) FROM CONTINUING OPERATIONS	15,837	-3,505	-15,584
DISCONTINUED OPERATIONS (Note 17)	'	'	'
Income from discontinued operations	16,476	21,361	31,486
Net gain on dispositions of discontinued operations	12,252	259,245	51,587
Total income from discontinued operations	28,728	280,606	83,073
NET INCOME	44,565	277,101	67,489
Net income attributable to noncontrolling common units of the Operating Partnership	685	6,187	1,474
NET INCOME ATTRIBUTABLE TO KILROY REALTY	43,880	270,914	66,015
PREFERRED DISTRIBUTIONS AND DIVIDENDS:	'	'	'
Distributions to noncontrolling cumulative redeemable preferred units of the Operating Partnership (Note 9)	0	-3,541	-5,588
Preferred dividends (Note 10)	-13,250	-10,567	-9,608
Original issuance costs of redeemed preferred stock and preferred units (Notes 9 and 11)	0	-6,980	0
Total preferred distributions	-13,250	-21,088	-15,196
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS / UNITHOLDERS	$30,630	$249,826	$50,819
Income (loss) from continuing operations available to common stockholders per share (dollars per share)	$0.01	($0.37)	($0.55)
Income (loss) from continuing operations available to common stockholders per share (dollars per share)	$0.01	($0.37)	($0.55)
Net income available to common stockholders per share-basic (Note 18)	$0.37	$3.56	$0.87
Net income available to common stockholders per share-diluted (Note 18)	$0.36	$3.56	$0.87
Weighted average common shares outstanding-basic (Note 18)	77,343,853	69,639,623	56,717,121
Weighted average common shares outstanding-diluted (Note 18)	79,108,878	69,639,623	56,717,121
Dividends declared per common share	$1.40	$1.40	$1.40

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]

Series A Preferred Units [Member]

Total Stockholders' Equity

Preferred Stock [Member]

Common Stock Distributions in Excess of Earnings

Total Stockholders' Equity

Preferred Stock [Member]

Total Stockholders' Equity

Common Stock Distributions in Excess of Earnings

Beginning Balance at Dec. 31, 2010

$1,117,730,000

$1,086,351,000

$121,582,000

$523,000

$1,211,498,000

($247,252,000)

$31,379,000

'

'

'

'

'

'

'

'

'

'

Beginning Balance, shares at Dec. 31, 2010

'

'

'

52,349,670

'

'

'

'

'

'

'

'

'

'

'

'

'

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

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net income

67,489,000

66,015,000

'

'

'

66,015,000

1,474,000

'

'

'

'

'

'

'

'

'

'

Issuance of common stock, shares (Note 10)

'

'

'

6,392,805

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of share-based compensation awards, shares (Note 12)

'

'

'

68,727

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of share-based compensation awards

2,739,000

2,739,000

'

1,000

2,738,000

'

'

'

'

'

'

'

'

'

'

'

'

Noncash amortization of share-based compensation

5,588,000

5,588,000

'

'

5,588,000

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of stock options, shares

'

'

'

15,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of common stock (Note 10)

233,312,000

233,312,000

'

64,000

233,248,000

'

'

'

'

'

'

'

'

'

'

'

'

Exchange Of Common Units Of The Operating Partnership Into Shares Of The Companys Common Stock

'

91,000

'

'

91,000

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of stock options

'

395,000

'

'

395,000

'

-91,000

'

'

'

'

'

'

'

'

'

'

Repurchase of common stock and restricted stock units (Note 12)

-1,152,000

-1,152,000

'

'

-1,152,000

'

'

'

'

'

'

'

'

'

'

'

'

Repurchase of common stock and restricted stock units, shares (Note 12)

'

'

'

-11,485

'

'

'

'

'

'

'

'

'

'

'

'

'

Settlement of restricted stock units for shares of common stock (Note 12)

395,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exchange of common units of the Operating Partnership, shares (Note 10)

'

'

'

5,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Adjustment for noncontrolling interest (Note 2)

'

-3,409,000

'

'

-3,409,000

'

3,409,000

'

'

'

'

'

'

'

'

'

'

Preferred distributions

-15,196,000

-15,196,000

'

'

'

-15,196,000

'

'

'

'

'

'

'

'

'

'

'

Dividends declared per common share and common unit ($1.40 per share/ unit for 2010, 2011 and $1.63 per share/unit for 2009)

-83,423,000

-81,017,000

'

'

'

-81,017,000

-2,406,000

'

'

'

'

'

'

'

'

'

'

Ending Balance at Dec. 31, 2011

1,327,482,000

1,293,717,000

121,582,000

588,000

1,448,997,000

-277,450,000

33,765,000

'

'

'

'

'

'

'

'

'

'

Ending Balance, shares at Dec. 31, 2011

'

'

'

58,819,717

'

'

'

'

'

'

'

'

'

'

'

'

'

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

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net income

277,101,000

270,914,000

'

'

'

270,914,000

6,187,000

'

'

'

'

'

'

'

'

'

'

Stock redeemed during period, value

'

'

'

'

'

'

'

126,500,000

126,500,000

121,582,000

4,918,000

'

'

'

2,062,000

2,062,000

2,062,000

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

1,291,000

1,291,000

'

'

1,291,000

'

'

'

'

'

'

'

'

'

'

'

'

Noncash amortization of share-based compensation

8,537,000

8,537,000

'

'

8,537,000

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of stock options, shares

'

'

'

5,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of common stock (Note 10)

672,102,000

672,102,000

'

161,000

671,941,000

'

'

'

'

'

'

192,411,000

192,411,000

192,411,000

'

'

'

Exercise of stock options

129,000

129,000

'

'

129,000

'

'

'

'

'

'

'

'

'

'

'

'

Noncontrolling Interest, Increase from Business Combination

5,604,000

'

'

'

'

'

5,604,000

'

'

'

'

'

'

'

'

'

'

Repurchase of common stock and restricted stock units (Note 12)

-877,000

-877,000

'

'

-877,000

'

'

'

'

'

'

'

'

'

'

'

'

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)

-784,000

-784,000

'

'

-784,000

'

'

'

'

'

'

'

'

'

'

'

'

Settlement of restricted stock units for shares of common stock, shares (Note 12)

'

'

'

27,821

'

'

'

'

'

'

'

'

'

'

'

'

'

Exchange of common units of the Operating Partnership (Note 10)

'

231,000

'

'

231,000

'

-231,000

'

'

'

'

'

'

'

'

'

'

Exchange of common units of the Operating Partnership, shares (Note 10)

'

'

'

10,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Adjustment for noncontrolling interest (Note 2)

'

-3,460,000

'

'

-3,460,000

'

3,460,000

'

'

'

'

'

'

'

'

'

'

Preferred distributions

-14,108,000

-14,108,000

'

'

'

-14,108,000

'

'

'

'

'

'

'

'

'

'

'

Dividends declared per common share and common unit ($1.40 per share/ unit for 2010, 2011 and $1.63 per share/unit for 2009)

-104,393,000

-101,911,000

'

'

'

-101,911,000

-2,482,000

'

'

'

'

'

'

'

'

'

'

Ending Balance at Dec. 31, 2012

2,235,933,000

2,189,630,000

192,411,000

749,000

2,126,005,000

-129,535,000

46,303,000

'

'

'

'

'

'

'

'

'

'

Ending Balance, shares at Dec. 31, 2012

74,926,981

[1]

'

'

74,926,981

'

'

'

'

'

'

'

'

'

'

'

'

'

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

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net income

44,565,000

43,880,000

'

'

'

43,880,000

685,000

'

'

'

'

'

'

'

'

'

'

Issuance of common stock, shares (Note 10)

'

'

'

7,215,838

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of share-based compensation awards

1,448,000

1,448,000

'

'

1,448,000

'

'

'

'

'

'

'

'

'

'

'

'

Noncash amortization of share-based compensation

9,563,000

9,563,000

'

'

9,563,000

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of stock options, shares

'

'

'

473

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of common stock (Note 10)

349,951,000

349,951,000

'

72,000

349,879,000

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of stock options

128,000

128,000

'

'

128,000

'

'

'

'

'

'

'

'

'

'

'

'

Noncontrolling Interest, Increase from Business Combination

4,885,000

'

'

'

'

'

4,885,000

'

'

'

'

'

'

'

'

'

'

Repurchase of common stock and restricted stock units (Note 12)

-2,521,000

-2,521,000

'

'

-2,521,000

'

'

'

'

'

'

'

'

'

'

'

'

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)

1,000

1,000

'

1,000

'

'

'

'

'

'

'

'

'

'

'

'

'

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)

'

450,000

'

'

450,000

'

-450,000

'

'

'

'

'

'

'

'

'

'

Exchange of common units of the Operating Partnership, shares (Note 10)

'

'

'

16,303

'

'

'

'

'

'

'

'

'

'

'

'

'

Adjustment for noncontrolling interest (Note 2)

'

-5,977,000

'

'

-5,977,000

'

5,977,000

'

'

'

'

'

'

'

'

'

'

Preferred distributions

-13,250,000

-13,250,000

'

'

'

-13,250,000

'

'

'

'

'

'

'

'

'

'

'

Dividends declared per common share and common unit ($1.40 per share/ unit for 2010, 2011 and $1.63 per share/unit for 2009)

-114,543,000

-111,991,000

'

'

'

-111,991,000

-2,552,000

'

'

'

'

'

'

'

'

'

'

Ending Balance at Dec. 31, 2013

$2,516,160,000

$2,461,312,000

$192,411,000

$822,000

$2,478,975,000

($210,896,000)

$54,848,000

'

'

'

'

'

'

'

'

'

'

Ending Balance, shares at Dec. 31, 2013

82,153,944

[1]

'

'

82,153,944

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

The amount includes nonvested shares.

Consolidated_Statements_of_Equ1

Consolidated Statements of Equity (Parenthetical) (USD $)	1 Months Ended	12 Months Ended
	Feb. 13, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement of Stockholders' Equity [Abstract]	'	'	'	'
Dividends declared per common share	$0.35	$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, 2013	Dec. 31, 2012	Dec. 31, 2011
CASH FLOWS FROM OPERATING ACTIVITIES:	'	'	'
Net income	$44,565	$277,101	$67,489
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	199,558	168,687	135,467
Increase (decrease) in provision for bad debts	396	-42	644
Depreciation of furniture, fixtures and equipment	1,929	1,213	1,130
Noncash amortization of share-based compensation awards (Note 12)	8,616	7,670	4,482
Noncash amortization of deferred financing costs and net debt discounts	5,315	8,433	13,540
Noncash amortization of net (below)/above market rents (Note 4)	-7,777	-6,699	1,056
Net gain on dispositions of discontinued operations (Note 17)	-12,252	-259,245	-51,587
Noncash amortization of deferred revenue related to tenant-funded tenant improvements (Note 8)	-10,713	-9,136	-9,349
Straight-line rents	-24,135	-21,530	-21,331
Net change in other operating assets	-4,615	-1,297	-5,434
Net change in other operating liabilities	40,137	17,320	2,779
Insurance proceeds received for property damage and other, net	-448	-1,751	-630
Net cash provided by operating activities	240,576	180,724	138,256
CASH FLOWS FROM INVESTING ACTIVITIES:	'	'	'
Expenditures for acquisitions of operating properties, net of cash acquired (Note 3)	202,682	454,841	603,301
Expenditures for acquisitions of development and redevelopment properties (Note 3)	-102,769	-333,942	0
Expenditures for operating properties	-129,873	-86,377	-62,739
Expenditures for development and redevelopment properties and undeveloped land	-320,141	-83,310	-28,517
Net proceeds received from dispositions of operating properties (Note 17)	21,178	263,572	64,171
Insurance proceeds received for property damage	448	1,751	0
(Increase) decrease in acquisition-related deposits	-2,596	5,000	-5,000
Decrease (increase) in restricted cash (Note 3)	229,915	-18,359	1,103
Net cash used in investing activities	-506,520	-706,506	-634,283
CASH FLOWS FROM FINANCING ACTIVITIES:	'	'	'
Net proceeds from issuance of common stock (Note 10)	349,951	672,102	233,312
Net proceeds from issuance of Series G and Series H preferred stock (Note 10)	0	192,411	0
Borrowings on unsecured line of credit	55,000	704,000	550,000
Repayments on unsecured line of credit	-195,000	-701,000	-527,000
Proceeds from the issuance of secured debt (Note 7)	0	97,000	135,000
Principal payments on secured debt	-93,688	-106,262	-127,665
Proceeds from the issuance of unsecured debt (Note 7)	299,901	150,000	324,476
Repayments of exchangeable senior notes (Note 7)	0	-148,000	0
Financing costs	-4,384	-7,963	-9,060
Decrease in loan deposits and other	0	0	2,859
Repurchase of common stock and restricted stock units	-2,520	-1,661	-1,152
Proceeds from exercise of stock options	128	129	395
Dividends and distributions paid to common stockholders and common unitholders	-111,517	-97,386	-80,005
Dividends and distributions paid to preferred stockholders and preferred unitholders	-13,250	-14,165	-15,196
Net cash provided by financing activities	284,621	537,705	485,964
Net increase (decrease) in cash and cash equivalents	18,677	11,923	-10,063
Cash and cash equivalents, beginning of period	16,700	4,777	14,840
Cash and cash equivalents, end of period	35,377	16,700	4,777
SUPPLEMENTAL CASH FLOWS INFORMATION:	'	'	'
Cash paid for interest, net of capitalized interest of $32,742, $17,657, and $7,615 as of December 31, 2013, 2012 and 2011, respectively	65,157	71,633	68,280
NONCASH INVESTING TRANSACTIONS:	'	'	'
Accrual for expenditures for operating properties and development and redevelopment properties	73,482	54,198	14,301
Tenant improvements funded directly by tenants to third parties	7,633	17,719	3,288
Assumption of secured debt with property acquisition (Notes 3 and 7)	95,496	221,032	30,042
Assumption of other assets and liabilities in connection with operating and development property acquisitions, net (Note 3)	1,811	37,535	4,515
Contribution of land, net of related liabilities, by noncontrolling interest to consolidated subsidiary	4,885	0	0
NONCASH FINANCING TRANSACTIONS:	'	'	'
Accrual of dividends and distributions payable to common stockholders and common unitholders (Note 10)	29,392	26,863	21,188
Accrual of dividends and distributions payable to preferred stockholders and preferred unitholders (Note 10)	1,694	1,694	1,909
Grant date fair value of share-based compensation awards (Note 12)	10,721	31,396	7,797
Issuance of common units in the Operating Partnership in connection with an operating property acquisition (Note 3)	0	5,604	0
Exchange of common units of the Operating Partnership into shares of the Company’s common stock (Note 10)	450	231	91
Series A Preferred Units [Member]	'	'	'
CASH FLOWS FROM FINANCING ACTIVITIES:	'	'	'
Payments for Repurchase of Redeemable Preferred Stock	0	-75,000	0
Series E and Series F Cumulative Redeemable Preferred Stock	'	'	'
CASH FLOWS FROM FINANCING ACTIVITIES:	'	'	'
Payments for Repurchase of Redeemable Preferred Stock	$0	($126,500)	$0

Consolidated_Statements_of_Cas1

Consolidated Statements of Cash Flows (Parenthetical) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement of Cash Flows [Abstract]	'	'	'
Capitalized interest	$32,742	$17,657	$7,615

Consolidated_Balance_Sheets_KI

Consolidated Balance Sheets (KILROY REALTY, L.P.) (USD $)	Dec. 31, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
REAL ESTATE ASSETS (Notes 3 and 17):	'		'
Buildings and improvements	$3,590,699		$3,335,026
Undeveloped land and construction in progress	1,016,757		809,654
Total real estate held for investment	5,264,947		4,757,394
Accumulated depreciation and amortization	-818,957		-756,515
Total real estate held for investment, net ($206,319 and $319,770 of VIE, Note 2)	4,445,990		4,000,879
Assets of Disposal Group, Including Discontinued Operation	213,100		0
CASH AND CASH EQUIVALENTS	35,377		16,700
RESTRICTED CASH (Note 17)	49,780		247,544
MARKETABLE SECURITIES (Notes 13 and 16)	10,008	[1],[2]	7,435	[1],[2]
CURRENT RECEIVABLES, NET (Note 5)	10,743	[3]	9,220
DEFERRED RENT RECEIVABLES, NET (Note 5)	127,123	[4]	115,418
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Notes 3 and 4)	186,622		189,968
DEFERRED FINANCING COSTS, NET (Notes 2 and 7)	16,502		18,971
PREPAID EXPENSES AND OTHER ASSETS, NET	15,783		9,949
Total Assets	5,111,028		4,616,084
LIABILITIES:	'		'
Secured debt	560,434		561,096
Net carrying amount of liability component	168,372		163,944
Unsecured debt, net	1,431,132		1,130,895
Unsecured line of credit (Notes 6, 7 and 16)	45,000		185,000
Accounts payable, accrued expenses and other liabilities (Note 15)	198,467		154,734
Accrued distributions (Note 10)	31,490		28,924
Deferred revenue and acquisition-related intangible liabilities, net (Notes 3, 4 and 8)	101,286		117,904
Liabilities of Disposal Group, Including Discontinued Operation	14,447		0
Total liabilities	2,594,868		2,380,151
COMMITMENTS AND CONTINGENCIES (Note 15)	'		'
Partners' Capital:	'		'
TOTAL LIABILITIES AND EQUITY	5,111,028		4,616,084
Kilroy Realty, L.P. [Member]	'		'
REAL ESTATE ASSETS (Notes 3 and 17):	'		'
Land and Land Improvements	657,491		612,714
Buildings and improvements	3,590,699		3,335,026
Undeveloped land and construction in progress	1,016,757		809,654
Total real estate held for investment	5,264,947		4,757,394
Accumulated depreciation and amortization	-818,957		-756,515
Total real estate held for investment, net ($206,319 and $319,770 of VIE, Note 2)	4,445,990		4,000,879
Assets of Disposal Group, Including Discontinued Operation	213,100		0
CASH AND CASH EQUIVALENTS	35,377		16,700
RESTRICTED CASH (Note 17)	49,780		247,544
MARKETABLE SECURITIES (Notes 13 and 16)	10,008		7,435
CURRENT RECEIVABLES, NET (Note 5)	10,743		9,220
DEFERRED RENT RECEIVABLES, NET (Note 5)	127,123		115,418
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Notes 3 and 4)	186,622		189,968
DEFERRED FINANCING COSTS, NET (Notes 2 and 7)	16,502		18,971
PREPAID EXPENSES AND OTHER ASSETS, NET	15,783		9,949
Total Assets	5,111,028		4,616,084
LIABILITIES:	'		'
Secured debt	560,434		561,096
Net carrying amount of liability component	168,372		163,944
Unsecured debt, net	1,431,132		1,130,895
Unsecured line of credit (Notes 6, 7 and 16)	45,000		185,000
Accounts payable, accrued expenses and other liabilities (Note 15)	198,467		154,734
Accrued distributions (Note 10)	31,490		28,924
Deferred revenue and acquisition-related intangible liabilities, net (Notes 3, 4 and 8)	101,286		117,904
Deferred Revenue and Credits	44,240		37,654
Liabilities of Disposal Group, Including Discontinued Operation	14,447		0
Total liabilities	2,594,868		2,380,151
COMMITMENTS AND CONTINGENCIES (Note 15)	'		'
Partners' Capital:	'		'
General Partners' Capital Account	2,315,361		2,040,243
Total Partners' Capital	2,507,772		2,232,654
Noncontrolling interests in consolidated subsidiaries	8,388		3,279
Total capital	2,516,160		2,235,933
TOTAL LIABILITIES AND EQUITY	5,111,028		4,616,084
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]	The marketable securities are held in a limited rabbi trust.
[2]	Based on quoted prices in active markets for identical securities.
[3]	Excludes current receivables, net related to properties held for sale at December 31, 2013.
[4]	Excludes deferred rent receivables, net related to properties held for sale at December 31, 2013.

Consolidated_Balance_Sheets_KI1

Consolidated Balance Sheets (KILROY REALTY, L.P.) (Parenthetical) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Variable Interest Entity, Consolidated, Carrying Amount, Assets	$251,800	$337,000
Noncontrolling common units of the Operating Partnership	1,805,200	1,826,503
Kilroy Realty, L.P. [Member]	'	'
Variable Interest Entity, Consolidated, Carrying Amount, Assets	234,532	319,770
Noncontrolling common units of the Operating Partnership	1,805,200	1,826,503
Kilroy Realty, L.P. [Member] | Capital Units [Member]	'	'
General Partners' Capital Account, Units Issued	82,153,944	74,926,981
General Partners' Capital Account, Units Outstanding	82,153,944	74,926,981
Limited Partners' Capital Account, Units Issued	1,805,200	1,826,503
Noncontrolling common units of the Operating Partnership	1,805,200	1,826,503
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	100,000
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	$100,000

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, 2013	Dec. 31, 2012	Dec. 31, 2011
REVENUES:	'	'	'
Rental income	$419,189	$349,613	$287,078
Tenant reimbursements	38,313	29,889	20,957
Other property income (Note 15)	7,596	1,498	2,389
Total revenues	465,098	381,000	310,424
EXPENSES:	'	'	'
Property expenses	96,606	76,219	63,722
Real estate taxes	40,156	32,323	26,981
Provision for bad debts	404	153	695
Ground leases (Note 4 and 15)	3,504	3,168	1,565
General and administrative expenses	39,660	36,188	28,148
Acquisition-related expenses	1,962	4,937	4,053
Depreciation and amortization (Notes 2 and 4)	192,734	153,251	115,630
Total expenses	375,026	306,239	240,794
OTHER (EXPENSES) INCOME:	'	'	'
Interest income and other net investment gains (Note 16)	1,635	848	571
Interest expense (Note 7)	-75,870	-79,114	-85,785
Total other (expenses) income	-74,235	-78,266	-85,214
INCOME (LOSS) FROM CONTINUING OPERATIONS	15,837	-3,505	-15,584
DISCONTINUED OPERATIONS (Note 17)	'	'	'
Income from discontinued operations	16,476	21,361	31,486
Net gain on dispositions of discontinued operations	12,252	259,245	51,587
Income from discontinued operations	28,728	280,606	83,073
NET INCOME	44,565	277,101	67,489
NET INCOME ATTRIBUTABLE TO KILROY REALTY	43,880	270,914	66,015
Original issuance costs of redeemed preferred units (Notes 9 and 11)	0	-6,980	0
Total preferred distributions	13,250	21,088	15,196
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS / UNITHOLDERS	30,630	249,826	50,819
Loss from continuing operations available to common unitholders per unit-basic (Note 19)	$0.01	($0.37)	($0.55)
Loss from continuing operations available to common unitholders per unit-diluted (Note 19)	$0.01	($0.37)	($0.55)
Net income available to common unitholders per unit (dollars per unit)	$0.37	$3.56	$0.87
Net income available to common unitholders per unit (dollars per unit)	$0.36	$3.56	$0.87
Weighted average common units outstanding - basic (Note 19)	77,343,853	69,639,623	56,717,121
Weighted average common units outstanding - diluted (Note 19)	79,108,878	69,639,623	56,717,121
Kilroy Realty, L.P. [Member]	'	'	'
REVENUES:	'	'	'
Rental income	419,189	349,613	287,078
Tenant reimbursements	38,313	29,889	20,957
Other property income (Note 15)	7,596	1,498	2,389
Total revenues	465,098	381,000	310,424
EXPENSES:	'	'	'
Property expenses	96,606	76,219	63,722
Real estate taxes	40,156	32,323	26,981
Provision for bad debts	404	153	695
Ground leases (Note 4 and 15)	3,504	3,168	1,565
General and administrative expenses	39,660	36,188	28,148
Acquisition-related expenses	1,962	4,937	4,053
Depreciation and amortization (Notes 2 and 4)	192,734	153,251	115,630
Total expenses	375,026	306,239	240,794
OTHER (EXPENSES) INCOME:	'	'	'
Interest income and other net investment gains (Note 16)	1,635	848	571
Interest expense (Note 7)	-75,870	-79,114	-85,785
Total other (expenses) income	-74,235	-78,266	-85,214
INCOME (LOSS) FROM CONTINUING OPERATIONS	15,837	-3,505	-15,584
DISCONTINUED OPERATIONS (Note 17)	'	'	'
Income from discontinued operations	16,476	21,361	31,486
Net gain on dispositions of discontinued operations	12,252	259,245	51,587
Income from discontinued operations	28,728	280,606	83,073
NET INCOME	44,565	277,101	67,489
Net income attributable to noncontrolling interests in consolidated subsidiaries	-224	-638	-529
NET INCOME ATTRIBUTABLE TO KILROY REALTY	44,341	276,463	66,960
Preferred distributions (Note 11)	-13,250	-14,108	-15,196
Original issuance costs of redeemed preferred units (Notes 9 and 11)	0	-6,980	0
Total preferred distributions	13,250	21,088	15,196
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS / UNITHOLDERS	$31,091	$255,375	$51,764
Loss from continuing operations available to common unitholders per unit-basic (Note 19)	$0.01	($0.37)	($0.56)
Loss from continuing operations available to common unitholders per unit-diluted (Note 19)	$0.01	($0.37)	($0.56)
Net income available to common unitholders per unit (dollars per unit)	$0.37	$3.56	$0.86
Net income available to common unitholders per unit (dollars per unit)	$0.36	$3.56	$0.86
Weighted average common units outstanding - basic (Note 19)	79,166,260	71,403,258	58,437,444
Weighted average common units outstanding - diluted (Note 19)	80,931,285	71,403,258	58,437,444
Distributions declared per common unit	$1.40	$1.40	$1.40

Consolidated_Statements_of_Cap

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

12 Months Ended

12 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2010

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Total Partners Capital [Member]

Total Partners Capital [Member]

Total Partners Capital [Member]

Total Partners Capital [Member]

Partners Capital Preferred Units [Member]

Partners Capital Preferred Units [Member]

Partners Capital Preferred Units [Member]

Partners Capital Common Unit [Member]

Partners Capital Common Unit [Member]

Partners Capital Common Unit [Member]

Partners Capital Common Unit [Member]

Noncontrolling Interest In Consolidated Subsidiaries [Member]

Noncontrolling Interest In Consolidated Subsidiaries [Member]

Noncontrolling Interest In Consolidated Subsidiaries [Member]

Series A Preferred Units [Member]

Series A Preferred Units [Member]

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

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Beginning Balance

$2,235,933,000

$1,327,482,000

$1,117,730,000

$2,232,654,000

$1,324,841,000

$1,116,093,000

'

$121,582,000

$192,411,000

$121,582,000

$2,040,243,000

$1,203,259,000

$994,511,000

'

$3,279,000

$2,641,000

$1,637,000

Beginning Balance units

'

'

'

'

'

'

'

'

'

'

76,753,484

60,537,848

54,072,801

'

'

'

'

Net income

44,565,000

277,101,000

67,489,000

44,341,000

276,463,000

66,960,000

'

'

'

'

44,341,000

276,463,000

66,960,000

'

224,000

638,000

529,000

Proceeds from issuance of preferred stock

'

192,411,000

'

'

192,411,000

'

'

192,411,000

'

'

'

'

'

'

'

'

'

Redemption of Series E and Series F Preferred units (Note 11), shares

'

126,500,000

'

'

126,500,000

'

'

121,582,000

'

'

'

4,918,000

'

'

'

'

'

Original issuance costs of redeemed preferred units (Notes 9 and 11)

0

6,980,000

0

'

'

'

2,062,000

'

'

'

'

'

'

2,062,000

'

'

'

Issuance of common units (Note 11)

349,951,000

672,102,000

233,312,000

349,951,000

672,102,000

233,312,000

'

'

'

'

349,951,000

672,102,000

233,312,000

'

'

'

'

Issuance of common units in connection with an operating property acquisition ( Notes 2 and 11)

'

'

'

'

'

'

'

'

'

'

'

118,372

'

'

'

'

'

Noncontrolling Interest, Increase from Business Combination

4,885,000

5,604,000

'

'

5,604,000

'

'

'

'

'

'

5,604,000

'

'

4,885,000

'

'

Issuance of common units, units

'

'

'

'

'

'

'

'

'

'

7,210,838

16,024,618

'

'

'

'

'

Issuance of share-based compensation awards (Note 12)

1,448,000

1,291,000

2,739,000

1,448,000

1,291,000

2,739,000

'

'

'

'

1,448,000

1,291,000

2,739,000

'

'

'

'

Issuance of share-based compensation awards, units (Note 12)

'

'

'

'

'

'

'

'

'

'

0

62,137

68,727

'

'

'

'

Noncash amortization of share-based compensation

9,563,000

8,537,000

5,588,000

9,563,000

8,537,000

5,588,000

'

'

'

'

9,563,000

8,537,000

5,588,000

'

'

'

'

Repurchase of common units and restricted stock units (Note 12)

2,521,000

877,000

1,152,000

2,521,000

877,000

1,152,000

'

'

'

'

2,521,000

877,000

1,152,000

'

'

'

'

Repurchase of common units and restricted stock units, units (Note 12)

'

'

'

'

'

'

'

'

'

'

42,896

22,312

11,485

'

'

'

'

Other

'

'

'

'

'

-475,000

'

'

'

'

'

'

-475,000

'

'

'

475,000

Preferred distributions

-13,250,000

-14,108,000

-15,196,000

-13,250,000

-14,108,000

-15,196,000

'

'

'

'

-13,250,000

-14,108,000

-15,196,000

'

'

'

'

Distributions declared per common unit ($1.40 per unit)

-114,543,000

-104,393,000

-83,423,000

-114,543,000

-104,393,000

-83,423,000

'

'

'

'

-114,543,000

-104,393,000

-83,423,000

'

'

'

'

Settlement of restricted stock units for shares of common stock

1,000

-784,000

'

1,000

-784,000

'

'

'

'

'

1,000

-784,000

'

'

'

'

'

Settlement of restricted stock units for shares of common stock units

'

'

'

'

'

'

'

'

'

'

37,245

27,821

'

'

'

'

'

Exercise of stock options

128,000

129,000

395,000

128,000

129,000

395,000

'

'

'

'

128,000

129,000

395,000

'

'

'

'

Exercise of stock options, units

'

'

'

'

'

'

'

'

'

'

473

5,000

15,000

'

'

'

'

Ending Balance

$2,516,160,000

$2,235,933,000

$1,327,482,000

$2,507,772,000

$2,232,654,000

$1,324,841,000

'

$192,411,000

$192,411,000

$121,582,000

$2,315,361,000

$2,040,243,000

$1,203,259,000

'

$8,388,000

$3,279,000

$2,641,000

Ending Balance units

'

'

'

'

'

'

'

'

'

'

83,959,144

76,753,484

60,537,848

'

'

'

'

Consolidated_Statements_of_Cap1

Consolidated Statements of Capital (KILROY REALTY, L.P.) - Parenthetical (Kilroy Realty, L.P. [Member], USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	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, 2013	Dec. 31, 2012	Dec. 31, 2011
Capitalized interest	$32,742	$17,657	$7,615
CASH FLOWS FROM OPERATING ACTIVITIES:	'	'	'
Net income	44,565	277,101	67,489
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	199,558	168,687	135,467
Increase (decrease) in provision for bad debts	396	-42	644
Depreciation of furniture, fixtures and equipment	1,929	1,213	1,130
Noncash amortization of share-based compensation awards (Note 12)	8,616	7,670	4,482
Noncash amortization of deferred financing costs and net debt discounts	5,315	8,433	13,540
Noncash amortization of net (below)/above market rents (Note 4)	-7,777	-6,699	1,056
Net gain on dispositions of discontinued operations (Note 17)	-12,252	-259,245	-51,587
Noncash amortization of deferred revenue related to tenant-funded tenant improvements (Note 8)	-10,713	-9,136	-9,349
Straight-line rents	-24,135	-21,530	-21,331
Net change in other operating assets	-4,615	-1,297	-5,434
Net change in other operating liabilities	40,137	17,320	2,779
Insurance proceeds received for property damage and other, net	-448	-1,751	-630
Net cash provided by operating activities	240,576	180,724	138,256
CASH FLOWS FROM INVESTING ACTIVITIES:	'	'	'
Expenditures for acquisitions of operating properties, net of cash acquired (Note 3)	-202,682	-454,841	-603,301
Expenditures for acquisitions of development and redevelopment properties (Note 3)	-102,769	-333,942	0
Expenditures for operating properties	-129,873	-86,377	-62,739
Expenditures for development and redevelopment properties and undeveloped land	-320,141	-83,310	-28,517
Net proceeds received from dispositions of operating properties (Note 17)	21,178	263,572	64,171
Insurance proceeds received for property damage	448	1,751	0
(Increase) decrease in acquisition-related deposits	-2,596	5,000	-5,000
Decrease (increase) in restricted cash (Note 3)	229,915	-18,359	1,103
Net cash used in investing activities	-506,520	-706,506	-634,283
CASH FLOWS FROM FINANCING ACTIVITIES:	'	'	'
Net proceeds from issuance of Series G and Series H preferred stock (Note 10)	0	192,411	0
Borrowings on unsecured line of credit	55,000	704,000	550,000
Repayments on unsecured line of credit	-195,000	-701,000	-527,000
Proceeds from the issuance of secured debt (Note 7)	0	97,000	135,000
Principal payments on secured debt	-93,688	-106,262	-127,665
Proceeds from the issuance of unsecured debt (Note 7)	299,901	150,000	324,476
Repayments of exchangeable senior notes (Note 7)	0	-148,000	0
Financing costs	-4,384	-7,963	-9,060
Decrease in loan deposits and other	0	0	2,859
Repurchase/redemption of common units and restricted stock units	-2,520	-1,661	-1,152
Proceeds from exercise of stock options	128	129	395
Distributions paid to common unitholders	-111,517	-97,386	-80,005
Distributions paid to preferred unitholders	-13,250	-14,165	-15,196
Net cash provided by financing activities	284,621	537,705	485,964
Net increase (decrease) in cash and cash equivalents	18,677	11,923	-10,063
Cash and cash equivalents, beginning of period	16,700	4,777	14,840
Cash and cash equivalents, end of period	35,377	16,700	4,777
SUPPLEMENTAL CASH FLOWS INFORMATION:	'	'	'
Cash paid for interest, net of capitalized interest of $32,742, $17,657, and $7,615 as of December 31, 2013, 2012 and 2011, respectively	65,157	71,633	68,280
NONCASH INVESTING TRANSACTIONS:	'	'	'
Accrual for expenditures for operating properties and development and redevelopment properties	73,482	54,198	14,301
Tenant improvements funded directly by tenants to third parties	7,633	17,719	3,288
Assumption of secured debt with property acquisition (Notes 3 and 7)	95,496	221,032	30,042
Assumption of other assets and liabilities in connection with operating and development property acquisitions, net (Note 3)	1,811	37,535	4,515
Contribution of land, net of related liabilities, by noncontrolling interest to consolidated subsidiary	4,885	0	0
NONCASH FINANCING TRANSACTIONS:	'	'	'
Accrual of distributions payable to common unitholders (Note 11)	29,392	26,863	21,188
Accrual of distributions payable to preferred unitholders (Note 11)	1,694	1,694	1,909
Grant date fair value of share-based compensation awards (Note 12)	10,721	31,396	7,797
Issuance of common units in the Operating Partnership in connection with an operating property acquisition (Note 3)	0	5,604	0
Series A Preferred Units [Member]	'	'	'
CASH FLOWS FROM FINANCING ACTIVITIES:	'	'	'
Payments for Repurchase of Redeemable Preferred Stock	0	-75,000	0
Kilroy Realty, L.P. [Member]	'	'	'
Capitalized interest	32,742	17,657	7,615
CASH FLOWS FROM OPERATING ACTIVITIES:	'	'	'
Net income	44,565	277,101	67,489
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	199,558	168,687	135,467
Increase (decrease) in provision for bad debts	396	-42	644
Depreciation of furniture, fixtures and equipment	1,929	1,213	1,130
Noncash amortization of share-based compensation awards (Note 12)	8,616	7,670	4,482
Noncash amortization of deferred financing costs and net debt discounts	5,315	8,433	13,540
Noncash amortization of net (below)/above market rents (Note 4)	-7,777	-6,699	1,056
Net gain on dispositions of discontinued operations (Note 17)	-12,252	-259,245	-51,587
Noncash amortization of deferred revenue related to tenant-funded tenant improvements (Note 8)	-10,713	-9,136	-9,349
Straight-line rents	-24,135	-21,530	-21,331
Net change in other operating assets	-4,615	-1,297	-5,434
Net change in other operating liabilities	40,137	17,320	2,779
Insurance proceeds received for property damage and other, net	-448	-1,751	-630
Net cash provided by operating activities	240,576	180,724	138,256
CASH FLOWS FROM INVESTING ACTIVITIES:	'	'	'
Expenditures for acquisitions of operating properties, net of cash acquired (Note 3)	-202,682	-454,841	-603,301
Expenditures for acquisitions of development and redevelopment properties (Note 3)	-102,769	-333,942	0
Expenditures for operating properties	-129,873	-86,377	-62,739
Expenditures for development and redevelopment properties and undeveloped land	-320,141	-83,310	-28,517
Net proceeds received from dispositions of operating properties (Note 17)	21,178	263,572	64,171
Insurance proceeds received for property damage	448	1,751	0
(Increase) decrease in acquisition-related deposits	-2,596	5,000	-5,000
Decrease (increase) in restricted cash (Note 3)	229,915	-18,359	1,103
Net cash used in investing activities	-506,520	-706,506	-634,283
CASH FLOWS FROM FINANCING ACTIVITIES:	'	'	'
Net proceeds from issuance of common units (Note 11)	349,951	672,102	233,312
Net proceeds from issuance of Series G and Series H preferred stock (Note 10)	0	192,411	0
Borrowings on unsecured line of credit	55,000	704,000	550,000
Repayments on unsecured line of credit	-195,000	-701,000	-527,000
Proceeds from the issuance of secured debt (Note 7)	0	97,000	135,000
Principal payments on secured debt	-93,688	-106,262	-127,665
Proceeds from the issuance of unsecured debt (Note 7)	299,901	150,000	324,476
Repayments of exchangeable senior notes (Note 7)	0	-148,000	0
Financing costs	-4,384	-7,963	-9,060
Decrease in loan deposits and other	0	0	2,859
Repurchase/redemption of common units and restricted stock units	-2,520	-1,661	-1,152
Proceeds from exercise of stock options	128	129	395
Distributions paid to common unitholders	-111,517	-97,386	-80,005
Distributions paid to preferred unitholders	-13,250	-14,165	-15,196
Net cash provided by financing activities	284,621	537,705	485,964
Net increase (decrease) in cash and cash equivalents	18,677	11,923	-10,063
Cash and cash equivalents, beginning of period	16,700	4,777	14,840
Cash and cash equivalents, end of period	35,377	16,700	4,777
SUPPLEMENTAL CASH FLOWS INFORMATION:	'	'	'
Cash paid for interest, net of capitalized interest of $32,742, $17,657, and $7,615 as of December 31, 2013, 2012 and 2011, respectively	65,157	71,633	68,280
NONCASH INVESTING TRANSACTIONS:	'	'	'
Accrual for expenditures for operating properties and development and redevelopment properties	73,482	54,198	14,301
Tenant improvements funded directly by tenants to third parties	7,633	17,719	3,288
Assumption of secured debt with property acquisition (Notes 3 and 7)	95,496	221,032	30,042
Assumption of other assets and liabilities in connection with operating and development property acquisitions, net (Note 3)	1,811	37,535	4,515
Contribution of land, net of related liabilities, by noncontrolling interest to consolidated subsidiary	4,885	0	0
NONCASH FINANCING TRANSACTIONS:	'	'	'
Accrual of distributions payable to common unitholders (Note 11)	29,392	26,863	21,188
Accrual of distributions payable to preferred unitholders (Note 11)	1,694	1,694	1,909
Grant date fair value of share-based compensation awards (Note 12)	10,721	31,396	7,797
Issuance of common units in the Operating Partnership in connection with an operating property acquisition (Note 3)	0	5,604	0
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	-126,500	0
Kilroy Realty, L.P. [Member] | Series A Preferred Units [Member]	'	'	'
CASH FLOWS FROM FINANCING ACTIVITIES:	'	'	'
Payments for Repurchase of Redeemable Preferred Stock	$0	($75,000)	$0

Organization_and_Ownership

Organization and Ownership	12 Months Ended
	Dec. 31, 2013
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 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, 2013:
		Number of		Rentable	Number of	Percentage
		Buildings		Square Feet (unaudited)	Tenants	Occupied (unaudited)
	Stabilized Office Properties (1)	105		12,736,099	514	93.4	%
	______________
	-1	Excludes 12 properties located in San Diego, California that were held for sale at December 31, 2013 (see Note 17 “Discontinued Operations” for additional information). The sale of these properties closed on January 9, 2014 (see Note 23 “Subsequent Events” for additional information).
	Our stabilized portfolio includes all of our properties with the exception of properties held for sale, undeveloped land, development and redevelopment properties currently under construction or committed for construction, and “lease-up” properties. We define redevelopment properties as those properties for which we expect to spend significant development and construction costs on the existing or acquired buildings pursuant to a formal plan, the intended result of which is a higher economic return on the property. We define “lease-up” properties as properties we recently developed or redeveloped that have not yet reached 95% occupancy and are within one year following cessation of major construction activities. During the fourth quarter of 2013, we completed one development property in San Francisco, California and stabilized a redevelopment property in Long Beach, California. As a result, these properties are included in our stabilized portfolio as of December 31, 2013.
	As of December 31, 2013, the following properties were excluded from our stabilized portfolio:
		Number of Properties	Estimated Rentable
			Square Feet (unaudited)
	Properties Held for Sale (1)	12	1,049,035
	Development properties under construction (2)	6	2,538,000
	Lease-up properties	1	410,000
	_______________
	-1	Includes 12 properties located in San Diego, California. The sale of these properties closed on January 9, 2014 (see Note 23 “Subsequent Events” for additional information).
	(2)    Estimated rentable square feet upon completion.
	As of December 31, 2013, all of our properties and development and redevelopment projects and all of our business was conducted in the state of California with the exception of twelve office properties located in the state of Washington. All of our properties and development and redevelopment projects are 100% owned, excluding a development project owned by Redwood City Partners, LLC, a consolidated subsidiary created on June 27, 2013 (see Note 3 “Acquisitions” for additional information) and certain properties held in Section 1031 Exchanges, 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, 2013, the Company owned a 97.8% common general partnership interest in the Operating Partnership. The remaining 2.2% common limited partnership interest in the Operating Partnership as of December 31, 2013 was owned by non-affiliated investors and certain of our executive officers and directors (see Note 9 “Noncontrolling Interests on the Company’s Consolidated Financial Statements” for additional information). Both the general and limited common partnership interests in the Operating Partnership are denominated in common units. The number of common units held by the Company is at all times equivalent to the number of outstanding shares of the Company’s common stock, and the rights of all the common units to quarterly distributions and payments in liquidation mirror those of the Company’s common stockholders. The common limited partners have certain redemption rights as provided in the Operating Partnership’s Seventh Amended and Restated Agreement of Limited Partnership (as amended, the “Partnership Agreement.” See Note 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 conduct substantially all of our development activities. With the exception of the Operating Partnership and Redwood City Partners, LLC (see Note 3 “Acquisitions” and Note 9 “Noncontrolling Interests on the Company’s Consolidated Financial Statements” for additional information), all of our subsidiaries are wholly owned.

Basis_of_Presentation_and_Sign

Basis of Presentation and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2013
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 City Partners, LLC and all of our wholly owned and controlled subsidiaries. The consolidated financial statements of the Operating Partnership include the consolidated financial position and results of operations of the Operating Partnership, the Finance Partnership, KSLLC, Redwood City Partners, LLC and all wholly owned and controlled subsidiaries of the Operating Partnership. All intercompany balances and transactions have been eliminated in the consolidated financial statements.
	Partially Owned Entities and Variable Interest Entities
	Our accounting policy is to consolidate entities in which we have a controlling financial interest and significant decision making control over the entities 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 also consolidate entities in which the other member has 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 that 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, 2013 or December 31, 2012.
	As of December 31, 2013, the consolidated financial statements of the Company and the Operating Partnership included four VIEs, in which we were deemed to be the primary beneficiary. One of the VIEs was established during the second quarter of 2013 as a result of an acquisition (see Note 3 “Acquisitions” for additional information regarding the Redwood City, California acquisition) and the remaining VIEs were established during the third and fourth quarter of 2013 to facilitate a potential like-kind exchange pursuant to Section 1031 of the Code (“Section 1031 Exchanges”) to defer taxable gains on dispositions for federal and state income tax purposes. To realize the tax deferral available under a Section 1031 Exchange, the Company must complete the Section 1031 Exchanges, if any, and complete the sale of the to-be-exchanged properties within 180 days of the acquisition date (see Note 3 “Acquisitions” for additional information). The VIEs established during the third and fourth quarter of 2013 will be terminated upon the completion of the Section 1031 Exchanges or the expiration of the 180 day period, as applicable. 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 is related to real estate held for investment on our consolidated balance sheet), $12.1 million and $4.9 million, respectively, at December 31, 2013. In February 2014, we successfully completed one of the Section 1031 Exchanges.
	As of December 31, 2012, the consolidated financial statements of the Company and the Operating Partnership included two VIEs, in which we were deemed to be the primary beneficiary. The VIEs were established during 2012 to facilitate potential 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 and liabilities by approximately $337.0 million (of which $319.8 million is related to real estate held for investment on our consolidated balance sheet) and $111.1 million, respectively, at December 31, 2012. The Section 1031 Exchanges were completed in March 2013 and these entities were no longer VIEs at 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, 2013 and 2012, we capitalized $2.3 million and $0.7 million, respectively, in acquisition costs associated with the acquisition of undeveloped land. We did not capitalize any acquisition costs during the year ended December 31, 2011.
	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, 2013, 2012, and 2011 was $145.3 million, $125.9 million and $106.0 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
	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.
	An operating property 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 property held for sale, if material, separately on the balance sheet and we would cease to record depreciation and amortization expense. Properties 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, 2013, there are 12 properties located in San Diego, California that were held for sale. As of December 31, 2012, we did not have any buildings and improvements classified as held for sale.
	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, whether 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. As of December 31, 2013 and 2012, deferred financing costs were reported net of accumulated amortization of $13.2 million and $16.6 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 $14.6 million and $7.2 million as of December 31, 2013 and 2012, respectively. Our unsecured senior notes are presented net of unamortized discounts of $1.9 million and $2.1 million, as of December 31, 2013 and 2012, 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 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, formed during the year ended December 31, 2013, Redwood City Partners, LLC (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, 2013 and 2012.
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 be redeemed only 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 a new consolidated subsidiary, Redwood City Partners, 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 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 and recognition of the 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.
During the performance period for a share-based award program when the performance period precedes the grant date, we estimate the total compensation cost of the potential future awards. We then record compensation cost equal to the portion of the requisite service period that has elapsed through the end of the reporting period. 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 reporting 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 certain key 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 the allocation of income to participating securities, by the weighted-average number of vested 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 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 18 “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 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. The dilutive effect of the exchangeable debt instruments is 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 presented 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 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 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.
The dilutive effect of stock options, Exchangeable Notes, 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 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 line of credit, and unsecured term loan facility 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. We calculate the market rate of our unsecured line of credit and unsecured term loan facility by obtaining the period-end London Interbank Offered Rate (“LIBOR”) rate 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 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. Accordingly, no provision for income taxes has been made in the accompanying financial statements. We believe that we have met all of the REIT distribution and technical requirements for the years ended December 31, 2013, 2012 and 2011, and we were not subject to any federal income taxes (see Note 20 “Tax Treatment of Distributions” for additional information). We intend to continue to adhere to these requirements and maintain the Company’s REIT status.
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, 2013, 2012 and 2011 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 potential 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 potential audit. As of December 31, 2013, the years still subject to audit are 2009 through 2012 under the California state income tax law and 2010 through 2012 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, 2013 and 2012.
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. As of December 31, 2013, all of our properties and development and redevelopment projects and all of our business was conducted in the state of California with the exception of twelve office properties located in the state of Washington.
Concentration of Credit Risk
All of our properties and development and redevelopment projects and all of our business is currently conducted in the state of California with the exception of the ownership and operation of twelve office properties located in the state of Washington. The ability of the tenants to honor the terms of their leases is dependent upon the economic, regulatory, and social factors affecting the communities in which the tenants operate.
As of December 31, 2013, our 15 largest tenants represented approximately 33.0% 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, 2013 and 2012, we had cash accounts in excess of FDIC insured limits.
Recent Accounting Pronouncements
There are no recently issued accounting pronouncements that are expected to have a material effect on our financial condition and results of operations in future periods.

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2013
Business Combinations [Abstract]	'
Acquisitions	'
	Acquisitions
	Operating Properties
	During the years ended December 31, 2013 and 2012, we acquired the 18 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 (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 17 “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, 2013 (unaudited)		Purchase Price (in millions) (1)
	2013 Acquisitions
	320 Westlake Ave. N. and 321 Terry Ave. N.,		January 16, 2013	2		320,398		100.00%		$	170
	Seattle, WA (2)(3)
	12780 and 12790 El Camino Real, San Diego,		September 19, 2013	2		218,940		100.00%		126.4
	CA (4)
	Total (5)			4		539,338				$	296.4
	2012 Acquisitions
	4100-4700 Bohannon Dr., Menlo Park, CA		February 29, 2012	7		374,139		89.00%		$	162.5
	701 and 801 N. 34th St., Seattle, WA (6)		June 1, 2012	2		308,407		100.00%		105.4
	837 N. 34th St., Seattle, WA		June 1, 2012	1		111,580		100.00%		39.2
	10900 NE 4th St., Bellevue, WA (7)		July 24, 2012	1		416,755		87.30%		186.1
	6255 W. Sunset Blvd., Los Angeles, CA (8)		July 31, 2012	1		321,883		82.50%		78.8
	12233 Olympic Blvd., Los Angeles, CA (9)		October 5, 2012	1		151,029		96.40%		72.9
	599 N. Mathilda Ave., Sunnyvale, CA (10)		December 17, 2012	1		75,810		100.00%		29.1
	Total (11)			14		1,759,603				$	674
	________________________
	-1	Excludes acquisition-related costs and non-lease related accrued liabilities assumed. Includes assumed unpaid leasing commissions and tenant improvements.
	-2	We acquired these properties through a new special purpose entity wholly owned by the Finance Partnership.
	-3	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”).
	-4	As of December 31, 2013, these properties, together the “Heights of Del Mar” project, are 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.
	-5	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.
	-6	We acquired these properties through the acquisition of the ownership interest of the bankruptcy remote LLC that owned the properties. In connection with this acquisition we also acquired cash of approximately $4.0 million and other assets of approximately $0.2 million and we assumed current liabilities of approximately $0.6 million and secured debt with an outstanding principal balance of $34.0 million and a premium of $1.7 million as a result of recording the debt at fair value at the acquisition date (see Note 7 “Secured and Unsecured Debt of the Operating Partnership”).
	-7	In connection with this acquisition, we assumed secured debt with an outstanding principal balance of $83.6 million and a premium of $1.4 million as a result of recording this debt at fair value on the acquisition date. In January 2013, we repaid this loan prior to the stated maturity (see Note 7 “Secured and Unsecured Debt of the Operating Partnership” for additional information).
	-8	As part of the consideration for this transaction, we issued 118,372 common units of the Operating Partnership valued at $47.34 per unit, which was the Company’s closing stock price on the NYSE on the acquisition date. In connection with this acquisition we also assumed secured debt with an outstanding principal balance of $53.9 million and a premium of $3.1 million as a result of recording this debt at fair value on the acquisition date (see Note 7 “Secured and Unsecured Debt of the Operating Partnership”). We also assumed $4.7 million of accrued liabilities in connection with this acquisition that are not included in the purchase price above.
	-9	In connection with this acquisition, we assumed secured debt with an outstanding principal balance of $40.7 million and a premium of $2.7 million as a result of recording this debt at fair value on the acquisition date (see Note 7 “Secured and Unsecured Debt of the Operating Partnership”).
	-10	This operating property was acquired in connection with the purchase of the 555 N. Mathilda Ave. development property discussed in further detail in the “Development and Redevelopment Project Sites” section of this footnote, for a total purchase price of $137.6 million.
	-11	The results of operations for the properties acquired during 2012 contributed $18.9 million and $3.4 million to revenues and net income from continuing operations, respectively, for the year ended December 31, 2012.
	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 2013 acquisitions:
	2013 Acquisitions	Total 2013
		Acquisitions (1)
		(in thousands)
	Assets
	Land and improvements	$	53,790
	Buildings and improvements (2)	218,211
	Undeveloped land and construction in progress (3)	9,360
	Deferred leasing costs and acquisition-related intangible assets (4)	30,789
	Total assets acquired	312,150
	Liabilities
	Deferred revenue and acquisition-related intangible liabilities (5)	4,190
	Secured debt (6)	95,496
	Accounts payable, accrued expenses and other liabilities	422
	Total liabilities assumed	100,108
	Net assets and liabilities acquired (7)	$	212,042
	_______________
	-1	The purchase price of 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, 2013.
	-2	Represents buildings, building improvements and tenant improvements.
	-3	In connection with one of the 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 $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).
	-5	Represents below-market leases (approximately $4.2 million with a weighted average amortization period of 7.7 years).
	-6	Represents the mortgage loan, which includes an unamortized premium 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.
	The following table summarizes the estimated fair values of the assets acquired and liabilities assumed at the respective acquisition dates for our 2012 acquisitions:
	2012 Acquisitions	4100-4700 Bohannon Dr.,			10900			599 N. Mathilda, Sunnyvale, CA				All Other		Total 2012
		Menlo Park, CA			NE 4th St.,							Acquisitions (1)		Acquisitions
					Bellevue, WA
		(in thousands)
	Assets
	Land and improvements (2)	$	38,810		$	25,080		$	13,538			$	40,211	$	117,639
	Buildings and improvements (3)	124,617			150,877			12,558				257,458		545,510
Cash and cash equivalents	—			—			—				3,973		3,973
Restricted cash	—			—			—				5,329		5,329
Deferred leasing costs and acquisition-related	9,470			16,469			3,004				30,570		59,513
intangible assets (4)
Prepaid expenses and other assets	—			—			—				184		184
Total assets acquired	172,897			192,426			29,100				337,725		732,148
Liabilities
Deferred revenue and acquisition-related	10,380			4,940			—				19,700		35,020
intangible liabilities (5)
Secured debt, net (6)	—			84,984			—				136,048		221,032
Accounts payable, accrued expenses and other	137			627			—				5,584		6,348
liabilities
Total liabilities assumed	10,517			90,551			—				161,332		262,400
Net assets and liabilities acquired (7)	$	162,380		$	101,875		$	29,100			$	176,393	$	469,748
________________________
-1	The purchase price of all other acquisitions during the year ended December 31, 2012 were individually less than 5% and in aggregate less than 10% of the Company’s total assets as of 2012.
-2	In connection with the acquisitions of 701, 801, and 837 N. 34th St., Seattle, WA, we assumed the lessee obligations under a ground lease with an initial expiration in December 2041. The ground lease obligation contains three 10-year extension options and one 45-year extension option. In connection with the acquisitions of 601 108th Ave., N.E., Bellevue, WA, we assumed the lessee obligation under a ground lease that is scheduled to expire in November 2093 (see Note 15 “Commitments and Contingencies” for additional information pertaining to these ground leases).
-3	Represents buildings, building improvements and tenant improvements.
-4	Represents in-place leases (approximately $43.4 million with a weighted average amortization period of 4.7 years), above-market leases (approximately $1.4 million with a weighted average amortization period of 3.8 years), leasing commissions (approximately $14.2 million with a weighted average amortization period of 3.4 years), and a below-market ground lease obligation (approximately $0.5 million with a weighted average amortization period of 59.6 years).
-5	Represents below-market leases (approximately $33.9 million with a weighted average amortization period of 6.5 years) and an above-market ground lease obligation (approximately $1.1 million with a weighted average amortization period of 29.6 years).
-6	Represents the fair value of the mortgage loans assumed, which includes an aggregate unamortized premium balance of approximately $8.9 million at the dates of acquisition (see Note 7 “Secured and Unsecured Debt of the Operating Partnership”).
-7	Reflects the purchase price plus cash and restricted cash received, net of assumed secured debt, lease-related obligations and other accrued liabilities.
Development and Redevelopment Project Sites
Crossing/900
On June 27, 2013, the Company entered into an agreement with an unaffiliated third party and formed a new consolidated subsidiary, Redwood City Partners, LLC. 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 the Crossing/900 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 date (in thousands):
	Phase I			Phase II			Total Crossing/900
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.
Academy Project
In November 2013, we acquired an undeveloped land project site, Academy Project, in Hollywood, California for a purchase price of $45.7 million, including the assumption of $0.7 million of accrued liabilities. As of December 31, 2013, this property was temporarily being held in a separate VIE to facilitate a potential Section 1031 Exchange (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As of December 31, 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.
360 Third Street
In November 2012, we exercised an option to purchase the land underlying the ground leases at 360 Third Street in San Francisco, California for $27.5 million. This transaction closed in October 2013 and the land was included as land and improvements in our consolidated financial statements on the acquisition date. As of December 31, 2013, this property was temporarily being held in a separate VIE to facilitate a potential Section 1031 Exchange (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). In February 2014, we successfully completed this Section 1031 Exchange.
During the year ended December 31, 2012, we acquired six development and redevelopment project sites, respectively from unrelated third parties. Unless otherwise noted, we funded these acquisitions with proceeds from the Company’s public offering of common stock (see Note 10 “Stockholders’ Equity of the Company”), disposition proceeds (see Note 17 “Discontinued Operations”) and/or borrowings under the unsecured line of credit (see Note 7 “Secured and Unsecured Debt of the Operating Partnership” for additional information).
Project		Date of Acquisition	Type		Purchase Price
					(in millions) (1)
2012 Acquisitions
690 E. Middlefield Road, Mountain View, CA (2)(3)		9-May-12	Development		$	74.5
333 Brannan Street, San Francisco, CA		20-Jul-12	Development		18.5
Columbia Square, Los Angeles, CA (4)		28-Sep-12	Development and Redevelopment		65
350 Mission Street, San Francisco, CA		23-Oct-12	Development		52
331 Fairchild Drive, Mountain View, CA (2)(5)(6)		4-Dec-12	Development		21.8
555 N. Mathilda Avenue, Sunnyvale, CA (2)(7)(8)		17-Dec-12	Development		108.5
Total					$	340.3
________________________
-1	Excludes leasing costs and/or other accrued liabilities assumed in connection with the acquisitions.
-2	Acquisition of these development sites are accounted for as business combinations because the projects were 100% pre-leased upon acquisition.
-3	The total purchase price for this acquisition was comprised of a cash purchase price of $74.5 million plus $9.5 million of assumed leasing commissions and other accrued liabilities.
-4	In connection with this acquisition we also assumed $1.1 million of other accrued liabilities which are not included in the purchase price above.
-5	The total purchase price for this acquisition was comprised of a cash purchase price of $18.9 million plus $2.9 million of development costs reimbursed to the seller. In addition, we assumed $2.1 million of leasing commissions and other accrued liabilities which are not included in the purchase price above.
-6	In October, we stabilized the 331 Fairchild Drive development project in Mountain View, California.
-7	As of December 31, 2012, this property was temporarily being held in a separate VIE to facilitate a potential Section 1031 Exchange (see Note 2 “Basis of Presentation and Significant Accounting Policies”). The VIE was terminated in upon exchange in 2013.
-8	This development site was acquired with the purchase of the 555 Mathilda operating property for a total cash purchase price of $137.6 million plus $2.4 million of development costs reimbursed to the seller. In addition, we assumed $11.8 million of other accrued liabilities which are not included in the purchase price above.
The related assets and liabilities of the acquired projects 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 2012 development and redevelopment acquisitions:
2012 Acquisitions	555 N. Mathilda, Sunnyvale, CA			All Other Acquisitions			Total
	(in thousands)
Assets
Undeveloped land and construction in progress	$	120,243		$	244,584		$	364,827
Restricted cash (1)	11,250			—			11,250
Prepaid expenses and other assets	—			1,300			1,300
Total assets acquired	131,493			245,884			377,377
Liabilities
Accounts payable, accrued expenses and other liabilities (1)	23,071			9,752			32,823
Total liabilities assumed	23,071			9,752			32,823
Net assets and liabilities acquired (2)	$	108,422		$	236,132		$	344,554
________________________
-1	In connection with this acquisition, restricted cash is being held in escrow to pay for potential environmental costs and contingent development costs. Any unused amounts will be released to the seller.
-2	Reflects the purchase price including assumed leasing commissions, net of assumed accrued liabilities.

Deferred_Leasing_Costs_and_Acq

Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, net	12 Months Ended
	Dec. 31, 2013
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, 2013 and 2012:
		December 31, 2013			December 31, 2012
		(in thousands)
	Deferred Leasing Costs and Acquisition-related Intangible Assets, net:
	Deferred leasing costs	$	178,720		$	168,087
	Accumulated amortization	(63,246		)	(61,443		)
	Deferred leasing costs, net	115,474			106,644
	Above-market operating leases	27,635			27,977
	Accumulated amortization	(14,283		)	(12,180		)
	Above-market operating leases, net	13,352			15,797
	In-place leases	100,318			101,061
	Accumulated amortization	(42,999		)	(34,019		)
	In-place leases, net	57,319			67,042
	Below-market ground lease obligation	490			690
	Accumulated amortization	(13		)	(205		)
	Below-market ground lease obligation, net	477			485
	Total deferred leasing costs and acquisition-related intangible assets, net	$	186,622		$	189,968
	Acquisition-related Intangible Liabilities, net: (1)
	Below-market operating leases	$	69,385		$	70,486
	Accumulated amortization	(25,706		)	(17,555		)
	Below-market operating leases, net	43,679			52,931
	Above-market ground lease obligation	6,320			6,320
	Accumulated amortization	(223		)	(122		)
	Above-market ground lease obligation, net	6,097			6,198
	Total acquisition-related intangible liabilities, net	$	49,776		$	59,129
	_______________
	-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, 2013, 2012 and 2011:
		Year Ended December 31,
		2013			2012			2011
		(in thousands)
	Deferred leasing costs (1)	$	25,902		$	20,804		$	16,905
	Above-market operating leases (2)	5,664			5,695			5,946
	In-place leases (1)	29,363			21,976			12,575
	Below-market ground lease obligation (3)	8			205			—
	Below-market operating leases (4)	(13,441		)	(12,393		)	(4,890		)
	Above-market ground lease obligation (5)	(101		)	(85		)	(37		)
	Total	$	47,395		$	36,202		$	30,499
	_______________
	-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, 2013 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)
	2014	$	25,454		$	4,946		$	19,168		$	8	$	(11,891	)	$	(101	)
	2015	21,293			2,991			12,584			8		(9,385		)	(101		)
	2016	18,435			1,963			9,361			8		(7,195		)	(101		)
	2017	15,872			1,646			7,659			8		(6,127		)	(101		)
	2018	12,255			1,045			4,574			8		(4,525		)	(101		)
	Thereafter	22,165			761			3,973			437		(4,556		)	(5,592		)
	Total	$	115,474		$	13,352		$	57,319		$	477	$	(43,679	)	$	(6,097	)
	_______________
	-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, 2013
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, 2013 and 2012:
		December 31, 2013 (1)			December 31, 2012
		(in thousands)
	Current receivables	$	12,866		$	11,801
	Allowance for uncollectible tenant receivables	(2,123		)	(2,581		)
	Current receivables, net	$	10,743		$	9,220
	_______________
	-1	Excludes current receivables, net related to properties held for sale at December 31, 2013.
	Deferred Rent Receivables, net
	Deferred rent receivables, net consisted of the following as of December 31, 2013 and 2012:
		December 31, 2013 (1)			December 31, 2012
		(in thousands)
	Deferred rent receivables	$	129,198		$	118,025
	Allowance for deferred rent receivables	(2,075		)	(2,607		)
	Deferred rent receivables, net	$	127,123		$	115,418
	_______________
	-1	Excludes deferred rent receivables, net related to properties held for sale at December 31, 2013.

Secured_and_Unsecured_Debt_of_

Secured and Unsecured Debt of the Company	12 Months Ended
	Dec. 31, 2013
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 6.45% unsecured senior notes due 2014, 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% Exchangeable Notes. As of December 31, 2013 and 2012, the Operating Partnership had $1.6 billion and $1.5 billion, respectively, outstanding in total under these unsecured debt obligations.
	In addition, although the remaining $0.6 billion of the Operating Partnership’s debt for both December 31, 2013 and 2012 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.
	The Company and the Operating Partnership are both named parties to the capped call option transactions discussed further in Note 7.
	Debt Covenants and Restrictions
	One of the covenants contained within the credit facility and the term loan facility, 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, 2013
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 6.45% unsecured senior notes due 2014, 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% Exchangeable Notes. As of December 31, 2013 and 2012, the Operating Partnership had $1.6 billion and $1.5 billion, respectively, outstanding in total under these unsecured debt obligations.
	In addition, although the remaining $0.6 billion of the Operating Partnership’s debt for both December 31, 2013 and 2012 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.
	The Company and the Operating Partnership are both named parties to the capped call option transactions discussed further in Note 7.
	Debt Covenants and Restrictions
	One of the covenants contained within the credit facility and the term loan facility, 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 and Unsecured Debt of the Operating Partnership
	Secured Debt
	The following table sets forth the composition of our secured debt as of December 31, 2013 and 2012:
							December 31,
	Type of Debt	Annual Stated Interest Rate (1)		GAAP	Maturity Date		2013 (3)				2012 (3)
				Effective Rate (1)(2)
							(in thousands)
	Mortgage note payable	4.27%		4.27%	Feb-18		$	133,117			$	135,000
	Mortgage note payable (4)	4.48%		4.48%	Jul-27		97,000				97,000
	Mortgage note payable (5)	6.05%		3.50%	Jun-19		92,502				—
	Mortgage note payable (6)	6.37%		3.55%	Apr-13		—				83,116
	Mortgage note payable	6.51%		6.51%	Feb-17		67,663				68,615
	Mortgage note payable (7)	5.23%		3.50%	Jan-16		54,570				56,302
	Mortgage note payable (8)	5.57%		3.25%	Feb-16		41,654				43,016
	Mortgage note payable (9)	5.09%		3.50%	Aug-15		34,845				35,379
	Mortgage note payable	4.94%		4.00%	Apr-15		27,641				28,941
	Mortgage note payable	7.15%		7.15%	May-17		8,972				11,210
	Other	Various		Various	Various		2,470				2,517
	Total						$	560,434			$	561,096
	______________
	-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 $14.6 million and $7.2 million as of December 31, 2013 and 2012, respectively.
	-4	In June 2012, we obtained a mortgage loan that is secured by one office property located in Irvine, California and two office properties located in Los Angeles, California and requires monthly principal and interest payments based on a 30 year amortization period with an initial three years of interest only payments.
	-5	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 assumed mortgage had a principal balance of $83.9 million at the acquisition date and was recorded at fair value on the date of the acquisition resulting in a premium of approximately $11.6 million. The loan requires monthly principal and interest payments based on a 6.4 year amortization period.
	-6	In January 2013, we repaid this loan prior to the stated maturity date.
	-7	In July 2012, in connection with the acquisition of one office building in Los Angeles, California, we assumed a mortgage loan that is secured by the project. The assumed mortgage had a principal balance of $53.9 million at the acquisition date and was recorded at fair value on the date of the acquisition resulting in a premium of approximately $3.1 million. The loan requires monthly principal and interest payments based on a 30 year amortization period.
	-8	In October 2012, in connection with the acquisition of one office building in Los Angeles, California, we assumed a mortgage loan that is secured by the project. The assumed mortgage loan had a principal balance of $40.7 million at the acquisition date and was recorded at fair value at the date of acquisition resulting in an initial premium of approximately $2.7 million.
	-9	In June 2012, in connection with the acquisition of two office buildings in Seattle, Washington, we assumed a mortgage loan that is secured by the project. The assumed mortgage loan had a principal balance of $34.0 million at the acquisition date and was recorded at fair value at the date of acquisition resulting in an initial premium of approximately $1.7 million.
	The Operating Partnership’s secured debt was collateralized by 21 operating properties as of December 31, 2013 with a combined net book value of approximately $1.0 billion and 20 operating properties at December 31, 2012 with a combined net book value of approximately $1.0 billion.
	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, 2013, 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”) outstanding as of December 31, 2013 and 2012.
	4.25% Exchangeable Notes	December 31,
		2013			2012
		(in thousands)
	Principal amount	$	172,500		$	172,500
	Unamortized discount	(4,128		)	(8,556		)
	Net carrying amount of liability component	$	168,372		$	163,944
	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 is payable semi-annually in arrears on May 15th and November 15th of each year.
	-2	The rate at which we record interest expense for financial reporting purposes, which reflects the amortization of the discounts on the 4.25% Exchangeable Notes. This rate represents our conventional debt borrowing rate at the date of issuance.
	-3	The exchange rate, exchange price, and the number of shares to be delivered upon conversion are subject to adjustment under certain circumstances including increases in our common dividends.
	The 4.25% Exchangeable Notes are exchangeable for shares of the Company’s common stock prior to maturity only upon the occurrence of certain events as follows: (i) during any calendar quarter, if the closing sale price per share of the common stock of the Company is 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 have been called for redemption, (iv) upon the occurrence of specified corporate transactions, (v) if the Company’s common stock ceases to be listed or approved for quotation for 30 consecutive trading days, or (vi) on or after August 15, 2014.
	Upon exchange, the holders of the 4.25% Exchangeable Notes will receive (i) cash up to the principal amount of the Exchangeable Notes and (ii) to the extent the exchange value exceeds the principal amount of the 4.25% Exchangeable Notes, shares of the Company’s common stock. At any time prior to August 15, 2014, the Operating Partnership may irrevocably elect, 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 will be based on a daily exchange value calculated on a proportionate basis for each day of a 30 trading-day observation period.
	During the year ended December 31, 2013 and the three months ended December 31, 2012, the closing sale price per share of the common stock of the Company was more than 130% of the exchange price per share of the Company’s common stock for at least 20 trading days in the specified period. As a result, for the three month period ended December 31, 2012 and for the year ended December 31, 2013, the 4.25% Exchangeable Notes were exchangeable at the exchange rate stated above and may be exchangeable thereafter, if one or more of the events were again to occur during future measurement periods. No holders exchanged the 4.25% Exchangeable Notes during 2013 and 2012.
	For the years ended December 31, 2013 and 2012, the per share average trading price of the Company’s common stock on the NYSE was higher than the $35.93 exchange price for the 4.25% Exchangeable Notes, as presented below:
		Year Ended December 31,
		2013		2012
	Per share average trading price of the Company’s common stock	$52.12		$45.72
	The approximate fair value of the shares exchangeable at December 31, 2013 and 2012, using the per share average trading price presented in the table above, would have been as follows:
		Year Ended December 31,
		2013			2012
	(in thousands)
Approximate fair value of shares upon conversion	$	247,000		$	221,200
Principal amount of the 4.25% Exchangeable Notes	172,500			172,500
Approximate fair value in excess amount of principal amount	$	74,500		$	48,700
See Notes 18 “Net Income Available to Common Stockholders Per Share of the Company” and 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 Exchangeable Notes
The unamortized discount on the 4.25% Exchangeable Notes and the 3.25% Exchangeable Notes due April 2012 (the “3.25% Exchangeable Notes” and together with the 4.25% Exchangeable Notes, the “Exchangeable Notes”) is accreted as additional interest expense from the date of issuance through the maturity date of the applicable Exchangeable Notes. The following table summarizes the total interest expense attributable to the 4.25% Exchangeable Notes and attributable to the 3.25% Exchangeable Notes (which were repaid upon maturity in April 2012), in each case based on the respective effective interest rates, before the effect of capitalized interest, for the years ended December 31, 2013, 2012 and 2011:
	Year Ended December 31,
	2013			2012				2011
	(in thousands)
Contractual interest payments (1)	$	7,331		$	8,721			$	12,141
Amortization of discount (1)	4,427			5,052				6,928
Interest expense attributable to the Exchangeable Notes (1)	$	11,758		$	13,773			$	19,069
_______________
-1	The Company repaid the 3.25% Exchangeable Notes in April 2012. Interest payments and discount amortization for the year ended December 31, 2013 are solely attributable to the 4.25% Exchangeable Notes.
Capped Call Transactions
In connection with the offerings of the Exchangeable Notes, we entered into capped call option transactions (“capped calls”) to mitigate the dilutive impact of the potential conversion of the Exchangeable Notes. The capped calls, as amended, are separate transactions entered into by us with the relevant financial institutions, are not part of the terms of the Exchangeable Notes, and do not affect the holders’ rights under the Exchangeable Notes. The strike prices of the capped calls, which are subject to customary anti-dilution adjustments, correspond to the exchange prices of the applicable Exchangeable Notes. The capped calls for the 3.25% Exchangeable Notes were terminated when the notes were repaid in April 2012. The table below summarizes our capped call option positions for the 4.25% Exchangeable Notes for both December 31, 2013 and December 31, 2012:
	4.25% Exchangeable Notes (1)
Referenced shares of common stock	4,800,796
Exchange price including effect of capped calls	$42.81
________________________
-1	The capped calls mitigate the dilutive impact to us of the potential exchange of all of the 4.25% Exchangeable Notes into shares of common stock.
The capped calls are expected to terminate upon the earlier of the maturity date of the 4.25% Exchangeable Notes or upon the date upon which the 4.25% Exchangeable Notes are no longer outstanding resulting from an exchange or repurchase by us. The initial costs of capped calls were recorded as a reduction to additional paid-in capital.
Unsecured Senior Notes
The following table summarizes the balance and significant terms of the registered unsecured senior notes issued by the Operating Partnership as of December 31, 2013 and 2012:
								Principal Amount
								as of December 31,
	Issuance date		Maturity date	Stated		Effective interest rate (1)		2013				2012
				coupon rate
								(in thousands)
3.800% Unsecured Senior Notes (2)	Jan-13		Jan-23	3.80%		3.80%		$	300,000			$	—
Unamortized discount								(90		)		—
Net carrying amount								$	299,910			$	—
4.800% Unsecured Senior Notes (3)	Jul-11		Jul-18	4.80%		4.83%		$	325,000			$	325,000
Unamortized discount								(339		)		(413		)
Net carrying amount								$	324,661			$	324,587
6.625% Unsecured Senior Notes (4)	May-10		Jun-20	6.63%		6.74%		$	250,000			$	250,000
Unamortized discount								(1,367		)		(1,580		)
Net carrying amount								$	248,633			$	248,420
5.000% Unsecured Senior Notes (5)	Nov-10		Nov-15	5.00%		5.01%		$	325,000			$	325,000
Unamortized discount								(73		)		(112		)
Net carrying amount								$	324,927			$	324,888
________________________
-1	This represents the rate at which interest expense is recorded for financial reporting purposes, which reflects the amortization of initial issuance discounts, excluding debt issuance costs.
-2	Interest on the 3.800% unsecured senior notes is payable semi-annually in arrears on January 15th and July 15th of each year.
-3	Interest on the 4.800% unsecured senior notes is payable semi-annually in arrears on January 15th and July 15th of each year.
-4	Interest on the 6.625% unsecured senior notes is payable semi-annually in arrears on June 1st and December 1st of each year.
-5	Interest on the 5.000% unsecured senior notes is payable semi-annually in arrears on May 3rd and November 3rd of each year.
In 2013, we used a portion of the net proceeds from the 3.800% unsecured senior note offering for general corporate purposes, including the repayment of borrowings under the Operating Partnership’s revolving credit facility.
In addition to the registered unsecured senior note issuances listed above, we also had outstanding Series B unsecured senior notes with an aggregate principal balance of $83.0 million and effective interest rate of 6.45% as of December 31, 2013 and 2012, that mature in August 2014. The Series B notes require semi-annual interest payment each February and August based on a fixed annual interest rate of 6.45%.
Term Loan Facility
In March 2012, the Operating Partnership entered into a $150.0 million term loan facility, which is included in unsecured debt, net on our consolidated balance sheets. The term loan facility bears interest at an annual rate of LIBOR plus 1.750%, which can vary depending on the Operating Partnership’s credit rating, and is scheduled to mature on March 29, 2016. Under the terms of the term loan facility, we may exercise an option to extend the maturity date by one year. We may elect to borrow up to an additional $100.0 million under an accordion option, subject to bank approval. We used the borrowings under the term loan facility to repay the 3.25% Exchangeable Notes in April 2012 upon maturity. The Company’s outstanding borrowings under the term loan facility were $150.0 million as of December 31, 2013 and 2012.
Unsecured Revolving Credit Facility
In August 2010 we entered into our current $500.0 million revolving credit facility and used the borrowings under the revolving credit facility to repay and then terminate our prior $550.0 million unsecured revolving credit facility. In March 2012, we amended the revolving credit facility to reduce the FMV Cap Rate (as defined in the revolving credit facility agreement), which is used to calculate the fair value of our assets for certain covenants under the revolving credit facility, from 7.50% to 6.75%. There were no other changes to the terms of the revolving credit facility in connection with this amendment. In November 2012, we amended and restated our revolving credit facility to extend the maturity date and reduce the interest rate and facility fee. The following table summarizes the balance and terms of our revolving credit facility as of December 31, 2013 and 2012, respectively:
	December 31, 2013			December 31, 2012
	(in thousands)
Outstanding borrowings	$	45,000		$	185,000
Remaining borrowing capacity	455,000			315,000
Total borrowing capacity (1)	$	500,000		$	500,000
Interest rate (2)	1.62		%	1.66		%
Facility fee-annual rate (3)	0.30%
Maturity date (4)	Apr-17
_______________
-1	We may elect to borrow, subject to bank approval, up to an additional $200.0 million under an accordion feature under the terms of the revolving credit facility.
-2	The revolving credit facility interest rate was calculated based on an annual rate of LIBOR plus 1.450% as of both December 31, 2013 and December 31, 2012.
-3	The facility fee is paid on a quarterly basis and is calculated based on the total borrowing capacity. In addition to the facility fee, we also incurred debt origination and legal costs of approximately $5.0 million when we entered into the revolving credit facility in 2010, an additional $3.3 million when we amended the terms of the revolving credit facility in June 2011 and an additional $1.9 million when we amended the terms of the revolving credit facility in November 2012. The unamortized balance of these costs is amortized through the extended maturity date of the revolving credit facility.
-4	Under the terms of the revolving credit facility, we may exercise an option to extend the maturity date by one year.
The Company intends to borrow amounts under the revolving credit facility from time to time for general corporate purposes, to fund potential acquisitions, to finance development and redevelopment expenditures and to potentially repay long-term debt.
Debt Covenants and Restrictions
The revolving credit facility, the term loan facility, the unsecured senior notes, and certain other secured debt arrangements contain covenants and restrictions requiring us to meet certain financial ratios and reporting requirements. Some of the more restrictive financial covenants include a maximum ratio of total debt to total asset value, a minimum fixed-charge coverage ratio, a minimum unsecured debt ratio, and a minimum unencumbered asset pool debt service coverage ratio. Noncompliance with one or more of the covenants and restrictions could result in the full or partial principal balance of the associated debt becoming immediately due and payable. We believe we were in compliance with all of our debt covenants as of December 31, 2013 and 2012.
Debt Maturities
The following table summarizes the stated debt maturities and scheduled amortization payments, excluding debt discounts and premiums, as of December 31, 2013:
Year	(in thousands)
2014	$	265,346
2015	395,104
2016	249,431
2017	116,748
2018	451,728
Thereafter	718,011
Total (1)	$	2,196,368
________________________
-1	Includes gross principal balance of outstanding debt before impact of net unamortized premiums totaling approximately $8.6 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, 2013, 2012 and 2011. 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. (See Note 17 “Discontinued Operations” for interest expense reported in discontinued operations).
	Year Ended December 31,
	2013			2012				2011
	(in thousands)
Gross interest expense	$	111,238		$	98,906			$	94,915
Capitalized interest	(35,368		)	(19,792		)		(9,130		)
Interest expense	$	75,870		$	79,114			$	85,785

Deferred_Revenue_and_Acquisiti

Deferred Revenue and Acquisition Related Liabilities, net	12 Months Ended
	Dec. 31, 2013
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 consisted of the following at December 31, 2013 and 2012:
		December 31,
		2013		2012
		(in thousands)
	Deferred revenue related to tenant-funded tenant improvements (1)	$	48,341	$	56,461
	Other deferred revenue	3,169		2,314
	Acquisition-related intangible liabilities, net (2)	49,776		59,129
	Total	$	101,286	$	117,904
	________________________
	-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 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, 2013, 2012, and 2011, $10.7 million, $9.1 million, and $9.3 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, 2013 for the next five years and thereafter:
	Year Ending	(in thousands)
	2014	$	8,686
	2015	7,620
	2016	7,165
	2017	6,070
	2018	4,479
	Thereafter	14,321
	Total	$	48,341

Noncontrolling_Interests_on_th

Noncontrolling Interests on the Company's Consolidated Financial Statements	12 Months Ended
	Dec. 31, 2013
Noncontrolling Interest [Abstract]	'
Noncontrolling Interests on the Company's Consolidated Financial Statements	'
	Noncontrolling Interests on the Company’s Consolidated Financial Statements
	Common Units of the Operating Partnership
	The Company owned a 97.8% and 97.6% common general partnership interest in the Operating Partnership as of December 31, 2013 and 2012, respectively. The remaining 2.2% and 2.4% common limited partnership interest as of December 31, 2013 and 2012, respectively, was owned by non-affiliate investors and certain of our executive officers and directors in the form of noncontrolling common units. There were 1,805,200 and 1,826,503 common units outstanding held by these investors, executive officers and directors as of December 31, 2013 and 2012, respectively.
	The noncontrolling common units may be redeemed by unitholders for cash. Except under certain circumstances, we, at our option, may satisfy the cash redemption obligation with shares of the Company’s common stock on a one-for-one basis. If satisfied in cash, the value for each noncontrolling common unit upon redemption is the amount equal to the average of the closing quoted price per share of the Company’s common stock, par value $.01 per share, as reported on the NYSE for the ten trading days immediately preceding the applicable redemption date. The aggregate value upon redemption of the then-outstanding noncontrolling common units was $90.8 million and $85.4 million as of December 31, 2013 and December 31, 2012, 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 $4.9 million at December 31, 2013.
	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, 2013
Equity [Abstract]	'
Stockholders' Equity of the Company	'
	Stockholders’ Equity of the Company
	2012 Preferred Stock Issuances
	6.375% Series H and 6.875% Series G Cumulative Redeemable Preferred Stock
	In August 2012, the Company issued 4,000,000 shares of its 6.375% Series H Cumulative Redeemable Preferred Stock (“Series H Preferred Stock”) at a public offering price of $25.00 per share, for a total of approximately $96.2 million of net proceeds, after deducting the underwriting discount and other offering-related costs. We used a portion of the net proceeds to redeem the Series A Preferred Units as discussed in Note 9 and the remaining portion for general corporate purposes. Dividends on the Series H Preferred Stock are cumulative and are payable quarterly in arrears on the 15th day of each February, May, August and November, and commenced on November 15, 2012. The Series H Preferred Stock is presented in stockholders’ equity on the consolidated balance sheet net of issuance costs.
	In March 2012, the Company issued 4,000,000 shares of its 6.875% Series G Cumulative Redeemable Preferred Stock (“Series G Preferred Stock”) at a public offering price of $25.00 per share, for a total of approximately $96.2 million of net proceeds, after deducting the underwriting discount and other offering-related costs. We used the net proceeds to redeem the 7.80% Series E Cumulative Redeemable Preferred Stock (“Series E Preferred Stock”) and 7.50% Series F Cumulative Redeemable Preferred Stock (“Series F Preferred Stock”) as discussed below. Dividends on the Series G Preferred Stock are cumulative and are payable quarterly in arrears on the 15th day of each February, May, August and November, and commenced on May 15, 2012. The Series G Preferred Stock is presented in stockholders’ equity on the consolidated balance sheet net of issuance costs.
	The outstanding shares of the Series G Preferred Stock and the Series H Preferred Stock do not have a stated maturity date and are not subject to any sinking fund or mandatory redemption. Upon liquidation, dissolution or winding up, the Series G Preferred Stock and the Series H Preferred Stock will rank senior to the Company’s common stock with respect to the payment of distributions and other amounts. Holders of the Series G Preferred Stock and the Series H Preferred Stock generally have no voting rights except for limited voting rights if the Company fails to pay dividends for six or more quarterly dividend periods (whether or not consecutive). The Company may not redeem the Series G Preferred Stock prior to March 27, 2017 nor the Series H Preferred Stock prior to August 15, 2017, except in limited circumstances relating to the Company’s continuing qualification as a REIT and upon certain specified change in control transactions in which the Company’s shares of common stock and the acquiring or surviving entity common securities would not be listed on the NYSE, NYSE Amex or NASDAQ, or any successor exchanges. On or after March 27, 2017 or August 15, 2017, the Company may, at its option, redeem the Series G Preferred Stock or the Series H Preferred Stock, respectively, in whole or in part at any time or from time to time, by payment of $25.00 per share in cash, plus any accumulated, accrued and unpaid distributions through the date of redemption. Upon the occurrence of a specified change of control transaction, the Company may, at its option, redeem the Series G Preferred Stock or the Series H Preferred Stock in whole or in part within 120 days after the change of control occurred, by paying $25.00 per share in cash, plus any accrued and unpaid distributions through the date of redemption. If the Company does not exercise its right to redeem the Series G Preferred Stock or the Series H Preferred Stock upon the occurrence of a specified change of control transaction, the holders of Series G Preferred Stock and the Series H Preferred Stock have the right to convert some or all of their shares into a number of the Company’s shares of common stock based on a pre-determined
	formula subject to a maximum share cap of 4,390,000 shares of common stock for the Series G Preferred Stock and 4,187,600 shares of common stock for the Series H Preferred Stock.
	2012 Preferred Stock Redemption
	7.80% Series E and 7.50% Series F Cumulative Redeemable Preferred Stock
	On April 16, 2012 (the “Series E and F Redemption Date”), the Company redeemed all 1,610,000 outstanding shares of its Series E Preferred Stock and all 3,450,000 outstanding shares of its Series F Preferred Stock. On the Series E and F Redemption Date, the shares of Series E and Series F Preferred Stock (together, the “Redeemed Preferred Stock”) were redeemed at a redemption price equal to their stated liquidation preference of $25.00 per share, representing $126.5 million in aggregate, plus all accrued and unpaid dividends to the Series E and F Redemption Date.
	During 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.
	Common Stock
	Issuance of Common Stock
	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 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 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 revolving credit facility, and for general corporate purposes.
	In April 2011, the Company completed an underwritten public offering of 6,037,500 shares of its common stock. The net offering proceeds, after deducting sales agent compensation and offering expenses, were approximately $221.0 million. We used a portion of the net proceeds from the offering to fund acquisitions and for general corporate purposes.
	At-The-Market Stock Offering Program
	Under our at-the-market stock offering program, which commenced in July 2011, we may offer and sell shares of our common stock having an aggregate gross sales price of up to $200.0 million from time to time in “at-the-market” offerings. The following table sets for information regarding sales of our common stock under our at-the-market offering program for the years ended December 31, 2013, 2012 and 2011:
		Year Ended December 31,
		2013			2012		2011
		(in millions, except share data)
	Share of common stock sold during the period	1,040,838			787,118		355,305
	Aggregate gross proceeds	$	55.3		$	37	$	13
	Aggregate net proceeds after sales agent compensation	$	54.4		$	36.3	$	12.8
	The proceeds sales were used to fund acquisitions, development and redevelopment expenditures and general corporate purposes including repayment of borrowings under the revolving credit facility. Since commencement of the program, we have sold 2,183,261 shares of common stock and, as of December 31, 2013, approximately $94.7 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 this 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, 2013, 2012 or 2011.
	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, 2013 and 2012:
		December 31,
		2013			2012
		(in thousands)
	Dividends and Distributions payable to:
	Common stockholders	$	28,754		$	26,224
	Noncontrolling common unitholders of the Operating Partnership	632			639
	RSU holders (1)	405			367
	Total accrued dividends and distribution to common stockholders and noncontrolling unitholders	29,791			27,230
	Preferred stockholders	1,699			1,694
	Total accrued dividends and distributions	$	31,490		$	28,924
	______________________
	-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,
		2013		2012
	Outstanding Shares and Units:
	Common stock (1)	82,153,944		74,926,981
	Noncontrolling common units	1,805,200		1,826,503
	RSUs (2)	1,158,407		1,048,863
	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 143,022 market measure-based RSUs since not all the necessary performance conditions have been met as of December 31, 2013.

Preferred_and_Common_Units_of_

Preferred and Common Units of the Operating Partnership	12 Months Ended
	Dec. 31, 2013
Partners' Capital Notes [Abstract]	'
Preferred and Common Units of the Operating Partnership	'
	Preferred and Common Units of the Operating Partnership
	2012 Preferred Unit Issuances
	The Company issued 4,000,000 shares of its Series H Preferred Stock in August 2012 and issued 4,000,000 shares of its Series G Preferred Stock in March 2012 as discussed in Note 10. The net proceeds of approximately $96.2 million and $96.2 million were contributed by the Company to the Operating Partnership in exchange for 4,000,000 Series H Preferred Units and 4,000,000 Series G Preferred Units, respectively. The Company is the sole holder of the Series H Preferred Units and Series G Preferred Units. The terms of the Series H Preferred Units and Series G Preferred Units are substantially similar to the terms of the Series H Preferred Stock and Series G Preferred Stock, respectively, as discussed in Note 10. Distributions on the Series H Preferred Units and Series G Preferred Units are paid to the Company.
	2012 Preferred Unit Redemption
	7.45% Series A Cumulative Redeemable Preferred Units
	On the Series A Redemption Date, the Operating Partnership redeemed all 1,500,000 outstanding units of its Series A Preferred Units as discussed in Note 9.
	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 (“Series E Preferred Units”) and all 3,450,000 outstanding units of its 7.50% Series F Cumulative Redeemable Preferred Units (“Series F Preferred Units”). For each share of Series E and Series F Preferred Stock that was outstanding, the Company had an equivalent number of Series E Preferred Units and Series F Preferred Units outstanding with substantially similar terms as the Series E and Series F Preferred Stock.
	Common Units
	Issuance of Common Units
	In September 2013, the Company completed an underwritten public offering of 6,175,000 shares of its common stock as discussed in Note 10. 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 as discussed in Note 10. 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 as discussed in Note 3. 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 as discussed in Note 10. 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.
	In April 2011, the Company completed an underwritten public offering of 6,037,500 shares of its common stock as discussed in Note 10. The net offering proceeds of approximately $221.0 million were contributed by the Company to the Operating Partnership in exchange for 6,037,500 common units.
	At-The-Market Stock Offering Program
	During the year ended December 31, 2013, 2012 and 2011, the Company utilized its at-the-market stock offering program to issue shares of common stock as discussed in Note 10. The net offering proceeds and the shares of common stock contributed by the Company to the Operating Partnership in exchange for common units for the years ended December 31, 2013, 2012 and 2011 are as follows:
		Year Ended December 31,
		2013			2012		2011
		(in millions, except share and per share data)
	Shares of common stock contributed by the Company	1,040,838			787,118		355,305
	Common units exchanged for share of common stock by the Company	1,040,838			787,118		355,305
	Aggregate gross proceeds	$	55.3		$	37	$	13
	Aggregate net proceeds after sales agent compensation	$	54.4		$	36.3	$	12.8
	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, 2013		31-Dec-12
	Company owned common units in the Operating Partnership	82,153,944		74,926,981
	Company owned general partnership interest	97.8	%	97.6	%
	Noncontrolling common units of the Operating Partnership	1,805,200		1,826,503
	Ownership interest of noncontrolling interest	2.2	%	2.4	%
	For a further discussion of the noncontrolling common units during the years ended December 31, 2013 and 2012, 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, 2013 and 2012:
		December 31, 2013			31-Dec-12
		(in thousands)
	Distributions payable to:
	General partner	$	28,754		$	26,224
	Common limited partners	632			639
	RSU holders (1)	405			367
	Total accrued distributions to common unitholders	29,791			27,230
	Preferred unitholders	1,699			1,694
	Total accrued distributions	$	31,490		$	28,924
	______________________
	-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, 2013		31-Dec-12
	Outstanding Units:
	Common units held by the general partner	82,153,944		74,926,981
	Common units held by the limited partners	1,805,200		1,826,503
	RSUs (1)	1,158,407		1,048,863
	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 143,022 market measure-based RSUs since not all the necessary performance conditions have been met as of December 31, 2013.

ShareBased_Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Share-Based Compensation	'
	Share-Based Compensation
	Stockholder Approved Equity Compensation Plans
	As of December 31, 2013, we maintained one share-based incentive compensation plan, the Kilroy Realty 2006 Incentive Award Plan as amended (the “2006 Plan”). As of December 31, 2013, 7,414 shares were available for grant under the 2006 Plan. The number of shares that remains available for grant is calculated using the weighted share counting provisions set forth in the 2006 Plan, which are based on the type of awards that are granted. The maximum number of shares available for grant subject to full value awards (which generally include equity awards other than options and stock appreciation rights) was 2,539 shares as of December 31, 2013.
	The Executive Compensation Committee, which is comprised of four 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, 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 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, fully-vested RSUs at the time dividends are paid equal to the value of the dividend paid on the shares underlying participant RSUs. Shares issued in settlement of vested RSUs including RSUs paid on dividend equivalents will be 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) upon other certain 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. Dividends are paid on all outstanding shares and RSUs whether vested or nonvested and are not forfeitable if the underlying shares or RSUs ultimately do not vest.
	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, Chief Operating Officer, Chief Investment Officer and Chief Financial Officer (“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.
	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 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, as well as (in each case) continued employment through the applicable vesting date. 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
	On March 30, 2012, the Executive Compensation Committee of the Company’s Board of Directors granted 206,477 RSUs to the Company’s Chief Executive Officer. Fifty-percent of the RSUs granted will vest in seven equal annual installments beginning on December 31, 2012 through December 31, 2018, subject to continued employment through the applicable vesting date. The grant date fair value of these time-based RSUs was $4.8 million, which was based on the $46.61 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 will vest in seven equal annual installments for each calendar year during 2012 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, as well as (in each case) continued employment through the applicable vesting date. The grant date fair value of these market measure-based RSUs was $4.3 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 seven 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.
		March 2012 Market Measure-based RSU Grant
	Grant date fair value per share	$41.20
	Expected share price volatility	31.00%
	Risk-free interest rate	1.60%
	Dividend yield	3.80%
	Expected life	7 years
	The computation of expected volatility is based on a blend of the historical volatility of our shares of common stock over 14 years as that is expected to be most consistent with future volatility and equates to a time period twice as long as the seven-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 seven-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 seven year vesting period.
	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, 2013 through December 31, 2013 is presented below:
		Nonvested RSUs				Vested RSUs		Total RSUs
		Amount		Weighted-Average
				Grant Date
				Fair Value
				Per Share
	Outstanding at January 1, 2013	88,491		$	41.2	—		88,491
	Granted	9,542		44.55		—		9,542
	Vested	(16,338	)	41.53		16,338		—
	Settled (1)	—				(16,338	)	(16,338	)
	Issuance of dividend equivalents	—				—		—
	Modified from time based (2)	61,327		53.05		—		61,327
	Canceled					—		—
	Outstanding as of December 31, 2013	143,022		$	46.47	—		143,022
	_______________
	-1	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.
	-2	On April 4, 2013 the terms of time-based RSU’s granted to certain officers of the Company in January were modified to include market-measure and performance-based vesting requirements.
	A summary of our market-measure based RSU activity for years ended December 31, 2013 and 2012 is presented below:
		RSUs Granted				RSUs Vested
	Years ended December 31,	Non-Vested		Weighted-Average Grant Date		Vested RSUs		Total Vest-Date Fair Value
		RSUs Issued		Fair Value				(in thousands)
				Per Share
	2013	9,542		$	44.55	(16,338	)	$	811
	2012	103,239		41.2		(14,748	)	695
	There were no market measure awards granted in 2011.
	Summary of Time-Based RSUs
	A summary of our time-based RSU activity from January 1, 2013 through December 31, 2013 is presented below:
		Nonvested RSUs				Vested RSUs		Total RSUs
		Amount		Weighted-Average
Grant Date
Fair Value
Per Share
Outstanding at January 1, 2013	279,102		$	41.3	769,761		1,048,863
Granted, net of forfeitures	173,758		49.45		—		173,758
Vested	(89,873	)	40.33		89,873		—
Settled (1)					(26,886	)	(26,886	)
Issuance of dividend equivalents (2)					27,593		27,593
Modified to market-measure based (3)	(61,327	)	53.05		—		(61,327	)
Canceled (1)(4)					(3,594	)	(3,594	)
Outstanding as of December 31, 2013	301,660		$	44.74	856,747		1,158,407
_______________
-1	Represents vested RSUs that were settled in cash or shares of the Company’s common stock. Total shares settled include 13,490 shares that were tendered in accordance with the terms of the 2006 Plan to satisfy minimum statutory tax withholding requirements related to the RSUs settled. We accept the return of RSUs, at the current quoted closing share price of the Company’s common stock to satisfy tax obligations.
-2	RSUs issued as dividend equivalents are vested upon issuance.
-3	On April 4, 2013, the terms of time-based RSUs granted to certain officers of the Company in January were modified to include market-measure based vesting requirements.
-4	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.
A summary of our time-based RSU activity for the years ended December 31, 2013, 2012 and 2011 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
2013	173,758		$	49.45	(89,873	)	$	4,495
2012	204,829		44.34		(73,688	)	3,118
2011	107,673		37.94		(85,466	)	3,273
_______________
-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, 2013 through December 31, 2013 is presented below:
	Non-Vested		Weighted-Average
	Restricted Stock		Grant Date
			Fair Value
			Per Share
Outstanding at January 1, 2013	95,241		$	40.42
Granted	—		—
Vested (1)	(47,291	)	39.12
Outstanding as of December 31, 2013	47,950		$	41.71
_______________
-1	The total shares vested include 20,880 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, 2013, 2012 and 2011 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
2013	—		$	—	(47,291	)	$	2,290
2012	62,137		41.84		(50,862	)	2,110
2011	68,727		37.83		(34,793	)	1,334
_______________
-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 at an exercise price per share equal to $42.61, the closing price of the Company’s common stock on the grant date (the “February 2012” grant). 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.
A summary of our stock option activity from January 1, 2013 through December 31, 2013 is presented below:
	Number of Options		Exercise Price		Remaining Contractual Term (years)
Outstanding at January 1, 2013	1,540,000		$	42.61
Granted	—		—
Exercised	(3,000	)	42.61
Forfeited	(12,000	)	42.61
Outstanding at December 31, 2013 (1)(2)	1,525,000		$	42.61	8.2
_______________
-1	As of December 31, 2013, 305,000 of the outstanding stock options were exercisable.
-2	The total intrinsic value of options outstanding at December 31, 2013 was $11.5 million.
Share-based Compensation Cost Recorded During the Period
The total compensation cost for all share-based compensation programs was $9.6 million, $8.5 million and $5.6 million for the years ended December 31, 2013, 2012 and 2011, respectively. Of the total share-based compensation costs, $0.9 million, $0.9 million and $1.1 million was capitalized as part of real estate assets for the years ended December 31, 2013, 2012 and 2011, respectively. As of December 31, 2013, there was approximately $25.5 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 2.2 years. The remaining compensation cost related to these nonvested incentive awards had been recognized in periods prior to December 31, 2013. The $25.5 million of unrecognized compensation costs does not reflect the future compensation cost related to share-based awards that were granted subsequent to December 31, 2013.

Employee_Benefit_Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2013
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, 2013, 2012, and 2011, we contributed $0.9 million, $0.7 million and $0.6 million, respectively, to the 401(k) Plan.
	Deferred Compensation Plan
	In 2007, we adopted the Deferred Compensation Plan, under which directors and certain management employees may defer receipt of their compensation, including up to 70% of their salaries and up to 100% of their director fees and bonuses, as applicable. In addition, employee participants will receive mandatory Company contributions to their Deferred Compensation Plan accounts equal to 10% of their gross monthly salaries, without regard to whether such employees elect to defer salary or bonus compensation under the Deferred Compensation Plan. Our board 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, 2013 and 2012. Our liability of $9.9 million and $7.3 million under the Deferred Compensation Plan was fully funded as of December 31, 2013 and 2012, respectively.

Future_Minimum_Rent

Future Minimum Rent	12 Months Ended
	Dec. 31, 2013
Leases [Abstract]	'
Future Minimum Rent	'
	Future Minimum Rent
	We have operating leases with tenants that expire at various dates through 2027 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, 2013 for future periods is summarized as follows:
	Year Ending	(in thousands)
	2014	$	387,188
	2015	371,948
	2016	351,540
	2017	309,221
	2018	252,933
	Thereafter	725,964
	Total	$	2,398,794

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Commitments and Contingencies
	General
	As of December 31, 2013, we had commitments of approximately $645.4 million, excluding our ground lease commitments, for contracts and executed leases directly related to our operating and redevelopment 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, 2013 for five years and thereafter was as follows:
	Year Ending	(in thousands)
	2014	$	3,095
	2015	3,095
	2016	3,095
	2017	3,095
	2018	3,095
	Thereafter	156,912
	Total (1)(2)(3)(4)	$	172,387
	________________________
	-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, 2013.
	-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, 2013.
	-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, 2013.
	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.
	During the year ended December 31, 2011, we settled a matter with a prior tenant at one of the properties held for sale as of December 31, 2013. In connection with this settlement, we received a net cash payment totaling $3.7 million. In the fourth quarter of 2012, we received the final cash distribution under the bankruptcy claim of $0.9 million. Both payments are included in income from discontinued operations in our consolidated statements of operations.
	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 our properties for the presence of hazardous or toxic substances. While there can be no assurance that a material environmental liability does not exist, we are not currently aware of any environmental liability with respect to the properties that would have a material adverse effect on our financial condition, results of operations, and cash flow. Further, we are not aware of any environmental liability or any unasserted claim or assessment with respect to an environmental liability that we believe would require additional disclosure or the recording of a loss contingency.

Fair_Value_Measurements_and_Di

Fair Value Measurements and Disclosures	12 Months Ended
	Dec. 31, 2013
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, 2013 and 2012:
		Fair Value (Level 1) (1)
		2013		2012
	Description	(in thousands)
	Marketable securities (2)	$	10,008	$	7,435
	_______________
	-1	Based on quoted prices in active markets for identical securities.
	-2	The marketable securities are held in a limited rabbi trust.
	We report the change in the fair value of the marketable securities at the end of each accounting period in interest income and other net investment gains in the consolidated statements of operations. We 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 (loss) on marketable securities recorded during the years ended December 31, 2013, 2012 and 2011:
		December 31,
		2013		2012		2011
	Description	(in thousands)
	Net gain (loss) on marketable securities	$	1,489	$	723	$	(153	)
	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, 2013 and 2012:
		December 31,
		2013				2012
		Carrying Value		Fair Value		Carrying Value			Fair Value
		(in thousands)
	Liabilities
	Secured debt (1)	$	560,434	$	568,760	$	561,096		$	591,993
	Exchangeable senior notes, net (1)	168,372		178,190		163,944			181,223
	Unsecured debt, net (2)	1,431,132		1,523,052		1,130,895			1,254,047
	Unsecured line of credit (1)	45,000		45,012		185,000			185,049
	_______________
	-1	Fair value calculated using Level II inputs which are based on model-derived valuations in which significant inputs and significant value drivers are observable in active markets.
	-2	Fair value calculated 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 $873.5 million and $929.3 million, respectively, as of December 31, 2013. The carrying value and fair value of the Level I instruments at December 31, 2012, was $573.0 million and $653.0 million, respectively. The carrying value and fair value of the Level II instruments was $557.7 million and $593.7 million, respectively, as of December 31, 2013. The carrying value and fair value of the Level II instruments at December 31, 2012, was $558.0 million and$601.0 million, respectively.

Discontinued_Operations

Discontinued Operations	12 Months Ended
	Dec. 31, 2013
Discontinued Operations and Disposal Groups [Abstract]	'
Discontinued Operations	'
	Discontinued Operations
	Properties Held for Sale
	As of December 31, 2013, the following properties were classified as held for sale:
	Location		City/Submarket		Property Type		Number of Buildings			Rentable Square Feet
										(unaudited)
	San Diego Properties, San Diego, CA (1)		I-15 Corridor/Sorrento Mesa		Office		12			1,049,035
	________________________
	-1	The San Diego Properties included the following: 10020 Pacific Mesa Boulevard, 6055 Lusk Avenue, 5010 and 5005 Wateridge Vista Drive, 15435 and 15445 Innovation Drive, and 15051, 15073, 15231, 15253, 15333 and 15378 Avenue of Science.
	There were no properties held for sale as of December 31, 2012. On January 9, 2014, the Company completed the sale of the 12 properties located in San Diego, California. See Note 23 “Subsequent Events” for further details.
	Dispositions
	The following table summarizes the properties sold during the years ended December 31, 2013, 2012 and 2011:
	Location		Property Type		Month of Disposition		Number of Buildings		Rentable			Sales Price
									Square Feet (unaudited)			(in millions) (1)
	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 (2)		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
	2011 Dispositions
	10350 Barnes Canyon and 10120 Pacific Heights Drive,		Office		September		2		90,558			$	23.9
	San Diego, CA
	2031 E. Mariposa Avenue, Los Angeles, CA		Industrial		December		1		192,053			42.2
	Total 2011 dispositions						3		282,611			$	66.1
	__________________
	-1	Represents gross sales price before the impact of broker commissions and closing costs.
	-2	The industrial portfolio was sold in two tranches in November and December 2012 to two separate third party buyers.
	At December 31, 2013 and 2012, approximately $32.2 million and $228.8 million, respectively, of net proceeds related to the sale of the buildings during the years ended December 31, 2013 and 2012 were temporarily being held at a qualified intermediary, at our direction, for the purpose of facilitating Section 1031 Exchanges. The cash proceeds are included in restricted cash on the consolidated balance sheets at December 31, 2013 and 2012. In February 2014, we successfully completed one of the Section 1031 Exchanges and the $32.2 million cash proceeds were released from the qualified intermediary. In January 2013, we successfully completed two Section 1031 Exchanges and $228.8 million cash proceeds were released from the qualified intermediary.
	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 years ended December 31, 2013, 2012 and 2011, discontinued operations included the income of all properties sold in 2013, 2012 and 2011 and classified as held for sale at December 31, 2013. For the years ended December 31, 2012 and 2011, discontinued operations also included the income of all the properties sold in 2012. For the year ended December 31, 2011, discontinued operations also included the income of all the properties sold in 2011 and classified as held for sale as of December 31, 2011. The following table summarizes the revenue and expense components that comprise income from discontinued operations for the years ended December 31, 2013, 2012 and 2011:
		Year Ended December 31,
		2013				2012				2011
		(in thousands)
	Revenues:
	Rental income	$	24,694			$	42,240			$	59,266
	Tenant reimbursements	3,408				6,322				8,522
	Other property income	4,619				1,912				4,935
	Total revenues	32,721				50,474				72,723
	Expenses:
Property expenses	4,716				7,724				9,832
Real estate taxes	2,784				4,935				6,652
Provision for bad debts	(8		)		(195		)		(51		)
Ground leases	—				—				214
Depreciation and amortization	8,753				16,649				20,966
Interest expense (1)	—				—				3,624
Total expenses	16,245				29,113				41,237
Income from discontinued operations before net gain on dispositions of discontinued operations	16,476				21,361				31,486
Net gain on dispositions of discontinued operations	12,252				259,245				51,587
Total income from discontinued operations	$	28,728			$	280,606			$	83,073
__________________
-1	Interest expense relates to a $70.0 million mortgage loan that was secured by 13 of our industrial properties. The mortgage loan was repaid in October 2011 prior to maturity.

Net_Income_Available_to_Common

Net Income Available to Common Stockholders Per Share of the Company	12 Months Ended
	Dec. 31, 2013
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, 2013, 2012 and 2011:
		Year Ended December 31,
		2013			2012			2011
		(in thousands, except unit and per unit amounts)
	Numerator:
	Income (loss) from continuing operations	$	15,837		$	(3,505	)	$	(15,584	)
	(Income) loss from continuing operations attributable to noncontrolling common units of the Operating Partnership	(56		)	609			863
	Preferred distributions and dividends	(13,250		)	(21,088		)	(15,196		)
	Allocation to participating securities (1)	(1,689		)	(1,602		)	(1,309		)
	Numerator for basic and diluted income (loss) from continuing operations available to common stockholders	842			(25,586		)	(31,226		)
	Income from discontinued operations	28,728			280,606			83,073
	Income from discontinued operations attributable to noncontrolling common units of the Operating Partnership	(629		)	(6,796		)	(2,337		)
	Numerator for basic and diluted net income available to common stockholders	$	28,941		$	248,224		$	49,510
	Denominator:
	Basic weighted average vested shares outstanding	77,343,853			69,639,623			56,717,121
	Effect of dilutive securities – contingently issuable shares and stock options	1,765,025			—			—
	Diluted weighted average vested shares and common stock equivalents outstanding	79,108,878			69,639,623			56,717,121
	Basic earnings per share:
	Income (loss) from continuing operations available to common stockholders per share	$	0.01		$	(0.37	)	$	(0.55	)
	Income from discontinued operations per share of common stock	0.36			3.93			1.42
	Net income available to common stockholders per share	$	0.37		$	3.56		$	0.87
	Diluted earnings per share:
	Income (loss) from continuing operations available to common stockholders per share	$	0.01		$	(0.37	)	$	(0.55	)
	Income from discontinued operations per share of common stock	0.35			3.93			1.42
	Net income available to common stockholders per share	$	0.36		$	3.56		$	0.87
	________________________
	-1	Participating securities include nonvested shares, vested and non-vested time-based RSUs and vested market-measure RSUs.
	The impact of the contingently issuable shares, which consist of the 4.25% Exchangeable Notes and 1,525,000 stock options, were considered in our diluted earnings per share calculation for year ended December 31, 2013 because we reported income from continuing operations attributable to common stockholders in the respective period and the effect was dilutive. The 143,022 market measure-based RSUs are not included in dilutive securities since they are considered contingently issuable shares as not all the necessary performance conditions have been met as of December 31, 2013. The impact of the Exchangeable Notes and stock options was not considered in our diluted earnings per share calculation for the years ended December 31, 2012 and 2011 because we reported a loss from continuing operations attributable to common stockholders and the effect was anti-dilutive. See Note 7 “Secured and Unsecured Debt of the Operating Partnership” for additional information regarding the 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, 2013
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, 2013, 2012 and 2011:
		Year Ended December 31,
		2013			2012			2011
		(in thousands, except unit and per unit amounts)
	Numerator:
	Income (loss) from continuing operations	$	15,837		$	(3,505	)	$	(15,584	)
	Income from continuing operations attributable to noncontrolling interests in consolidated subsidiaries	(224		)	(174		)	(529		)
	Preferred distributions	(13,250		)	(21,088		)	(15,196		)
	Allocation to participating securities (1)	(1,689		)	(1,602		)	(1,309		)
	Numerator for basic and diluted income (loss) from continuing operations available to common unitholders	674			(26,369		)	(32,618		)
	Income from discontinued operations	28,728			280,606			83,073
	Income from discontinued operations attributable to noncontrolling interests in consolidated subsidiaries	—			(464		)	—
	Numerator for basic and diluted net income available to common unitholders	$	29,402		$	253,773		$	50,455
	Denominator:
	Basic weighted average vested units outstanding	79,166,260			71,403,258			58,437,444
	Effect of dilutive securities - contingently issuable shares and stock options	1,765,025			—			—
	Diluted weighted average vested units and common unit equivalents outstanding	80,931,285			71,403,258			58,437,444
	Basic earnings per unit:
	Income (loss) from continuing operations available to common unitholders per unit	$	0.01		$	(0.37	)	$	(0.56	)
	Income from discontinued operations per common unit	0.36			3.93			1.42
	Net income available to common unitholders per unit	$	0.37		$	3.56		$	0.86
	Diluted earnings per unit:
	Income (loss) from continuing operations available to common unitholders per unit	$	0.01		$	(0.37	)	$	(0.56	)
	Income from discontinued operations per common unit	0.35			3.93			1.42
	Net income available to common unitholders per unit	$	0.36		$	3.56		$	0.86
	________________________
	-1	Participating securities include nonvested shares, vested and non-vested time-based RSUs and vested market-measure RSUs.
	The impact of the contingently issuable units, which consist of the 4.25% Exchangeable Notes and 1,525,000 stock options, were considered in our diluted earnings per unit calculation for the years ended December 31, 2013 because the Operating Partnership reported income from continuing operations attributable to common unitholders in the respective periods and the effect was dilutive. The 143,022 market measure-based RSUs are not included in dilutive securities since they are considered contingently issuable shares as not all the necessary performance conditions have been met as of December 31, 2013. The impact of the Exchangeable Notes and stock options was not considered in our diluted earnings per unit calculation for the years ended December 31, 2012 and 2011 because the Operating Partnership reported a loss from continuing operations attributable to common unitholders and the effect was anti-dilutive. See Note 7 “Secured and Unsecured Debt of the Operating Partnership” for additional information regarding the 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, 2013
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, 2013, 2012 and 2011 as follows:
		Year Ended December 31,
	Dividends	2013		2012			2011
	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, 2013, 2012 and 2011 as identified in the table above was as follows:
		Year Ended December 31,
	Shares of Common Stock	2013						2012				2011
	Ordinary income	$	0.756		54	%		$	0.577	41.21	%	$	0.23	16.43	%
	Qualified dividend	0.003			0.21			—		—		—		—
	Return of capital	0.62			44.29			0.823		58.79		1.17		83.57
	Capital gains (1)	—			—			—		—		—		—
	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 2013 and 15% rate gains for 2012 and 2011.
	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, 2013 and 2012 was as follows:
		Year Ended December 31,
	Preferred Shares	2013						2012
	Ordinary income	$	1.668		97.03	%		$	1.089	100	%
	Qualified dividend	0.006			0.35			—		—
	Capital gains (1)	—			—			—		—
	Unrecaptured section 1250 gains	0.045			2.62			—		—
		$	1.719		100	%		$	1.089	100	%
	__________________
	-1	Capital gains are comprised entirely of 20% rate gains for 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, 2013 and 2012 was as follows:
		Year Ended December 31,
	Preferred Shares	2013						2012
	Ordinary income	$	1.546		96.99	%		$	0.398	100	%
	Qualified dividend	0.006			0.38			—		—
	Capital gains (1)	—			—			—		—
	Unrecaptured section 1250 gains	0.042			2.63			—		—
		$	1.594		100	%		$	0.398	100	%
	__________________
	-1	Capital gains are comprised entirely of 20% rate gains for 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 years ended December 31, 2012 and 2011 is seen in the table below.
		Year Ended December 31,
	Preferred Shares	2012						2011
	Ordinary income	$	0.818		100	%		$	1.95	100	%
	Capital gains (1)	—			—			—		—
	Unrecaptured section 1250 gains	—			—			—		—
		$	0.818		100	%		$	1.95	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 years ended December 31, 2012 and 2011 is seen in the table below.
		Year Ended December 31,
	Preferred Shares	2012						2011
	Ordinary income	$	0.786		100	%		$	1.875	100	%
	Capital gains (1)	—			—			—		—
	Unrecaptured section 1250 gains	—			—			—		—
		$	0.786		100	%		$	1.875	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, 2013
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, 2013 and 2012 was as follows:
		2013 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per share amounts)
	Revenues from continuing operations (2)	$	110,964		$	117,835		$	115,697		$	120,602
	Income from continuing operations (2)	186			7,437			2,683			5,531
	Income from discontinued operations (2)	2,202			2,666			6,344			17,516
	Net income	2,388			10,103			9,027			23,047
	Net income attributable to Kilroy Realty Corporation	2,409			9,946			8,897			22,628
	Preferred dividends and distributions	(3,313		)	(3,313		)	(3,312		)	(3,312		)
	Net (loss) income available to common stockholders	(904		)	6,633			5,585			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
		2012 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per share amounts)
	Revenues from continuing operations (2)	$	85,858		$	91,584		$	98,985		$	104,573
	(Loss) income from continuing operations (2)	(848		)	(1,873		)	(2,141		)	1,357
	Income from discontinued operations (2)	79,519			4,150			4,663			192,274
	Net income	78,671			2,277			2,522			193,631
	Net income attributable to Kilroy Realty Corporation	76,876			2,297			2,589			189,152
	Preferred dividends and distributions	(9,336		)	(3,097		)	(5,342		)	(3,313		)
	Net income (loss) available to common stockholders	67,540			(800		)	(2,753		)	185,839
	Net income (loss) available to common stockholders per share – basic	1.06			(0.02		)	(0.04		)	2.49
	Net income (loss) available to common stockholders per share – diluted	1.06			(0.02		)	(0.04		)	2.49
	____________________
	-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 impact of equity offerings that occurred during the years ended December 31, 2013 and 2012.
	-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 17 “Discontinued Operations” for additional information).

Quarterly_Financial_Informatio1

Quarterly Financial Information of the Operating Partnership (Unaudited)	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Information of the Operating Partnership	'
	Quarterly Financial Information of the Company (Unaudited)
	Summarized quarterly financial data for the years ended December 31, 2013 and 2012 was as follows:
		2013 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per share amounts)
	Revenues from continuing operations (2)	$	110,964		$	117,835		$	115,697		$	120,602
	Income from continuing operations (2)	186			7,437			2,683			5,531
	Income from discontinued operations (2)	2,202			2,666			6,344			17,516
	Net income	2,388			10,103			9,027			23,047
	Net income attributable to Kilroy Realty Corporation	2,409			9,946			8,897			22,628
	Preferred dividends and distributions	(3,313		)	(3,313		)	(3,312		)	(3,312		)
	Net (loss) income available to common stockholders	(904		)	6,633			5,585			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
		2012 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per share amounts)
	Revenues from continuing operations (2)	$	85,858		$	91,584		$	98,985		$	104,573
	(Loss) income from continuing operations (2)	(848		)	(1,873		)	(2,141		)	1,357
	Income from discontinued operations (2)	79,519			4,150			4,663			192,274
	Net income	78,671			2,277			2,522			193,631
	Net income attributable to Kilroy Realty Corporation	76,876			2,297			2,589			189,152
	Preferred dividends and distributions	(9,336		)	(3,097		)	(5,342		)	(3,313		)
	Net income (loss) available to common stockholders	67,540			(800		)	(2,753		)	185,839
	Net income (loss) available to common stockholders per share – basic	1.06			(0.02		)	(0.04		)	2.49
	Net income (loss) available to common stockholders per share – diluted	1.06			(0.02		)	(0.04		)	2.49
	____________________
	-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 impact of equity offerings that occurred during the years ended December 31, 2013 and 2012.
	-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 17 “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, 2013 and 2012 was as follows:
		2013 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per unit amounts)
	Revenues from continuing operations (2)	$	110,964		$	117,835		$	115,697		$	120,602
	Income (loss) from continuing operations (2)	186			7,437			2,683			5,531
	Income from discontinued operations (2)	2,202			2,666			6,344			17,516
	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 income (loss) available to common unitholders	(994		)	6,728			5,668			19,689
	Net income (loss) available to common unitholders per unit – basic	(0.02		)	0.08			0.07			0.23
	Net income (loss) available to common unitholders per unit – diluted	(0.02		)	0.08			0.07			0.23
		2012 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per unit amounts)
	Revenues from continuing operations (2)	$	85,858		$	91,584		$	98,985		$	104,573
	Income from continuing operations (2)	(848		)	(1,873		)	(2,141		)	1,357
	Income from discontinued operations (2)	79,519			4,150			4,663			192,274
	Net income	78,671			2,277			2,522			193,631
	Net income attributable to the Operating Partnership	78,618			2,234			2,474			193,137
	Preferred distributions	(9,336		)	(3,097		)	(5,342		)	(3,313		)
	Net income (loss) available to common unitholders	69,282			(863		)	(2,868		)	189,824
	Net income (loss) available to common unitholders per unit – basic	1.05			(0.02		)	(0.04		)	2.48
	Net income (loss) available to common unitholders per unit – diluted	1.05			(0.02		)	(0.04		)	2.44
	___________________
	-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 equity offerings that occurred during the years ended December 31, 2013 and 2012.
	-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 17 “Discontinued Operations”).

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2013
Subsequent Events [Abstract]	'
Subsequent Events	'
	Subsequent Events
	On January 9, 2014, the Company completed the sale of the 12 properties located in San Diego, California that were held for sale at December 31, 2013 for a gross sales price of $294.7 million.
	On January 15, 2014, aggregate dividends, distributions and dividend equivalents of $29.8 million were paid to common stockholders and common unitholders of record on December 31, 2013 and RSU holders of record on January 15, 2014.
	On January 29, 2014, the Executive Compensation Committee granted 236,604 RSUs to the Executive Officers and other key employees under the 2006 Plan. 119,098 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 the time-based RSUs is expected to be recognized over a period of four years. The compensation cost related to the market-measure based RSUs is expected to be recognized over a period of three years. In addition, if our stockholders do not approve an increase to the share limit under our 2006 Plan then these awards may be cash settled and will be subject to variable plan accounting until a sufficient amount of shares are authorized for issuance under the 2006 Plan to cover the payment of these awards.
	On February 13, 2014, the Board of Directors declared a regular quarterly cash dividend of $0.35 per share of common stock payable on April 16, 2014 to stockholders of record on March 31, 2014. The Board of Directors also declared a dividend of $0.42969 per share on the Series G Preferred Stock and $0.39844 per share on the Series H Preferred Stock for the period commencing on and including February 18, 2014 and ending on and including May 14, 2014. The dividend will be payable on May 15, 2014 to Series G Preferred and Series H Preferred stockholders of record on April 30, 2014.

Schedule_II_Valuation_and_Qual

Schedule II Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2013
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
	Allowance for Uncollectible Tenant Receivables for the year ended
	December 31,
	2013 – Allowance for uncollectible tenant receivables	$	2,581	$	396		$	(843	)	$	2,134
	2012 – Allowance for uncollectible tenant receivables	2,590		(42		)	33			2,581
	2011 – Allowance for uncollectible tenant receivables	2,819		923			(1,152		)	2,590
	Allowance for Unbilled Deferred Rent for the year ended
	December 31,
	2013 – Allowance for deferred rent	$	2,607	$	—		$	(532	)	$	2,075
	2012 – Allowance for deferred rent	3,406		—			(799		)	2,607
	2011 – Allowance for deferred rent	3,831		(279		)	(146		)	3,406
	_______________
	-1	Includes amounts reported in Discontinued Operations (see Note 17 “Discontinued Operations”).

Schedule_III_Real_Estate_and_A

Schedule III - Real Estate and Accumulated Depreciation	12 Months Ended
	Dec. 31, 2013
SEC Schedule III, Real Estate and Accumulated Depreciation Disclosure [Abstract]	'
Schedule III - Real Estate and Accumulated Depreciation	'
	KILROY REALTY CORPORATION AND KILROY REALTY, L.P.
	SCHEDULE III – REAL ESTATE AND ACCUMULATED DEPRECIATION
	December 31, 2013
			Initial Cost																Gross Amounts at Which
																			Carried at Close of Period
	Property Location		Encumb-				Land and improve-ments				Buildings				Costs				Land and improve-ments				Buildings				Total				Accumulated			Deprecia-		Date of			Rentable
			rances								and				Capitalized								and								Depreciation			tion		Acquisition			Square
											Improve-				Subsequent to								Improve-											Life (1)		(A)/			Feet (3)
											ments				Acquisition/								ments													Construction			(unaudited)
															Improvement																					(C) (2)
			(in thousands)
	Office Properties:
	23925 Park Sorrento, Calabasas, CA		$	8,972		-5	$	50			$	2,346			$	306			$	50			$	2,652			$	2,702			$	1,355		35		2001		(C)	11,789
	23975 Park Sorrento, Calabasas, CA					-5	765				17,720				5,703				765				23,423				24,188				11,838			35		2002		(C)	104,797
	24025 Park Sorrento, Calabasas, CA					-5	845				15,896				4,739				845				20,635				21,480				10,722			35		2000		(C)	108,670
	2240 E. Imperial Highway, El Segundo, CA						1,044				11,763				25,423				1,048				37,182				38,230				18,782			35		1983		(C)	122,870
	2250 E. Imperial Highway, El Segundo, CA						2,579				29,062				28,016				2,547				57,110				59,657				42,353			35		1983		(C)	298,728
	2260 E. Imperial Highway, El Segundo, CA						2,518				28,370				35,519				2,547				63,860				66,407				2,809			35		1983		(C)	298,728
	909 Sepulveda Blvd., El Segundo, CA		67,663			-6	3,577				34,042				42,343				3,577				76,385				79,962				23,669			35		2005		(C)	241,607
	999 Sepulveda Blvd., El Segundo, CA					-6	1,407				34,326				11,677				1,407				46,003				47,410				15,113			35		2003		(C)	128,592
	3750 Kilroy Airport Way, Long Beach, CA										1,941				10,327								12,268				12,268				8,618			35		1989		(C)	10,457
	3760 Kilroy Airport Way, Long Beach, CA										17,467				8,888								26,355				26,355				20,057			35		1989		(C)	165,278
	3780 Kilroy Airport Way, Long Beach, CA										22,319				14,766								37,085				37,085				30,223			35		1989		(C)	219,745
	3800 Kilroy Airport Way, Long Beach, CA										19,408				15,265								34,673				34,673				17,783			35		2000		(C)	192,476
	3840 Kilroy Airport Way, Long Beach, CA										13,586				9,218								22,804				22,804				11,827			35		1999		(C)	136,026
	3880 Kilroy Airport Way, Long Beach, CA										9,704				6,860								16,564				16,564				583			35		1997		(A)	98,243
	3900 Kilroy Airport Way, Long Beach, CA										12,615				9,128								21,743				21,743				11,848			35		1997		(A)	126,840
	Kilroy Airport Center, Phase IV, Long Beach, CA(4)														4,997								4,997				4,997				4,976			35
	12100 W. Olympic Blvd., Los Angeles, CA						352				45,611				15,532				9,633				51,862				61,495				17,338			35		2003		(C)	150,167
	12200 W. Olympic Blvd., Los Angeles, CA						4,329				35,488				15,501				3,977				51,341				55,318				27,960			35		2000		(C)	150,302
	12233 W. Olympic Blvd., Los Angeles, CA		39,948			-7	22,100				53,170				1,145				22,100				54,315				76,415				2,145			35		2012		(A)	151,029
	12312 W. Olympic Blvd., Los Angeles, CA						3,325				12,202				813				3,399				12,941				16,340				6,046			35		1997		(A)	78,000
	6255 W. Sunset Blvd., Los Angeles, CA		52,738			-8	18,111				60,320				18,501				18,111				78,821				96,932				4,508			35		2012		(A)	321,883
	1633 26th St., Santa Monica, CA						2,080				6,672				3,037				2,040				9,749				11,789				5,263			35		1997		(A)	44,915
	2100/2110 Colorado Ave., Santa Monica, CA		97,000			-9	5,474				26,087				13,125				5,476				39,210				44,686				15,647			35		1997		(A)	102,864
	3130 Wilshire Blvd., Santa Monica, CA						8,921				6,579				11,409				9,188				17,721				26,909				10,428			35		1997		(A)	88,339
	501 Santa Monica Blvd., Santa Monica, CA						4,547				12,044				6,667				4,551				18,707				23,258				10,245			35		1998		(A)	73,115
	2829 Townsgate Rd., Thousand Oaks, CA						5,248				8,001				6,069				5,248				14,070				19,318				8,026			35		1997		(A)	81,067
	12225 El Camino Real, Del Mar, CA						1,700				9,633				2,992				1,683				12,642				14,325				5,750			35		1.998		(A)	58,401
	12235 El Camino Real, Del Mar, CA						1,507				8,543				4,637				1,530				13,157				14,687				7,009			35		1998		(A)	54,673
	12340 El Camino Real, Del Mar, CA					-6	4,201				13,896				7,366				4,201				21,262				25,463				7,505			35		2002		(C)	87,405
	12390 El Camino Real, Del Mar, CA					-6	3,453				11,981				1,264				3,453				13,245				16,698				7,200			35		2000		(C)	72,332
	12348 High Bluff Dr., Del Mar, CA						1,629				3,096				3,452				1,629				6,548				8,177				4,621			35		1999		(C)	38,710
	12400 High Bluff Dr., Del Mar, CA						15,167				40,497				11,610				15,167				52,107				67,274				18,064			35		2004		(C)	208,464
	3579 Valley Centre Dr., Del Mar, CA						2,167				6,897				7,139				2,858				13,345				16,203				6,304			35		1999		(C)	51,167
	3611 Valley Centre Dr., Del Mar, CA						4,184				19,352				17,453				5,259				35,730				40,989				16,382			35		2000		(C)	130,349
	3661 Valley Centre Dr., Del Mar, CA						4,038				21,144				10,204				4,725				30,661				35,386				14,482			35		2001		(C)	129,752
	KILROY REALTY CORPORATION AND KILROY REALTY, L.P.
	SCHEDULE III – REAL ESTATE AND ACCUMULATED DEPRECIATION – (Continued)
	December 31, 2013
			Initial Cost														Gross Amounts at Which
																	Carried at Close of Period
	Property Location		Encumb-		Land and improve-ments				Buildings				Costs				Land and improve-ments				Buildings				Total				Accumulated				Deprecia-	Date of		Rentable
			rances						and				Capitalized								and								Depreciation				tion	Acquisition		Square
									Improve-				Subsequent to								Improve-												Life (1)	(A)/		Feet (3)
									ments				Acquisition/								ments													Construction		(unaudited)
													Improvement																					(C) (2)
			(in thousands)
	3721 Valley Centre Dr., Del Mar, CA				$	4,297			$	18,967			$	12,913			$	4,254			$	31,923			$	36,177			$	8,511			35	2003	(C)	114,780
	3811 Valley Centre Dr., Del Mar, CA				3,452				16,152				20,077				4,457				35,224				39,681				15,032				35	2000	(C)	112,067
	12780 El Camino Real, CA				18,398				54,954				—				18,398				54,954				73,352				548				35	2013	(A)	140,591
	12790 El Camino Real, CA				10,252				21,236				—				10,252				21,236				31,488				216				35	2013	(A)	78,349
	6200 Greenwich Dr., Governor Park, CA				1,583				5,235				3,994				1,722				9,090				10,812				4,950				35	1999	(C)	73,507
6220 Greenwich Dr., Governor Park, CA				3,213				10,628				19,365				3,426				29,780				33,206				9,023				35	1997	(A)	141,214
13280 Evening Creek Dr. South, I-15 Corridor, CA				3,701				8,398				3,163				3,701				11,561				15,262				2,200				35	2008	(C)	41,194
13290 Evening Creek Dr. South, I-15 Corridor, CA				5,229				11,871				1,687				5,229				13,558				18,787				1,975				35	2008	(C)	59,188
13480 Evening Creek Dr. North, I-15 Corridor, CA				7,997								41,766				7,997				41,766				49,763				8,485				35	2008	(C)	149,817
13500 Evening Creek Dr. North, I-15 Corridor, CA				7,581				35,903				10,873				7,580				46,777				54,357				13,272				35	2004	(A)	147,533
13520 Evening Creek Dr. North, I-15 Corridor, CA				7,581				35,903				12,784				7,580				48,688				56,268				14,636				35	2004	(A)	141,128
7525 Torrey Santa Fe, 56 Corridor, CA				2,348				28,035				4,061				2,348				32,096				34,444				7,685				35	2007	(C)	103,979
7535 Torrey Santa Fe, 56 Corridor, CA				2,950				33,808				5,992				2,950				39,800				42,750				9,857				35	2007	(C)	130,243
7545 Torrey Santa Fe, 56 Corridor, CA				2,950				33,708				8,118				2,950				41,826				44,776				11,099				35	2007	(C)	130,354
7555 Torrey Santa Fe, 56 Corridor, CA				2,287				24,916				3,712				2,287				28,628				30,915				6,833				35	2007	(C)	101,236
2355 Northside Dr., Mission Valley, CA				4,066				8,332				884				3,270				10,012				13,282				1,743				35	2010	(A)	53,610
2365 Northside Dr., Mission Valley, CA				7,359				15,257				1,061				5,919				17,758				23,677				2,735				35	2010	(A)	96,436
2375 Northside Dr., Mission Valley, CA				3,947				8,146				2,121				3,175				11,039				14,214				1,578				35	2010	(A)	51,516
2385 Northside Dr., Mission Valley, CA				2,752				14,513				5,303				5,759				16,809				22,568				2,585				35	2010	(A)	89,023
2305 Historic Decatur Rd., Point Loma, CA				5,240				22,220				424				5,240				22,644				27,884				2,451				35	2010	(A)	103,900
4921 Directors Place, Sorrento Mesa, CA				3,792				11,091				4,761				3,792				15,852				19,644				2,740				35	2008	(C)	56,136
4939 Directors Place, Sorrento Mesa, CA				2,225				12,698				4,360				2,198				17,085				19,283				7,673				35	2002	(C)	60,662
4955 Directors Place, Sorrento Mesa, CA				2,521				14,122				3,697				3,179				17,161				20,340				11,303				35	2000	(C)	76,246
10770 Wateridge Circle, Sorrento Mesa, CA				4,560				26,671				236				4,560				26,907				31,467				5,313				35	2011	(A)	174,310
6260 Sequence Dr., Sorrento Mesa, CA				3,206				9,803				1,414				3,212				11,211				14,423				5,580				35	1997	(A)	130,536
6290 Sequence Dr., Sorrento Mesa, CA				2,403				7,349				4,925				2,407				12,270				14,677				7,058				35	1997	(A)	90,000
KILROY REALTY CORPORATION AND KILROY REALTY, L.P.
SCHEDULE III – REAL ESTATE AND ACCUMULATED DEPRECIATION – (Continued)
December 31, 2013
		Initial Cost													Gross Amounts at Which
															Carried at Close of Period
Property Location		Encumb-				Land and improve-ments			Buildings			Costs			Land and improve-ments			Buildings			Total			Accumulated			Deprecia-		Date of		Rentable
		rances							and			Capitalized						and						Depreciation			tion		Acquisition		Square
									Improve-			Subsequent to						Improve-									Life (1)		(A)/		Feet (3)
									ments			Acquisition/						ments											Construction		(unaudited)
												Improvement																	(C) (2)
		(in thousands)
6310 Sequence Dr., Sorrento Mesa, CA						2,940			4,946			329			2,941			5,274			8,215			2,875			35		2000	(C)	62,415
6340 Sequence Dr., Sorrento Mesa, CA						2,434			7,302			9,964			2,464			17,236			19,700			9,058			35		1998	(A)	66,400
6350 Sequence Dr., Sorrento Mesa, CA						4,941			14,824			(4,109	)		4,922			10,734			15,656			6,282			35		1998	(A)	132,600
10390 Pacific Center Ct., Sorrento Mesa, CA						3,267			5,779			7,501			3,267			13,280			16,547			4,917			35		2002	(C)	68,400
10394 Pacific Center Ct., Sorrento Mesa, CA						2,696			7,134			(781	)		1,671			7,378			9,049			3,511			35		1998	(A)	59,630
10398 Pacific Center Ct., Sorrento Mesa, CA						1,947			5,152			1,317			1,222			7,194			8,416			3,174			35		1998	(A)	43,645
10421 Pacific Center Ct., Sorrento Mesa, CA						2,926			7,979			21,864			2,926			29,843			32,769			13,320			35		1998	(A)	75,899
10445 Pacific Center Ct., Sorrento Mesa, CA						2,247			5,945			1,837			1,809			8,220			10,029			3,155			35		1998	(A)	48,709
10455 Pacific Center Ct., Sorrento Mesa, CA						4,044			10,701			(2,250	)		3,780			8,715			12,495			3,968			35		1998	(A)	90,000
5717 Pacific Center Blvd., Sorrento Mesa, CA						2,693			6,280			4,220			2,693			10,500			13,193			3,024			35		2001	(C)	67,995
4690 Executive Dr., UTC, CA					-6	1,623			7,926			2,400			1,623			10,326			11,949			5,361			35		1999	(A)	47,212
9785 Towne Center Dr., UTC, CA						2,722			9,932			(1,076	)		2,329			9,249			11,578			3,898			35		1999	(A)	75,534
9791 Towne Center Dr., UTC, CA						1,814			6,622			1,122			2,217			7,341			9,558			3,094			35		1999	(A)	50,466
2211 Michelson, Irvine, CA					-9	9,319			82,836			2,377			9,319			85,213			94,532			11,078			35		2010	(A)	271,556
111 Pacifica, Irvine, CA						5,165			4,653			4,491			5,166			9,143			14,309			5,465			35		1997	(A)	67,496
999 Town & Country, Orange, CA						7,867			9,579			148			7,867			9,727			17,594			1,459			35		2010	(A)	98,551
4100 Bohannon Dr., Menlo Park, CA						4,835			15,526			213			4,835			15,739			20,574			1,007			35		2012	(A)	46,614
4200 Bohannon Dr., Menlo Park, CA						4,798			15,406			441			4,798			15,847			20,645			945			35		2012	(A)	46,255
4300 Bohannon Dr., Menlo Park, CA						6,527			20,958			1,351			6,527			22,309			28,836			1,504			35		2012	(A)	62,920
4400 Bohannon Dr., Menlo Park, CA						4,798			15,406			1,096			4,798			16,502			21,300			1,078			35		2012	(A)	46,255
4500 Bohannon Dr., Menlo Park, CA						6,527			20,957			1,355			6,527			22,312			28,839			1,446			35		2012	(A)	62,920
4600 Bohannon Dr., Menlo Park, CA						4,798			15,406			872			4,798			16,278			21,076			840			35		2012	(A)	46,255
4700 Bohannon Dr., Menlo Park, CA						6,527			20,958			1,134			6,527			22,092			28,619			1,403			35		2012	(A)	62,920
331 Fairchild Drive, CA						18,396			17,712			6,549			18,396			24,261			42,657			220			35		2013	(C)	87,565
303 Second St., San Francisco, CA		$	133,117		-10	63,550			154,153			23,306			63,550			177,459			241,009			25,676			35		2010	(A)	740,047
100 First St., San Francisco, CA						49,150			131,238			15,824			49,150			147,062			196,212			18,375			35		2010	(A)	466,490
250 Brannan St., San Francisco, CA						7,630			22,770			3,999			7,630			26,769			34,399			3,494			35		2011	(A)	95,008
201 Third St., San Francisco, CA						19,260			84,018			18,300			19,260			102,318			121,578			12,621			35		2011	(A)	332,893
301 Brannan St., San Francisco, CA						5,910			22,450			1,669			5,910			24,119			30,029			2,145			35		2011	(A)	74,430
360 Third St., San Francisco, CA												182,325			28,460			153,865			182,325			4,064			35		2011	(A)	-14
4040 Civic Center, San Rafael, CA						10,210			18,029			2,643			10,210			20,672			30,882			2,556			35		2011	(A)	130,237
599 N. Mathilda Ave., Sunnyvale, CA						13,538			12,559			—			13,538			12,559			26,097			591			35		2012	(A)	75,810
601 108th Ave., Bellevue, WA						—			214,095			12,169			—			226,264			226,264			23,061			35		2011	(A)	488,470
10900 NE 4th St., Bellevue, WA						25,080			150,877			14,624			25,080			165,501			190,581			8,872			35		2012	(A)	416,755
KILROY REALTY CORPORATION AND KILROY REALTY, L.P.
SCHEDULE III – REAL ESTATE AND ACCUMULATED DEPRECIATION – (Continued)
December 31, 2013
		Initial Cost																Gross Amounts at Which
																		Carried at Close of Period
Property Location		Encumb-				Land and improve-ments				Buildings				Costs				Land and improve-ments				Buildings				Total				Accumulated			Deprecia-		Date of		Rentable
		rances								and				Capitalized								and								Depreciation			tion		Acquisition		Square
										Improve-				Subsequent to								Improve-											Life (1)		(A)/		Feet (3)
										ments				Acquisition/								ments													Construction		(unaudited)
														Improvement																					(C) (2)
		(in thousands)
10220 NE Points Dr., Kirkland, WA		$	27,322		-11	2,554				12,080				891				2,554				12,971				15,525				1,345			35		2011	(A)	49,851
10230 NE Points Dr., Kirkland, WA					-11	5,071				24,694				3,184				5,071				27,878				32,949				2,895			35		2011	(A)	98,982
10210 NE Points Dr., Kirkland, WA					-11	4,336				24,187				2,256				4,336				26,443				30,779				2,688			35		2011	(A)	84,641
3933 Lake WA Blvd. NE, Kirkland, WA					-11	2,380				15,114				1,058				2,380				16,172				18,552				1,735			35		2011	(A)	46,450
15050 N.E. 36th St., Redmond, WA						9,260				34,650				197				9,260				34,847				44,107				3,524			35		2010	(A)	122,103
837 N. 34th St., Lake Union, WA						—				37,404				548				—				37,952				37,952				2,419			35		2012	(A)	111,580
320 Westlake Avenue North, WA		82,638			-12	14,710				82,018				—				14,710				82,018				96,728				2,720			35		2013	(A)	184,643
321 Terry Avenue North, WA					-12	10,430				60,003				281				10,430				60,284				70,714				1,963			35		2013	(A)	135,755
701 N. 34th St., Lake Union, WA		34,000			-13	—				48,027				241				—				48,268				48,268				3,193			35		2012	(A)	138,995
801 N. 34th St., Lake Union, WA					-13	—				58,537				193				—				58,730				58,730				3,371			35		2012	(A)	169,412
17150 Von Karman, Irvine, CA						4,848				7,342				2,501				7,684				7,007				14,691				7,007			35		1997	(A)	-16
TOTAL OPERATING PROPERTIES		$	543,398			$	614,976			$	2,715,858			$	917,356			$	657,491			$	3,590,699			$	4,248,190			$	818,957						12,736,099
Undeveloped land and construction in progress (17)		$	2,470		-16	616,226				90,512				310,019				588,479				428,278				1,016,757				—
TOTAL ALL PROPERTIES		$	545,868		-18	$	1,231,202			$	2,806,370			$	1,227,375			$	1,245,970			$	4,018,977			$	5,264,947			$	818,957						12,736,099
__________________________
-1	The initial costs of buildings and improvements are depreciated over 35 years using a straight-line method of accounting; improvements capitalized subsequent to acquisition are depreciated over the shorter of the lease term or useful life, generally ranging from one to 20 years.
-2	Represents our date of construction or acquisition, or our predecessor, the Kilroy Group.
-3	Includes square footage from our stabilized portfolio.
-4	These costs represent infrastructure costs incurred in 1989. During the third quarter of 2009, we exercised our option to terminate the ground lease at Kilroy Airport Center, Phase IV in Long Beach, California. We had previously leased this land, which is adjacent to our Office Properties at Kilroy Airport Center, Long Beach, for potential future development opportunities.
-5	These properties secure a $8.9 million mortgage note.
-6	These properties secure a $67.7 million mortgage note.
-7	This property secures a $39.9 million mortgage note.
-8	This property secures a $52.7 million mortgage note.
-9	These properties secure a $97.0 million mortgage note.
-10	This property secures a $133.1 million mortgage note.
-11	This property secures a $27.3 million mortgage note.
-12	These properties secure a $82.6 million mortgage note.
-13	These properties secure a $34.0 million mortgage note.
-14	Excludes approximately 410,000 rentable square feet as this building was under redevelopment at December 31, 2013. The cost basis is included in “Undeveloped land and construction in progress” below.
-15	During the fourth quarter of 2011, we completed demolition of the industrial building on this site to prepare for the possible sale of the land and improvements, since we successfully obtained entitlements to reposition this site for residential use. Our ultimate decision to sell this site and the timing of any potential future sale will depend upon market conditions and other factors.
-16	Represents the principal balance of the public facility bonds (the “Bonds”), the proceeds from which were used to finance infrastructure improvements on one of our undeveloped land parcels. The Bonds are secured by property tax payments.
-17	Includes initial cost of 9455 Towne Center Drive, which was transferred to the future development portfolio and is included in construction in progress during the year ended December 31, 2013.
-18	Represents gross aggregate principal amount before the effect of the unamortized premium of approximately $7.2 million as of December 31, 2013.
The aggregate gross cost of property included above for federal income tax purposes approximated $4.6 billion as of December 31, 2013.
The following table reconciles the historical cost of total real estate held for investment from January 1, 2011 to December 31, 2013:
	Year Ended December 31,
	2013				2012				2011
	(in thousands)
Total real estate held for investment, beginning of year	$	4,757,394			$	3,798,690			$	3,216,871
Additions during period:
Acquisitions	384,650				1,023,384				617,923
Improvements, etc.	452,331				207,345				84,736
Total additions during period	836,981				1,230,729				702,659
Deductions during period:
Cost of real estate sold	(56,993		)		(264,533		)		(21,052		)
Properties held for sale	(259,251		)		—				(89,937		)
Other (1)	(13,184		)		(7,492		)		(9,851		)
Total deductions during period	(329,428		)		(272,025		)		(120,840		)
Total real estate held for investment, end of year	$	5,264,947			$	4,757,394			$	3,798,690
__________________________
-1	Related to the redevelopment property transferred to construction in progress during the year.
The following table reconciles the accumulated depreciation from January 1, 2011 to December 31, 2013:
	Year Ended December 31,
	2013				2012				2011
	(in thousands)
Accumulated depreciation, beginning of year	$	756,515			$	742,503			$	672,429
Additions during period:
Depreciation of real estate	145,325				125,906				105,982
Total additions during period	145,325				125,906				105,982
Deductions during period:
Write-offs due to sale	(17,144		)		(109,797		)		(11,152		)
Properties held for sale	(63,110		)		—				(14,905		)
Other (1)	(2,629		)		(2,097		)		(9,851		)
Total deductions during period	(82,883		)		(111,894		)		(35,908		)
Accumulated depreciation, end of year	$	818,957			$	756,515			$	742,503
__________________________
-1	Related to the redevelopment property transferred to construction in progress during the year.

Basis_of_Presentation_and_Sign1

Basis of Presentation and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2013
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 City Partners, LLC and all of our wholly owned and controlled subsidiaries. The consolidated financial statements of the Operating Partnership include the consolidated financial position and results of operations of the Operating Partnership, the Finance Partnership, KSLLC, Redwood City Partners, LLC and all wholly owned and controlled subsidiaries of the Operating Partnership. All intercompany balances and transactions have been eliminated in the consolidated financial statements.
Partially Owned Entities and Variable Interest Entities	'
	Partially Owned Entities and Variable Interest Entities
	Our accounting policy is to consolidate entities in which we have a controlling financial interest and significant decision making control over the entities 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 also consolidate entities in which the other member has 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 that 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, 2013 or December 31, 2012.
	As of December 31, 2013, the consolidated financial statements of the Company and the Operating Partnership included four VIEs, in which we were deemed to be the primary beneficiary. One of the VIEs was established during the second quarter of 2013 as a result of an acquisition (see Note 3 “Acquisitions” for additional information regarding the Redwood City, California acquisition) and the remaining VIEs were established during the third and fourth quarter of 2013 to facilitate a potential like-kind exchange pursuant to Section 1031 of the Code (“Section 1031 Exchanges”) to defer taxable gains on dispositions for federal and state income tax purposes. To realize the tax deferral available under a Section 1031 Exchange, the Company must complete the Section 1031 Exchanges, if any, and complete the sale of the to-be-exchanged properties within 180 days of the acquisition date (see Note 3 “Acquisitions” for additional information). The VIEs established during the third and fourth quarter of 2013 will be terminated upon the completion of the Section 1031 Exchanges or the expiration of the 180 day period, as applicable. 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 is related to real estate held for investment on our consolidated balance sheet), $12.1 million and $4.9 million, respectively, at December 31, 2013. In February 2014, we successfully completed one of the Section 1031 Exchanges.
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, 2013 and 2012, we capitalized $2.3 million and $0.7 million, respectively, in acquisition costs associated with the acquisition of undeveloped land. We did not capitalize any acquisition costs during the year ended December 31, 2011.
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, 2013, 2012, and 2011 was $145.3 million, $125.9 million and $106.0 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	'
	Discontinued Operations and Properties 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.
	An operating property 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 property held for sale, if material, separately on the balance sheet and we would cease to record depreciation and amortization expense. Properties held for sale are reported at the lower of their carrying value or their estimated fair value less the estimated costs to sell.
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, whether 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. As of December 31, 2013 and 2012, deferred financing costs were reported net of accumulated amortization of $13.2 million and $16.6 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 $14.6 million and $7.2 million as of December 31, 2013 and 2012, respectively. Our unsecured senior notes are presented net of unamortized discounts of $1.9 million and $2.1 million, as of December 31, 2013 and 2012, 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	'
	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, 2013 and 2012.
	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 be redeemed only 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.
	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, formed during the year ended December 31, 2013, Redwood City Partners, LLC (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.
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 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 and recognition of the 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.
	During the performance period for a share-based award program when the performance period precedes the grant date, we estimate the total compensation cost of the potential future awards. We then record compensation cost equal to the portion of the requisite service period that has elapsed through the end of the reporting period. 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 reporting 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 certain key 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 the allocation of income to participating securities, by the weighted-average number of vested 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 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 18 “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 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. The dilutive effect of the exchangeable debt instruments is 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 presented 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 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 line of credit, and unsecured term loan facility 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. We calculate the market rate of our unsecured line of credit and unsecured term loan facility by obtaining the period-end London Interbank Offered Rate (“LIBOR”) rate 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 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. Accordingly, no provision for income taxes has been made in the accompanying financial statements. We believe that we have met all of the REIT distribution and technical requirements for the years ended December 31, 2013, 2012 and 2011, and we were not subject to any federal income taxes (see Note 20 “Tax Treatment of Distributions” for additional information). We intend to continue to adhere to these requirements and maintain the Company’s REIT status.
	In addition, any taxable income from our taxable REIT subsidiary, which was formed in 2002, is subject to federal, state, and local income taxes.
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 potential 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 potential audit. As of December 31, 2013, the years still subject to audit are 2009 through 2012 under the California state income tax law and 2010 through 2012 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, 2013 and 2012.
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 and all of our business is currently conducted in the state of California with the exception of the ownership and operation of twelve office properties located in the state of Washington. The ability of the tenants to honor the terms of their leases is dependent upon the economic, regulatory, and social factors affecting the communities in which the tenants operate.
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	There are no recently issued accounting pronouncements that are expected to have a material effect on our financial condition and results of operations in future periods.
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 a new consolidated subsidiary, Redwood City Partners, 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 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 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.
	The dilutive effect of stock options, Exchangeable Notes, 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.

Organization_and_Ownership_Tab

Organization and Ownership (Tables)	12 Months Ended
	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Summary of stabilized portfolio of operating properties	'
	As of December 31, 2013, the following properties were excluded from our stabilized portfolio:
		Number of Properties	Estimated Rentable
			Square Feet (unaudited)
	Properties Held for Sale (1)	12	1,049,035
	Development properties under construction (2)	6	2,538,000
	Lease-up properties	1	410,000
	_______________
	-1	Includes 12 properties located in San Diego, California. The sale of these properties closed on January 9, 2014 (see Note 23 “Subsequent Events” for additional information).
	(2)    Estimated rentable square feet upon completion.
	Our stabilized portfolio of operating properties was comprised of the following office properties at December 31, 2013:
		Number of		Rentable	Number of	Percentage
		Buildings		Square Feet (unaudited)	Tenants	Occupied (unaudited)
	Stabilized Office Properties (1)	105		12,736,099	514	93.4	%
	______________
	-1	Excludes 12 properties located in San Diego, California that were held for sale at December 31, 2013 (see Note 17 “Discontinued Operations” for additional information). The sale of these properties closed on January 9, 2014 (see Note 23 “Subsequent Events” for additional information).

Basis_of_Presentation_and_Sign2

Basis of Presentation and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2013
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, 2013
Office Properties Acquisitions	'
Business Acquisition [Line Items]	'
Acquired operating properties from unrelated third parties	'
	Property		Date of Acquisition	Number of Buildings		Rentable Square Feet (unaudited)		Occupancy as of December 31, 2013 (unaudited)		Purchase Price (in millions) (1)
	2013 Acquisitions
	320 Westlake Ave. N. and 321 Terry Ave. N.,		January 16, 2013	2		320,398		100.00%		$	170
	Seattle, WA (2)(3)
	12780 and 12790 El Camino Real, San Diego,		September 19, 2013	2		218,940		100.00%		126.4
	CA (4)
	Total (5)			4		539,338				$	296.4
	2012 Acquisitions
	4100-4700 Bohannon Dr., Menlo Park, CA		February 29, 2012	7		374,139		89.00%		$	162.5
	701 and 801 N. 34th St., Seattle, WA (6)		June 1, 2012	2		308,407		100.00%		105.4
	837 N. 34th St., Seattle, WA		June 1, 2012	1		111,580		100.00%		39.2
	10900 NE 4th St., Bellevue, WA (7)		July 24, 2012	1		416,755		87.30%		186.1
	6255 W. Sunset Blvd., Los Angeles, CA (8)		July 31, 2012	1		321,883		82.50%		78.8
	12233 Olympic Blvd., Los Angeles, CA (9)		October 5, 2012	1		151,029		96.40%		72.9
	599 N. Mathilda Ave., Sunnyvale, CA (10)		December 17, 2012	1		75,810		100.00%		29.1
	Total (11)			14		1,759,603				$	674
	________________________
	-1	Excludes acquisition-related costs and non-lease related accrued liabilities assumed. Includes assumed unpaid leasing commissions and tenant improvements.
	-2	We acquired these properties through a new special purpose entity wholly owned by the Finance Partnership.
	-3	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”).
	-4	As of December 31, 2013, these properties, together the “Heights of Del Mar” project, are 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.
	-5	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.
	-6	We acquired these properties through the acquisition of the ownership interest of the bankruptcy remote LLC that owned the properties. In connection with this acquisition we also acquired cash of approximately $4.0 million and other assets of approximately $0.2 million and we assumed current liabilities of approximately $0.6 million and secured debt with an outstanding principal balance of $34.0 million and a premium of $1.7 million as a result of recording the debt at fair value at the acquisition date (see Note 7 “Secured and Unsecured Debt of the Operating Partnership”).
	-7	In connection with this acquisition, we assumed secured debt with an outstanding principal balance of $83.6 million and a premium of $1.4 million as a result of recording this debt at fair value on the acquisition date. In January 2013, we repaid this loan prior to the stated maturity (see Note 7 “Secured and Unsecured Debt of the Operating Partnership” for additional information).
	-8	As part of the consideration for this transaction, we issued 118,372 common units of the Operating Partnership valued at $47.34 per unit, which was the Company’s closing stock price on the NYSE on the acquisition date. In connection with this acquisition we also assumed secured debt with an outstanding principal balance of $53.9 million and a premium of $3.1 million as a result of recording this debt at fair value on the acquisition date (see Note 7 “Secured and Unsecured Debt of the Operating Partnership”). We also assumed $4.7 million of accrued liabilities in connection with this acquisition that are not included in the purchase price above.
	-9	In connection with this acquisition, we assumed secured debt with an outstanding principal balance of $40.7 million and a premium of $2.7 million as a result of recording this debt at fair value on the acquisition date (see Note 7 “Secured and Unsecured Debt of the Operating Partnership”).
	-10	This operating property was acquired in connection with the purchase of the 555 N. Mathilda Ave. development property discussed in further detail in the “Development and Redevelopment Project Sites” section of this footnote, for a total purchase price of $137.6 million.
	-11	The results of operations for the properties acquired during 2012 contributed $18.9 million and $3.4 million to revenues and net income from continuing operations, respectively, for the year ended December 31, 2012.
Fair values of assets acquired and liabilities assumed	'
	The following table summarizes the estimated fair values of the assets acquired and liabilities assumed at the respective acquisition dates for our 2013 acquisitions:
	2013 Acquisitions	Total 2013
		Acquisitions (1)
		(in thousands)
	Assets
	Land and improvements	$	53,790
	Buildings and improvements (2)	218,211
	Undeveloped land and construction in progress (3)	9,360
	Deferred leasing costs and acquisition-related intangible assets (4)	30,789
	Total assets acquired	312,150
	Liabilities
	Deferred revenue and acquisition-related intangible liabilities (5)	4,190
	Secured debt (6)	95,496
	Accounts payable, accrued expenses and other liabilities	422
	Total liabilities assumed	100,108
	Net assets and liabilities acquired (7)	$	212,042
	_______________
	-1	The purchase price of 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, 2013.
	-2	Represents buildings, building improvements and tenant improvements.
	-3	In connection with one of the 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 $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).
	-5	Represents below-market leases (approximately $4.2 million with a weighted average amortization period of 7.7 years).
	-6	Represents the mortgage loan, which includes an unamortized premium 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.
	The following table summarizes the estimated fair values of the assets acquired and liabilities assumed at the respective acquisition dates for our 2012 acquisitions:
	2012 Acquisitions	4100-4700 Bohannon Dr.,			10900			599 N. Mathilda, Sunnyvale, CA				All Other		Total 2012
		Menlo Park, CA			NE 4th St.,							Acquisitions (1)		Acquisitions
					Bellevue, WA
		(in thousands)
	Assets
	Land and improvements (2)	$	38,810		$	25,080		$	13,538			$	40,211	$	117,639
	Buildings and improvements (3)	124,617			150,877			12,558				257,458		545,510
	Cash and cash equivalents	—			—			—				3,973		3,973
	Restricted cash	—			—			—				5,329		5,329
	Deferred leasing costs and acquisition-related	9,470			16,469			3,004				30,570		59,513
	intangible assets (4)
	Prepaid expenses and other assets	—			—			—				184		184
	Total assets acquired	172,897			192,426			29,100				337,725		732,148
	Liabilities
	Deferred revenue and acquisition-related	10,380			4,940			—				19,700		35,020
	intangible liabilities (5)
	Secured debt, net (6)	—			84,984			—				136,048		221,032
	Accounts payable, accrued expenses and other	137			627			—				5,584		6,348
	liabilities
	Total liabilities assumed	10,517			90,551			—				161,332		262,400
	Net assets and liabilities acquired (7)	$	162,380		$	101,875		$	29,100			$	176,393	$	469,748
	________________________
	-1	The purchase price of all other acquisitions during the year ended December 31, 2012 were individually less than 5% and in aggregate less than 10% of the Company’s total assets as of 2012.
	-2	In connection with the acquisitions of 701, 801, and 837 N. 34th St., Seattle, WA, we assumed the lessee obligations under a ground lease with an initial expiration in December 2041. The ground lease obligation contains three 10-year extension options and one 45-year extension option. In connection with the acquisitions of 601 108th Ave., N.E., Bellevue, WA, we assumed the lessee obligation under a ground lease that is scheduled to expire in November 2093 (see Note 15 “Commitments and Contingencies” for additional information pertaining to these ground leases).
	-3	Represents buildings, building improvements and tenant improvements.
	-4	Represents in-place leases (approximately $43.4 million with a weighted average amortization period of 4.7 years), above-market leases (approximately $1.4 million with a weighted average amortization period of 3.8 years), leasing commissions (approximately $14.2 million with a weighted average amortization period of 3.4 years), and a below-market ground lease obligation (approximately $0.5 million with a weighted average amortization period of 59.6 years).
	-5	Represents below-market leases (approximately $33.9 million with a weighted average amortization period of 6.5 years) and an above-market ground lease obligation (approximately $1.1 million with a weighted average amortization period of 29.6 years).
	-6	Represents the fair value of the mortgage loans assumed, which includes an aggregate unamortized premium balance of approximately $8.9 million at the dates of acquisition (see Note 7 “Secured and Unsecured Debt of the Operating Partnership”).
	-7	Reflects the purchase price plus cash and restricted cash received, net of assumed secured debt, lease-related obligations and other accrued liabilities.
Development and Redevelopment Project Acquisitions [Member]	'
Business Acquisition [Line Items]	'
Acquired operating properties from unrelated third parties	'
	During the year ended December 31, 2012, we acquired six development and redevelopment project sites, respectively from unrelated third parties. Unless otherwise noted, we funded these acquisitions with proceeds from the Company’s public offering of common stock (see Note 10 “Stockholders’ Equity of the Company”), disposition proceeds (see Note 17 “Discontinued Operations”) and/or borrowings under the unsecured line of credit (see Note 7 “Secured and Unsecured Debt of the Operating Partnership” for additional information).
	Project		Date of Acquisition	Type		Purchase Price
						(in millions) (1)
	2012 Acquisitions
	690 E. Middlefield Road, Mountain View, CA (2)(3)		9-May-12	Development		$	74.5
	333 Brannan Street, San Francisco, CA		20-Jul-12	Development		18.5
	Columbia Square, Los Angeles, CA (4)		28-Sep-12	Development and Redevelopment		65
	350 Mission Street, San Francisco, CA		23-Oct-12	Development		52
	331 Fairchild Drive, Mountain View, CA (2)(5)(6)		4-Dec-12	Development		21.8
	555 N. Mathilda Avenue, Sunnyvale, CA (2)(7)(8)		17-Dec-12	Development		108.5
	Total					$	340.3
	________________________
	-1	Excludes leasing costs and/or other accrued liabilities assumed in connection with the acquisitions.
	-2	Acquisition of these development sites are accounted for as business combinations because the projects were 100% pre-leased upon acquisition.
	-3	The total purchase price for this acquisition was comprised of a cash purchase price of $74.5 million plus $9.5 million of assumed leasing commissions and other accrued liabilities.
	-4	In connection with this acquisition we also assumed $1.1 million of other accrued liabilities which are not included in the purchase price above.
	-5	The total purchase price for this acquisition was comprised of a cash purchase price of $18.9 million plus $2.9 million of development costs reimbursed to the seller. In addition, we assumed $2.1 million of leasing commissions and other accrued liabilities which are not included in the purchase price above.
	-6	In October, we stabilized the 331 Fairchild Drive development project in Mountain View, California.
	-7	As of December 31, 2012, this property was temporarily being held in a separate VIE to facilitate a potential Section 1031 Exchange (see Note 2 “Basis of Presentation and Significant Accounting Policies”). The VIE was terminated in upon exchange in 2013.
	-8	This development site was acquired with the purchase of the 555 Mathilda operating property for a total cash purchase price of $137.6 million plus $2.4 million of development costs reimbursed to the seller. In addition, we assumed $11.8 million of other accrued liabilities which are not included in the purchase price above.
Fair values of assets acquired and liabilities assumed	'
	The related assets and liabilities of the acquired projects 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 2012 development and redevelopment acquisitions:
	2012 Acquisitions	555 N. Mathilda, Sunnyvale, CA			All Other Acquisitions			Total
		(in thousands)
	Assets
	Undeveloped land and construction in progress	$	120,243		$	244,584		$	364,827
	Restricted cash (1)	11,250			—			11,250
	Prepaid expenses and other assets	—			1,300			1,300
	Total assets acquired	131,493			245,884			377,377
	Liabilities
	Accounts payable, accrued expenses and other liabilities (1)	23,071			9,752			32,823
	Total liabilities assumed	23,071			9,752			32,823
	Net assets and liabilities acquired (2)	$	108,422		$	236,132		$	344,554
	________________________
	-1	In connection with this acquisition, restricted cash is being held in escrow to pay for potential environmental costs and contingent development costs. Any unused amounts will be released to the seller.
	-2	Reflects the purchase price including assumed leasing commissions, net of assumed accrued liabilities.
	The following table summarizes the allocation of the assets acquired and liabilities assumed at the acquisition date (in thousands):
		Phase I			Phase II			Total Crossing/900
	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, 2013
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, 2013 and 2012:
		December 31, 2013			December 31, 2012
		(in thousands)
	Deferred Leasing Costs and Acquisition-related Intangible Assets, net:
	Deferred leasing costs	$	178,720		$	168,087
	Accumulated amortization	(63,246		)	(61,443		)
	Deferred leasing costs, net	115,474			106,644
	Above-market operating leases	27,635			27,977
	Accumulated amortization	(14,283		)	(12,180		)
	Above-market operating leases, net	13,352			15,797
	In-place leases	100,318			101,061
	Accumulated amortization	(42,999		)	(34,019		)
	In-place leases, net	57,319			67,042
	Below-market ground lease obligation	490			690
	Accumulated amortization	(13		)	(205		)
	Below-market ground lease obligation, net	477			485
	Total deferred leasing costs and acquisition-related intangible assets, net	$	186,622		$	189,968
	Acquisition-related Intangible Liabilities, net: (1)
	Below-market operating leases	$	69,385		$	70,486
	Accumulated amortization	(25,706		)	(17,555		)
	Below-market operating leases, net	43,679			52,931
	Above-market ground lease obligation	6,320			6,320
	Accumulated amortization	(223		)	(122		)
	Above-market ground lease obligation, net	6,097			6,198
	Total acquisition-related intangible liabilities, net	$	49,776		$	59,129
	_______________
	-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, 2013, 2012 and 2011:
		Year Ended December 31,
		2013			2012			2011
		(in thousands)
	Deferred leasing costs (1)	$	25,902		$	20,804		$	16,905
	Above-market operating leases (2)	5,664			5,695			5,946
	In-place leases (1)	29,363			21,976			12,575
	Below-market ground lease obligation (3)	8			205			—
	Below-market operating leases (4)	(13,441		)	(12,393		)	(4,890		)
	Above-market ground lease obligation (5)	(101		)	(85		)	(37		)
	Total	$	47,395		$	36,202		$	30,499
	_______________
	-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, 2013 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)
	2014	$	25,454		$	4,946		$	19,168		$	8	$	(11,891	)	$	(101	)
	2015	21,293			2,991			12,584			8		(9,385		)	(101		)
	2016	18,435			1,963			9,361			8		(7,195		)	(101		)
	2017	15,872			1,646			7,659			8		(6,127		)	(101		)
	2018	12,255			1,045			4,574			8		(4,525		)	(101		)
	Thereafter	22,165			761			3,973			437		(4,556		)	(5,592		)
	Total	$	115,474		$	13,352		$	57,319		$	477	$	(43,679	)	$	(6,097	)
	_______________
	-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, 2013
Receivables [Abstract]	'
Current Receivables, net	'
	The balance consisted of the following as of December 31, 2013 and 2012:
		December 31, 2013 (1)			December 31, 2012
		(in thousands)
	Current receivables	$	12,866		$	11,801
	Allowance for uncollectible tenant receivables	(2,123		)	(2,581		)
	Current receivables, net	$	10,743		$	9,220
	_______________
	-1	Excludes current receivables, net related to properties held for sale at December 31, 2013
Deferred Rent Receivables, net	'
	Deferred rent receivables, net consisted of the following as of December 31, 2013 and 2012:
		December 31, 2013 (1)			December 31, 2012
		(in thousands)
	Deferred rent receivables	$	129,198		$	118,025
	Allowance for deferred rent receivables	(2,075		)	(2,607		)
	Deferred rent receivables, net	$	127,123		$	115,418
	_______________
	-1	Excludes deferred rent receivables, net related to properties held for sale at December 31, 2013.

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, 2013
Debt Instrument [Line Items]	'
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, 2013:
	Year	(in thousands)
	2014	$	265,346
	2015	395,104
	2016	249,431
	2017	116,748
	2018	451,728
	Thereafter	718,011
	Total (1)	$	2,196,368
	________________________
	-1	Includes gross principal balance of outstanding debt before impact of net unamortized premiums totaling approximately $8.6 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, 2013, 2012 and 2011. 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. (See Note 17 “Discontinued Operations” for interest expense reported in discontinued operations).
		Year Ended December 31,
		2013			2012				2011
		(in thousands)
	Gross interest expense	$	111,238		$	98,906			$	94,915
	Capitalized interest	(35,368		)	(19,792		)		(9,130		)
	Interest expense	$	75,870		$	79,114			$	85,785
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, 2013 and 2012:
							December 31,
	Type of Debt	Annual Stated Interest Rate (1)		GAAP	Maturity Date		2013 (3)				2012 (3)
				Effective Rate (1)(2)
							(in thousands)
	Mortgage note payable	4.27%		4.27%	Feb-18		$	133,117			$	135,000
	Mortgage note payable (4)	4.48%		4.48%	Jul-27		97,000				97,000
	Mortgage note payable (5)	6.05%		3.50%	Jun-19		92,502				—
	Mortgage note payable (6)	6.37%		3.55%	Apr-13		—				83,116
	Mortgage note payable	6.51%		6.51%	Feb-17		67,663				68,615
	Mortgage note payable (7)	5.23%		3.50%	Jan-16		54,570				56,302
	Mortgage note payable (8)	5.57%		3.25%	Feb-16		41,654				43,016
	Mortgage note payable (9)	5.09%		3.50%	Aug-15		34,845				35,379
	Mortgage note payable	4.94%		4.00%	Apr-15		27,641				28,941
	Mortgage note payable	7.15%		7.15%	May-17		8,972				11,210
	Other	Various		Various	Various		2,470				2,517
	Total						$	560,434			$	561,096
	______________
	-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 $14.6 million and $7.2 million as of December 31, 2013 and 2012, respectively.
	-4	In June 2012, we obtained a mortgage loan that is secured by one office property located in Irvine, California and two office properties located in Los Angeles, California and requires monthly principal and interest payments based on a 30 year amortization period with an initial three years of interest only payments.
	-5	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 assumed mortgage had a principal balance of $83.9 million at the acquisition date and was recorded at fair value on the date of the acquisition resulting in a premium of approximately $11.6 million. The loan requires monthly principal and interest payments based on a 6.4 year amortization period.
	-6	In January 2013, we repaid this loan prior to the stated maturity date.
	-7	In July 2012, in connection with the acquisition of one office building in Los Angeles, California, we assumed a mortgage loan that is secured by the project. The assumed mortgage had a principal balance of $53.9 million at the acquisition date and was recorded at fair value on the date of the acquisition resulting in a premium of approximately $3.1 million. The loan requires monthly principal and interest payments based on a 30 year amortization period.
	-8	In October 2012, in connection with the acquisition of one office building in Los Angeles, California, we assumed a mortgage loan that is secured by the project. The assumed mortgage loan had a principal balance of $40.7 million at the acquisition date and was recorded at fair value at the date of acquisition resulting in an initial premium of approximately $2.7 million.
	-9	In June 2012, in connection with the acquisition of two office buildings in Seattle, Washington, we assumed a mortgage loan that is secured by the project. The assumed mortgage loan had a principal balance of $34.0 million at the acquisition date and was recorded at fair value at the date of acquisition resulting in an initial premium of approximately $1.7 million.
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”) outstanding as of December 31, 2013 and 2012.
	4.25% Exchangeable Notes	December 31,
		2013			2012
		(in thousands)
	Principal amount	$	172,500		$	172,500
	Unamortized discount	(4,128		)	(8,556		)
	Net carrying amount of liability component	$	168,372		$	163,944
	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 is payable semi-annually in arrears on May 15th and November 15th of each year.
	-2	The rate at which we record interest expense for financial reporting purposes, which reflects the amortization of the discounts on the 4.25% Exchangeable Notes. This rate represents our conventional debt borrowing rate at the date of issuance.
	-3	The exchange rate, exchange price, and the number of shares to be delivered upon conversion are subject to adjustment under certain circumstances including increases in our common dividends.
Exchangeable Notes If-Converted Value	'
	For the years ended December 31, 2013 and 2012, the per share average trading price of the Company’s common stock on the NYSE was higher than the $35.93 exchange price for the 4.25% Exchangeable Notes, as presented below:
		Year Ended December 31,
		2013		2012
	Per share average trading price of the Company’s common stock	$52.12		$45.72
Approximate fair value of shares upon conversion	'
	The approximate fair value of the shares exchangeable at December 31, 2013 and 2012, using the per share average trading price presented in the table above, would have been as follows:
		Year Ended December 31,
		2013			2012
		(in thousands)
	Approximate fair value of shares upon conversion	$	247,000		$	221,200
	Principal amount of the 4.25% Exchangeable Notes	172,500			172,500
	Approximate fair value in excess amount of principal amount	$	74,500		$	48,700
	The following table summarizes the total interest expense attributable to the 4.25% Exchangeable Notes and attributable to the 3.25% Exchangeable Notes (which were repaid upon maturity in April 2012), in each case based on the respective effective interest rates, before the effect of capitalized interest, for the years ended December 31, 2013, 2012 and 2011:
		Year Ended December 31,
		2013			2012				2011
		(in thousands)
	Contractual interest payments (1)	$	7,331		$	8,721			$	12,141
	Amortization of discount (1)	4,427			5,052				6,928
	Interest expense attributable to the Exchangeable Notes (1)	$	11,758		$	13,773			$	19,069
	_______________
	-1	The Company repaid the 3.25% Exchangeable Notes in April 2012. Interest payments and discount amortization for the year ended December 31, 2013 are solely attributable to the 4.25% Exchangeable Notes.
Capped call Transactions	'
	The table below summarizes our capped call option positions for the 4.25% Exchangeable Notes for both December 31, 2013 and December 31, 2012:
		4.25% Exchangeable Notes (1)
	Referenced shares of common stock	4,800,796
	Exchange price including effect of capped calls	$42.81
	________________________
	-1	The capped calls mitigate the dilutive impact to us of the potential exchange of all of the 4.25% Exchangeable Notes into shares of common stock.
Unsecured Senior Notes [Member]	'
Debt Instrument [Line Items]	'
Debt balance and significant terms	'
	The following table summarizes the balance and significant terms of the registered unsecured senior notes issued by the Operating Partnership as of December 31, 2013 and 2012:
									Principal Amount
									as of December 31,
		Issuance date		Maturity date	Stated		Effective interest rate (1)		2013				2012
					coupon rate
									(in thousands)
	3.800% Unsecured Senior Notes (2)	Jan-13		Jan-23	3.80%		3.80%		$	300,000			$	—
	Unamortized discount								(90		)		—
	Net carrying amount								$	299,910			$	—
	4.800% Unsecured Senior Notes (3)	Jul-11		Jul-18	4.80%		4.83%		$	325,000			$	325,000
	Unamortized discount								(339		)		(413		)
	Net carrying amount								$	324,661			$	324,587
	6.625% Unsecured Senior Notes (4)	May-10		Jun-20	6.63%		6.74%		$	250,000			$	250,000
	Unamortized discount								(1,367		)		(1,580		)
	Net carrying amount								$	248,633			$	248,420
	5.000% Unsecured Senior Notes (5)	Nov-10		Nov-15	5.00%		5.01%		$	325,000			$	325,000
	Unamortized discount								(73		)		(112		)
	Net carrying amount								$	324,927			$	324,888
	________________________
	-1	This represents the rate at which interest expense is recorded for financial reporting purposes, which reflects the amortization of initial issuance discounts, excluding debt issuance costs.
	-2	Interest on the 3.800% unsecured senior notes is payable semi-annually in arrears on January 15th and July 15th of each year.
	-3	Interest on the 4.800% unsecured senior notes is payable semi-annually in arrears on January 15th and July 15th of each year.
	-4	Interest on the 6.625% unsecured senior notes is payable semi-annually in arrears on June 1st and December 1st of each year.
	-5	Interest on the 5.000% unsecured senior notes is payable semi-annually in arrears on May 3rd and November 3rd of each year.
Revolving Credit Facility [Member]	'
Debt Instrument [Line Items]	'
Terms of the Credit Facility	'
	The following table summarizes the balance and terms of our revolving credit facility as of December 31, 2013 and 2012, respectively:
		December 31, 2013			December 31, 2012
		(in thousands)
	Outstanding borrowings	$	45,000		$	185,000
	Remaining borrowing capacity	455,000			315,000
	Total borrowing capacity (1)	$	500,000		$	500,000
	Interest rate (2)	1.62		%	1.66		%
	Facility fee-annual rate (3)	0.30%
	Maturity date (4)	Apr-17
	_______________
	-1	We may elect to borrow, subject to bank approval, up to an additional $200.0 million under an accordion feature under the terms of the revolving credit facility.
	-2	The revolving credit facility interest rate was calculated based on an annual rate of LIBOR plus 1.450% as of both December 31, 2013 and December 31, 2012.
	-3	The facility fee is paid on a quarterly basis and is calculated based on the total borrowing capacity. In addition to the facility fee, we also incurred debt origination and legal costs of approximately $5.0 million when we entered into the revolving credit facility in 2010, an additional $3.3 million when we amended the terms of the revolving credit facility in June 2011 and an additional $1.9 million when we amended the terms of the revolving credit facility in November 2012. The unamortized balance of these costs is amortized through the extended maturity date of the revolving credit facility.
	-4	Under the terms of the revolving credit facility, we may exercise an option to extend the maturity date by one year.

Deferred_Revenue_and_Acquisiti1

Deferred Revenue and Acquisition Related Liabilities, net (Tables)	12 Months Ended
	Dec. 31, 2013
Deferred Revenue Disclosure [Abstract]	'
Deferred Revenue and Acquisition-related Liabilities	'
	Deferred revenue and acquisition-related liabilities, net consisted of the following at December 31, 2013 and 2012:
		December 31,
		2013		2012
		(in thousands)
	Deferred revenue related to tenant-funded tenant improvements (1)	$	48,341	$	56,461
	Other deferred revenue	3,169		2,314
	Acquisition-related intangible liabilities, net (2)	49,776		59,129
	Total	$	101,286	$	117,904
	________________________
	-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 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	'
	The following is the estimated amortization of deferred revenue related to tenant-funded tenant improvements as of December 31, 2013 for the next five years and thereafter:
	Year Ending	(in thousands)
	2014	$	8,686
	2015	7,620
	2016	7,165
	2017	6,070
	2018	4,479
	Thereafter	14,321
	Total	$	48,341

Stockholders_Equity_of_the_Com1

Stockholders' Equity of the Company Stockholders' Equity of the Company (Tables)	12 Months Ended
	Dec. 31, 2013
Equity [Abstract]	'
Schedule of Common Stock Sales Under the At-the-Market Offering	'
	The following table sets for information regarding sales of our common stock under our at-the-market offering program for the years ended December 31, 2013, 2012 and 2011:
		Year Ended December 31,
		2013			2012		2011
		(in millions, except share data)
	Share of common stock sold during the period	1,040,838			787,118		355,305
	Aggregate gross proceeds	$	55.3		$	37	$	13
	Aggregate net proceeds after sales agent compensation	$	54.4		$	36.3	$	12.8
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, 2013 and 2012:
		December 31,
		2013			2012
		(in thousands)
	Dividends and Distributions payable to:
	Common stockholders	$	28,754		$	26,224
	Noncontrolling common unitholders of the Operating Partnership	632			639
	RSU holders (1)	405			367
	Total accrued dividends and distribution to common stockholders and noncontrolling unitholders	29,791			27,230
	Preferred stockholders	1,699			1,694
	Total accrued dividends and distributions	$	31,490		$	28,924
	______________________
	-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,
		2013		2012
	Outstanding Shares and Units:
	Common stock (1)	82,153,944		74,926,981
	Noncontrolling common units	1,805,200		1,826,503
	RSUs (2)	1,158,407		1,048,863
	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 143,022 market measure-based RSUs since not all the necessary performance conditions have been met as of December 31, 2013.

Preferred_and_Common_Units_of_1

Preferred and Common Units of the Operating Partnership (Tables)	12 Months Ended
	Dec. 31, 2013
Class of Stock [Line Items]	'
Schedule of Common Stock Sales Under the At-the-Market Offering	'
	The following table sets for information regarding sales of our common stock under our at-the-market offering program for the years ended December 31, 2013, 2012 and 2011:
		Year Ended December 31,
		2013			2012		2011
		(in millions, except share data)
	Share of common stock sold during the period	1,040,838			787,118		355,305
	Aggregate gross proceeds	$	55.3		$	37	$	13
	Aggregate net proceeds after sales agent compensation	$	54.4		$	36.3	$	12.8
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, 2013 and 2012:
		December 31,
		2013			2012
		(in thousands)
	Dividends and Distributions payable to:
	Common stockholders	$	28,754		$	26,224
	Noncontrolling common unitholders of the Operating Partnership	632			639
	RSU holders (1)	405			367
	Total accrued dividends and distribution to common stockholders and noncontrolling unitholders	29,791			27,230
	Preferred stockholders	1,699			1,694
	Total accrued dividends and distributions	$	31,490		$	28,924
	______________________
	-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,
		2013		2012
	Outstanding Shares and Units:
	Common stock (1)	82,153,944		74,926,981
	Noncontrolling common units	1,805,200		1,826,503
	RSUs (2)	1,158,407		1,048,863
	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 143,022 market measure-based RSUs since not all the necessary performance conditions have been met as of December 31, 2013.
Kilroy Realty, L.P. [Member]	'
Class of Stock [Line Items]	'
Schedule of Common Stock Sales Under the At-the-Market Offering	'
	The net offering proceeds and the shares of common stock contributed by the Company to the Operating Partnership in exchange for common units for the years ended December 31, 2013, 2012 and 2011 are as follows:
		Year Ended December 31,
		2013			2012		2011
		(in millions, except share and per share data)
	Shares of common stock contributed by the Company	1,040,838			787,118		355,305
	Common units exchanged for share of common stock by the Company	1,040,838			787,118		355,305
	Aggregate gross proceeds	$	55.3		$	37	$	13
	Aggregate net proceeds after sales agent compensation	$	54.4		$	36.3	$	12.8
	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, 2013		31-Dec-12
	Company owned common units in the Operating Partnership	82,153,944		74,926,981
	Company owned general partnership interest	97.8	%	97.6	%
	Noncontrolling common units of the Operating Partnership	1,805,200		1,826,503
	Ownership interest of noncontrolling interest	2.2	%	2.4	%
Schedule of Accrued Dividends and Distributions	'
	The following tables summarize accrued distributions for the noted common and preferred units as of December 31, 2013 and 2012:
		December 31, 2013			31-Dec-12
		(in thousands)
	Distributions payable to:
	General partner	$	28,754		$	26,224
	Common limited partners	632			639
	RSU holders (1)	405			367
	Total accrued distributions to common unitholders	29,791			27,230
	Preferred unitholders	1,699			1,694
	Total accrued distributions	$	31,490		$	28,924
	______________________
	-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, 2013		31-Dec-12
	Outstanding Units:
	Common units held by the general partner	82,153,944		74,926,981
	Common units held by the limited partners	1,805,200		1,826,503
	RSUs (1)	1,158,407		1,048,863
	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 143,022 market measure-based RSUs since not all the necessary performance conditions have been met as of December 31, 2013.

ShareBased_Compensation_Tables

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Schedule of Restricted Stock Units Valuation Assumptions	'
		March 2012 Market Measure-based RSU Grant
	Grant date fair value per share	$41.20
	Expected share price volatility	31.00%
	Risk-free interest rate	1.60%
	Dividend yield	3.80%
	Expected life	7 years
		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, 2013 through December 31, 2013 is presented below:
		Non-Vested		Weighted-Average
		Restricted Stock		Grant Date
				Fair Value
				Per Share
	Outstanding at January 1, 2013	95,241		$	40.42
	Granted	—		—
	Vested (1)	(47,291	)	39.12
	Outstanding as of December 31, 2013	47,950		$	41.71
	_______________
	-1	The total shares vested include 20,880 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, 2013, 2012 and 2011 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
	2013	—		$	—	(47,291	)	$	2,290
	2012	62,137		41.84		(50,862	)	2,110
	2011	68,727		37.83		(34,793	)	1,334
	_______________
	-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 from January 1, 2013 through December 31, 2013 is presented below:
		Number of Options		Exercise Price		Remaining Contractual Term (years)
	Outstanding at January 1, 2013	1,540,000		$	42.61
	Granted	—		—
	Exercised	(3,000	)	42.61
	Forfeited	(12,000	)	42.61
	Outstanding at December 31, 2013 (1)(2)	1,525,000		$	42.61	8.2
	_______________
	-1	As of December 31, 2013, 305,000 of the outstanding stock options were exercisable.
	-2	The total intrinsic value of options outstanding at December 31, 2013 was $11.5 million.
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 from January 1, 2013 through December 31, 2013 is presented below:
		Nonvested RSUs				Vested RSUs		Total RSUs
		Amount		Weighted-Average
				Grant Date
				Fair Value
				Per Share
	Outstanding at January 1, 2013	88,491		$	41.2	—		88,491
	Granted	9,542		44.55		—		9,542
	Vested	(16,338	)	41.53		16,338		—
	Settled (1)	—				(16,338	)	(16,338	)
	Issuance of dividend equivalents	—				—		—
	Modified from time based (2)	61,327		53.05		—		61,327
	Canceled					—		—
	Outstanding as of December 31, 2013	143,022		$	46.47	—		143,022
	_______________
	-1	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.
	-2	On April 4, 2013 the terms of time-based RSU’s granted to certain officers of the Company in January were modified to include market-measure and performance-based vesting requirements.
	A summary of our market-measure based RSU activity for years ended December 31, 2013 and 2012 is presented below:
		RSUs Granted				RSUs Vested
	Years ended December 31,	Non-Vested		Weighted-Average Grant Date		Vested RSUs		Total Vest-Date Fair Value
		RSUs Issued		Fair Value				(in thousands)
				Per Share
	2013	9,542		$	44.55	(16,338	)	$	811
	2012	103,239		41.2		(14,748	)	695
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, 2013 through December 31, 2013 is presented below:
		Nonvested RSUs				Vested RSUs		Total RSUs
		Amount		Weighted-Average
				Grant Date
				Fair Value
				Per Share
	Outstanding at January 1, 2013	279,102		$	41.3	769,761		1,048,863
	Granted, net of forfeitures	173,758		49.45		—		173,758
	Vested	(89,873	)	40.33		89,873		—
	Settled (1)					(26,886	)	(26,886	)
	Issuance of dividend equivalents (2)					27,593		27,593
	Modified to market-measure based (3)	(61,327	)	53.05		—		(61,327	)
	Canceled (1)(4)					(3,594	)	(3,594	)
	Outstanding as of December 31, 2013	301,660		$	44.74	856,747		1,158,407
	_______________
	-1	Represents vested RSUs that were settled in cash or shares of the Company’s common stock. Total shares settled include 13,490 shares that were tendered in accordance with the terms of the 2006 Plan to satisfy minimum statutory tax withholding requirements related to the RSUs settled. We accept the return of RSUs, at the current quoted closing share price of the Company’s common stock to satisfy tax obligations.
	-2	RSUs issued as dividend equivalents are vested upon issuance.
	-3	On April 4, 2013, the terms of time-based RSUs granted to certain officers of the Company in January were modified to include market-measure based vesting requirements.
	-4	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.
	A summary of our time-based RSU activity for the years ended December 31, 2013, 2012 and 2011 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
	2013	173,758		$	49.45	(89,873	)	$	4,495
	2012	204,829		44.34		(73,688	)	3,118
	2011	107,673		37.94		(85,466	)	3,273
	_______________
	-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, 2013
Leases [Abstract]	'
Future contractual minimum rent under operating lease	'
	Future contractual minimum rent under operating leases as of December 31, 2013 for future periods is summarized as follows:
	Year Ending	(in thousands)
	2014	$	387,188
	2015	371,948
	2016	351,540
	2017	309,221
	2018	252,933
	Thereafter	725,964
	Total	$	2,398,794
	The minimum commitment under our ground leases as of December 31, 2013 for five years and thereafter was as follows:
	Year Ending	(in thousands)
	2014	$	3,095
	2015	3,095
	2016	3,095
	2017	3,095
	2018	3,095
	Thereafter	156,912
	Total (1)(2)(3)(4)	$	172,387
	________________________
	-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, 2013.
	-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, 2013.
	-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, 2013.

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2013
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, 2013 for future periods is summarized as follows:
	Year Ending	(in thousands)
	2014	$	387,188
	2015	371,948
	2016	351,540
	2017	309,221
	2018	252,933
	Thereafter	725,964
	Total	$	2,398,794
	The minimum commitment under our ground leases as of December 31, 2013 for five years and thereafter was as follows:
	Year Ending	(in thousands)
	2014	$	3,095
	2015	3,095
	2016	3,095
	2017	3,095
	2018	3,095
	Thereafter	156,912
	Total (1)(2)(3)(4)	$	172,387
	________________________
	-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, 2013.
	-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, 2013.
	-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, 2013.

Fair_Value_Measurements_and_Di1

Fair Value Measurements and Disclosures (Tables)	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Fair value of the company's marketable securities	'
	The following table sets forth the fair value of our marketable securities as of December 31, 2013 and 2012:
		Fair Value (Level 1) (1)
		2013		2012
	Description	(in thousands)
	Marketable securities (2)	$	10,008	$	7,435
	_______________
	-1	Based on quoted prices in active markets for identical securities.
	-2	The marketable securities are held in a limited rabbi trust.
Fair Value Adjustment Of Marketable Securities And Deferred Compensation Plan Liability [Table Text Block]	'
	The following table sets forth the net gain (loss) on marketable securities recorded during the years ended December 31, 2013, 2012 and 2011:
		December 31,
		2013		2012		2011
	Description	(in thousands)
	Net gain (loss) on marketable securities	$	1,489	$	723	$	(153	)
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, 2013 and 2012:
		December 31,
		2013				2012
		Carrying Value		Fair Value		Carrying Value			Fair Value
		(in thousands)
	Liabilities
	Secured debt (1)	$	560,434	$	568,760	$	561,096		$	591,993
	Exchangeable senior notes, net (1)	168,372		178,190		163,944			181,223
	Unsecured debt, net (2)	1,431,132		1,523,052		1,130,895			1,254,047
	Unsecured line of credit (1)	45,000		45,012		185,000			185,049
	_______________
	-1	Fair value calculated using Level II inputs which are based on model-derived valuations in which significant inputs and significant value drivers are observable in active markets.
	-2	Fair value calculated 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 $873.5 million and $929.3 million, respectively, as of December 31, 2013. The carrying value and fair value of the Level I instruments at December 31, 2012, was $573.0 million and $653.0 million, respectively. The carrying value and fair value of the Level II instruments was $557.7 million and $593.7 million, respectively, as of December 31, 2013. The carrying value and fair value of the Level II instruments at December 31, 2012, was $558.0 million and$601.0 million, respectively.

Discontinued_Operations_Tables

Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2013
Discontinued Operations and Disposal Groups [Abstract]	'
Schedule of Assets and Liabilities of Properties Held for Sale	'
	As of December 31, 2013, the following properties were classified as held for sale:
	Location		City/Submarket		Property Type		Number of Buildings			Rentable Square Feet
										(unaudited)
	San Diego Properties, San Diego, CA (1)		I-15 Corridor/Sorrento Mesa		Office		12			1,049,035
	________________________
	-1	The San Diego Properties included the following: 10020 Pacific Mesa Boulevard, 6055 Lusk Avenue, 5010 and 5005 Wateridge Vista Drive, 15435 and 15445 Innovation Drive, and 15051, 15073, 15231, 15253, 15333 and 15378 Avenue of Science.
	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
Schedule of Properties Sold	'
	The following table summarizes the properties sold during the years ended December 31, 2013, 2012 and 2011:
	Location		Property Type		Month of Disposition		Number of Buildings		Rentable			Sales Price
									Square Feet (unaudited)			(in millions) (1)
	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 (2)		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
	2011 Dispositions
	10350 Barnes Canyon and 10120 Pacific Heights Drive,		Office		September		2		90,558			$	23.9
	San Diego, CA
	2031 E. Mariposa Avenue, Los Angeles, CA		Industrial		December		1		192,053			42.2
	Total 2011 dispositions						3		282,611			$	66.1
	__________________
	-1	Represents gross sales price before the impact of broker commissions and closing costs.
	-2	The industrial portfolio was sold in two tranches in November and December 2012 to two separate third party buyers.
Revenue and Expense Components Comprising Income from Discontinued Operations	'
	The following table summarizes the revenue and expense components that comprise income from discontinued operations for the years ended December 31, 2013, 2012 and 2011:
		Year Ended December 31,
		2013				2012				2011
		(in thousands)
	Revenues:
	Rental income	$	24,694			$	42,240			$	59,266
	Tenant reimbursements	3,408				6,322				8,522
	Other property income	4,619				1,912				4,935
	Total revenues	32,721				50,474				72,723
	Expenses:
	Property expenses	4,716				7,724				9,832
	Real estate taxes	2,784				4,935				6,652
	Provision for bad debts	(8		)		(195		)		(51		)
	Ground leases	—				—				214
	Depreciation and amortization	8,753				16,649				20,966
	Interest expense (1)	—				—				3,624
	Total expenses	16,245				29,113				41,237
	Income from discontinued operations before net gain on dispositions of discontinued operations	16,476				21,361				31,486
	Net gain on dispositions of discontinued operations	12,252				259,245				51,587
	Total income from discontinued operations	$	28,728			$	280,606			$	83,073
	__________________
	-1	Interest expense relates to a $70.0 million mortgage loan that was secured by 13 of our industrial properties. The mortgage loan was repaid in October 2011 prior to maturity.

Net_Income_Available_to_Common2

Net Income Available to Common Stockholders Per Share of the Company (Tables)	12 Months Ended
	Dec. 31, 2013
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, 2013, 2012 and 2011:
		Year Ended December 31,
		2013			2012			2011
		(in thousands, except unit and per unit amounts)
	Numerator:
	Income (loss) from continuing operations	$	15,837		$	(3,505	)	$	(15,584	)
	(Income) loss from continuing operations attributable to noncontrolling common units of the Operating Partnership	(56		)	609			863
	Preferred distributions and dividends	(13,250		)	(21,088		)	(15,196		)
	Allocation to participating securities (1)	(1,689		)	(1,602		)	(1,309		)
	Numerator for basic and diluted income (loss) from continuing operations available to common stockholders	842			(25,586		)	(31,226		)
	Income from discontinued operations	28,728			280,606			83,073
	Income from discontinued operations attributable to noncontrolling common units of the Operating Partnership	(629		)	(6,796		)	(2,337		)
	Numerator for basic and diluted net income available to common stockholders	$	28,941		$	248,224		$	49,510
	Denominator:
	Basic weighted average vested shares outstanding	77,343,853			69,639,623			56,717,121
	Effect of dilutive securities – contingently issuable shares and stock options	1,765,025			—			—
	Diluted weighted average vested shares and common stock equivalents outstanding	79,108,878			69,639,623			56,717,121
	Basic earnings per share:
	Income (loss) from continuing operations available to common stockholders per share	$	0.01		$	(0.37	)	$	(0.55	)
	Income from discontinued operations per share of common stock	0.36			3.93			1.42
	Net income available to common stockholders per share	$	0.37		$	3.56		$	0.87
	Diluted earnings per share:
	Income (loss) from continuing operations available to common stockholders per share	$	0.01		$	(0.37	)	$	(0.55	)
	Income from discontinued operations per share of common stock	0.35			3.93			1.42
	Net income available to common stockholders per share	$	0.36		$	3.56		$	0.87
	________________________
	-1	Participating securities include nonvested shares, vested and non-vested time-based RSUs and vested market-measure RSUs.

Net_Income_Available_to_Common3

Net Income Available to Common Unitholders Per Unit of the Operating Partnership (Tables)	12 Months Ended
	Dec. 31, 2013
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, 2013, 2012 and 2011:
		Year Ended December 31,
		2013			2012			2011
		(in thousands, except unit and per unit amounts)
	Numerator:
	Income (loss) from continuing operations	$	15,837		$	(3,505	)	$	(15,584	)
	(Income) loss from continuing operations attributable to noncontrolling common units of the Operating Partnership	(56		)	609			863
	Preferred distributions and dividends	(13,250		)	(21,088		)	(15,196		)
	Allocation to participating securities (1)	(1,689		)	(1,602		)	(1,309		)
	Numerator for basic and diluted income (loss) from continuing operations available to common stockholders	842			(25,586		)	(31,226		)
	Income from discontinued operations	28,728			280,606			83,073
	Income from discontinued operations attributable to noncontrolling common units of the Operating Partnership	(629		)	(6,796		)	(2,337		)
	Numerator for basic and diluted net income available to common stockholders	$	28,941		$	248,224		$	49,510
	Denominator:
	Basic weighted average vested shares outstanding	77,343,853			69,639,623			56,717,121
	Effect of dilutive securities – contingently issuable shares and stock options	1,765,025			—			—
	Diluted weighted average vested shares and common stock equivalents outstanding	79,108,878			69,639,623			56,717,121
	Basic earnings per share:
	Income (loss) from continuing operations available to common stockholders per share	$	0.01		$	(0.37	)	$	(0.55	)
	Income from discontinued operations per share of common stock	0.36			3.93			1.42
	Net income available to common stockholders per share	$	0.37		$	3.56		$	0.87
	Diluted earnings per share:
	Income (loss) from continuing operations available to common stockholders per share	$	0.01		$	(0.37	)	$	(0.55	)
	Income from discontinued operations per share of common stock	0.35			3.93			1.42
	Net income available to common stockholders per share	$	0.36		$	3.56		$	0.87
	________________________
	-1	Participating securities include nonvested shares, vested and non-vested time-based RSUs and vested market-measure 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, 2013, 2012 and 2011:
		Year Ended December 31,
		2013			2012			2011
		(in thousands, except unit and per unit amounts)
	Numerator:
	Income (loss) from continuing operations	$	15,837		$	(3,505	)	$	(15,584	)
	Income from continuing operations attributable to noncontrolling interests in consolidated subsidiaries	(224		)	(174		)	(529		)
	Preferred distributions	(13,250		)	(21,088		)	(15,196		)
	Allocation to participating securities (1)	(1,689		)	(1,602		)	(1,309		)
	Numerator for basic and diluted income (loss) from continuing operations available to common unitholders	674			(26,369		)	(32,618		)
	Income from discontinued operations	28,728			280,606			83,073
	Income from discontinued operations attributable to noncontrolling interests in consolidated subsidiaries	—			(464		)	—
	Numerator for basic and diluted net income available to common unitholders	$	29,402		$	253,773		$	50,455
	Denominator:
	Basic weighted average vested units outstanding	79,166,260			71,403,258			58,437,444
	Effect of dilutive securities - contingently issuable shares and stock options	1,765,025			—			—
	Diluted weighted average vested units and common unit equivalents outstanding	80,931,285			71,403,258			58,437,444
	Basic earnings per unit:
	Income (loss) from continuing operations available to common unitholders per unit	$	0.01		$	(0.37	)	$	(0.56	)
	Income from discontinued operations per common unit	0.36			3.93			1.42
	Net income available to common unitholders per unit	$	0.37		$	3.56		$	0.86
	Diluted earnings per unit:
	Income (loss) from continuing operations available to common unitholders per unit	$	0.01		$	(0.37	)	$	(0.56	)
	Income from discontinued operations per common unit	0.35			3.93			1.42
	Net income available to common unitholders per unit	$	0.36		$	3.56		$	0.86
	________________________
	-1	Participating securities include nonvested shares, vested and non-vested time-based RSUs and vested market-measure RSUs.

Tax_Treatment_of_Distributions1

Tax Treatment of Distributions (Tables)	12 Months Ended
	Dec. 31, 2013
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, 2013, 2012 and 2011 as follows:
		Year Ended December 31,
	Dividends	2013		2012			2011
	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 [Member]	'
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, 2013, 2012 and 2011 as identified in the table above was as follows:
		Year Ended December 31,
	Shares of Common Stock	2013						2012				2011
	Ordinary income	$	0.756		54	%		$	0.577	41.21	%	$	0.23	16.43	%
	Qualified dividend	0.003			0.21			—		—		—		—
	Return of capital	0.62			44.29			0.823		58.79		1.17		83.57
	Capital gains (1)	—			—			—		—		—		—
	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 2013 and 15% rate gains for 2012 and 2011.
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, 2013 and 2012 was as follows:
		Year Ended December 31,
	Preferred Shares	2013						2012
	Ordinary income	$	1.668		97.03	%		$	1.089	100	%
	Qualified dividend	0.006			0.35			—		—
	Capital gains (1)	—			—			—		—
	Unrecaptured section 1250 gains	0.045			2.62			—		—
		$	1.719		100	%		$	1.089	100	%
	__________________
	-1	Capital gains are comprised entirely of 20% rate gains for 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, 2013 and 2012 was as follows:
		Year Ended December 31,
	Preferred Shares	2013						2012
	Ordinary income	$	1.546		96.99	%		$	0.398	100	%
	Qualified dividend	0.006			0.38			—		—
	Capital gains (1)	—			—			—		—
	Unrecaptured section 1250 gains	0.042			2.63			—		—
		$	1.594		100	%		$	0.398	100	%
	__________________
	-1	Capital gains are comprised entirely of 20% rate gains for 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 years ended December 31, 2012 and 2011 is seen in the table below.
		Year Ended December 31,
	Preferred Shares	2012						2011
	Ordinary income	$	0.818		100	%		$	1.95	100	%
	Capital gains (1)	—			—			—		—
	Unrecaptured section 1250 gains	—			—			—		—
		$	0.818		100	%		$	1.95	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 years ended December 31, 2012 and 2011 is seen in the table below.
		Year Ended December 31,
	Preferred Shares	2012						2011
	Ordinary income	$	0.786		100	%		$	1.875	100	%
	Capital gains (1)	—			—			—		—
	Unrecaptured section 1250 gains	—			—			—		—
		$	0.786		100	%		$	1.875	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, 2013
Quarterly Financial Information Disclosure [Abstract]	'
Schedule of Summarized Quarterly Financial Data	'
	Summarized quarterly financial data for the years ended December 31, 2013 and 2012 was as follows:
		2013 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per share amounts)
	Revenues from continuing operations (2)	$	110,964		$	117,835		$	115,697		$	120,602
	Income from continuing operations (2)	186			7,437			2,683			5,531
	Income from discontinued operations (2)	2,202			2,666			6,344			17,516
	Net income	2,388			10,103			9,027			23,047
	Net income attributable to Kilroy Realty Corporation	2,409			9,946			8,897			22,628
	Preferred dividends and distributions	(3,313		)	(3,313		)	(3,312		)	(3,312		)
	Net (loss) income available to common stockholders	(904		)	6,633			5,585			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
		2012 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per share amounts)
	Revenues from continuing operations (2)	$	85,858		$	91,584		$	98,985		$	104,573
	(Loss) income from continuing operations (2)	(848		)	(1,873		)	(2,141		)	1,357
	Income from discontinued operations (2)	79,519			4,150			4,663			192,274
	Net income	78,671			2,277			2,522			193,631
	Net income attributable to Kilroy Realty Corporation	76,876			2,297			2,589			189,152
	Preferred dividends and distributions	(9,336		)	(3,097		)	(5,342		)	(3,313		)
	Net income (loss) available to common stockholders	67,540			(800		)	(2,753		)	185,839
	Net income (loss) available to common stockholders per share – basic	1.06			(0.02		)	(0.04		)	2.49
	Net income (loss) available to common stockholders per share – diluted	1.06			(0.02		)	(0.04		)	2.49
	____________________
	-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 impact of equity offerings that occurred during the years ended December 31, 2013 and 2012.
	-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 17 “Discontinued Operations” for additional information).

Quarterly_Financial_Informatio3

Quarterly Financial Information of the Operating Partnership (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2013
Schedule of Summarized Quarterly Financial Data	'
	Summarized quarterly financial data for the years ended December 31, 2013 and 2012 was as follows:
		2013 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per share amounts)
	Revenues from continuing operations (2)	$	110,964		$	117,835		$	115,697		$	120,602
	Income from continuing operations (2)	186			7,437			2,683			5,531
	Income from discontinued operations (2)	2,202			2,666			6,344			17,516
	Net income	2,388			10,103			9,027			23,047
	Net income attributable to Kilroy Realty Corporation	2,409			9,946			8,897			22,628
	Preferred dividends and distributions	(3,313		)	(3,313		)	(3,312		)	(3,312		)
	Net (loss) income available to common stockholders	(904		)	6,633			5,585			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
		2012 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per share amounts)
	Revenues from continuing operations (2)	$	85,858		$	91,584		$	98,985		$	104,573
	(Loss) income from continuing operations (2)	(848		)	(1,873		)	(2,141		)	1,357
	Income from discontinued operations (2)	79,519			4,150			4,663			192,274
	Net income	78,671			2,277			2,522			193,631
	Net income attributable to Kilroy Realty Corporation	76,876			2,297			2,589			189,152
	Preferred dividends and distributions	(9,336		)	(3,097		)	(5,342		)	(3,313		)
	Net income (loss) available to common stockholders	67,540			(800		)	(2,753		)	185,839
	Net income (loss) available to common stockholders per share – basic	1.06			(0.02		)	(0.04		)	2.49
	Net income (loss) available to common stockholders per share – diluted	1.06			(0.02		)	(0.04		)	2.49
	____________________
	-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 impact of equity offerings that occurred during the years ended December 31, 2013 and 2012.
	-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 17 “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, 2013 and 2012 was as follows:
		2013 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per unit amounts)
	Revenues from continuing operations (2)	$	110,964		$	117,835		$	115,697		$	120,602
	Income (loss) from continuing operations (2)	186			7,437			2,683			5,531
	Income from discontinued operations (2)	2,202			2,666			6,344			17,516
	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 income (loss) available to common unitholders	(994		)	6,728			5,668			19,689
	Net income (loss) available to common unitholders per unit – basic	(0.02		)	0.08			0.07			0.23
	Net income (loss) available to common unitholders per unit – diluted	(0.02		)	0.08			0.07			0.23
		2012 Quarter Ended (1)
		March 31,			June 30,			September 30,			December 31,
		(in thousands, except per unit amounts)
	Revenues from continuing operations (2)	$	85,858		$	91,584		$	98,985		$	104,573
	Income from continuing operations (2)	(848		)	(1,873		)	(2,141		)	1,357
	Income from discontinued operations (2)	79,519			4,150			4,663			192,274
	Net income	78,671			2,277			2,522			193,631
	Net income attributable to the Operating Partnership	78,618			2,234			2,474			193,137
	Preferred distributions	(9,336		)	(3,097		)	(5,342		)	(3,313		)
	Net income (loss) available to common unitholders	69,282			(863		)	(2,868		)	189,824
	Net income (loss) available to common unitholders per unit – basic	1.05			(0.02		)	(0.04		)	2.48
	Net income (loss) available to common unitholders per unit – diluted	1.05			(0.02		)	(0.04		)	2.44
	___________________
	-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 equity offerings that occurred during the years ended December 31, 2013 and 2012.
	-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 17 “Discontinued Operations”).

Organization_and_Ownership_Det

Organization and Ownership (Details)	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
	property		building	building
Real Estate Properties [Line Items]	'		'	'
Number of buildings	18		46	3
Stabilized Office Properties [Member]	'		'	'
Real Estate Properties [Line Items]	'		'	'
Number of buildings	105	[1]	'	'
Rentable square feet (unaudited)	12,736,099	[1]	'	'
Number of Tenants	514	[1]	'	'
Percentage Occupied (unaudited)	93.40%	[1]	'	'
Properties Held for Sale [Member]	'		'	'
Real Estate Properties [Line Items]	'		'	'
Number of buildings	12	[2]	0	'
Rentable square feet (unaudited)	1,049,035	[2]	'	'
Development Properties [Member]	'		'	'
Real Estate Properties [Line Items]	'		'	'
Number of buildings	6	[3]	'	'
Rentable square feet (unaudited)	2,538,000	[3]	'	'
Lease Up Properties [Member]	'		'	'
Real Estate Properties [Line Items]	'		'	'
Number of buildings	1		'	'
Rentable square feet (unaudited)	410,000		'	'
[1]	Excludes 12 properties located in San Diego, California that were held for sale at December 31, 2013 (see Note 17 “Discontinued Operations” for additional information). The sale of these properties closed on January 9, 2014 (see Note 23 “Subsequent Events” for additional information).
[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.
[3]	Estimated rentable square feet upon completion.

Organization_and_Ownership_Det1

Organization and Ownership (Details Textuals)

12 Months Ended

12 Months Ended

3 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

building

building

building

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty Finance, Inc. [Member]

San Francisco, California

Washington

Properties Held for Sale [Member]

Properties Held for Sale [Member]

Properties Held for Sale [Member]

property

property

building

building

building

San Diego, California

building

Organization, Consolidation and Presentation of Financial Statements [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

Stabilized occupancy

95.00%

'

'

'

'

'

'

'

'

'

'

'

Maximum period after construction activities

'1 year

'

'

'

'

'

'

'

'

'

'

'

Real Estate Properties [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Number of properties completed

'

'

'

'

'

'

'

1

'

'

'

'

Number of real estate properties

18

46

3

'

'

'

'

'

12

12

[1]

0

12

Percentage of general partnership interest owned by the company in the Operating Partnership

'

'

'

97.80%

97.60%

'

'

'

'

'

'

'

Ownership interest of noncontrolling interest

'

'

'

2.20%

2.40%

'

'

'

'

'

'

'

Percentage of General partnership interest owned by wholly-owned subsidiary of the Company

'

'

'

'

'

'

1.00%

'

'

'

'

'

Percentage of limited partnership interest owned by Operating Partnership

'

'

'

'

'

99.00%

'

'

'

'

'

'

[1]

The San Diego Properties included the following: 10020 Pacific Mesa Boulevard, 6055 Lusk Avenue, 5010 and 5005 Wateridge Vista Drive, 15435 and 15445 Innovation Drive, and 15051, 15073, 15231, 15253, 15333 and 15378 Avenue of Science.

Basis_of_Presentation_and_Sign3

Basis of Presentation and Significant Accounting Policies (Partially Owned Entities and Variable Interest Entities (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	building	entity	building
	entity	building
Variable Interest Entity [Line Items]	'	'	'
Number of real estate properties	3	46	3
Number of consolidated variable interest entities	4	2	'
VIE Asset Amount	251,800,000	$337,000,000	'
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	12,100,000	111,100,000	'
Noncontrolling interest in consolidated subsidiary	4,885,000	0	'
Real Estate Investment [Member]	'	'	'
Variable Interest Entity [Line Items]	'	'	'
VIE Asset Amount	234,532,000	$319,770,000	'
Washington	'	'	'
Variable Interest Entity [Line Items]	'	'	'
Number of real estate properties	12	'	'

Basis_of_Presentation_and_Sign4

Basis of Presentation and Significant Accounting Policies (Acquisitions and Building Properties) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
	building		building	building
	property
Property, Plant and Equipment [Line Items]	'		'	'
Depreciation of real estate	($145,325,000)		($125,906,000)	($105,982,000)
Number of buildings	18		46	3
Undeveloped Land [Member]	'		'	'
Property, Plant and Equipment [Line Items]	'		'	'
Business acquisition costs capitalized	$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		'	'
Properties Held for Sale [Member]	'		'	'
Property, Plant and Equipment [Line Items]	'		'	'
Number of buildings	12	[1]	0	'
Properties Held for Sale [Member] | San Diego, California	'		'	'
Property, Plant and Equipment [Line Items]	'		'	'
Number of buildings	12		'	'
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		'	'
[1]	The San Diego Properties included the following: 10020 Pacific Mesa Boulevard, 6055 Lusk Avenue, 5010 and 5005 Wateridge Vista Drive, 15435 and 15445 Innovation Drive, and 15051, 15073, 15231, 15253, 15333 and 15378 Avenue of Science.

Basis_of_Presentation_and_Sign5

Basis of Presentation and Significant Accounting Policies (Deferred Finance Costs and Debt) (Details) (USD $)

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

In Millions, except Share data, unless otherwise specified

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Aug. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Secured Debt [Member]

Secured Debt [Member]

Unsecured Debt [Member]

Unsecured Debt [Member]

Series G Cumulative Redeemable Preferred Stock

Series G Cumulative Redeemable Preferred Stock

Series G Cumulative Redeemable Preferred Stock

Series H Cumulative Redeemable Preferred Stock

Series H Cumulative Redeemable Preferred Stock

Series H Cumulative Redeemable Preferred Stock

Series G Cumulative Redeemable Preferred Unit [Member]

Series H Cumulative Redeemable Preferred Unit [Member]

Series G Cumulative Redeemable Preferred Stock

Series H Cumulative Redeemable Preferred Stock

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization of Financing Costs

$13.20

$16.60

'

'

'

'

'

'

'

'

'

'

'

'

Debt premium

7.2

'

14.6

7.2

'

'

'

'

'

'

'

'

'

'

Unamortized discount (premium), Net

'

'

'

($7.20)

$1.90

$2.10

'

'

'

'

'

'

'

'

Preferred Units, Issued

'

'

'

'

'

'

'

'

4,000,000

'

'

4,000,000

4,000,000

4,000,000

Preferred stock dividend rate (percentage)

'

'

'

'

'

'

6.88%

6.88%

6.88%

6.38%

6.38%

6.38%

'

'

Basis_of_Presentation_and_Sign6

Basis of Presentation and Significant Accounting Policies (Details) (USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2011	Dec. 31, 2012
	building		building	building
	property
Basis of presentation and significant accounting policies [Line Items]	'		'	'
Number of real estate properties	18		3	46
REIT annual taxable income distribution requirement percentage	90.00%		90.00%	'
Company annual taxable income distribution	100.00%		'	'
Concentration Risk of Significant Tenants, Percentage	33.00%		'	'
Cash, FDIC Insured Amount	$250,000		'	'
Properties Held for Sale [Member]	'		'	'
Basis of presentation and significant accounting policies [Line Items]	'		'	'
Number of real estate properties	12	[1]	'	0
Properties Held for Sale [Member] | San Diego, California	'		'	'
Basis of presentation and significant accounting policies [Line Items]	'		'	'
Number of real estate properties	12		'	'
[1]	The San Diego Properties included the following: 10020 Pacific Mesa Boulevard, 6055 Lusk Avenue, 5010 and 5005 Wateridge Vista Drive, 15435 and 15445 Innovation Drive, and 15051, 15073, 15231, 15253, 15333 and 15378 Avenue of Science.

Acquisitions_Details

Acquisitions (Details) (USD $)

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jun. 27, 2013

Jun. 27, 2013

Jun. 27, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

building

property

building

building

The Crossing / 900 Project [Member]

Crossing / 900 Project, Phase I [Member]

Crossing / 900 Project, Phase II [Member]

Office Properties Acquisitions [Member]

Office Properties Acquisitions [Member]

320 & 321 Westlake Terry, Seattle WA [Member]

12780 and 12790 El Camino Real, Sandiego, CA [Member]

4100 - 4700 Bohannon Dr, Menlo Park, CA [Member]

4100 - 4700 Bohannon Dr, Menlo Park, CA [Member]

701 and 801 N. 34th St, Seattle, WA [Member]

701 and 801 N. 34th St, Seattle, WA [Member]

837 N. 34th St, Seattle, WA [Member]

10900 NE 4th St. Bellevue, WA [Member]

10900 NE 4th St. Bellevue, WA [Member]

6255 Sunset Boulevard, Los Angeles, CA [Member]

12233 Olympic Blvd, Los Angeles, CA [Member]

599 N. Mathilda Avenue, Sunnyvale, CA [Member]

599 N. Mathilda Avenue, Sunnyvale, CA [Member]

All Other Acquisitions

Development and Redevelopment Project Acquisitions [Member]

Middlefield, Mountain View, CA [Member]

Brannan Street 333, San Francisco, CA [Member]

6121 Sunset Boulevard, Los Angeles, CA [Member]

Mission St., 350, San Francisco, CA [Member]

Fairchild Drive, 331, Mountain View, CA [Member]

Mathilda, 555, Sunnyvale, CA [Member]

Mathilda, 555, Sunnyvale, CA [Member]

All Other Acquisitions [Member]

building

building

building

building

building

building

building

building

building

sqft

sqft

project

sqft

sqft

sqft

sqft

sqft

sqft

sqft

sqft

sqft

building

building

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Date of Acquisition

'

'

'

'

'

'

'

'

'

16-Jan-13

[1],[2]

19-Sep-13

[3]

29-Feb-12

'

1-Jun-12

[4]

'

1-Jun-12

24-Jul-12

[5]

'

31-Jul-12

[6]

5-Oct-12

[7]

17-Dec-12

[8]

'

'

'

'

'

'

'

'

'

'

'

Number of buildings

3

18

46

3

'

'

'

4

[9]

14

[10]

2

[1],[2]

2

[3]

7

'

2

[4]

'

1

1

[5]

'

1

[6]

1

[7]

1

[8]

'

'

6

'

'

'

'

'

'

'

'

Rentable square feet (unaudited)

'

'

'

'

'

'

'

539,338

[9]

1,759,603

[10]

320,398

[1],[2]

218,940

[3]

374,139

'

308,407

[4]

'

111,580

416,755

[5]

'

321,883

[6]

151,029

[7]

75,810

[8]

'

'

'

'

'

'

'

'

'

'

'

Occupancy as of December 31, 2013

'

'

'

'

'

'

'

'

'

100.00%

[1],[2]

100.00%

[3]

89.00%

'

100.00%

[4]

'

100.00%

87.30%

[5]

'

82.50%

[6]

96.40%

[7]

100.00%

[8]

'

'

'

'

'

'

'

'

'

'

'

Purchase Price

'

'

'

'

'

'

'

$296,400,000

[11],[9]

$674,000,000

[10],[11]

$170,000,000

[1],[11],[2]

$126,400,000

[11],[3]

$162,500,000

[11]

'

$105,400,000

[11],[4]

'

$39,200,000

[11]

$186,100,000

[11],[5]

'

$78,800,000

[11],[6]

$72,900,000

[11],[7]

$29,100,000

[11],[8]

'

'

$340,300,000

[12]

$74,500,000

[12],[13],[14]

$18,500,000

[12]

$65,000,000

[12],[15]

$52,000,000

[12]

$21,800,000

[12],[13],[16],[17]

$108,500,000

[12],[13],[18],[19]

'

'

Assets

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Land and improvements

'

117,639,000

[20]

'

'

'

'

'

53,790,000

[21]

'

'

'

'

38,810,000

[20]

'

'

'

'

25,080,000

[20]

'

'

'

13,538,000

[20]

40,211,000

[20],[22]

'

'

'

'

'

'

'

'

'

Buildings and improvements

'

545,510,000

[23]

'

'

'

'

'

218,211,000

[21],[23]

'

'

'

'

124,617,000

[23]

'

'

'

'

150,877,000

[23]

'

'

'

12,558,000

[23]

257,458,000

[22],[23]

'

'

'

'

'

'

'

'

'

Undeveloped land and construction in progress

'

'

'

'

28,222,000

11,222,000

17,000,000

9,360,000

[21],[24]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

364,827,000

'

'

'

'

'

'

120,243,000

244,584,000

Cash and cash equivalents

'

3,973,000

'

'

'

'

'

'

'

'

'

'

0

'

4,000,000

'

'

0

'

'

'

0

3,973,000

[22]

'

'

'

'

'

'

'

'

'

Restricted cash

'

5,329,000

'

'

'

'

'

'

'

'

'

'

0

'

'

'

'

0

'

'

'

0

5,329,000

[22]

11,250,000

[25]

'

'

'

'

'

'

11,250,000

[25]

0

[25]

Deferred leasing costs and acquisition-related intangible assets

'

59,513,000

[26]

'

'

'

'

'

30,789,000

[21],[27]

'

'

'

'

9,470,000

[26]

'

'

'

'

16,469,000

[26]

'

'

'

3,004,000

[26]

30,570,000

[22],[26]

'

'

'

'

'

'

'

'

'

Prepaid expenses and other assets

'

184,000

'

'

'

'

'

'

'

'

'

'

0

'

'

'

'

0

'

'

'

0

184,000

[22]

1,300,000

'

'

'

'

'

'

0

1,300,000

Total assets

'

732,148,000

'

'

28,222,000

11,222,000

17,000,000

312,150,000

[21]

'

'

'

'

172,897,000

'

'

'

'

192,426,000

'

'

'

29,100,000

337,725,000

[22]

377,377,000

'

'

'

'

'

'

131,493,000

245,884,000

Liabilities

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred revenue and acquisition-related intangible liabilities

'

35,020,000

[28]

'

'

'

'

'

4,190,000

[21],[29]

'

'

'

'

10,380,000

[28]

'

'

'

'

4,940,000

[28]

'

'

'

0

[28]

19,700,000

[22],[28]

'

'

'

'

'

'

'

'

'

Secured debt

'

221,032,000

[30]

'

'

1,750,000

[31]

1,750,000

[31]

0

[31]

95,496,000

[21],[32]

'

'

'

'

0

[30]

'

'

'

'

84,984,000

[30]

'

'

'

0

[30]

136,048,000

[22],[30]

'

'

'

'

'

'

'

'

'

Accounts payable, accrued expenses and other liabilities

'

6,348,000

'

'

3,427,000

1,952,000

1,475,000

422,000

[21]

'

'

'

'

137,000

'

'

'

'

627,000

'

'

'

0

5,584,000

[22]

32,823,000

[25]

'

'

'

'

'

'

23,071,000

[25]

9,752,000

[25]

Total liabilities assumed

'

262,400,000

'

'

5,177,000

3,702,000

1,475,000

100,108,000

[21]

'

'

'

'

10,517,000

'

'

'

'

90,551,000

'

'

'

0

161,332,000

[22]

32,823,000

'

'

'

'

'

'

23,071,000

9,752,000

Noncontrolling interest in consolidated subsidiary

'

'

'

'

4,885,000

4,885,000

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net assets and liabilities acquired

'

$469,748,000

[33]

'

'

$18,160,000

$2,635,000

$15,525,000

$212,042,000

[21],[34]

'

'

'

'

$162,380,000

[33]

'

'

'

'

$101,875,000

[33]

'

'

'

$29,100,000

[33]

$176,393,000

[22],[33]

$344,554,000

[35]

'

'

'

'

'

'

$108,422,000

[35]

$236,132,000

[35]

[1]

We acquired these properties through a new special purpose entity wholly owned by the Finance Partnership.

[2]

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”).

[3]

As of December 31, 2013, these properties, together the “Heights of Del Mar” project, are 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.

[4]

We acquired these properties through the acquisition of the ownership interest of the bankruptcy remote LLC that owned the properties. In connection with this acquisition we also acquired cash of approximately $4.0 million and other assets of approximately $0.2 million and we assumed current liabilities of approximately $0.6 million and secured debt with an outstanding principal balance of $34.0 million and a premium of $1.7 million as a result of recording the debt at fair value at the acquisition date (see Note 7 “Secured and Unsecured Debt of the Operating Partnership”).

[5]

In connection with this acquisition, we assumed secured debt with an outstanding principal balance of $83.6 million and a premium of $1.4 million as a result of recording this debt at fair value on the acquisition date. In January 2013, we repaid this loan prior to the stated maturity (see Note 7 “Secured and Unsecured Debt of the Operating Partnership” for additional information).

[6]

As part of the consideration for this transaction, we issued 118,372 common units of the Operating Partnership valued at $47.34 per unit, which was the Company’s closing stock price on the NYSE on the acquisition date. In connection with this acquisition we also assumed secured debt with an outstanding principal balance of $53.9 million and a premium of $3.1 million as a result of recording this debt at fair value on the acquisition date (see Note 7 “Secured and Unsecured Debt of the Operating Partnership”). We also assumed $4.7 million of accrued liabilities in connection with this acquisition that are not included in the purchase price above.

[7]

In connection with this acquisition, we assumed secured debt with an outstanding principal balance of $40.7 million and a premium of $2.7 million as a result of recording this debt at fair value on the acquisition date (see Note 7 “Secured and Unsecured Debt of the Operating Partnership”).

[8]

This operating property was acquired in connection with the purchase of the 555 N. Mathilda Ave. development property discussed in further detail in the “Development and Redevelopment Project Sites” section of this footnote, for a total purchase price of $137.6 million.

[9]

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.

[10]

The results of operations for the properties acquired during 2012 contributed $18.9 million and $3.4 million to revenues and net income from continuing operations, respectively, for the year ended December 31, 2012.

[11]

Excludes acquisition-related costs and non-lease related accrued liabilities assumed. Includes assumed unpaid leasing commissions and tenant improvements.

[12]

Excludes leasing costs and/or other accrued liabilities assumed in connection with the acquisitions.

[13]

Acquisition of these development sites are accounted for as business combinations because the projects were 100% pre-leased upon acquisition.

[14]

The total purchase price for this acquisition was comprised of a cash purchase price of $74.5 million plus $9.5 million of assumed leasing commissions and other accrued liabilities.

[15]

In connection with this acquisition we also assumed $1.1 million of other accrued liabilities which are not included in the purchase price above.

[16]

In October, we stabilized the 331 Fairchild Drive development project in Mountain View, California.

[17]

The total purchase price for this acquisition was comprised of a cash purchase price of $18.9 million plus $2.9 million of development costs reimbursed to the seller. In addition, we assumed $2.1 million of leasing commissions and other accrued liabilities which are not included in the purchase price above.

[18]

As of December 31, 2012, this property was temporarily being held in a separate VIE to facilitate a potential Section 1031 Exchange (see Note 2 “Basis of Presentation and Significant Accounting Policies”). The VIE was terminated in upon exchange in 2013.

[19]

This development site was acquired with the purchase of the 555 Mathilda operating property for a total cash purchase price of $137.6 million plus $2.4 million of development costs reimbursed to the seller. In addition, we assumed $11.8 million of other accrued liabilities which are not included in the purchase price above.

[20]

In connection with the acquisitions of 701, 801, and 837 N. 34th St., Seattle, WA, we assumed the lessee obligations under a ground lease with an initial expiration in December 2041. The ground lease obligation contains three 10-year extension options and one 45-year extension option. In connection with the acquisitions of 601 108th Ave., N.E., Bellevue, WA, we assumed the lessee obligation under a ground lease that is scheduled to expire in November 2093 (see Note 15 “Commitments and Contingencies” for additional information pertaining to these ground leases).

[21]

The purchase price of 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, 2013.

[22]

The purchase price of all other acquisitions during the year ended December 31, 2012 were individually less than 5% and in aggregate less than 10% of the Company’s total assets as of 2012.

[23]

Represents buildings, building improvements and tenant improvements.

[24]

In connection with one of the acquisitions, we acquired undeveloped land of approximately 4.2 acres that was added to the Company’s future development pipeline upon acquisition.

[25]

In connection with this acquisition, restricted cash is being held in escrow to pay for potential environmental costs and contingent development costs. Any unused amounts will be released to the seller.

[26]

Represents in-place leases (approximately $43.4 million with a weighted average amortization period of 4.7 years), above-market leases (approximately $1.4 million with a weighted average amortization period of 3.8 years), leasing commissions (approximately $14.2 million with a weighted average amortization period of 3.4 years), and a below-market ground lease obligation (approximately $0.5 million with a weighted average amortization period of 59.6 years).

[27]

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).

[28]

Represents below-market leases (approximately $33.9 million with a weighted average amortization period of 6.5 years) and an above-market ground lease obligation (approximately $1.1 million with a weighted average amortization period of 29.6 years).

[29]

Represents below-market leases (approximately $4.2 million with a weighted average amortization period of 7.7 years).

[30]

Represents the fair value of the mortgage loans assumed, which includes an aggregate unamortized premium balance of approximately $8.9 million at the dates of acquisition (see Note 7 “Secured and Unsecured Debt of the Operating Partnership”).

[31]

This note was repaid as of December 31, 2013.

[32]

Represents the mortgage loan, which includes an unamortized premium 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).

[33]

Reflects the purchase price plus cash and restricted cash received, net of assumed secured debt, lease-related obligations and other accrued liabilities.

[34]

Reflects the purchase price net of assumed secured debt and other lease-related obligations.

[35]

Reflects the purchase price including assumed leasing commissions, net of assumed accrued liabilities.

Acquisitions_Details_Textuals

Acquisitions (Details Textuals) (USD $)

12 Months Ended

12 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

9-May-12

Dec. 31, 2012

Sep. 28, 2012

Dec. 31, 2012

Dec. 04, 2012

Dec. 31, 2012

Dec. 17, 2012

Dec. 31, 2012

Nov. 30, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Jun. 27, 2013

Jun. 27, 2013

Oct. 31, 2013

Nov. 30, 2013

Jul. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Jun. 30, 2012

Jul. 24, 2012

Oct. 31, 2012

Jul. 31, 2012

building

sqft

building

Office Properties Acquisitions [Member]

Office Properties Acquisitions [Member]

701 and 801 N. 34th St, Seattle, WA [Member]

701 and 801 N. 34th St, Seattle, WA [Member]

6255 Sunset Boulevard, Los Angeles, CA [Member]

320 & 321 Westlake Terry, Seattle WA [Member]

12780 and 12790 El Camino Real, Sandiego, CA [Member]

601 108th Avenue N.E Bellevue, WA [Member]

Development and Redevelopment Project Acquisitions [Member]

Middlefield, Mountain View, CA [Member]

Middlefield, Mountain View, CA [Member]

6121 Sunset Boulevard, Los Angeles, CA [Member]

6121 Sunset Boulevard, Los Angeles, CA [Member]

Fairchild Drive, 331, Mountain View, CA [Member]

Fairchild Drive, 331, Mountain View, CA [Member]

N. Mathilda Avenue 599 and 555, Sunnyvale, CA [Member]

Mathilda, 555, Sunnyvale, CA [Member]

Three Sixty, Third Street, San Francisco, CA [Member]

Secured Debt [Member]

Secured Debt [Member]

Maximum [Member]

In-Place Leases [Member]

In-Place Leases [Member]

Above Market Leases [Member]

Above Market Leases [Member]

Deferred Leasing Costs [Member]

Deferred Leasing Costs [Member]

Below-Market Ground Lease Obligation [Member]

Below-Market Leases [Member]

Above-Market Ground Lease [Member]

Ten Year Ground Lease Extension Option [Member]

Forty-Five Year Ground Lease Extension Option [Member]

The Crossing / 900 Project [Member]

Crossing / 900 Project, Phase I [Member]

Crossing / 900 Project, Phase II [Member]

Academy Project, Hollywood, CA [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

sqft

building

sqft

building

building

building

building

building

building

project

sqft

Extensions

Extensions

sqft

acre

acre

6255 Sunset Boulevard, Los Angeles, CA [Member]

Secured Debt [Member]

6.05% Mortgage Payable Due June 1, 2019 [Member]

5.09% Mortgage Payable due August 2015 [Member] [Member]

5.09% Mortgage Payable due August 2015 [Member] [Member]

6.37% Mortgage Payable due April 2013 [Member]

5.57% Mortgage Note Payable due February 2016 [Member]

5.23% Mortgage Payable due January 2016 [Member]

property

acre

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Business Acquisition [Line Items]

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Number of buildings

18

46

3

4

[1]

14

[2]

2

[3]

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1

[4]

2

[5],[6]

2

[7]

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6

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Outstanding principal balance

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$83,900,000

$34,000,000

$34,000,000

$83,600,000

$40,700,000

$53,900,000

Initial premium on outstanding amount of secured debt

7,200,000

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14,600,000

7,200,000

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'

'

8,900,000

11,600,000

1,700,000

1,700,000

1,400,000

2,700,000

3,100,000

Purchase price

'

'

'

296,400,000

[1],[8]

674,000,000

[2],[8]

105,400,000

[3],[8]

'

78,800,000

[4],[8]

170,000,000

[5],[6],[8]

126,400,000

[7],[8]

'

340,300,000

[9]

'

74,500,000

[10],[11],[9]

'

65,000,000

[12],[9]

'

21,800,000

[10],[13],[14],[9]

'

108,500,000

[10],[15],[16],[9]

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'

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45,700,000

'

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'

'

Payments to acquire land

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'

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9,400,000

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27,500,000

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17,000,000

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Area of Land

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4.2

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0.35

2

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Revenues

17,500,000

18,900,000

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'

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Net income

900,000

3,400,000

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'

'

Cash and cash equivalents

3,973,000

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'

'

4,000,000

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Other assets acquired

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200,000

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'

'

Current liabilities assumed in acquisition

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'

'

600,000

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700,000

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'

Accrued liabilities assumed in acquisition that are not included in purchase price

'

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2,100,000

'

11,800,000

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4,700,000

'

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'

'

'

Purchase price of individual acquisition as percentage of Company's assets (percentage)

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5.00%

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5.00%

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Purchase price of aggregated acquisitions as percentage of Company's assets (percentage

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10.00%

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10.00%

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In-place leases, above-market leases, and leasing commissions acquired

59,513,000

[17]

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30,789,000

[18],[19]

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19,600,000

43,400,000

3,200,000

1,400,000

7,900,000

14,200,000

'

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1,100,000

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Weighted average amortization period of above-market leases in years

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'4 years 8 months 0 days

'4 years 8 months 0 days

'6 years 1 month 0 days

'3 years 9 months 0 days

'5 years 11 months 0 days

'3 years 5 months 0 days

'

'

'29 years 7 months 6 days

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'

'

'

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Below-market leases acquired

4,200,000

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500,000

33,900,000

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Weighted average amortization period of below-market leases

'7 years 8 months 0 days

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'59 years 7 months 6 days

'6 years 6 months 0 days

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Number of extension options

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3

1

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Ground lease extension option term

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'10 years

'45 years

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Assumed noncancellable ground lease expiration

'

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30-Nov-93

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'

'

'

'

'

'

Deferred revenue and acquisition-related intangible liabilities

35,020,000

[20]

'

'

4,190,000

[19],[21]

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Area of Real Estate Property

200,306

3,975,665

282,611

'

'

'

'

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'

'

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'

'

'

'

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'

'

410,000

'

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'

'

'

'

'

'

'

'

'

300,000

'

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'

'

'

'

'

'

'

'

'

Business Acquisition, Percentage of Voting Interests Acquired

'

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'

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'

'

100.00%

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Business Acquisition, Cost of Acquired Entity, Cash Paid

'

'

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'

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'

'

74,500,000

'

'

'

18,900,000

'

137,600,000

[4],[8]

'

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Business Combination, Consideration Transferred, Development Costs Paid

'

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2,900,000

'

2,400,000

'

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'

Leasing commissions assumed

'

'

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'

'

'

'

'

'

'

9,500,000

'

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'

'

Business Acquisition, Cost of Acquired Entity, Liabilities Incurred

'

'

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'

'

'

'

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$1,100,000

'

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'

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'

'

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'

'

'

[1]

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.

[2]

The results of operations for the properties acquired during 2012 contributed $18.9 million and $3.4 million to revenues and net income from continuing operations, respectively, for the year ended December 31, 2012.

[3]

We acquired these properties through the acquisition of the ownership interest of the bankruptcy remote LLC that owned the properties. In connection with this acquisition we also acquired cash of approximately $4.0 million and other assets of approximately $0.2 million and we assumed current liabilities of approximately $0.6 million and secured debt with an outstanding principal balance of $34.0 million and a premium of $1.7 million as a result of recording the debt at fair value at the acquisition date (see Note 7 “Secured and Unsecured Debt of the Operating Partnership”).

[4]

As part of the consideration for this transaction, we issued 118,372 common units of the Operating Partnership valued at $47.34 per unit, which was the Company’s closing stock price on the NYSE on the acquisition date. In connection with this acquisition we also assumed secured debt with an outstanding principal balance of $53.9 million and a premium of $3.1 million as a result of recording this debt at fair value on the acquisition date (see Note 7 “Secured and Unsecured Debt of the Operating Partnership”). We also assumed $4.7 million of accrued liabilities in connection with this acquisition that are not included in the purchase price above.

[5]

We acquired these properties through a new special purpose entity wholly owned by the Finance Partnership.

[6]

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”).

[7]

As of December 31, 2013, these properties, together the “Heights of Del Mar” project, are 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.

[8]

Excludes acquisition-related costs and non-lease related accrued liabilities assumed. Includes assumed unpaid leasing commissions and tenant improvements.

[9]

Excludes leasing costs and/or other accrued liabilities assumed in connection with the acquisitions.

[10]

Acquisition of these development sites are accounted for as business combinations because the projects were 100% pre-leased upon acquisition.

[11]

The total purchase price for this acquisition was comprised of a cash purchase price of $74.5 million plus $9.5 million of assumed leasing commissions and other accrued liabilities.

[12]

In connection with this acquisition we also assumed $1.1 million of other accrued liabilities which are not included in the purchase price above.

[13]

In October, we stabilized the 331 Fairchild Drive development project in Mountain View, California.

[14]

The total purchase price for this acquisition was comprised of a cash purchase price of $18.9 million plus $2.9 million of development costs reimbursed to the seller. In addition, we assumed $2.1 million of leasing commissions and other accrued liabilities which are not included in the purchase price above.

[15]

As of December 31, 2012, this property was temporarily being held in a separate VIE to facilitate a potential Section 1031 Exchange (see Note 2 “Basis of Presentation and Significant Accounting Policies”). The VIE was terminated in upon exchange in 2013.

[16]

This development site was acquired with the purchase of the 555 Mathilda operating property for a total cash purchase price of $137.6 million plus $2.4 million of development costs reimbursed to the seller. In addition, we assumed $11.8 million of other accrued liabilities which are not included in the purchase price above.

[17]

Represents in-place leases (approximately $43.4 million with a weighted average amortization period of 4.7 years), above-market leases (approximately $1.4 million with a weighted average amortization period of 3.8 years), leasing commissions (approximately $14.2 million with a weighted average amortization period of 3.4 years), and a below-market ground lease obligation (approximately $0.5 million with a weighted average amortization period of 59.6 years).

[18]

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).

[19]

The purchase price of 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, 2013.

[20]

Represents below-market leases (approximately $33.9 million with a weighted average amortization period of 6.5 years) and an above-market ground lease obligation (approximately $1.1 million with a weighted average amortization period of 29.6 years).

[21]

Represents below-market leases (approximately $4.2 million with a weighted average amortization period of 7.7 years).

Deferred_Leasing_Costs_and_Acq2

Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, net (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012
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	$186,622		$189,968
Acquisition-related Intangible Liabilities, Net [Abstract]	'		'
Total acquisitions-related intangible liabilities, net	49,776	[1]	59,129	[1]
Deferred Leasing Costs [Member]	'		'
Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, Net	'		'
Finite-lived intangible assets/liabilities, gross	178,720		168,087
Accumulated amortization	-63,246		-61,443
Finite-lived intangible assets/liabilities, net	115,474		106,644
Above Market Operating Leases [Member]	'		'
Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, Net	'		'
Finite-lived intangible assets/liabilities, gross	27,635		27,977
Accumulated amortization	-14,283		-12,180
Finite-lived intangible assets/liabilities, net	13,352	[2]	15,797
Leases, Acquired-in-Place [Member]	'		'
Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, Net	'		'
Finite-lived intangible assets/liabilities, gross	100,318		101,061
Accumulated amortization	-42,999		-34,019
Finite-lived intangible assets/liabilities, net	57,319		67,042
Below-Market Ground Lease Obligation [Member]	'		'
Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, Net	'		'
Finite-lived intangible assets/liabilities, gross	490		690
Accumulated amortization	-13		-205
Finite-lived intangible assets/liabilities, net	477	[3]	485
Below Market Operating Lease [Member]	'		'
Acquisition-related Intangible Liabilities, Net [Abstract]	'		'
Acquisition-related intangible liabilities, gross	69,385		70,486
Accumulated amortization	-25,706		-17,555
Acquisition-related intangible liabilities, net	43,679	[4]	52,931
Above-Market Ground Lease Obligation [Member]	'		'
Acquisition-related Intangible Liabilities, Net [Abstract]	'		'
Acquisition-related intangible liabilities, gross	6,320		6,320
Accumulated amortization	-223		-122
Acquisition-related intangible liabilities, net	$6,097	[5]	$6,198
[1]	See Note 2 “Basis of Presentation and Significant Accounting Policies” and 4 “Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, net” for additional information.
[2]	Represents estimated annual amortization related to above-market operating leases. Amounts will be recorded as a decrease to rental income in the consolidated statements of operations.
[3]	Represents estimated annual amortization related to below-market ground lease obligations. Amounts will be recorded as an increase to ground lease expense in the consolidated statements of operations
[4]	Represents estimated annual amortization related to below-market operating leases. Amounts will be recorded as an increase to rental income in the consolidated statements of operations.
[5]	Represents estimated annual amortization related to above-market ground lease obligations. Amounts will be recorded as a decrease to ground lease expense in the consolidated statements of operations

Deferred_Leasing_Costs_and_Acq3

Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, net (Details 1) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
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	$47,395		$36,202		$30,499
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	25,902	[1]	20,804	[1]	16,905	[1]
Estimated annual amortization related to acquisition-related intangibles	'		'		'
2014	25,454		'		'
2015	21,293		'		'
2016	18,435		'		'
2017	15,872		'		'
2018	12,255		'		'
Thereafter	22,165		'		'
Finite-lived intangible assets/liabilities, net	115,474		106,644		'
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	5,664	[2]	5,695	[2]	5,946	[2]
Estimated annual amortization related to acquisition-related intangibles	'		'		'
2014	4,946	[3]	'		'
2015	2,991	[3]	'		'
2016	1,963	[3]	'		'
2017	1,646	[3]	'		'
2018	1,045	[3]	'		'
Thereafter	761	[3]	'		'
Finite-lived intangible assets/liabilities, net	13,352	[3]	15,797		'
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	29,363	[1]	21,976	[1]	12,575	[1]
Estimated annual amortization related to acquisition-related intangibles	'		'		'
2014	19,168		'		'
2015	12,584		'		'
2016	9,361		'		'
2017	7,659		'		'
2018	4,574		'		'
Thereafter	3,973		'		'
Finite-lived intangible assets/liabilities, net	57,319		67,042		'
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]	205	[4]	0	[4]
Estimated annual amortization related to acquisition-related intangibles	'		'		'
2014	8	[5]	'		'
2015	8	[5]	'		'
2016	8	[5]	'		'
2017	8	[5]	'		'
2018	8	[5]	'		'
Thereafter	437	[5]	'		'
Finite-lived intangible assets/liabilities, net	477	[5]	485		'
Below Market Operating Lease [Member]	'		'		'
Amortization for the period related to deferred leasing costs and acquisition-related intangibles	'		'		'
Amortization Of Intangible Liabilities	-13,441	[6]	-12,393	[6]	-4,890	[6]
Estimated annual amortization related to acquisition-related intangibles	'		'		'
2014	-11,891	[7]	'		'
2015	-9,385	[7]	'		'
2016	-7,195	[7]	'		'
2017	-6,127	[7]	'		'
2018	-4,525	[7]	'		'
Thereafter	-4,556	[7]	'		'
Total	-43,679	[7]	-52,931		'
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]	-85	[8]	-37	[8]
Estimated annual amortization related to acquisition-related intangibles	'		'		'
2014	-101	[9]	'		'
2015	-101	[9]	'		'
2016	-101	[9]	'		'
2017	-101	[9]	'		'
2018	-101	[9]	'		'
Thereafter	-5,592	[9]	'		'
Total	($6,097)	[9]	($6,198)		'
[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, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Current Receivables, net	'		'
Current receivables	$12,866	[1]	$11,801
Allowance for uncollectible tenant receivables	-2,123	[1]	-2,581
Current receivables, net	10,743	[1]	9,220
Deferred Rent Receivables, net	'		'
Deferred rent receivables	129,198	[2]	118,025
Allowance for deferred rent receivables	-2,075	[2]	-2,607
Deferred rent receivables, net	$127,123	[2]	$115,418
[1]	Excludes current receivables, net related to properties held for sale at December 31, 2013.
[2]	Excludes deferred rent receivables, net related to properties held for sale at December 31, 2013.

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, 2013		Dec. 31, 2012
Debt Instrument [Line Items]	'		'
Unsecured Debt	$1,431,132,000		$1,130,895,000
Secured debt	560,434,000		561,096,000
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	$1,600,000,000		$1,500,000,000
Unsecured Senior Notes [Member] | 6.45% Unsecured Senior Notes due Aug 4 2014 [Member]	'		'
Debt Instrument [Line Items]	'		'
Stated interest rate	6.45%		'
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]	'
Exchangeable Notes [Member] | Exchangeable Note Two [Member]	'		'
Debt Instrument [Line Items]	'		'
Stated interest rate	4.25%		'
[1]	Interest on the 3.800% 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 $)

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Jun. 30, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Jan. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Jul. 24, 2012

Dec. 31, 2013

Dec. 31, 2012

Jul. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Oct. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Jun. 30, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Jun. 30, 2012

Jun. 30, 2012

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Irvine, California [Member]

Los Angeles, California [Member]

4.27% Mortgage Payable due Feb 1, 2018 [Member]

4.48% Mortgage Payable due July 2027

4.48% Mortgage Payable due July 2027

4.48% Mortgage Payable due July 2027

6.05% Mortgage Payable Due June 1, 2019 [Member]

6.51% Mortgage Payable due February 1, 2017 [Member]

5.23% Mortgage Payable due January 2016 [Member]

5.57% Mortgage Note Payable due February 2016 [Member]

5.09% Mortgage Payable due August 2015 [Member] [Member]

4.94% Mortgage Payable due April 15, 2015 [Member]

7.15% Mortgage Payable due May 1, 2017 [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

loans

properties

4.27% Mortgage Payable due Feb 1, 2018 [Member]

4.27% Mortgage Payable due Feb 1, 2018 [Member]

6.05% Mortgage Payable Due June 1, 2019 [Member]

6.05% Mortgage Payable Due June 1, 2019 [Member]

6.05% Mortgage Payable Due June 1, 2019 [Member]

6.37% Mortgage Payable due April 2013 [Member]

6.37% Mortgage Payable due April 2013 [Member]

6.37% Mortgage Payable due April 2013 [Member]

6.51% Mortgage Payable due February 1, 2017 [Member]

6.51% Mortgage Payable due February 1, 2017 [Member]

5.23% Mortgage Payable due January 2016 [Member]

5.23% Mortgage Payable due January 2016 [Member]

5.23% Mortgage Payable due January 2016 [Member]

5.57% Mortgage Note Payable due February 2016 [Member]

5.57% Mortgage Note Payable due February 2016 [Member]

5.57% Mortgage Note Payable due February 2016 [Member]

5.09% Mortgage Payable due August 2015 [Member] [Member]

5.09% Mortgage Payable due August 2015 [Member] [Member]

5.09% Mortgage Payable due August 2015 [Member] [Member]

4.94% Mortgage Payable due April 15, 2015 [Member]

4.94% Mortgage Payable due April 15, 2015 [Member]

7.15% Mortgage Payable due May 1, 2017 [Member]

7.15% Mortgage Payable due May 1, 2017 [Member]

Other [Member]

Other [Member]

4.48% Mortgage Payable due July 2027

4.48% Mortgage Payable due July 2027

property

building

property

property

property

Secured Debt

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stated interest rate

'

'

'

'

'

'

4.48%

[1],[2]

'

'

'

'

'

'

'

'

'

'

'

'

4.27%

[2]

'

6.05%

[2],[3]

'

'

6.37%

[2],[4]

'

'

6.51%

[2]

'

'

5.23%

[2],[5]

'

5.57%

[2],[6]

'

'

5.09%

[2],[7]

'

'

4.94%

[2]

'

7.15%

[2]

'

'

'

'

'

Effective interest rate

'

'

'

'

'

'

4.48%

[1],[2],[8]

'

'

'

'

'

'

'

'

'

'

'

'

4.27%

[2],[8]

'

3.50%

[2],[3],[8]

'

'

3.55%

[2],[4],[8]

'

'

6.51%

[2],[8]

'

'

3.50%

[2],[5],[8]

'

3.25%

[2],[6],[8]

'

'

3.50%

[2],[7],[8]

'

'

4.00%

[2],[8]

'

7.15%

[2],[8]

'

'

'

'

'

Maturity date

'

'

'

'

'

'

1-Jul-27

[1]

'

'

'

'

'

'

'

'

'

'

'

'

1-Feb-18

'

1-Jun-19

[3]

'

'

1-Apr-13

[4]

'

'

1-Feb-17

'

'

1-Jan-16

[5]

'

11-Feb-16

[6]

'

'

7-Aug-15

[7]

'

'

15-Apr-15

'

1-May-17

'

'

'

'

'

Secured debt

$560,434,000

$561,096,000

'

'

$133,100,000

'

$97,000,000

[1],[9]

$97,000,000

[1],[9]

$82,600,000

$67,700,000

$52,700,000

$39,900,000

$34,000,000

$27,300,000

$8,900,000

$560,434,000

$561,096,000

$560,434,000

[9]

$561,096,000

[9]

$133,117,000

[9]

$135,000,000

[9]

$92,502,000

[3],[9]

'

$0

[3],[9]

$0

[4],[9]

$83,116,000

[4],[9]

'

$67,663,000

[9]

$68,615,000

[9]

'

$54,570,000

[5],[9]

$56,302,000

[5],[9]

$41,654,000

[6],[9]

$43,016,000

[6],[9]

'

$34,845,000

[7],[9]

$35,379,000

[7],[9]

'

$27,641,000

[9]

$28,941,000

[9]

$8,972,000

[9]

$11,210,000

[9]

$2,470,000

[9]

$2,517,000

[9]

'

'

Debt premium

7,200,000

'

14,600,000

7,200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

8,900,000

'

'

'

11,600,000

'

'

'

'

1,400,000

'

'

3,100,000

'

'

'

'

2,700,000

'

1,700,000

1,700,000

'

'

'

'

'

'

'

'

Number of properties used as collateral for secured debbt

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

21

20

'

'

'

2

'

'

'

'

'

'

1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1

2

Debt amortization period

'

'

'

'

'

'30 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'6 years 5 months

'

'

'

'

'

'

'

'30 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Period of interest only payments

'

'

'

'

'

'3 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Principal amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

83,900,000

'

'

'

'

83,600,000

'

'

53,900,000

'

'

'

'

40,700,000

'

34,000,000

34,000,000

'

'

'

'

'

'

'

'

Net book value of properties pledged as collateral for secured debt

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$1,000,000,000

$1,000,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of secured loans with restrictions

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

9

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of secured debt

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

10

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

In June 2012, we obtained a mortgage loan that is secured by one office property located in Irvine, California and two office properties located in Los Angeles, California and requires monthly principal and interest payments based on a 30 year amortization period with an initial three years of interest only payments.

[2]

All interest rates presented are fixed-rate interest rates.

[3]

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 assumed mortgage had a principal balance of $83.9 million at the acquisition date and was recorded at fair value on the date of the acquisition resulting in a premium of approximately $11.6 million. The loan requires monthly principal and interest payments based on a 6.4 year amortization period.

[4]

In January 2013, we repaid this loan prior to the stated maturity date.

[5]

In July 2012, in connection with the acquisition of one office building in Los Angeles, California, we assumed a mortgage loan that is secured by the project. The assumed mortgage had a principal balance of $53.9 million at the acquisition date and was recorded at fair value on the date of the acquisition resulting in a premium of approximately $3.1 million. The loan requires monthly principal and interest payments based on a 30 year amortization period.

[6]

In October 2012, in connection with the acquisition of one office building in Los Angeles, California, we assumed a mortgage loan that is secured by the project. The assumed mortgage loan had a principal balance of $40.7 million at the acquisition date and was recorded at fair value at the date of acquisition resulting in an initial premium of approximately $2.7 million.

[7]

In June 2012, in connection with the acquisition of two office buildings in Seattle, Washington, we assumed a mortgage loan that is secured by the project. The assumed mortgage loan had a principal balance of $34.0 million at the acquisition date and was recorded at fair value at the date of acquisition resulting in an initial premium of approximately $1.7 million.

[8]

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.

[9]

Amounts reported include the amounts of unamortized debt premiums of $14.6 million and $7.2 million as of December 31, 2013 and 2012, respectively.

Secured_and_Unsecured_Debt_of_5

Secured and Unsecured Debt of the Operating Partnership - Exchangeable Senior Notes (Details) (USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Balance and significant terms of the Exchangeable Notes outstanding	'		'		'
Net carrying amount of liability component	$168,372,000		$163,944,000		'
Exchangeable Notes [Member] | 4.25% Exchangeable Notes [Member]	'		'		'
Balance and significant terms of the Exchangeable Notes outstanding	'		'		'
Stated interest rate	4.25%		'		'
Kilroy Realty, L.P. [Member]	'		'		'
Balance and significant terms of the Exchangeable Notes outstanding	'		'		'
Net carrying amount of liability component	168,372,000		163,944,000		'
Kilroy Realty, L.P. [Member] | Exchangeable Notes [Member]	'		'		'
Interest expense for the Exchangeable Notes	'		'		'
Contractual interest payments	7,331,000	[1]	8,721,000	[1]	12,141,000	[1]
Amortization of discount	4,427,000	[1]	5,052,000	[1]	6,928,000	[1]
Interest expense attributable to the Exchangeable Notes	11,758,000	[1]	13,773,000	[1]	19,069,000	[1]
Kilroy Realty, L.P. [Member] | Exchangeable Notes [Member] | 3.25% Exchangeable Notes [Member]	'		'		'
Balance and significant terms of the Exchangeable Notes outstanding	'		'		'
Stated interest rate	3.25%		'		'
Kilroy Realty, L.P. [Member] | Exchangeable Notes [Member] | 4.25% Exchangeable Notes [Member]	'		'		'
Balance and significant terms of the Exchangeable Notes outstanding	'		'		'
Principal amount	172,500,000		172,500,000		'
Unamortized discount	-4,128,000		-8,556,000		'
Net carrying amount of liability component	168,372,000		163,944,000		'
Carrying amount of equity component	19,835,000		'		'
Maturity date	15-Nov-14		'		'
Stated interest rate	4.25%	[2]	'		'
Effective interest rate	7.13%	[3]	'		'
Exchange rate per $1,000 principal value of the Exchangeable Notes, as adjusted	27.8307	[4]	'		'
Exchange price, as adjusted	$35.93	[4]	'		'
Number of shares on which aggregate consideration to be delivered upon conversion is determined	4,800,796	[4]	'		'
Trading price of the company's stock	$52.12		$45.72		'
Fair value of the shares upon conversion if Exchangeable Notes were converted on specified date	247,000,000		221,200,000		'
Excess amount of if-converted value over the principal amount	74,500,000		48,700,000		'
Capped call transactions	'		'		'
Referenced shares of common stock	4,800,796	[5]	'		'
Exchange price including effect of capped calls	$42.81	[5]	'		'
[1]	The Company repaid the 3.25% Exchangeable Notes in April 2012. Interest payments and discount amortization for the year ended December 31, 2013 are solely attributable to the 4.25% Exchangeable Notes.
[2]	Interest on the 4.25% Exchangeable Notes is payable semi-annually in arrears on May 15th and November 15th of each year.
[3]	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.
[4]	The exchange rate, exchange price, and the number of shares to be delivered upon conversion are subject to adjustment under certain circumstances including increases in our common dividends.
[5]	The capped calls mitigate the dilutive impact to us of the potential exchange of all of the 4.25% Exchangeable Notes into shares of common stock.

Secured_and_Unsecured_Debt_of_6

Secured and Unsecured Debt of the Operating Partnership - Exchangeable Senior Notes (Details Textuals) (Exchangeable Notes [Member], USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012
	D
Exchangeable Note Two [Member]	'		'
Debt Instrument [Line Items]	'		'
Stated interest rate	4.25%		'
Kilroy Realty, L.P. [Member]	'		'
Debt Instrument [Line Items]	'		'
Number of consecutive days trading price is less than product of closing price and exchange rate	'5 days		'
Number of consecutive trading days	'5 days		'
Exchangeable Notes principal amount for conversion ratio	$1,000		'
Percent of the product of the closing sale price of the common stock multiplied by the applicable exchange rate	98.00%		'
Number of days the Company's common stock ceases to be listed or approved for quotation	30		'
Kilroy Realty, L.P. [Member] | Exchangeable Note Two [Member]	'		'
Debt Instrument [Line Items]	'		'
Stated interest rate	4.25%	[1]	'
Threshold percentage of stock price trigger	130.00%		'
Minimum number of trading days closing per share price is higher than exchange price	20		'
Exchangeable note repurchased prinicipal amount	$0		$0
Exchange price, as adjusted	$35.93	[2]	'
Kilroy Realty, L.P. [Member] | Exchangeable Note One [Member]	'		'
Debt Instrument [Line Items]	'		'
Stated interest rate	3.25%		'
Number of trading days used for calculation of shares of common stock delivered for settlement	30		'
[1]	Interest on the 4.25% Exchangeable Notes is payable semi-annually in arrears on May 15th and November 15th of each year.
[2]	The exchange rate, exchange price, and the number of shares to be delivered upon conversion are subject to adjustment under certain circumstances including increases in our common dividends.

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
	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Debt Instrument [Line Items]	'		'	'
Net carrying amount	$1,431,132,000		$1,130,895,000	'
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%		'	'
Unsecured Senior Notes [Member] | 6.45% Unsecured Senior Notes due Aug 4 2014 [Member]	'		'	'
Debt Instrument [Line Items]	'		'	'
Stated interest rate	6.45%		'	'
Line of Credit [Member] | $150.0 Term Loan Facility [Member]	'		'	'
Debt Instrument [Line Items]	'		'	'
Net carrying amount	150,000,000		'	'
Kilroy Realty, L.P. [Member]	'		'	'
Debt Instrument [Line Items]	'		'	'
Net carrying amount	1,431,132,000		1,130,895,000	'
Kilroy Realty, L.P. [Member] | Unsecured Senior Notes [Member] | 3.800% Unsecured Senior Notes [Member]	'		'	'
Debt Instrument [Line Items]	'		'	'
Stated interest rate	3.80%	[1]	'	'
Effective interest rate	3.80%	[1],[2]	'	'
Principal amount	300,000,000		0	'
Unamortized discount	-90,000		0	'
Net carrying amount	299,910,000		0	'
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%	[3]	'	'
Effective interest rate	4.83%	[2],[3]	'	'
Principal amount	325,000,000		325,000,000	'
Unamortized discount	-339,000		-413,000	'
Net carrying amount	324,661,000		324,587,000	'
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%	[4]	'	'
Effective interest rate	6.74%	[2],[4]	'	'
Principal amount	250,000,000		250,000,000	'
Unamortized discount	-1,367,000		-1,580,000	'
Net carrying amount	248,633,000		248,420,000	'
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%	[5]	'	'
Effective interest rate	5.01%	[2],[5]	'	'
Principal amount	325,000,000		325,000,000	'
Unamortized discount	-73,000		-112,000	'
Net carrying amount	324,927,000		324,888,000	'
Kilroy Realty, L.P. [Member] | Unsecured Senior Notes [Member] | 6.45% Unsecured Senior Notes due Aug 4 2014 [Member]	'		'	'
Debt Instrument [Line Items]	'		'	'
Maturity date	4-Aug-14		'	'
Stated interest rate	6.45%		'	'
Effective interest rate	6.45%		'	6.45%
Net carrying amount	83,000,000		83,000,000	'
Kilroy Realty, L.P. [Member] | Line of Credit [Member] | $150.0 Term Loan Facility [Member]	'		'	'
Debt Instrument [Line Items]	'		'	'
Net carrying amount	150,000,000		'	'
Spread on variable rate	1.75%		'	'
Unsecured debt additional borrowing amount	$100,000,000		'	'
[1]	Interest on the 3.800% unsecured senior notes is payable semi-annually in arrears on January 15th and July 15th of each year.
[2]	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.
[3]	Interest on the 4.800% unsecured senior notes is payable semi-annually in arrears on January 15th and July 15th of each year.
[4]	Interest on the 6.625% unsecured senior notes is payable semi-annually in arrears on June 1st and December 1st of each year.
[5]	Interest on the 5.000% unsecured senior notes is payable semi-annually in arrears on May 3rd and November 3rd of each year.

Secured_and_Unsecured_Debt_of_8

Secured and Unsecured Debt of the Operating Partnership - Unsecured Revolving Credit Facility (Details) (USD $)	1 Months Ended			3 Months Ended	12 Months Ended		19 Months Ended
	Nov. 30, 2012	Mar. 31, 2012	Jun. 30, 2011	Oct. 31, 2010	Dec. 31, 2013		Feb. 29, 2012	Dec. 31, 2012		Sep. 30, 2010
Terms of the Credit Facility	'	'	'	'	'		'	'		'
Outstanding borrowings	'	'	'	'	$45,000,000		'	$185,000,000		'
Kilroy Realty, L.P. [Member]	'	'	'	'	'		'	'		'
Terms of the Credit Facility	'	'	'	'	'		'	'		'
Outstanding borrowings	'	'	'	'	45,000,000		'	185,000,000		'
Revolving Credit Facility [Member] | Kilroy Realty, L.P. [Member]	'	'	'	'	'		'	'		'
Terms of the Credit Facility	'	'	'	'	'		'	'		'
Outstanding borrowings	'	'	'	'	45,000,000		'	185,000,000		'
Remaining borrowing capacity	'	'	'	'	455,000,000		'	315,000,000		'
Total borrowing capacity	'	'	'	'	500,000,000	[1]	'	500,000,000	[1]	550,000,000
Interest rate	'	'	'	'	1.62%	[2]	'	1.66%	[2]	'
Facility fee - annual rate	'	'	'	'	0.30%	[3]	'	'		'
Maturity date	'	'	'	'	3-Apr-17	[4]	'	'		'
Unsecured debt additional borrowing amount	'	'	'	'	200,000,000		'	'		'
Spread on variable rate	'	'	'	'	1.45%		'	'		'
Fair value inputs, cap rate	'	6.75%	'	'	'		7.50%	'		'
Amount Incurred In Debt Origination And Legal Costs	$1,900,000	'	$3,300,000	$5,000,000	'		'	'		'
[1]	We may elect to borrow, subject to bank approval, up to an additional $200.0 million under an accordion feature under the terms of the revolving credit facility.
[2]	The revolving credit facility interest rate was calculated based on an annual rate of LIBOR plus 1.450% as of both December 31, 2013 and December 31, 2012.
[3]	The facility fee is paid on a quarterly basis and is calculated based on the total borrowing capacity. In addition to the facility fee, we also incurred debt origination and legal costs of approximately $5.0 million when we entered into the revolving credit facility in 2010, an additional $3.3 million when we amended the terms of the revolving credit facility in June 2011 and an additional $1.9 million when we amended the terms of the revolving credit facility in November 2012. The unamortized balance of these costs is amortized through the extended maturity date of the revolving credit facility.
[4]	Under the terms of the revolving credit facility, we may exercise an option to extend the maturity date by one year.

Secured_and_Unsecured_Debt_of_9

Secured and Unsecured Debt of the Operating Partnership - Debt Maturities (Details) (USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Capitalized interest and loan fees	'		'	'
Interest expense	$75,870,000		$79,114,000	$85,785,000
Kilroy Realty, L.P. [Member]	'		'	'
Capitalized interest and loan fees	'		'	'
Gross interest expense	111,238,000		98,906,000	94,915,000
Capitalized interest	-35,368,000		-19,792,000	-9,130,000
Interest expense	75,870,000		79,114,000	85,785,000
Debt [Member] | Kilroy Realty, L.P. [Member]	'		'	'
Stated debt maturities and scheduled amortization payments, excluding debt discounts	'		'	'
2014	265,346,000		'	'
2015	395,104,000		'	'
2016	249,431,000		'	'
2017	116,748,000		'	'
2018	451,728,000		'	'
Thereafter	718,011,000		'	'
Total	2,196,368,000	[1]	'	'
Unamortized discount (premium), Net	($8,600,000)		'	'
[1]	Includes gross principal balance of outstanding debt before impact of net unamortized premiums totaling approximately $8.6 million.

Deferred_Revenue_and_Acquisiti2

Deferred Revenue and Acquisition Related Liabilities, net (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Deferred Revenue Arrangement [Line Items]	'		'
Acquisition-related intangible liabilities, net	$49,776	[1]	$59,129	[1]
Deferred revenue and acquisition-related intangible liabilities, net	101,286		117,904
Tenant Funded Tenant Improvements [Member]	'		'
Deferred Revenue Arrangement [Line Items]	'		'
Deferred revenue related to tenant-funded tenant improvements	48,341	[2]	56,461	[2]
Other Deferred Revenue [Member]	'		'
Deferred Revenue Arrangement [Line Items]	'		'
Deferred revenue related to tenant-funded tenant improvements	$3,169		$2,314
[1]	See Note 2 “Basis of Presentation and Significant Accounting Policies” and 4 “Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, net” for additional information.
[2]	Excludes deferred revenue related to tenant-funded tenant improvements related to properties held for sale at December 31, 2013

Deferred_Revenue_and_Acquisiti3

Deferred Revenue and Acquisition Related Liabilities, net (Textuals) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Deferred Revenue Arrangement [Line Items]	'		'		'
Noncash amortization of deferred revenue related to tenant-funded tenant improvements	$10,713,000		$9,136,000		$9,349,000
Tenant Funded Tenant Improvements [Member]	'		'		'
Deferred Revenue Arrangement [Line Items]	'		'		'
Deferred revenues amortized and recognized as rental income	10,700,000		9,100,000		'
2014	8,686,000		'		'
2015	7,620,000		'		'
2016	7,165,000		'		'
2017	6,070,000		'		'
2018	4,479,000		'		'
Thereafter	14,321,000		'		'
Deferred revenue	$48,341,000	[1]	$56,461,000	[1]	'
[1]	Excludes deferred revenue related to tenant-funded tenant improvements related to properties held for sale at December 31, 2013

Noncontrolling_Interests_on_th1

Noncontrolling Interests on the Company's Consolidated Financial Statements (Details) (USD $)	12 Months Ended			0 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Aug. 15, 2012	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012
				Series A Cummulative Redeemable Preferred Unit [Member]	Series A Cummulative Redeemable Preferred Unit [Member]	Kilroy Realty, L.P. [Member]	Kilroy Realty, L.P. [Member]	Kilroy Realty, L.P. [Member]	Kilroy Realty, L.P. [Member]
									Series A Cummulative Redeemable Preferred Unit [Member]
Noncontrolling Interest [Abstract]	'	'	'	'	'	'	'	'	'
Common stock, par value	$0.01	'	'	'	'	'	'	'	'
Aggregate value upon redemption of outstanding noncontrolling common units	$90,800,000	$85,400,000	'	'	'	'	'	'	'
Noncontrolling Interest	4,885,000	0	'	'	'	'	'	'	'
Noncontrolling Interest [Line Items]	'	'	'	'	'	'	'	'	'
Percentage of general partnership interest owned by the company in the Operating Partnership	'	'	'	'	'	97.80%	97.60%	'	'
Ownership interest of noncontrolling interest	'	'	'	'	'	2.20%	2.40%	'	'
Noncontrolling common units	1,805,200	1,826,503	'	'	'	1,805,200	1,826,503	'	'
Preferred units outstanding	'	'	'	1,500,000	'	'	'	'	'
Preferred units redemption value per unit	'	'	'	$50	'	'	'	'	'
Redemption value	'	'	'	75,000,000	2,062,000	'	'	'	'
Original issuance costs of redeemed preferred units (Notes 9 and 11)	$0	($6,980,000)	$0	'	($2,100,000)	$0	($6,980,000)	$0	($2,062,000)

Stockholders_Equity_of_the_Com2

Stockholders' Equity of the Company (Details Textuals) (USD $)

12 Months Ended

0 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

12 Months Ended

1 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Apr. 16, 2012

Apr. 16, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Aug. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Apr. 16, 2012

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Sep. 30, 2013

Aug. 31, 2012

Feb. 28, 2012

Apr. 30, 2011

Sep. 30, 2013

Aug. 31, 2012

Feb. 28, 2012

Apr. 30, 2011

Series E Cumulative Redeemable Preferred Stock

Series F Cumulative Redeemable Preferred Stock

Series G Cumulative Redeemable Preferred Stock

Series G Cumulative Redeemable Preferred Stock

Series G Cumulative Redeemable Preferred Stock

Series H Cumulative Redeemable Preferred Stock

Series H Cumulative Redeemable Preferred Stock

Series H Cumulative Redeemable Preferred Stock

Series E and Series F Cumulative Redeemable Preferred Stock

Series E and Series F Cumulative Redeemable Preferred Stock

Common Stock

Common Stock

Issuance of Equity under ATM Program [Member]

Issuance of Equity under ATM Program [Member]

Issuance of Equity under ATM Program [Member]

Issuance of Equity under ATM Program [Member]

Issuance of Equity under ATM Program [Member]

Issuance of Equity under ATM Program [Member]

Issuance of Equity - equity offering [Domain]

Issuance of Equity - equity offering [Domain]

Issuance of Equity - equity offering [Domain]

Issuance of Equity - equity offering [Domain]

Issuance of Equity - equity offering [Domain]

Issuance of Equity - equity offering [Domain]

Issuance of Equity - equity offering [Domain]

Issuance of Equity - equity offering [Domain]

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Class of Stock [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Preferred stock, dividend rate

'

'

'

7.80%

7.50%

6.88%

6.88%

6.88%

6.38%

6.38%

6.38%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Preferred stock issued (in shares)

'

'

'

'

'

4,000,000

'

'

4,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Liquidation preference (in dollars per share)

'

'

'

'

'

$25

$25

'

$25

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Proceeds from issuance of preferred stock

'

'

'

'

'

$96,200,000

'

'

$96,200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of days within a change in control in which preferred stock may be redeemed

'

'

'

'

'

'

'120 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Redeemable preferred stock issued upon conversion, maximum

'

'

'

'

'

'

4,390,000

'

'

4,187,600

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Preferred stock (in shares)

'

'

'

1,610,000

3,450,000

'

4,000,000

4,000,000

'

4,000,000

4,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Redemption price (in dollars per share)

'

'

'

'

'

'

'

'

'

'

'

$25

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock redeemed during period, value

'

'

'

'

'

'

'

'

'

'

'

126,500,000

126,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Preferred stock redemption premium

0

6,980,000

0

'

'

'

'

'

'

'

'

'

4,900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share of common stock sold during the period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,040,838

787,118

355,305

'

'

'

'

6,175,000

5,750,000

9,487,500

6,037,500

Aggregate net proceeds after sales agent compensation

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

54,400,000

36,300,000

12,800,000

'

'

'

'

'

'

'

'

'

'

'

Aggregate gross proceeds

349,951,000

672,102,000

233,312,000

'

'

'

'

'

'

'

'

'

'

'

'

55,300,000

37,000,000

13,000,000

'

'

'

295,900,000

253,800,000

382,100,000

221,000,000

'

'

'

'

At Market Stock Offering Program Aggregate Value Of Common Stock

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

200,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock issued (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

82,153,944

74,926,981

2,183,261

'

'

'

'

'

'

'

'

'

'

'

'

'

At Market Stock Offering Program Remained Available For Issuance

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$94,700,000

'

'

'

'

'

'

'

'

'

'

Share Repurchase, remaining number of shares authorized to be repurchased

988,025

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stockholders_Equity_of_the_Com3

Stockholders' Equity of the Company Stockholders' Equity of the Company (Details) (USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Dividends Payable [Line Items]	'		'		'
Aggregate gross proceeds	$349,951,000		$672,102,000		$233,312,000
Accrued dividend and distributions	'		'		'
Accrued dividends and distributions	31,490,000		28,924,000		'
Summary of shares and units	'		'		'
Common stock	82,153,944	[1]	74,926,981	[1]	'
Noncontrolling common units	1,805,200		1,826,503		'
Common stockholders and noncontrolling unitholders [Member]	'		'		'
Accrued dividend and distributions	'		'		'
Accrued dividends and distributions	29,791,000		27,230,000		'
Common Stock [Member]	'		'		'
Accrued dividend and distributions	'		'		'
Accrued dividends and distributions	28,754,000		26,224,000		'
Summary of shares and units	'		'		'
Common stock	82,153,944		74,926,981		'
Capital Units [Member]	'		'		'
Accrued dividend and distributions	'		'		'
Accrued dividends and distributions	632,000		639,000		'
Preferred Stock [Member]	'		'		'
Accrued dividend and distributions	'		'		'
Accrued dividends and distributions	1,699,000		1,694,000		'
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	405,000	[2]	367,000	[2]	'
Time-Based Restricted Stock Units (RSUs) [Member]	'		'		'
Summary of shares and units	'		'		'
RSUs	1,158,407	[3]	1,048,863	[3]	'
Market Measure-Based Restricted Stock Units (RSUs) [Member]	'		'		'
Summary of shares and units	'		'		'
Number of RSUs outstanding	143,022	[3]	'		'
Issuance of Equity under ATM Program [Member]	'		'		'
Dividends Payable [Line Items]	'		'		'
Aggregate gross proceeds	55,300,000		37,000,000		13,000,000
Aggregate net proceeds after sales agent compensation	$54,400,000		$36,300,000		$12,800,000
Issuance of Equity under ATM Program [Member] | Common Stock [Member]	'		'		'
Dividends Payable [Line Items]	'		'		'
Share of common stock sold during the period	1,040,838		787,118		355,305
[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 “Share-Based Compensation” for additional information)
[3]	The amount includes nonvested RSUs. Does not include the 143,022 market measure-based RSUs since not all the necessary performance conditions have been met as of December 31, 2013.

Preferred_and_Common_Units_of_2

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

12 Months Ended

0 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Apr. 16, 2012

Apr. 16, 2012

Aug. 15, 2012

Aug. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Sep. 30, 2013

Aug. 31, 2012

Feb. 28, 2012

Apr. 30, 2011

Dec. 31, 2011

Jul. 31, 2012

Sep. 30, 2013

Aug. 31, 2012

Feb. 28, 2012

Apr. 30, 2011

Sep. 30, 2013

Aug. 31, 2012

Feb. 28, 2012

Apr. 30, 2011

Market Measure-Based Restricted Stock Units (RSUs) [Member]

Series E Cumulative Redeemable Preferred Unit [Member]

Series F Cumulative Redeemable Preferred Unit [Member]

Series A Preferred Units [Member]

Series H Cumulative Redeemable Preferred Stock

Series H Cumulative Redeemable Preferred Stock

Series H Cumulative Redeemable Preferred Stock

Series H Cumulative Redeemable Preferred Stock

Series G Cumulative Redeemable Preferred Stock

Series G Cumulative Redeemable Preferred Stock

Series G Cumulative Redeemable Preferred Stock

Series G Cumulative Redeemable Preferred Stock

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Issuance of Equity - equity offering [Domain]

Issuance of Equity - equity offering [Domain]

Issuance of Equity - equity offering [Domain]

Issuance of Equity - equity offering [Domain]

Issuance of Equity - equity offering [Domain]

Issuance of Equity - equity offering [Domain]

Issuance of Equity - equity offering [Domain]

Issuance of Equity - equity offering [Domain]

Series H Cumulative Redeemable Preferred Unit [Member]

Series G Cumulative Redeemable Preferred Unit [Member]

Series H Cumulative Redeemable Preferred Unit [Member]

Series H Cumulative Redeemable Preferred Unit [Member]

Series G Cumulative Redeemable Preferred Unit [Member]

Series G Cumulative Redeemable Preferred Unit [Member]

Partners Capital Common Unit [Member]

Partners Capital Common Unit [Member]

Partners Capital Common Unit [Member]

Partners Capital Common Unit [Member]

Partners Capital Common Unit [Member]

Partners Capital Common Unit [Member]

Common Stock

Common Stock

Common Stock

Common Stock

6255 Sunset Boulevard, Los Angeles, CA [Member]

Class of Stock [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Preferred stock issued (in shares)

'

'

'

'

'

'

'

4,000,000

'

'

'

4,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Proceeds from Issuance of Preferred Stock and Preference Stock

'

'

'

'

'

'

'

$96,200,000

'

'

'

$96,200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Preferred units issued

'

'

'

'

'

'

'

'

'

4,000,000

4,000,000

'

'

4,000,000

4,000,000

4,000,000

4,000,000

4,000,000

4,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Preferred units outstanding

'

'

'

'

1,610,000

3,450,000

1,500,000

'

'

'

'

'

'

'

'

4,000,000

4,000,000

4,000,000

4,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Preferred stock, dividend rate

'

'

'

'

7.80%

7.50%

'

6.38%

6.38%

6.38%

'

6.88%

6.88%

6.88%

'

6.38%

6.38%

6.88%

6.88%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share of common stock sold during the period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6,175,000

5,750,000

9,487,500

6,037,500

Net proceeds from issuance of common stock

$349,951,000

$672,102,000

$233,312,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$295,900,000

$253,800,000

$382,100,000

$221,000,000

'

'

'

'

Issuance of common units, units

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6,175,000

5,750,000

9,487,500

6,037,500

6,392,805

'

'

'

'

'

'

'

'

'

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

'

'

'

'

'

'

'

'

Number of RSUs outstanding

'

'

'

143,022

[1]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

The amount includes nonvested RSUs. Does not include the 143,022 market measure-based RSUs since not all the necessary performance conditions have been met as of December 31, 2013.

Preferred_and_Common_Units_of_3

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

12 Months Ended

12 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Sep. 30, 2013

Aug. 31, 2012

Feb. 28, 2012

Apr. 30, 2011

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Issuance of Equity under ATM Program [Member]

Issuance of Equity under ATM Program [Member]

Issuance of Equity under ATM Program [Member]

Issuance of Equity under ATM Program [Member]

Issuance of Equity under ATM Program [Member]

Issuance of Equity under ATM Program [Member]

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Kilroy Realty, L.P. [Member]

Partners Capital Common Unit [Member]

Partners Capital Common Unit [Member]

Partners Capital Common Unit [Member]

Issuance of Equity under ATM Program [Member]

Issuance of Equity under ATM Program [Member]

Issuance of Equity under ATM Program [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Partners Capital Common Unit [Member]

Partners Capital Common Unit [Member]

Partners Capital Common Unit [Member]

Partners Capital Common Unit [Member]

Partners Capital Common Unit [Member]

Partners Capital Common Unit [Member]

Partners Capital Common Unit [Member]

Partners Capital General Partner [Member]

Partners Capital General Partner [Member]

Partners Capital Limited Partner [Member]

Partners Capital Limited Partner [Member]

Partners Capital Preferred Units [Member]

Partners Capital Preferred Units [Member]

Series G Cumulative Redeemable Preferred Unit [Member]

Series G Cumulative Redeemable Preferred Unit [Member]

Series H Cumulative Redeemable Preferred Unit [Member]

Series H Cumulative Redeemable Preferred Unit [Member]

Class of Stock [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share of common stock sold during the period

'

'

'

'

'

'

'

'

'

'

'

'

'

1,040,838

787,118

355,305

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common units exchanged for share of common stock by the Company

'

'

'

'

'

'

'

'

1,040,838

787,118

355,305

'

'

'

'

'

'

'

'

'

6,175,000

5,750,000

9,487,500

6,037,500

6,392,805

'

'

'

'

'

'

'

'

'

'

'

'

Aggregate gross proceeds

$349,951,000

$672,102,000

$233,312,000

'

'

$55,300,000

$37,000,000

$13,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Aggregate net proceeds after sales agent compensation

'

'

'

'

'

54,400,000

36,300,000

12,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Accrued distributions

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Accrued dividends and distributions

$31,490,000

$28,924,000

'

$405,000

[1]

$367,000

[1]

'

'

'

'

'

'

$28,754,000

$26,224,000

'

'

'

$31,490,000

$28,924,000

$405,000

[2]

$367,000

[2]

'

'

'

'

'

$29,791,000

$27,230,000

$28,754,000

$26,224,000

$632,000

$639,000

$1,699,000

$1,694,000

'

'

'

'

Summary of units

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Company owned common units in the Operating Partnership

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

82,153,944

74,926,981

'

'

'

'

'

'

'

'

'

'

Company owned general partnership interest

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

97.80%

97.60%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Noncontrolling common units of the Operating Partnership

1,805,200

1,826,503

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,805,200

1,826,503

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Ownership interest of noncontrolling interest

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2.20%

2.40%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

RSUs

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,158,407

[3]

1,048,863

[3]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Preferred units outstanding

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4,000,000

4,000,000

4,000,000

4,000,000

[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)

[2]

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).

[3]

Does not include the 143,022 market measure-based RSUs since not all the necessary performance conditions have been met as of December 31, 2013.

ShareBased_Compensation_Detail

Share-Based Compensation (Details Textuals) (USD $)

12 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

In Millions, except Share data, unless otherwise specified

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Apr. 04, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Jan. 10, 2013

Apr. 04, 2013

Mar. 30, 2012

Apr. 04, 2013

Mar. 30, 2012

Apr. 04, 2013

Mar. 30, 2012

Feb. 22, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Apr. 04, 2013

Dec. 31, 2013

Dec. 31, 2013

plan

Time-Based Restricted Stock Units (RSUs) [Member]

Restricted Stock [Member]

Restricted Stock [Member]

Stock Options [Member]

Kilroy Realty 2006 Incentive Award Plan [Member]

Kilroy Realty 2006 Incentive Award Plan [Member]

Executive Officer Share-Based Compensation Programs [Member]

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Management [Member]

Nonvested Restricted Stock Units R S U [Member]

Nonvested Restricted Stock Units R S U [Member]

Nonvested Restricted Stock Units R S U [Member]

Nonvested Restricted Stock Units R S U [Member]

Nonvested Restricted Stock Units R S U [Member]

Nonvested Restricted Stock Units R S U [Member]

Nonvested Restricted Stock Units R S U [Member]

Vested Restricted Stock Units R S U [Member]

Vested Restricted Stock Units R S U [Member]

director

Full Value Awards [Member]

Market Measure-Based Restricted Stock Units (RSUs) [Member]

Executive Officer Share-Based Compensation Programs [Member]

Key Employee Share-Based Compensation Program [Member]

Executive Officer Share-Based Compensation Programs [Member]

Key Employee Share-Based Compensation Program [Member]

Executive Officer Share-Based Compensation Programs [Member]

Executive Officer Share-Based Compensation Programs [Member]

Executive Officer Share-Based Compensation Programs [Member]

Executive Officer Share-Based Compensation Programs [Member]

Executive Officer Share-Based Compensation Programs [Member]

Executive Officer Share-Based Compensation Programs [Member]

Executive Officer Share-Based Compensation Programs [Member]

Stock Options [Member]

Market Measure-Based Restricted Stock Units (RSUs) [Member]

Market Measure-Based Restricted Stock Units (RSUs) [Member]

Time-Based Restricted Stock Units (RSUs) [Member]

Time-Based Restricted Stock Units (RSUs) [Member]

Time-Based Restricted Stock Units (RSUs) [Member]

Restricted Stock [Member]

Executive Officer Share-Based Compensation Programs [Member]

Market Measure-Based Restricted Stock Units (RSUs) [Member]

Time-Based Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Market Measure-Based Restricted Stock Units (RSUs) [Member]

Market Measure-Based Restricted Stock Units (RSUs) [Member]

Time-Based Restricted Stock Units (RSUs) [Member]

Time-Based Restricted Stock Units (RSUs) [Member]

Market Measure-Based Restricted Stock Units (RSUs) [Member]

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

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of share-based incentive compensation plans

1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shares Available for Grant

'

'

'

'

'

'

'

7,414

2,539

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of executive compensation committee independent directors

'

'

'

'

'

'

'

4

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Service Vesting Period

'

'

'

'

'

'

'

'

'

'

'1 year

'2 years

'5 years

'5 years

'

'6 years

'

'

'7 years

'

'

'

'

'

'

'

'

'

'

'

'

Granted (in shares)

'

'

'

'

62,137

68,727

'

'

'

'

'

'

'

'

157,744

[1]

19,084

206,477

'

'

'

'

'

9,542

103,239

173,758

204,829

107,673

0

'

0

0

Modified from time based (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-61,327

[2]

'

'

'

61,327

[1]

0

[1]

0

[2]

Modified from time based, Weighted Average Grant Date Fair Value (in dollars per share)

'

'

'

$53.05

[2]

'

'

'

'

'

$53.05

[1]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Award vesting period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'6 years

'

'6 years

'7 years

'5 years

'

'

'

'

'

'

'

'

'

Exercise Price

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$53.05

$46.61

'

'

'

'

'

'

'

'

'

'

Historical volatility, period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'12 years

'14 years

'

'

'

'

'

'

'

'

'

'

'

'

Grants in period, grant date fair value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$0.40

$4.30

$0.50

$4.80

'

'

'

'

'

'

'

'

'

'

Number of shares that were tendered to satisfy minimum statutory tax withholding requirements

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

20,880

'

8,526

13,490

Options granted in period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,550,000

'

'

'

'

'

'

'

'

'

Trading price of the company's stock

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$42.61

'

'

'

'

'

'

'

'

'

Expiration period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'10 years

'

'

'

'

'

'

'

'

'

Options, exercisable number

'

'

'

'

'

'

305,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Options, intrinsic value

'

'

'

'

'

'

11.5

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Allocated Share-based Compensation Expense

9.6

8.5

5.6

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share-based compensation cost capitalized as part of real estate assets

0.9

0.9

1.1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total unrecognized compensation cost weighted-average period

'2 years 2 months

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total unrecognized compensation cost related to nonvested incentive awards granted

$25.50

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

On April 4, 2013 the terms of time-based RSU’s granted to certain officers of the Company in January were modified to include market-measure and performance-based vesting requirements.

[2]

On April 4, 2013, the terms of time-based RSUs granted to certain officers of the Company in January were modified to include market-measure based vesting requirements.

ShareBased_Compensation_Detail1

Share-Based Compensation (Details) (Market Measure-Based Restricted Stock Units (RSUs) [Member], USD $)	12 Months Ended		0 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Apr. 04, 2013	Mar. 30, 2012
			Chief Executive Officer [Member]	Chief Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Grant date fair value per share	$44.55	$41.20	$44.55	$41.20
Expected share price volatility	'	'	27.00%	31.00%
Risk-free interest rate	'	'	0.90%	1.60%
Dividend yield	'	'	3.60%	3.80%
Expected life	'	'	'6 years	'7 years

ShareBased_Compensation_Detail2

Share-Based Compensation (Details 1) (USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
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)	$40.42		'		'
Granted (in shares)	'		62,137		68,727
Granted, Weighted Average Grant Date Fair Value (in dollars per share)	$0		$41.84		$37.83
Vested (in shares)	'		-50,862		-34,793
Vested, Weighted Average Grant Date Fair Value (in dollars per share)	$39.12	[1]	'		'
Outstanding at end of year, Weighted Average Grant Date Fair Value (in dollars per share)	$41.71		$40.42		'
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)	$41.20		'		'
Granted, Weighted Average Grant Date Fair Value (in dollars per share)	$44.55		$41.20		'
Vested, Weighted Average Grant Date Fair Value (in dollars per share)	$41.53		'		'
Outstanding at end of year (in shares)	143,022	[2]	'		'
Outstanding at end of year, Weighted Average Grant Date Fair Value (in dollars per share)	$46.47		$41.20		'
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)	$41.30		'		'
Outstanding at beginning of year, Vested RSUs	1,048,863	[2]	'		'
Granted, Weighted Average Grant Date Fair Value (in dollars per share)	$49.45		$44.34		$37.94
Vested, Weighted Average Grant Date Fair Value (in dollars per share)	$40.33		'		'
Modified from time based, Weighted Average Grant Date Fair Value (in dollars per share)	$53.05	[3]	'		'
Outstanding at end of year, Weighted Average Grant Date Fair Value (in dollars per share)	$44.74		$41.30		'
Outstanding at end of year, Vested RSUs	1,158,407	[2]	1,048,863	[2]	'
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	88,491		'		'
Granted (in shares)	9,542		'		'
Vested (in shares)	0		'		'
Settled (in shares)	-16,338	[4]	'		'
Issuance of dividend equivalents (in shares)	0		'		'
Modified from time based (in shares)	61,327	[5]	'		'
Canceled, Vested RSUs and Total RSUs	0		'		'
Outstanding at beginning of year, Total RSUs	143,022		'		'
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	1,048,863		'		'
Granted (in shares)	173,758		'		'
Vested (in shares)	0		'		'
Settled (in shares)	-26,886	[6]	'		'
Issuance of dividend equivalents (in shares)	27,593	[7]	'		'
Modified from time based (in shares)	-61,327	[3]	'		'
Cancelled (in shares)	-3,594	[6],[8]	'		'
Outstanding at beginning of year, Total RSUs	1,158,407		'		'
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)	95,241		'		'
Granted (in shares)	0		'		'
Vested (in shares)	-47,291	[1]	'		'
Cancelled (in shares)	-20,880		'		'
Outstanding at end of year (in shares)	47,950		'		'
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]	'		'		'
Outstanding at beginning of year (in shares)	88,491		'		'
Granted (in shares)	9,542		103,239		'
Vested (in shares)	-16,338		'		'
Settled (in shares)	0	[4]	'		'
Issuance of dividend equivalents (in shares)	0		'		'
Outstanding at end of year (in shares)	143,022		88,491		'
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)	279,102		'		'
Granted (in shares)	173,758		204,829		107,673
Vested (in shares)	-89,873		'		'
Modified from time based (in shares)	-61,327	[3]	'		'
Outstanding at end of year (in shares)	301,660		279,102		'
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		-14,748		'
Vested, Weighted Average Grant Date Fair Value (in dollars per share)	$811,000		$695,000		'
Settled (in shares)	-16,338	[4]	'		'
Issuance of dividend equivalents (in shares)	0		'		'
Modified from time based (in shares)	0	[5]	'		'
Cancelled (in shares)	-8,526		'		'
Canceled, Vested RSUs and Total RSUs	0		'		'
Outstanding at end of year, Vested RSUs	0		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	769,761		'		'
Granted (in shares)	0		'		'
Vested (in shares)	-89,873		-73,688		-85,466
Settled (in shares)	-26,886	[6]	'		'
Issuance of dividend equivalents (in shares)	27,593	[7]	'		'
Modified from time based (in shares)	0	[3]	'		'
Cancelled (in shares)	-13,490		'		'
Canceled, Vested RSUs and Total RSUs	3,594	[6],[8]	'		'
Outstanding at end of year, Vested RSUs	856,747		769,761		'
[1]	The total shares vested include 20,880 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.
[2]	The amount includes nonvested RSUs. Does not include the 143,022 market measure-based RSUs since not all the necessary performance conditions have been met as of December 31, 2013.
[3]	On April 4, 2013, the terms of time-based RSUs granted to certain officers of the Company in January were modified to include market-measure based vesting requirements.
[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 April 4, 2013 the terms of time-based RSU’s granted to certain officers of the Company in January were modified to include market-measure and performance-based vesting requirements.
[6]	Represents vested RSUs that were settled in cash or shares of the Company’s common stock. Total shares settled include 13,490 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.
[7]	RSUs issued as dividend equivalents are vested upon issuance.
[8]	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.

ShareBased_Compensation_Detail3

Share-Based Compensation (Details 2) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Time-Based Restricted Stock Units (RSUs) [Member]	'		'		'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'
Granted, Weighted Average Grant Date Fair Value (in dollars per share)	$49.45		$44.34		$37.94
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	$40.33		'		'
Market Measure-Based Restricted Stock Units (RSUs) [Member]	'		'		'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'
Granted, Weighted Average Grant Date Fair Value (in dollars per share)	$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		'		'
Restricted Stock [Member]	'		'		'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'
Granted (in shares)	'		62,137		68,727
Granted, Weighted Average Grant Date Fair Value (in dollars per share)	$0		$41.84		$37.83
Vested (in shares)	'		-50,862		-34,793
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	$39.12	[1]	'		'
Vested, Total Vest-Date Fair Value	$2,290	[2]	$2,110	[2]	$1,334	[2]
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)	-89,873		-73,688		-85,466
Vested, Total Vest-Date Fair Value	$4,495	[3]	$3,118	[3]	$3,273	[3]
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		-14,748		'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	$811,000		$695,000		'
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)	173,758		204,829		107,673
Vested (in shares)	-89,873		'		'
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)	9,542		103,239		'
Vested (in shares)	-16,338		'		'
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)	0		'		'
Vested (in shares)	-47,291	[1]	'		'
[1]	The total shares vested include 20,880 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.
[2]	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.
[3]	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

ShareBased_Compensation_Stock_

Share-Based Compensation (Stock Options Activity) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]	'		'
Outstanding, Number of Options, End of Year	1,525,000		'
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	1,540,000		'
Granted (in shares)	0		'
Exercised (in shares)	-3,000		'
Forfeited (in shares)	-12,000		'
Outstanding, Number of Options, End of Year	1,525,000	[1],[2]	1,540,000
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		'
Granted, Exercise Price (in dollars per share)	$0		'
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],[2]	$42.61
Remaining Contractual Term	'8 years 2 months	[1],[2]	'
[1]	The total intrinsic value of options outstanding at December 31, 2013 was $11.5 million.
[2]	As of December 31, 2013, 305,000 of the outstanding stock options were exercisable.

Employee_Benefit_Plans_Employe

Employee Benefit Plans Employee Benefit Plans (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	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	900,000	700,000	600,000	'
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	$9,900,000	$7,300,000	'	'

Future_Minimum_Rent_Details

Future Minimum Rent (Details) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Future contractual minimum rent under operating lease	'
2014	$387,188
2015	371,948
2016	351,540
2017	309,221
2018	252,933
Thereafter	725,964
Total	$2,398,794

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Summary of minimum commitment	'
2014	$3,095
2015	3,095
2016	3,095
2017	3,095
2018	3,095
Thereafter	156,912
Total	$172,387	[1],[2],[3],[4]
[1]	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, 2013.
[2]	Reflects the minimum ground lease obligations before the impact of ground lease extension options.
[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, 2013.
[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, 2013.

Commitments_and_Contingencies_2

Commitments and Contingencies (Details 1) (USD $)	12 Months Ended					3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2011	Dec. 31, 2013
		Ten Year Ground Lease Extension Option [Member]	Forty-Five Year Ground Lease Extension Option [Member]	Property Damage Litigation Case [Member]	Property Damage Litigation Case [Member]	Former Tenant Litigation Case [Member]	Former Tenant Litigation Case [Member]	Former Tenant Litigation Case [Member]	Contracts And Executed Leases, Excluding Ground Leases [Member]
		Extensions	Extensions
Long-term Purchase Commitment [Line Items]	'	'	'	'	'	'	'	'	'
Commitments for contracts and executed leases, operating and redevelopment and development properties	'	'	'	'	'	'	'	'	$645.40
Number of extension options	'	3	1	'	'	'	'	'	'
Ground lease extension option term	'	'10 years	'45 years	'	'	'	'	'	'
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%	'	'	'	'	'	'	'	'
Proceeds from Legal Settlements	'	'	'	$5.20	$0.90	$0.90	$3.70	$3.70	'

Fair_Value_Measurements_and_Di2

Fair Value Measurements and Disclosures (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Assets and Liabilities Reported at Fair Value	'		'		'
Marketable securities	$10,008	[1],[2]	$7,435	[1],[2]	'
Fair value adjustment of marketable securities and deferred compensation plan liability	'		'		'
Net loss (gain) on marketable securities	$1,489		$723		($153)
[1]	The marketable securities are held in a limited rabbi trust.
[2]	Based on quoted prices in active markets for identical securities.

Fair_Value_Measurements_and_Di3

Fair Value Measurements and Disclosures (Details 1) (USD $)	Dec. 31, 2013		Dec. 31, 2012
Liabilities	'		'
Secured debt	$560,434,000		$561,096,000
Exchangeable senior notes, net	168,372,000		163,944,000
Unsecured debt, net	1,431,132,000		1,130,895,000
Unsecured line of credit	45,000,000		185,000,000
Fair Value [Member]	'		'
Liabilities	'		'
Secured debt	568,760,000	[1]	591,993,000	[1]
Exchangeable senior notes, net	178,190,000	[1]	181,223,000	[1]
Unsecured debt, net	1,523,052,000	[2]	1,254,047,000	[2]
Unsecured line of credit	45,012,000	[1]	185,049,000	[1]
Fair Value [Member] | Unsecured Debt [Member] | Level 1 [Member]	'		'
Liabilities	'		'
Debt	929,300,000		653,000,000
Fair Value [Member] | Unsecured Debt [Member] | Level 2 [Member]	'		'
Liabilities	'		'
Debt	593,700,000		601,000,000
Carrying Value [Member]	'		'
Liabilities	'		'
Secured debt	560,434,000	[1]	561,096,000	[1]
Exchangeable senior notes, net	168,372,000	[1]	163,944,000	[1]
Unsecured debt, net	1,431,132,000	[2]	1,130,895,000	[2]
Unsecured line of credit	45,000,000	[1]	185,000,000	[1]
Carrying Value [Member] | Unsecured Debt [Member] | Level 1 [Member]	'		'
Liabilities	'		'
Unsecured debt, net	873,500,000		573,000,000
Carrying Value [Member] | Unsecured Debt [Member] | Level 2 [Member]	'		'
Liabilities	'		'
Unsecured debt, net	$557,700,000		$558,000,000
[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]	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 $873.5 million and $929.3 million, respectively, as of December 31, 2013. The carrying value and fair value of the Level I instruments at December 31, 2012, was $573.0 million and $653.0 million, respectively. The carrying value and fair value of the Level II instruments was $557.7 million and $593.7 million, respectively, as of December 31, 2013. The carrying value and fair value of the Level II instruments at December 31, 2012, was $558.0 million and$601.0 million, respectively.

Discontinued_Operations_Discon

Discontinued Operations Discontinued Operations (Details) (USD $)

12 Months Ended

12 Months Ended

12 Months Ended

12 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2011

Dec. 31, 2013

Jan. 09, 2014

Dec. 31, 2013

Dec. 31, 2012

property

building

building

Land and Land Improvements [Member]

Building and Building Improvements [Member]

Real Estate [Member]

Properties Held for Sale [Member]

Properties Held for Sale [Member]

Agoura Road, 26541, Calabasas, CA [Member]

Kaiser Boulevard, Anaheim, California [Member]

Directors Place, Sorrento Mesa, California One [Member]

Innovation Drive and Genetic Center Drive, San Diego, CA [Member]

Industrial Portfolio and Other Properties [Member]

Industrial Portfolio [Member]

Carmino Ruiz CA [Member]

4175 E. La Palma Avenue, Anaheim, California [Member]

10350 Barnes Canyon and 10120 Pacific Heights Drive San Diego CA Disposition [Member]

2031 E Mariposa Avenue, Los Angeles, CA [Member]

San Diego, California

San Diego, California

Restricted cash [Member]

Restricted cash [Member]

building

sqft

sqft

building

building

sqft

sqft

sqft

building

building

sqft

sqft

sqft

building

sqft

Properties Held for Sale [Member]

Subsequent Event [Member]

sqft

sqft

building

building

building

sqft

sqft

building

building

building

sqft

building

building

Properties Held for Sale [Member]

building

Long Lived Assets Held-for-sale [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of real estate properties

3

46

3

'

'

'

12

[1]

0

1

1

1

2

44

39

[2]

4

1

2

1

12

12

'

'

Rentable square feet (unaudited)

'

'

'

'

'

'

1,049,035

[1]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Rentable Square Feet

200,306

3,975,665

282,611

'

'

'

'

'

90,156

59,790

50,360

253,676

3,721,989

3,413,354

[2]

265,372

43,263

90,558

192,053

'

'

'

'

Sales Price

$56,900,000

[3]

$500,300,000

[3]

$66,100,000

[3]

'

'

'

'

'

$14,700,000

[3]

$9,600,000

[3]

$32,600,000

[3]

$146,100,000

[3]

$354,200,000

[3]

'

'

'

$23,900,000

[3]

$42,200,000

[3]

'

'

'

'

Net proceeds received from dispositions of operating properties (Note 17)

21,178,000

263,572,000

64,171,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

32,200,000

228,800,000

Land and improvements

'

'

'

49,656,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Buildings and improvements

'

'

'

'

209,594,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total real estate held for sale

'

'

'

'

'

259,250,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Accumulated depreciation and amortization

'

'

'

'

'

63,110,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Current receivables, net

269,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred rent receivables, net

8,978,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred leasing costs and acquisition-related intangible assets, net

5,791,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Prepaid expenses and other assets, net

1,922,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Real estate and other assets held for sale, net

213,100,000

'

'

'

'

196,140,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Accounts payable, accrued expenses and other liabilities

1,153,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred revenue and acquisition-related intangible liabilities, net

10,723,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Rents received in advance and tenant security deposits

2,571,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Liabilities and deferred revenue of real estate assets held for sale

$14,447,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

The San Diego Properties included the following: 10020 Pacific Mesa Boulevard, 6055 Lusk Avenue, 5010 and 5005 Wateridge Vista Drive, 15435 and 15445 Innovation Drive, and 15051, 15073, 15231, 15253, 15333 and 15378 Avenue of Science.

[2]

The industrial portfolio was sold in two tranches in November and December 2012 to two separate third party buyers.

[3]

Represents gross sales price before the impact of broker commissions and closing costs.

Discontinued_Operations_Detail

Discontinued Operations (Details 1) (USD $)

3 Months Ended

12 Months Ended

In Thousands, unless otherwise specified

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Rental income

'

'

'

'

'

'

'

'

$24,694

$42,240

$59,266

Tenant reimbursements

'

'

'

'

'

'

'

'

3,408

6,322

8,522

Other property income

'

'

'

'

'

'

'

'

4,619

1,912

4,935

Total revenues

'

'

'

'

'

'

'

'

32,721

50,474

72,723

Property expenses

'

'

'

'

'

'

'

'

4,716

7,724

9,832

Real estate taxes

'

'

'

'

'

'

'

'

2,784

4,935

6,652

Provision for bad debts

'

'

'

'

'

'

'

'

-8

-195

-51

Ground leases

'

'

'

'

'

'

'

'

0

0

214

Depreciation and amortization

'

'

'

'

'

'

'

'

8,753

16,649

20,966

Interest expense

'

'

'

'

'

'

'

'

0

[1]

0

[1]

3,624

[1]

Total expenses

'

'

'

'

'

'

'

'

16,245

29,113

41,237

Income from discontinued operations before net gain on dispositions of discontinued operations

'

'

'

'

'

'

'

'

16,476

21,361

31,486

Net gain on dispositions of discontinued operations

'

'

'

'

'

'

'

'

12,252

259,245

51,587

Total income from discontinued operations

17,516

[2],[3]

6,344

[2],[3]

2,666

[2],[3]

2,202

[2],[3]

192,274

[2],[3]

4,663

[2],[3]

4,150

[2],[3]

79,519

[2],[3]

28,728

280,606

83,073

6.51% Mortgage Payable due February 1, 2017 [Member] | Mortgage Loans on Real Estate [Member]

'

'

'

'

'

'

'

'

'

'

'

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Principal amount

'

'

'

'

'

'

'

'

'

'

$70,000

Number of properties, collateral

'

'

'

'

'

'

'

'

'

'

13

[1]

Interest expense relates to a $70.0 million mortgage loan that was secured by 13 of our industrial properties. The mortgage loan was repaid in October 2011 prior to maturity.

[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 impact of equity offerings that occurred during the years ended December 31, 2013 and 2012.

[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 17 “Discontinued Operations” 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, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Numerator:

'

'

'

'

'

'

'

'

'

'

'

Income (loss) from continuing operations

$5,531

[1],[2]

$2,683

[1],[2]

$7,437

[1],[2]

$186

[1],[2]

$1,357

[1],[2]

($2,141)

[1],[2]

($1,873)

[1],[2]

($848)

[1],[2]

$15,837

($3,505)

($15,584)

(Income) loss from continuing operations attributable to noncontrolling common units of the Operating Partnership

'

'

'

'

'

'

'

'

-56

609

863

Preferred dividends and distributions

-3,312

[1]

-3,312

[1]

-3,313

[1]

-3,313

[1]

-3,313

[1]

-5,342

[1]

-3,097

[1]

-9,336

[1]

-13,250

-21,088

-15,196

Allocation to participating securities (1)

'

'

'

'

'

'

'

'

-1,689

-1,602

-1,309

Numerator for basic and diluted income (loss) from continuing operations available to common stockholders

'

'

'

'

'

'

'

'

842

-25,586

-31,226

Income from discontinued operations

17,516

[1],[2]

6,344

[1],[2]

2,666

[1],[2]

2,202

[1],[2]

192,274

[1],[2]

4,663

[1],[2]

4,150

[1],[2]

79,519

[1],[2]

28,728

280,606

83,073

Income from discontinued operations attributable to noncontrolling common units of the Operating Partnership

'

'

'

'

'

'

'

'

-629

-6,796

-2,337

Numerator for basic and diluted net income available to common stockholders

'

'

'

'

'

'

'

'

$28,941

$248,224

$49,510

Denominator:

'

'

'

'

'

'

'

'

'

'

'

Basic weighted average vested shares outstanding

'

'

'

'

'

'

'

'

77,343,853

69,639,623

56,717,121

Effect of dilutive securities – contingently issuable shares and stock options

'

'

'

'

'

'

'

'

1,765,025

0

0

Diluted weighted average vested shares and common stock equivalents outstanding

'

'

'

'

'

'

'

'

79,108,878

69,639,623

56,717,121

Basic earnings per share:

'

'

'

'

'

'

'

'

'

'

'

Income (loss) from continuing operations available to common stockholders per share (dollars per share)

'

'

'

'

'

'

'

'

$0.01

($0.37)

($0.55)

Income from discontinued operations per share of common stock (dollars per share)

'

'

'

'

'

'

'

'

$0.36

$3.93

$1.42

Net income available to common stockholders per share (dollars per share)

$0.23

[1]

$0.07

[1]

$0.08

[1]

($0.02)

[1]

$2.49

[1]

($0.04)

[1]

($0.02)

[1]

$1.06

[1]

$0.37

$3.56

$0.87

Diluted earnings per share:

'

'

'

'

'

'

'

'

'

'

'

Income (loss) from continuing operations available to common stockholders per share (dollars per share)

'

'

'

'

'

'

'

'

$0.01

($0.37)

($0.55)

Income from discontinued operations per share of common stock (dollars per share)

'

'

'

'

'

'

'

'

$0.35

$3.93

$1.42

Net income available to common stockholders per share (dollars per share)

$0.23

[1]

$0.07

[1]

$0.08

[1]

($0.02)

[1]

$2.49

[1]

($0.04)

[1]

($0.02)

[1]

$1.06

[1]

$0.36

$3.56

$0.87

Number of options, outstanding

1,525,000

'

'

'

'

'

'

'

1,525,000

'

'

Market Measure-Based Restricted Stock Units (RSUs) [Member]

'

'

'

'

'

'

'

'

'

'

'

Diluted earnings per share:

'

'

'

'

'

'

'

'

'

'

'

Number of RSUs outstanding

143,022

[3]

'

'

'

'

'

'

'

143,022

[3]

'

'

[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 impact of equity offerings that occurred during the years ended December 31, 2013 and 2012.

[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 17 “Discontinued Operations” for additional information).

[3]

The amount includes nonvested RSUs. Does not include the 143,022 market measure-based RSUs since not all the necessary performance conditions have been met as of December 31, 2013.

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, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Numerator:

'

'

'

'

'

'

'

'

'

'

'

Income (loss) from continuing operations

$5,531

[1],[2]

$2,683

[1],[2]

$7,437

[1],[2]

$186

[1],[2]

$1,357

[1],[2]

($2,141)

[1],[2]

($1,873)

[1],[2]

($848)

[1],[2]

$15,837

($3,505)

($15,584)

Income from continuing operations attributable to noncontrolling interests in consolidated subsidiaries

'

'

'

'

'

'

'

'

-56

609

863

Preferred dividends and distributions

-3,312

[1]

-3,312

[1]

-3,313

[1]

-3,313

[1]

-3,313

[1]

-5,342

[1]

-3,097

[1]

-9,336

[1]

-13,250

-21,088

-15,196

Allocation to participating securities (1)

'

'

'

'

'

'

'

'

-1,689

-1,602

-1,309

Numerator for basic and diluted income (loss) from continuing operations available to common unitholders

'

'

'

'

'

'

'

'

842

-25,586

-31,226

Income from discontinued operations

17,516

[1],[2]

6,344

[1],[2]

2,666

[1],[2]

2,202

[1],[2]

192,274

[1],[2]

4,663

[1],[2]

4,150

[1],[2]

79,519

[1],[2]

28,728

280,606

83,073

Income from discontinued operations attributable to noncontrolling interests in consolidated subsidiaries

'

'

'

'

'

'

'

'

-629

-6,796

-2,337

Numerator for basic and diluted net income available to common unitholders

'

'

'

'

'

'

'

'

28,941

248,224

49,510

Denominator:

'

'

'

'

'

'

'

'

'

'

'

Basic weighted average vested shares outstanding

'

'

'

'

'

'

'

'

77,343,853

69,639,623

56,717,121

Effect of dilutive securities – contingently issuable shares and stock options

'

'

'

'

'

'

'

'

1,765,025

0

0

Diluted weighted average vested units and common unit equivalents outstanding

'

'

'

'

'

'

'

'

79,108,878

69,639,623

56,717,121

Basic earnings per unit:

'

'

'

'

'

'

'

'

'

'

'

Income (loss) from continuing operations available to common unitholders per unit (dollars per unit)

'

'

'

'

'

'

'

'

$0.01

($0.37)

($0.55)

Income from discontinued operations per common unit (dollars per unit)

'

'

'

'

'

'

'

'

$0.36

$3.93

$1.42

Net income available to common unitholders per unit (dollars per unit)

$0.23

[1]

$0.07

[1]

$0.08

[1]

($0.02)

[1]

$2.49

[1]

($0.04)

[1]

($0.02)

[1]

$1.06

[1]

$0.37

$3.56

$0.87

Diluted earnings per unit:

'

'

'

'

'

'

'

'

'

'

'

Income (loss) from continuing operations available to common unitholders per unit (dollars per unit)

'

'

'

'

'

'

'

'

$0.01

($0.37)

($0.55)

Income from discontinued operations per common unit (dollars per unit)

'

'

'

'

'

'

'

'

$0.35

$3.93

$1.42

Net income available to common unitholders per unit (dollars per unit)

$0.23

[1]

$0.07

[1]

$0.08

[1]

($0.02)

[1]

$2.49

[1]

($0.04)

[1]

($0.02)

[1]

$1.06

[1]

$0.36

$3.56

$0.87

Number of options, outstanding

1,525,000

'

'

'

'

'

'

'

1,525,000

'

'

Kilroy Realty, L.P. [Member]

'

'

'

'

'

'

'

'

'

'

'

Numerator:

'

'

'

'

'

'

'

'

'

'

'

Income (loss) from continuing operations

5,531

[1],[3]

2,683

[1],[3]

7,437

[1],[3]

186

[1],[3]

1,357

[1],[3]

-2,141

[1],[3]

-1,873

[1],[3]

-848

[1],[3]

15,837

-3,505

-15,584

Income from continuing operations attributable to noncontrolling interests in consolidated subsidiaries

'

'

'

'

'

'

'

'

-224

-174

-529

Preferred dividends and distributions

-3,312

[1]

-3,312

[1]

-3,313

[1]

-3,313

[1]

-3,313

[1]

-5,342

[1]

-3,097

[1]

-9,336

[1]

-13,250

-21,088

-15,196

Allocation to participating securities (1)

'

'

'

'

'

'

'

'

-1,689

[4]

-1,602

[4]

-1,309

[4]

Numerator for basic and diluted income (loss) from continuing operations available to common unitholders

'

'

'

'

'

'

'

'

674

-26,369

-32,618

Income from discontinued operations

17,516

[1],[3]

6,344

[1],[3]

2,666

[1],[3]

2,202

[1],[3]

192,274

[1],[3]

4,663

[1],[3]

4,150

[1],[3]

79,519

[1],[3]

28,728

280,606

83,073

Income from discontinued operations attributable to noncontrolling interests in consolidated subsidiaries

'

'

'

'

'

'

'

'

0

-464

0

Numerator for basic and diluted net income available to common unitholders

'

'

'

'

'

'

'

'

$29,402

$253,773

$50,455

Denominator:

'

'

'

'

'

'

'

'

'

'

'

Basic weighted average vested shares outstanding

'

'

'

'

'

'

'

'

79,166,260

71,403,258

58,437,444

Effect of dilutive securities – contingently issuable shares and stock options

'

'

'

'

'

'

'

'

1,765,025

0

0

Diluted weighted average vested units and common unit equivalents outstanding

'

'

'

'

'

'

'

'

80,931,285

71,403,258

58,437,444

Basic earnings per unit:

'

'

'

'

'

'

'

'

'

'

'

Income (loss) from continuing operations available to common unitholders per unit (dollars per unit)

'

'

'

'

'

'

'

'

$0.01

($0.37)

($0.56)

Net income available to common unitholders per unit (dollars per unit)

$0.23

[1]

$0.07

[1]

$0.08

[1]

($0.02)

[1]

$2.48

[1]

($0.04)

[1]

($0.02)

[1]

$1.05

[1]

$0.37

$3.56

$0.86

Diluted earnings per unit:

'

'

'

'

'

'

'

'

'

'

'

Income (loss) from continuing operations available to common unitholders per unit (dollars per unit)

'

'

'

'

'

'

'

'

$0.01

($0.37)

($0.56)

Income from discontinued operations per common unit (dollars per unit)

'

'

'

'

'

'

'

'

$0.35

$3.93

$1.42

Net income available to common unitholders per unit (dollars per unit)

$0.23

[1]

$0.07

[1]

$0.08

[1]

($0.02)

[1]

$2.44

[1]

($0.04)

[1]

($0.02)

[1]

$1.05

[1]

$0.36

$3.56

$0.86

Market Measure-Based Restricted Stock Units (RSUs) [Member]

'

'

'

'

'

'

'

'

'

'

'

Diluted earnings per unit:

'

'

'

'

'

'

'

'

'

'

'

Number of RSUs outstanding

143,022

[5]

'

'

'

'

'

'

'

143,022

[5]

'

'

[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 impact of equity offerings that occurred during the years ended December 31, 2013 and 2012.

[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 17 “Discontinued Operations” 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 17 “Discontinued Operations”).

[4]

Participating securities include nonvested shares, vested and non-vested time-based RSUs and vested market-measure RSUs.

[5]

The amount includes nonvested RSUs. Does not include the 143,022 market measure-based RSUs since not all the necessary performance conditions have been met as of December 31, 2013.

Tax_Treatment_of_Distributions2

Tax Treatment of Distributions (Details) (USD $)	1 Months Ended	12 Months Ended
	Feb. 13, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Class of Stock [Line Items]	'	'	'	'
Dividends declared per common share	$0.35	$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 $)

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Aug. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Apr. 16, 2012

Dec. 31, 2012

Dec. 31, 2011

Apr. 16, 2012

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2012

Dec. 31, 2011

Common Stock

Common Stock

Common Stock

Series G Cumulative Redeemable Preferred Stock

Series G Cumulative Redeemable Preferred Stock

Series G Cumulative Redeemable Preferred Stock

Series H Cumulative Redeemable Preferred Stock

Series H Cumulative Redeemable Preferred Stock

Series H Cumulative Redeemable Preferred Stock

Series E Cumulative Redeemable Preferred Stock

Series E Cumulative Redeemable Preferred Stock

Series E Cumulative Redeemable Preferred Stock

Series F Cumulative Redeemable Preferred Stock

Series F Cumulative Redeemable Preferred Stock

Series F Cumulative Redeemable Preferred Stock

Tax Treatment, Ordinary Income

Tax Treatment, Ordinary Income

Tax Treatment, Ordinary Income

Tax Treatment, Ordinary Income

Tax Treatment, Ordinary Income

Tax Treatment, Ordinary Income

Tax Treatment, Ordinary Income

Tax Treatment, Ordinary Income

Tax Treatment, Ordinary Income

Tax Treatment, Ordinary Income

Tax Treatment, Ordinary Income

Tax Treatment, Qualified Dividend

Tax Treatment, Qualified Dividend

Tax Treatment, Qualified Dividend

Tax Treatment, Qualified Dividend

Tax Treatment, Qualified Dividend

Tax Treatment, Qualified Dividend

Tax Treatment, Qualified Dividend

Tax Treatment, Return of Capital

Tax Treatment, Return of Capital

Tax Treatment, Return of Capital

Tax Treatment, Capital Gains

Tax Treatment, Capital Gains

Tax Treatment, Capital Gains

Tax Treatment, Capital Gains

Tax Treatment, Capital Gains

Tax Treatment, Capital Gains

Tax Treatment, Capital Gains

Tax Treatment, Capital Gains

Tax Treatment, Capital Gains

Tax Treatment, Capital Gains

Tax Treatment, Capital Gains

Tax Treatment, Unrecaptured Section 1250 Gains

Tax Treatment, Unrecaptured Section 1250 Gains

Tax Treatment, Unrecaptured Section 1250 Gains

Tax Treatment, Unrecaptured Section 1250 Gains

Tax Treatment, Unrecaptured Section 1250 Gains

Tax Treatment, Unrecaptured Section 1250 Gains

Tax Treatment, Unrecaptured Section 1250 Gains

Tax Treatment, Unrecaptured Section 1250 Gains

Tax Treatment, Unrecaptured Section 1250 Gains

Tax Treatment, Unrecaptured Section 1250 Gains

Tax Treatment, Unrecaptured Section 1250 Gains

Common Stock

Common Stock

Common Stock

Series G Cumulative Redeemable Preferred Stock

Series G Cumulative Redeemable Preferred Stock

Series H Cumulative Redeemable Preferred Stock

Series H Cumulative Redeemable Preferred Stock

Series E Cumulative Redeemable Preferred Stock

Series E Cumulative Redeemable Preferred Stock

Series F Cumulative Redeemable Preferred Stock

Series F Cumulative Redeemable Preferred Stock

Common Stock

Common Stock

Common Stock

Series G Cumulative Redeemable Preferred Stock

Series G Cumulative Redeemable Preferred Stock

Series H Cumulative Redeemable Preferred Stock

Series H Cumulative Redeemable Preferred Stock

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Series G Cumulative Redeemable Preferred Stock

Series G Cumulative Redeemable Preferred Stock

Series H Cumulative Redeemable Preferred Stock

Series H Cumulative Redeemable Preferred Stock

Series E Cumulative Redeemable Preferred Stock

Series E Cumulative Redeemable Preferred Stock

Series F Cumulative Redeemable Preferred Stock

Series F Cumulative Redeemable Preferred Stock

Common Stock

Common Stock

Common Stock

Series G Cumulative Redeemable Preferred Stock

Series G Cumulative Redeemable Preferred Stock

Series H Cumulative Redeemable Preferred Stock

Series H Cumulative Redeemable Preferred Stock

Series E Cumulative Redeemable Preferred Stock

Series E Cumulative Redeemable Preferred Stock

Series F Cumulative Redeemable Preferred Stock

Series F Cumulative Redeemable Preferred Stock

Income Tax Treatment of Dividends Paid [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Dividends paid per common share

'

'

$1.40

$1.40

$1.40

'

'

'

'

'

'

'

'

'

'

'

'

$0.76

$0.58

$0.23

'

'

'

'

'

'

'

'

$0.00

$0

$0

'

'

'

'

$0.62

$0.82

$1.17

$0

[1]

$0

[1]

$0

[1]

'

'

'

'

'

'

'

'

$0.02

$0

$0

'

'

'

'

'

'

'

'

Common Stock, Dividends, Per Share, Cash Paid, Percentage

'

'

100.00%

100.00%

100.00%

'

'

'

'

'

'

'

'

'

'

'

'

54.00%

41.21%

16.43%

'

'

'

'

'

'

'

'

0.21%

0.00%

0.00%

'

'

'

'

44.29%

58.79%

83.57%

0.00%

[1]

0.00%

[1]

0.00%

[1]

'

'

'

'

'

'

'

'

1.50%

0.00%

0.00%

'

'

'

'

'

'

'

'

Preferred stock, dividend rate

'

'

'

'

'

6.88%

6.88%

6.88%

6.38%

6.38%

6.38%

7.80%

'

'

7.50%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Capital gains, federal statutory tax rate

20.00%

15.00%

20.00%

'

15.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Preferred Stock, Dividends, Per Share, Cash Paid

'

'

'

'

'

'

$1.72

$1.09

'

$1.59

$0.40

'

$0.82

$1.95

'

$0.79

$1.88

'

'

'

$1.67

$1.09

$1.55

$0.40

$0.82

$1.95

$0.79

$1.88

'

'

'

$0.01

$0

$0.01

$0

'

'

'

'

'

'

$0

[2]

$0

[2]

$0

[2]

$0

[2]

$0

[3]

$0

[3]

$0

[3]

$0

[3]

'

'

'

$0.05

$0

$0.04

$0

$0

$0

$0

$0

Preferred Stock, Dividends, Per Share, Cash Paid, Percentage

'

'

'

'

'

'

100.00%

100.00%

'

100.00%

100.00%

'

100.00%

100.00%

'

100.00%

100.00%

'

'

'

97.03%

100.00%

96.99%

100.00%

100.00%

100.00%

100.00%

100.00%

'

'

'

0.35%

0.00%

0.38%

0.00%

'

'

'

'

'

'

0.00%

[2]

0.00%

[2]

0.00%

[2]

0.00%

[2]

0.00%

[3]

0.00%

[3]

0.00%

[3]

0.00%

[3]

'

'

'

2.62%

0.00%

2.63%

0.00%

0.00%

0.00%

0.00%

0.00%

[1]

Capital gains are comprised entirely of 20% rate gains for 2013 and 15% rate gains for 2012 and 2011.

[2]

Capital gains are comprised entirely of 20% rate gains for 2013 and 15% rate gains for 2012.

[3]

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, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Quarterly Financial Information Disclosure [Abstract]	'		'		'		'		'		'		'		'		'	'	'
Revenues from continuing operations	$120,602	[1],[2]	$115,697	[1],[2]	$117,835	[1],[2]	$110,964	[1],[2]	$104,573	[1],[2]	$98,985	[1],[2]	$91,584	[1],[2]	$85,858	[1],[2]	$465,098	$381,000	$310,424
Income (loss) from continuing operations	5,531	[1],[2]	2,683	[1],[2]	7,437	[1],[2]	186	[1],[2]	1,357	[1],[2]	-2,141	[1],[2]	-1,873	[1],[2]	-848	[1],[2]	15,837	-3,505	-15,584
Income from discontinued operations	17,516	[1],[2]	6,344	[1],[2]	2,666	[1],[2]	2,202	[1],[2]	192,274	[1],[2]	4,663	[1],[2]	4,150	[1],[2]	79,519	[1],[2]	28,728	280,606	83,073
Net income	23,047	[1]	9,027	[1]	10,103	[1]	2,388	[1]	193,631	[1]	2,522	[1]	2,277	[1]	78,671	[1]	44,565	277,101	67,489
Net income attributable to Kilroy Realty Corporation	22,628	[1]	8,897	[1]	9,946	[1]	2,409	[1]	189,152	[1]	2,589	[1]	2,297	[1]	76,876	[1]	43,880	270,914	66,015
Preferred dividends and distributions	-3,312	[1]	-3,312	[1]	-3,313	[1]	-3,313	[1]	-3,313	[1]	-5,342	[1]	-3,097	[1]	-9,336	[1]	-13,250	-21,088	-15,196
Net (loss) income available to common stockholders	$19,316	[1]	$5,585	[1]	$6,633	[1]	($904)	[1]	$185,839	[1]	($2,753)	[1]	($800)	[1]	$67,540	[1]	$30,630	$249,826	$50,819
Net income (loss) available to common stockholders per share—basic (dollars per share)	$0.23	[1]	$0.07	[1]	$0.08	[1]	($0.02)	[1]	$2.49	[1]	($0.04)	[1]	($0.02)	[1]	$1.06	[1]	$0.37	$3.56	$0.87
Net income (loss) available to common stockholders per share—diluted (dollars per share)	$0.23	[1]	$0.07	[1]	$0.08	[1]	($0.02)	[1]	$2.49	[1]	($0.04)	[1]	($0.02)	[1]	$1.06	[1]	$0.36	$3.56	$0.87
[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 impact of equity offerings that occurred during the years ended December 31, 2013 and 2012.
[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 17 “Discontinued Operations” 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, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues from continuing operations	$120,602	[1],[2]	$115,697	[1],[2]	$117,835	[1],[2]	$110,964	[1],[2]	$104,573	[1],[2]	$98,985	[1],[2]	$91,584	[1],[2]	$85,858	[1],[2]	$465,098	$381,000	$310,424
Income (loss) from continuing operations	5,531	[1],[2]	2,683	[1],[2]	7,437	[1],[2]	186	[1],[2]	1,357	[1],[2]	-2,141	[1],[2]	-1,873	[1],[2]	-848	[1],[2]	15,837	-3,505	-15,584
Income from discontinued operations	17,516	[1],[2]	6,344	[1],[2]	2,666	[1],[2]	2,202	[1],[2]	192,274	[1],[2]	4,663	[1],[2]	4,150	[1],[2]	79,519	[1],[2]	28,728	280,606	83,073
Net income	23,047	[1]	9,027	[1]	10,103	[1]	2,388	[1]	193,631	[1]	2,522	[1]	2,277	[1]	78,671	[1]	44,565	277,101	67,489
Net income attributable to the Operating Partnership	22,628	[1]	8,897	[1]	9,946	[1]	2,409	[1]	189,152	[1]	2,589	[1]	2,297	[1]	76,876	[1]	43,880	270,914	66,015
Preferred distributions	-3,312	[1]	-3,312	[1]	-3,313	[1]	-3,313	[1]	-3,313	[1]	-5,342	[1]	-3,097	[1]	-9,336	[1]	-13,250	-21,088	-15,196
Net (loss) income available to common stockholders	19,316	[1]	5,585	[1]	6,633	[1]	-904	[1]	185,839	[1]	-2,753	[1]	-800	[1]	67,540	[1]	30,630	249,826	50,819
Net income (loss) available to common stockholders per share—basic (dollars per share)	$0.23	[1]	$0.07	[1]	$0.08	[1]	($0.02)	[1]	$2.49	[1]	($0.04)	[1]	($0.02)	[1]	$1.06	[1]	$0.37	$3.56	$0.87
Net income (loss) available to common stockholders per share—diluted (dollars per share)	$0.23	[1]	$0.07	[1]	$0.08	[1]	($0.02)	[1]	$2.49	[1]	($0.04)	[1]	($0.02)	[1]	$1.06	[1]	$0.36	$3.56	$0.87
Kilroy Realty, L.P. [Member]	'		'		'		'		'		'		'		'		'	'	'
Revenues from continuing operations	120,602	[1],[3]	115,697	[1],[3]	117,835	[1],[3]	110,964	[1],[3]	104,573	[1],[3]	98,985	[1],[3]	91,584	[1],[3]	85,858	[1],[3]	465,098	381,000	310,424
Income (loss) from continuing operations	5,531	[1],[3]	2,683	[1],[3]	7,437	[1],[3]	186	[1],[3]	1,357	[1],[3]	-2,141	[1],[3]	-1,873	[1],[3]	-848	[1],[3]	15,837	-3,505	-15,584
Income from discontinued operations	17,516	[1],[3]	6,344	[1],[3]	2,666	[1],[3]	2,202	[1],[3]	192,274	[1],[3]	4,663	[1],[3]	4,150	[1],[3]	79,519	[1],[3]	28,728	280,606	83,073
Net income	23,047	[1]	9,027	[1]	10,103	[1]	2,388	[1]	193,631	[1]	2,522	[1]	2,277	[1]	78,671	[1]	44,565	277,101	67,489
Net income attributable to the Operating Partnership	23,001	[1]	8,980	[1]	10,041	[1]	2,319	[1]	193,137	[1]	2,474	[1]	2,234	[1]	78,618	[1]	44,341	276,463	66,960
Preferred distributions	-3,312	[1]	-3,312	[1]	-3,313	[1]	-3,313	[1]	-3,313	[1]	-5,342	[1]	-3,097	[1]	-9,336	[1]	-13,250	-21,088	-15,196
Net (loss) income available to common stockholders	$19,689	[1]	$5,668	[1]	$6,728	[1]	($994)	[1]	$189,824	[1]	($2,868)	[1]	($863)	[1]	$69,282	[1]	$31,091	$255,375	$51,764
Net income (loss) available to common stockholders per share—basic (dollars per share)	$0.23	[1]	$0.07	[1]	$0.08	[1]	($0.02)	[1]	$2.48	[1]	($0.04)	[1]	($0.02)	[1]	$1.05	[1]	$0.37	$3.56	$0.86
Net income (loss) available to common stockholders per share—diluted (dollars per share)	$0.23	[1]	$0.07	[1]	$0.08	[1]	($0.02)	[1]	$2.44	[1]	($0.04)	[1]	($0.02)	[1]	$1.05	[1]	$0.36	$3.56	$0.86
[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 impact of equity offerings that occurred during the years ended December 31, 2013 and 2012.
[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 17 “Discontinued Operations” 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 17 “Discontinued Operations”).

Subsequent_Events_Details

Subsequent Events (Details) (USD $)

1 Months Ended

12 Months Ended

0 Months Ended

1 Months Ended

Feb. 13, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Jan. 15, 2014

Jan. 09, 2014

Jan. 29, 2014

Jan. 29, 2014

Jan. 29, 2014

Jan. 29, 2014

Feb. 13, 2014

Feb. 13, 2014

property

building

building

Properties Held for Sale [Member]

Properties Held for Sale [Member]

Properties Held for Sale [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Series G Preferred Stock [Member]

Series H Preferred Stock [Member]

building

building

building

San Diego, California

Properties Held for Sale [Member]

Executive Officer [Member]

Market and Performance-based Vesting [Member]

Market and Performance-based Vesting [Member]

Market and Performance-based Vesting [Member]

building

San Diego, California

Restricted Stock Units (RSUs) [Member]

Executive Officer [Member]

Executive Officer [Member]

Executive Officer [Member]

building

Restricted Stock Units (RSUs) [Member]

Time-Based Restricted Stock Units (RSUs) [Member]

Market Measure-Based Restricted Stock Units (RSUs) [Member]

Subsequent Event [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of buildings

'

3

46

3

12

[1]

0

12

'

12

'

'

'

'

'

'

Purchase price of properties sold

'

'

'

'

'

'

'

'

$294,700,000

'

'

'

'

'

'

Payments of Dividends

'

'

'

'

'

'

'

29,800,000

'

'

'

'

'

'

'

Granted (in shares)

'

'

'

'

'

'

'

'

'

236,604

119,098

'

'

'

'

Total unrecognized compensation cost weighted-average period

'

'2 years 2 months

'

'

'

'

'

'

'

'

'

'4 years

'3 years

'

'

Common Stock, Dividends, Per Share, Declared

$0.35

$1.40

$1.40

$1.40

'

'

'

'

'

'

'

'

'

'

'

Dividends, Preferred Stock

'

$13,250,000

$14,108,000

$15,196,000

'

'

'

'

'

'

'

'

'

$0.43

$0.40

[1]

The San Diego Properties included the following: 10020 Pacific Mesa Boulevard, 6055 Lusk Avenue, 5010 and 5005 Wateridge Vista Drive, 15435 and 15445 Innovation Drive, and 15051, 15073, 15231, 15253, 15333 and 15378 Avenue of Science.

Schedule_II_Valuation_and_Qual1

Schedule II Valuation and Qualifying Accounts (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Allowance for Uncollectible Tenant Receivables	'		'		'
Movement in Valuation Allowances and Reserves [Roll Forward]	'		'		'
Balance at Beginning of Period	$2,581		$2,590		$2,819
Charged to Costs and Expenses	396	[1]	-42	[1]	923	[1]
Recoveries (Deductions)	-843		33		-1,152
Balance at End of Period	2,134		2,581		2,590
Allowance for Unbilled Deferred Rent	'		'		'
Movement in Valuation Allowances and Reserves [Roll Forward]	'		'		'
Balance at Beginning of Period	2,607		3,406		3,831
Charged to Costs and Expenses	0	[1]	0	[1]	-279	[1]
Recoveries (Deductions)	-532		-799		-146
Balance at End of Period	$2,075		$2,607		$3,406
[1]	Includes amounts reported in Discontinued Operations (see Note 17 “Discontinued Operations”).

Schedule_III_Real_Estate_and_A1

Schedule III - Real Estate and Accumulated Depreciation (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2013
In Thousands, unless otherwise specified						Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Office Building [Member]		Undeveloped Land and CIP Properties [Member]
						sqft		23925 Park Sorrento, Calabasas, California [Member]		23975 Park Sorrento, Calabasas, California [Member]		24025 Park Sorrento, Calabasas, California [Member]		2240 E. Imperial Highway, El Segundo, California [Member]		2250 E. Imperial Highway, El Segundo, California [Member]		2260 E. Imperial Highway, El Segundo, California [Member]		909 Sepulveda Boulevard, El Segundo, California [Member]		999 Sepulveda Boulevard, El Segundo, California [Member]		3750 Kilroy Airport Way, Long Beach, California [Member]		3760 Kilroy Airport Way, Long Beach, California [Member]		3780 Kilroy Airport Way, Long Beach, California [Member]		3800 Kilroy Airport Way, Long Beach, California [Member]		3840 Kilroy Airport Way, Long Beach, California [Member]		3880 Kilroy Airport Way, Long Beach, California [Member]		3900 Kilroy Airport Way, Long Beach, California [Member]		Kilroy Airport Center, Phase IV, Long Beach, California [Member]		12100 W. Olympic Boulevard, Los Angeles, California [Member]		12200 W. Olympic Boulevard, Los Angeles, California [Member]		12233 Olympic Blvd, Los Angeles, CA [Member]		12312 W. Olympic Boulevard, Los Angeles, California [Member]		6255 Sunset Boulevard, Los Angeles, CA [Member]		1633 26th Street, Santa Monica, California [Member]		2100 Colorado Avenue, Santa Monica, California [Member]		3130 Wilshire Boulevard, Santa Monica, California [Member]		501 Santa Monica Boulevard, Santa Monica, California [Member]		2829 Townsgate Road, Thousand Oaks, California [Member]		12225 El Camino Real, Del Mar, California [Member]		12235 El Camino Real, Del Mar, California [Member]		12340 El Camino Real, Del Mar, California [Member]		12390 El Camino Real, Del Mar, California [Member]		12348 High Bluff Drive, Del Mar, California [Member]		12400 High Bluff Drive, Del Mar, California [Member]		3579 Valley Centre Drive, Del Mar, California One [Member]		3611 Valley Centre Drive, Del Mar, California [Member]		3661 Valley Centre Drive, Del Mar, California [Member]		3721 Valley Centre Drive, Del Mar, California [Member]		3811 Valley Centre Drive, Del Mar, California [Member]		El Camino Real, Del Mar, California Five [Member]		El Camino Real, Del Mar, California Six [Member]		6200 Greenwich Drive, Governor Park, California [Member]		6220 Greenwich Drive, Governor Park, California [Member]		13280 Evening Creek Drive, South I-15 Corridor, California [Member]		13290 Evening Creek Drive, South I-15 Corridor, California [Member]		13480 Evening Creek Drive, North I-15 Corridor, California [Member]		13500 Evening Creek Drive, North I-15 Corridor, California [Member]		13520 Evening Creek Drive, North I-15 Corridor, California [Member]		7525 Torrey Santa Fe, 56 Corridor, California [Member]		7535 Torrey Santa Fe, 56 Corridor, California [Member]		7545 Torrey Santa Fe, 56 Corridor, California [Member]		7555 Torrey Santa Fe, 56 Corridor, California [Member]		2355 Northside Drive, Mission Valley, California [Member]		2365 Northside Drive, Mission Valley, California [Member]		2375 Northside Drive, Mission Valley, California [Member]		2385 Northside Drive, Mission Valley, California [Member]		2305 Historic Decatur Road, San Diego, California [Member]		4921 Directors Place, Sorrento Mesa, California [Member]		4939 Directors Place, Sorrento Mesa, California [Member]		4955 Directors Place, Sorrento Mesa, California [Member]		10770 Wateridge Circle, San Diego, California [Member]		6260 Sequence Drive, Sorrento Mesa, California [Member]		6290 Sequence Drive, Sorrento Mesa, California [Member]		6310 Sequence Drive, Sorrento Mesa, California [Member]		6340 Sequence Drive, Sorrento Mesa, California [Member]		6350 Sequence Drive, Sorrento Mesa, California [Member]		10390 Pacific Center Court, Sorrento Mesa, California [Member]		10394 Pacific Center Court, Sorrento Mesa, California [Member]		10398 Pacific Center Court, Sorrento Mesa, California [Member]		10421 Pacific Center Court, Sorrento Mesa, California [Member]		10445 Pacific Center Court, Sorrento Mesa, California [Member]		10455 Pacific Center Court, Sorrento Mesa, California [Member]		5717 Pacific Center Boulevard, Sorrento Mesa, California [Member]		4690 Executive Drive, UTC, California [Member]		9785 Towne Center Drive, UTC, California [Member]		9791 Towne Center Drive, UTC, California Three [Member]		2211 Michelson Drive, Irvine, California [Member]		111 Pacifica, Irvine, California [Member]		999 Town and Country, Orange, California [Member]		Bohannon Drive 4100, Menlo Park, CA [Member]		Bohannon Drive 4200, Menlo Park, CA [Member]		Bohannon Drive 4300, Menlo Park, CA [Member]		Bohannon Drive 4400, Menlo Park, CA [Member]		Bohannon Drive 4500, Menlo Park, CA [Member]		Bohannon Drive 4600, Menlo Park, CA [Member]		Bohannon Drive 4700, Menlo Park, CA [Member]		Fairchild Drive, 331, Mountain View, CA [Member]		303 Second Street, San Francisco, California [Member]		100 First Street, San Francisco, California [Member]		250 Brannan Street, San Francisco, California [Member]		201 Third Street, San Francisco, California [Member]		301 Brannan Street, San Francisco, California [Member]		Brannan Street San Francisco Three [Member]		4040 Civic Center Drive, San Rafael, California [Member]		599 N. Mathilda Avenue, Sunnyvale, CA [Member]		601 108th Avenue, Bellevue, Washington [Member]		NE 4th Street 10900 Bellevue, Washington [Member]		10220 NE Points Drive, Kirkland, Washington [Member]		10230 NE Points Drive, Kirkland, Washington [Member]		10210 NE Points Drive, Kirkland, Washington [Member]		3933 Lake Washington Boulevard NE, Kirkland, Washington [Member]		15050 N.E. 36th Street, Redmond, Washington [Member]		837 N. 34th St. Lake Union, WA [Member]		320 Westlake Avenue North [Member]		321 Terry Avenue North, Washington Two [Member]		N 34th Street 701, Lake Union, Washington [Member]		N 34th Street 801, Lake Union, Washington [Member]		17150 Von Karman, Irvine, California [Member]
								sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft				sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft		sqft
Real Estate and Accumulated Depreciation [Line Items]	'		'	'	'	'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'
Real Estate and Accumulated Depreciation, Amount of Encumbrances	$545,868	[1]	'	'	'	$543,398		$8,972	[2]	'		'		'		'		'		$67,663	[3]	'		'		'		'		'		'		'		'		'		'		'		$39,948	[4]	'		$52,738	[5]	'		$97,000	[6]	'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		'		$133,117	[7]	'		'		'		'		'		'		'		'		'		$27,322	[8]	'		'		'		'		'		$82,638	[9]	'		$34,000	[10]	'		'		$2,470	[11]
Real Estate and Accumulated Depreciation, Initial Cost of Land	1,231,202		'	'	'	614,976		50		765		845		1,044		2,579		2,518		3,577		1,407		'		'		'		'		'		'		'		'		352		4,329		22,100		3,325		18,111		2,080		5,474		8,921		4,547		5,248		1,700		1,507		4,201		3,453		1,629		15,167		2,167		4,184		4,038		4,297		3,452		18,398		10,252		1,583		3,213		3,701		5,229		7,997		7,581		7,581		2,348		2,950		2,950		2,287		4,066		7,359		3,947		2,752		5,240		3,792		2,225		2,521		4,560		3,206		2,403		2,940		2,434		4,941		3,267		2,696		1,947		2,926		2,247		4,044		2,693		1,623		2,722		1,814		9,319		5,165		7,867		4,835		4,798		6,527		4,798		6,527		4,798		6,527		18,396		63,550		49,150		7,630		19,260		5,910		'		10,210		13,538		0		25,080		2,554		5,071		4,336		2,380		9,260		0		14,710		10,430		0		0		4,848		616,226
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	2,806,370		'	'	'	2,715,858		2,346		17,720		15,896		11,763		29,062		28,370		34,042		34,326		1,941		17,467		22,319		19,408		13,586		9,704		12,615		'		45,611		35,488		53,170		12,202		60,320		6,672		26,087		6,579		12,044		8,001		9,633		8,543		13,896		11,981		3,096		40,497		6,897		19,352		21,144		18,967		16,152		54,954		21,236		5,235		10,628		8,398		11,871		'		35,903		35,903		28,035		33,808		33,708		24,916		8,332		15,257		8,146		14,513		22,220		11,091		12,698		14,122		26,671		9,803		7,349		4,946		7,302		14,824		5,779		7,134		5,152		7,979		5,945		10,701		6,280		7,926		9,932		6,622		82,836		4,653		9,579		15,526		15,406		20,958		15,406		20,957		15,406		20,958		17,712		154,153		131,238		22,770		84,018		22,450		'		18,029		12,559		214,095		150,877		12,080		24,694		24,187		15,114		34,650		37,404		82,018		60,003		48,027		58,537		7,342		90,512
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,227,375		'	'	'	917,356		306		5,703		4,739		25,423		28,016		35,519		42,343		11,677		10,327		8,888		14,766		15,265		9,218		6,860		9,128		4,997	[12]	15,532		15,501		1,145		813		18,501		3,037		13,125		11,409		6,667		6,069		2,992		4,637		7,366		1,264		3,452		11,610		7,139		17,453		10,204		12,913		20,077		0		0		3,994		19,365		3,163		1,687		41,766		10,873		12,784		4,061		5,992		8,118		3,712		884		1,061		2,121		5,303		424		4,761		4,360		3,697		236		1,414		4,925		329		9,964		-4,109		7,501		-781		1,317		21,864		1,837		-2,250		4,220		2,400		-1,076		1,122		2,377		4,491		148		213		441		1,351		1,096		1,355		872		1,134		6,549		23,306		15,824		3,999		18,300		1,669		182,325		2,643		0		12,169		14,624		891		3,184		2,256		1,058		197		548		0		281		241		193		2,501		310,019
Real Estate and Accumulated Depreciation, Carrying Amount of Land	1,245,970		'	'	'	657,491		50		765		845		1,048		2,547		2,547		3,577		1,407		'		'		'		'		'		'		'		'		9,633		3,977		22,100		3,399		18,111		2,040		5,476		9,188		4,551		5,248		1,683		1,530		4,201		3,453		1,629		15,167		2,858		5,259		4,725		4,254		4,457		18,398		10,252		1,722		3,426		3,701		5,229		7,997		7,580		7,580		2,348		2,950		2,950		2,287		3,270		5,919		3,175		5,759		5,240		3,792		2,198		3,179		4,560		3,212		2,407		2,941		2,464		4,922		3,267		1,671		1,222		2,926		1,809		3,780		2,693		1,623		2,329		2,217		9,319		5,166		7,867		4,835		4,798		6,527		4,798		6,527		4,798		6,527		18,396		63,550		49,150		7,630		19,260		5,910		28,460		10,210		13,538		0		25,080		2,554		5,071		4,336		2,380		9,260		0		14,710		10,430		0		0		7,684		588,479
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	4,018,977	[1]	'	'	'	3,590,699		2,652	[2]	23,423	[2]	20,635	[2]	37,182		57,110		63,860		76,385	[3]	46,003	[3]	12,268		26,355		37,085		34,673		22,804		16,564		21,743		4,997	[12]	51,862		51,341		54,315	[4]	12,941		78,821	[5]	9,749		39,210	[6]	17,721		18,707		14,070		12,642		13,157		21,262	[3]	13,245	[3]	6,548		52,107		13,345		35,730		30,661		31,923		35,224		54,954		21,236		9,090		29,780		11,561		13,558		41,766		46,777		48,688		32,096		39,800		41,826		28,628		10,012		17,758		11,039		16,809		22,644		15,852		17,085		17,161		26,907		11,211		12,270		5,274		17,236		10,734		13,280		7,378		7,194		29,843		8,220		8,715		10,500		10,326	[3]	9,249		7,341		85,213	[6]	9,143		9,727		15,739		15,847		22,309		16,502		22,312		16,278		22,092		24,261		177,459	[7]	147,062		26,769		102,318		24,119		153,865		20,672		12,559		226,264		165,501		12,971	[8]	27,878	[8]	26,443	[8]	16,172	[8]	34,847		37,952		82,018	[9]	60,284	[9]	48,268	[10]	58,730	[10]	7,007		428,278	[11]
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	5,264,947		'	'	'	4,248,190		2,702	[2]	24,188	[2]	21,480	[2]	38,230		59,657		66,407		79,962	[3]	47,410	[3]	12,268		26,355		37,085		34,673		22,804		16,564		21,743		4,997	[12]	61,495		55,318		76,415		16,340		96,932		11,789		44,686		26,909		23,258		19,318		14,325		14,687		25,463		16,698		8,177		67,274		16,203		40,989		35,386		36,177		39,681		73,352		31,488		10,812		33,206		15,262		18,787		49,763		54,357		56,268		34,444		42,750		44,776		30,915		13,282		23,677		14,214		22,568		27,884		19,644		19,283		20,340		31,467		14,423		14,677		8,215		19,700		15,656		16,547		9,049		8,416		32,769		10,029		12,495		13,193		11,949		11,578		9,558		94,532		14,309		17,594		20,574		20,645		28,836		21,300		28,839		21,076		28,619		42,657		241,009		196,212		34,399		121,578		30,029		182,325		30,882		26,097		226,264		190,581		15,525		32,949		30,779		18,552		44,107		37,952		96,728		70,714		48,268		58,730		14,691		1,016,757
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$818,957		$756,515	$742,503	$672,429	$818,957		$1,355		$11,838		$10,722		$18,782		$42,353		$2,809		$23,669		$15,113		$8,618		$20,057		$30,223		$17,783		$11,827		$583		$11,848		$4,976	[12]	$17,338		$27,960		$2,145		$6,046		$4,508		$5,263		$15,647		$10,428		$10,245		$8,026		$5,750		$7,009		$7,505		$7,200		$4,621		$18,064		$6,304		$16,382		$14,482		$8,511		$15,032		$548		$216		$4,950		$9,023		$2,200		$1,975		$8,485		$13,272		$14,636		$7,685		$9,857		$11,099		$6,833		$1,743		$2,735		$1,578		$2,585		$2,451		$2,740		$7,673		$11,303		$5,313		$5,580		$7,058		$2,875		$9,058		$6,282		$4,917		$3,511		$3,174		$13,320		$3,155		$3,968		$3,024		$5,361		$3,898		$3,094		$11,078		$5,465		$1,459		$1,007		$945		$1,504		$1,078		$1,446		$840		$1,403		$220		$25,676		$18,375		$3,494		$12,621		$2,145		$4,064		$2,556		$591		$23,061		$8,872		$1,345		$2,895		$2,688		$1,735		$3,524		$2,419		$2,720		$1,963		$3,193		$3,371		$7,007		$0
Real Estate and Accumulated Depreciation, Life Used for Depreciation	'		'	'	'	'		'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'35 years	[13]	'
Rentable square feet (unaudited)	'		'	'	'	12,736,099	[14]	11,789	[14]	104,797	[14]	108,670	[14]	122,870	[14]	298,728	[14]	298,728	[14]	241,607	[14]	128,592	[14]	10,457	[14]	165,278	[14]	219,745	[14]	192,476	[14]	136,026	[14]	98,243	[14]	126,840	[14]	'		150,167	[14]	150,302	[14]	151,029	[14]	78,000	[14]	321,883	[14]	44,915	[14]	102,864	[14]	88,339	[14]	73,115	[14]	81,067	[14]	58,401	[14]	54,673	[14]	87,405	[14]	72,332	[14]	38,710	[14]	208,464	[14]	51,167	[14]	130,349	[14]	129,752	[14]	114,780	[14]	112,067	[14]	140,591	[14]	78,349	[14]	73,507	[14]	141,214	[14]	41,194	[14]	59,188	[14]	149,817	[14]	147,533	[14]	141,128	[14]	103,979	[14]	130,243	[14]	130,354	[14]	101,236	[14]	53,610	[14]	96,436	[14]	51,516	[14]	89,023	[14]	103,900	[14]	56,136	[14]	60,662	[14]	76,246	[14]	174,310	[14]	130,536	[14]	90,000	[14]	62,415	[14]	66,400	[14]	132,600	[14]	68,400	[14]	59,630	[14]	43,645	[14]	75,899	[14]	48,709	[14]	90,000	[14]	67,995	[14]	47,212	[14]	75,534	[14]	50,466	[14]	271,556	[14]	67,496	[14]	98,551	[14]	46,614	[14]	46,255	[14]	62,920	[14]	46,255	[14]	62,920	[14]	46,255	[14]	62,920	[14]	87,565	[14]	740,047	[14]	466,490	[14]	95,008	[14]	332,893	[14]	74,430	[14]	-14	[14]	130,237	[14]	75,810	[14]	488,470	[14]	416,755	[14]	49,851	[14]	98,982	[14]	84,641	[14]	46,450	[14]	122,103	[14]	111,580	[14]	184,643	[14]	135,755	[14]	138,995	[14]	169,412	[14]	-16	[14]	'
[1]	Includes initial cost of 9455 Towne Center Drive, which was transferred to the future development portfolio and is included in construction in progress during the year ended December 31, 2013.
[2]	These properties secure a $8.9 million mortgage note.
[3]	These properties secure a $67.7 million mortgage note.
[4]	This property secures a $39.9 million mortgage note.
[5]	This property secures a $52.7 million mortgage note.
[6]	These properties secure a $97.0 million mortgage note.
[7]	This property secures a $133.1 million mortgage note.
[8]	This property secures a $27.3 million mortgage note.
[9]	These properties secure a $82.6 million mortgage note.
[10]	These properties secure a $34.0 million mortgage note.
[11]	During the fourth quarter of 2011, we completed demolition of the industrial building on this site to prepare for the possible sale of the land and improvements, since we successfully obtained entitlements to reposition this site for residential use. Our ultimate decision to sell this site and the timing of any potential future sale will depend upon market conditions and other factors.
[12]	These costs represent infrastructure costs incurred in 1989. During the third quarter of 2009, we exercised our option to terminate the ground lease at Kilroy Airport Center, Phase IV in Long Beach, California. We had previously leased this land, which is adjacent to our Office Properties at Kilroy Airport Center, Long Beach, for potential future development opportunities.
[13]	The initial costs of buildings and improvements are depreciated over 35 years using a straight-line method of accounting; improvements capitalized subsequent to acquisition are depreciated over the shorter of the lease term or useful life, generally ranging from one to 20 years.
[14]	Includes square footage from our stabilized portfolio.

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, 2013		Dec. 31, 2012		Dec. 31, 2011
SEC Schedule III, Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]	'		'		'
Total real estate held for investment, beginning of year	$4,757,394		$3,798,690		$3,216,871
Acquisitions	384,650		1,023,384		617,923
Improvements, etc.	452,331		207,345		84,736
Total additions during period	836,981		1,230,729		702,659
Cost of real estate sold	-56,993		-264,533		-21,052
Properties held for sale	-259,251		0		-89,937
Other	-13,184	[1]	-7,492	[1]	-9,851	[1]
Total deductions during period	-329,428		-272,025		-120,840
Total real estate held for investment, end of year	$5,264,947		$4,757,394		$3,798,690
[1]	Related to the redevelopment property transferred to construction in progress during the year.

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, 2013		Dec. 31, 2012		Dec. 31, 2011
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]	'		'		'
Accumulated depreciation, beginning of year	$756,515		$742,503		$672,429
Depreciation of real estate	145,325		125,906		105,982
Total additions during period	145,325		125,906		105,982
Write-offs due to sale	-17,144		-109,797		-11,152
Properties held for sale	-63,110		0		-14,905
Other	-2,629	[1]	-2,097	[1]	-9,851	[1]
Total deductions during period	-82,883		-111,894		-35,908
Accumulated depreciation, end of year	$818,957		$756,515		$742,503
[1]	Related to the redevelopment property transferred to construction in progress during the year.

Schedule_III_Real_Estate_and_A4

Schedule III - Real Estate and Accumulated Depreciation (Details) (Textuals) (USD $)

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

sqft

sqft

sqft

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Building [Member]

Tenant Improvements [Member]

Tenant Improvements [Member]

sqft

7.15% Mortgage Payable due May 1, 2017 [Member]

6.51% Mortgage Payable due February 1, 2017 [Member]

5.57% Mortgage Note Payable due February 2016 [Member]

5.23% Mortgage Payable due January 2016 [Member]

4.48% Mortgage Payable due July 2027

4.48% Mortgage Payable due July 2027

4.27% Mortgage Payable due Feb 1, 2018 [Member]

4.94% Mortgage Payable due April 15, 2015 [Member]

6.05% Mortgage Payable Due June 1, 2019 [Member]

5.09% Mortgage Payable due August 2015 [Member] [Member]

Minimum [Member]

Maximum [Member]

Real Estate and Accumulated Depreciation [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Real Estate and Accumulated Depreciation, Life Used for Depreciation

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'35 years

'

'

Property, Plant and Equipment, Useful Life

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'1 year

'20 years

Secured debt

$560,434,000

$561,096,000

'

'

'

$8,900,000

$67,700,000

$39,900,000

$52,700,000

$97,000,000

[1],[2]

$97,000,000

[1],[2]

$133,100,000

$27,300,000

$82,600,000

$34,000,000

'

'

'

Rentable Square Feet

200,306

3,975,665

282,611

410,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt premium

7,200,000

'

'

14,600,000

7,200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Aggregate cost of property for federal income tax purposes

$4,600,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

In June 2012, we obtained a mortgage loan that is secured by one office property located in Irvine, California and two office properties located in Los Angeles, California and requires monthly principal and interest payments based on a 30 year amortization period with an initial three years of interest only payments.

[2]

Amounts reported include the amounts of unamortized debt premiums of $14.6 million and $7.2 million as of December 31, 2013 and 2012, respectively.