Kilroy Realty (KRC) 10-K 12 Feb 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information Document - USD ($)	12 Months Ended
	Dec. 31, 2015	Feb. 05, 2016	Jun. 30, 2015
Entity Information [Line Items]
Entity Registrant Name	KILROY REALTY CORP
Entity Central Index Key	1,025,996
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		92,275,561
Entity Public Float			$ 5,926,241,394
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	1,493,976
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015		Dec. 31, 2014
REAL ESTATE ASSETS (Notes 3 and 18):
Land and improvements	$ 875,794		$ 877,633
Buildings and improvements	4,091,012		4,059,639
Undeveloped land and construction in progress	1,361,340		1,120,660
Total real estate held for investment	6,328,146		6,057,932
Accumulated depreciation and amortization	(994,241)		(947,664)
Total real estate held for investment, net ($184,254 and $211,755 of VIE, Note 2)	5,333,905		5,110,268
REAL ESTATE ASSETS AND OTHER ASSETS HELD FOR SALE, NET (Note 4)	117,666		8,211
CASH AND CASH EQUIVALENTS	56,508		23,781
RESTRICTED CASH (Note 4)	696		75,185
MARKETABLE SECURITIES (Notes 14 and 17)	12,882		11,971
CURRENT RECEIVABLES, NET (Note 6)	11,153	[1]	7,229
DEFERRED RENT RECEIVABLES, NET (Note 6)	189,704		156,416
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Notes 3 and 5)	176,683		201,926
DEFERRED FINANCING COSTS, NET (Notes 2 and 8)	17,628		18,374
PREPAID EXPENSES AND OTHER ASSETS, NET	22,644		20,375
TOTAL ASSETS	5,939,469		5,633,736
LIABILITIES:
Secured debt (Notes 3, 7, 8 and 17)	381,918		546,292
Unsecured debt, net (Notes 7, 8 and 17)	1,856,590		1,783,121
Unsecured line of credit (Notes 7, 8 and 17)	0		140,000
Accounts payable, accrued expenses and other liabilities (Note 16)	246,323		225,830
Accrued distributions (Note 11)	34,992		32,899
Deferred revenue and acquisition-related intangible liabilities, net (Notes 3, 5 and 9)	128,156		132,239
Rents received in advance and tenant security deposits	49,361		49,363
Liabilities and deferred revenue of real estate assets held for sale (Note 4)	7,543		56
Total liabilities	$ 2,704,883		$ 2,909,800
COMMITMENTS AND CONTINGENCIES (Note 16)
Preferred stock, $.01 par value, 30,000,000 shares authorized:
Common stock, $.01 par value, 150,000,000 shares authorized, 92,258,690 and 86,259,684 shares issued and outstanding, respectively	$ 923		$ 863
Additional paid-in capital	3,047,894		2,635,900
Distributions in excess of earnings	70,262		162,964
Total stockholders' equity	3,170,966		2,666,210
Noncontrolling interest:
Common units of the Operating Partnership	57,100		51,864
Noncontrolling interest in consolidated subsidiary (Notes 2 and 10)	6,520		5,862
Total noncontrolling interests	63,620		57,726
Total equity	3,234,586		2,723,936
TOTAL LIABILITIES AND EQUITY	5,939,469		5,633,736
Series G Cumulative Redeemable Preferred Stock
Preferred stock, $.01 par value, 30,000,000 shares authorized:
Redeemable Preferred stock	96,155		96,155
Series H Cumulative Redeemable Preferred Stock
Preferred stock, $.01 par value, 30,000,000 shares authorized:
Redeemable Preferred stock	$ 96,256		$ 96,256
[1]	Excludes current receivables, net related to real estate held for sale.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2013	Jun. 30, 2015
Common Stock
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	86,259,684	92,258,690
Common stock, shares outstanding	86,259,684	92,258,690
Preferred Stock [Member]
Preferred stock, shares authorized	30,000,000	30,000,000
Preferred stock, par value	$ 0.01	$ 0.01
Series G Cumulative Redeemable Preferred Stock
Preferred stock, shares authorized	4,600,000	4,600,000
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock dividend rate (percentage)	6.875%
Preferred stock liquidation preference	$ 100,000	$ 100,000
Series H Cumulative Redeemable Preferred Stock
Preferred stock, shares authorized	4,000,000	4,000,000
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock dividend rate (percentage)	6.375%
Preferred stock liquidation preference	$ 100,000	$ 100,000

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
REVENUES:
Rental income	$ 525,355		$ 466,328		$ 411,899
Tenant reimbursements	53,774		46,717		38,047
Other property income (Note 16 and 18)	2,146		8,680		7,165
Total revenues	581,275		521,725		457,111
EXPENSES:
Property expenses	105,378		100,514		94,115
Real estate taxes	50,223		45,197		39,417
Provision for bad debts	545		58		396
Ground leases (Note 4 and 15)	3,096		3,075		3,504
General and administrative expenses	48,265		46,152		39,660
Acquisition-related expenses	497		1,479		1,962
Depreciation and amortization (Notes 2 and 4)	204,294		202,417		188,887
Total expenses	412,298		398,892		367,941
OTHER (EXPENSES) INCOME:
Interest income and other net investment gains (Note 16)	243		561		1,635
Interest expense (Note 7)	(57,682)		(67,571)		(75,870)
Total other (expenses) income	(57,439)		(67,010)		(74,235)
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE GAIN ON SALE OF LAND	111,538		55,823		14,935
Gain on sale of land (Note 18)	17,116		3,490		0
Gain on sale of depreciable operating properties (Note 4)	109,950		0		0
INCOME (LOSS) FROM CONTINUING OPERATIONS	238,604		59,313		14,935
DISCONTINUED OPERATIONS (Note 18)
Income from discontinued operations	0		2,573		17,378
Net gain on dispositions of discontinued operations (Note 19)	0		121,922		12,252
Total income from discontinued operations	0	[1]	124,495	[1]	29,630	[2]
NET INCOME	238,604		183,808		44,565
Net income attributable to noncontrolling common units of the Operating Partnership	(4,339)		(3,589)		(685)
Net Income (Loss) Attributable to Noncontrolling Interest in Consolidated Subsidiary	(184)		0		0
Net Income (Loss) Attributable to Noncontrolling Interest	(4,523)		(3,589)		(685)
NET INCOME ATTRIBUTABLE TO KILROY REALTY	234,081		180,219		43,880
PREFERRED DISTRIBUTIONS AND DIVIDENDS:
Preferred dividends (Note 10)	(13,250)		(13,250)		(13,250)
Total preferred distributions	(13,250)		(13,250)
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	$ 220,831		$ 166,969		$ 30,630
Income (loss) from continuing operations available to common stockholders per share of common stock – basic (Note 19)	$ 2.44		$ 0.52		$ 0
Income (loss) from continuing operations available to common stockholders per share (dollars per share)	2.42		0.51		0
Net income available to common stockholders per share-basic (Note 19)	2.44		1.99		0.37
Net income available to common stockholders per share-diluted (Note 19)	$ 2.42		$ 1.95		$ 0.37
Weighted average common shares outstanding-basic (Note 19)	89,854,096		83,090,235		77,343,853
Weighted average common shares outstanding-diluted (Note 19)	90,395,775		84,967,720		77,343,853
[1]	(2)The Company adopted ASU 2014-08 effective January 1, 2015 (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As a result, properties classified as held for sale and/or disposed of subsequent to January 1, 2015 that do not represent a strategic shift are no longer presented as discontinued operations.
[2]	The Operating Partnership adopted ASU 2014-08 effective January 1, 2015 (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As a result, properties classified as held for sale and/or disposed of subsequent to January 1, 2015 that do not represent a strategic shift are no longer presented as discontinued operations.

Consolidated Statements of Equi

Consolidated Statements of Equity - USD ($) $ in Thousands	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	Subsidiaries [Member]	Subsidiaries [Member]Noncontrolling Interests - Common Units of the Operating Partnership
Beginning Balance at Dec. 31, 2012	$ 2,235,933		$ 2,189,630	$ 192,411	$ 749	$ 2,126,005	$ (129,535)	$ 46,303
Beginning Balance, shares at Dec. 31, 2012					74,926,981
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	44,565		43,880				43,880	685	$ 44,565	$ 224
Issuance of common stock, shares (Note 10)					7,215,838
Issuance of share-based compensation awards, shares (Note 12)					0
Issuance of share-based compensation awards	1,448		1,448			1,448
Noncash amortization of share-based compensation	9,563		9,563			9,563			9,563
Exercise of stock options, shares					16,303
Issuance of common stock (Note 10)	349,951		349,951		$ 72	349,879
Exchange Of Common Units Of The Operating Partnership Into Shares Of The Companys Common Stock	0		450			(450)		450
Exercise of stock options	(128)		(128)			(128)
Noncontrolling Interest, Increase from Business Combination	4,885							4,885	4,885	4,885
Repurchase of common stock and restricted stock units (Note 12)	(2,521)		(2,521)			(2,521)
Repurchase of common stock and restricted stock units, shares (Note 12)					(42,896)
Settlement of restricted stock units for shares of common stock (Note 12)	1		1		$ 1	0			1
Settlement of restricted stock units for shares of common stock, shares (Note 12)					37,245
Exchange of common units of the Operating Partnership, shares (Note 10)					473
Adjustment for noncontrolling interest (Note 2)	0		(5,977)			5,977		(5,977)
Preferred distributions	(13,250)		(13,250)				(13,250)		(13,250)
Dividends declared per common share and common unit ($1.40 per share/ unit for 2010, 2011 and $1.63 per share/unit for 2009)	(114,543)		(111,991)				(111,991)	(2,552)
Ending Balance at Dec. 31, 2013	2,516,160		2,461,312	192,411	$ 822	2,478,975	(210,896)	54,848
Ending Balance, shares at Dec. 31, 2013					82,153,944
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	183,808		180,219				180,219	3,589	183,808	260
Issuance of common stock, shares (Note 10)					1,950,599
Issuance of share-based compensation awards	1,692		1,692			1,692
Noncash amortization of share-based compensation	14,471		14,471			14,471			14,471
Exercise of stock options, shares					495,000
Issuance of common stock (Note 10)	123,860		123,860		$ 20	123,840
Exercise of stock options	(21,092)		(21,092)		$ (5)	(21,087)
Noncontrolling Interest, Increase from Business Combination	977							977	977	977
Repurchase of common stock and restricted stock units (Note 12)	(3,533)		(3,533)			(3,533)
Repurchase of common stock and restricted stock units, shares (Note 12)					(58,045)
Settlement of restricted stock units for shares of common stock (Note 12)	(1)		(1)		$ 0	(1)
Stock Issued During Period, Shares, in Connection with Early Exchange of Notes					2,091,323
Stock Issued During Period, Value, in Connection with Early Exchange of Notes	223		223		$ 21	202			$ 223
Stock Received During Period, Call Options					515,342				0
Stock Issued During Period, Value, Capped Call Option Transactions	0		0		$ (5)	5
Shares of Common stock exercised in the capped call option					111,206
Settlement of restricted stock units for shares of common stock, shares (Note 12)					141,205
Exchange of common units of the Operating Partnership (Note 10)	0		28			28		(28)
Exchange of common units of the Operating Partnership, shares (Note 10)					1,000
Adjustment for noncontrolling interest (Note 2)	0		866			866		(866)
Preferred distributions	(13,250)		(13,250)				(13,250)		$ (13,250)
Dividends declared per common share and common unit ($1.40 per share/ unit for 2010, 2011 and $1.63 per share/unit for 2009)	(121,563)		(119,037)				(119,037)	(2,526)
Ending Balance at Dec. 31, 2014	$ 2,723,936		2,666,210	192,411	$ 863	2,635,900	(162,964)	57,726
Ending Balance, shares at Dec. 31, 2014	86,259,684	[1]			86,259,684
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 238,604		234,081				234,081	4,523	238,604	467
Issuance of common stock, shares (Note 10)					5,640,033
Issuance of share-based compensation awards	1,692		1,692			1,692
Noncash amortization of share-based compensation	18,869		18,869			18,869			18,869
Exercise of stock options, shares					342,000
Issuance of common stock (Note 10)	387,398		387,398		$ 56	387,342
Exercise of stock options	(14,573)		(14,573)		(4)	(14,569)
Noncontrolling Interest, Increase from Business Combination	474							474	474	$ 474
Repurchase of common stock and restricted stock units (Note 12)	(7,081)		(7,081)		$ 0	(7,081)
Repurchase of common stock and restricted stock units, shares (Note 12)					(101,389)
Settlement of restricted stock units for shares of common stock (Note 12)	(1)		(1)		$ 0	(1)
Settlement of restricted stock units for shares of common stock, shares (Note 12)					78,937
Exchange of common units of the Operating Partnership (Note 10)	0		1,223			1,223		(1,223)
Exchange of common units of the Operating Partnership, shares (Note 10)					39,425
Adjustment for noncontrolling interest (Note 2)	0		4,619			4,619		(4,619)
Preferred distributions	(13,250)		(13,250)				(13,250)		$ (13,250)
Dividends declared per common share and common unit ($1.40 per share/ unit for 2010, 2011 and $1.63 per share/unit for 2009)	(130,628)		(128,129)				(128,129)	(2,499)
Ending Balance at Dec. 31, 2015	$ 3,234,586		$ 3,170,966	$ 192,411	$ 923	$ 3,047,894	$ (70,262)	$ 63,620
Ending Balance, shares at Dec. 31, 2015	92,258,690	[1]			92,258,690
[1]	The amount includes nonvested shares.

Consolidated Statements of Equ6

Consolidated Statements of Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2011
Statement of Stockholders' Equity [Abstract]
Dividends declared per common share	$ 1.40	$ 1.40	$ 1.40

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 238,604	$ 183,808	$ 44,565
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	201,482	202,108	199,558
Increase (decrease) in provision for bad debts	545	58	396
Depreciation of furniture, fixtures and equipment	2,812	2,370	1,929
Noncash amortization of share-based compensation awards (Note 13)	15,537	12,095	8,616
Noncash amortization of deferred financing costs and debt discounts and premiums	1,853	4,315	5,315
Noncash amortization of net below market rents (Note 5)	(8,449)	(8,328)	(7,777)
Disposal Group Depreciable Operating Properties, Not Discontinued Operations, Gain (Loss) on Disposal (Note 4)	(109,950)	0	0
Net gain on dispositions of discontinued operations (Note 19)	0	(121,922)	(12,252)
Gain on sale of land (Note 4)	17,116	3,490	0
Noncash amortization of deferred revenue related to tenant-funded tenant improvements (Note 9)	(13,338)	(10,979)	(10,713)
Straight-line rents	(44,383)	(31,782)	(24,135)
Net change in other operating assets	(8,085)	367	(4,615)
Net change in other operating liabilities	12,496	16,633	40,137
Insurance proceeds received for property damage and other, net	0	0	(448)
Net cash provided by operating activities	272,008	245,253	240,576
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for acquisitions of operating properties, net of cash acquired (Note 3)	0	204,546	202,682
Expenditures for acquisitions of development and redevelopment properties (Note 3)	(139,073)	(147,182)	(102,769)
Payments for Capital Improvements	99,557	132,080	129,873
Payments to Develop Real Estate Assets	407,969	417,784	320,141
Net proceeds received from dispositions of operating properties and land (Notes 4 and 19)	319,639	427,544	21,178
Issuance of Note Receivable	(3,000)	0	0
Insurance proceeds received for property damage	0	0	448
(Increase) decrease in acquisition-related deposits	1,998	(1,983)	(2,596)
(Increase) decrease in restricted cash (Note 4)	65,210	(25,405)	229,915
Net cash used in investing activities	(262,752)	(501,436)	(506,520)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from issuance of common stock (Note 11)	387,398	102,229	349,951
Borrowings on unsecured line of credit	250,000	505,000	55,000
Repayments on unsecured line of credit	(390,000)	(410,000)	(195,000)
Proceeds from the issuance of unsecured debt (Note 8)	397,776	395,528	299,901
Repayments of exchangeable senior notes (Note 8)	0	(172,500)	0
Principal payments on secured debt (Note 8)	(159,766)	(9,845)	(93,688)
Borrowings on unsecured debt (Note 8)	0	39,000
Repayments of unsecured debt (Note 8)	325,000	83,000
Financing costs	(4,814)	(8,648)	(4,384)
Repurchase of common stock and restricted stock units	(7,081)	(3,533)	(2,520)
Proceeds from exercise of stock options	14,573	21,092	128
Contributions from noncontrolling interests in consolidated subsidiary (Note 2)	474	977
Dividends and distributions paid to common stockholders and common unitholders	(126,839)	(118,463)	(111,517)
Dividends and distributions paid to preferred stockholders and preferred unitholders	(13,250)	(13,250)	(13,250)
Net cash provided by financing activities	23,471	244,587	284,621
Net increase (decrease) in cash and cash equivalents	32,727	(11,596)	18,677
Cash and cash equivalents, beginning of period	23,781	35,377	16,700
Cash and cash equivalents, end of period	56,508	23,781	35,377
SUPPLEMENTAL CASH FLOWS INFORMATION:
Cash paid for interest, net of capitalized interest of $50,923, $44,385, and $32,742 as of December 31, 2015, 2014 and 2013, respectively	54,747	58,944	65,157
NONCASH INVESTING TRANSACTIONS:
Accrual for expenditures for operating properties and development and redevelopment properties	109,715	77,091	73,482
Tenant improvements funded directly by tenants to third parties	13,837	42,906	7,633
Assumption of secured debt with property acquisition (Note 8)	0	0	95,496
Assumption of other assets and liabilities in connection with operating and development property acquisitions, net (Note 3)	6,254	14,917	1,811
Release of Holdback Funds to Third Party	9,279	0	0
Contribution of land, net of related liabilities, by noncontrolling interest to consolidated subsidiary	0	0	4,885
NONCASH FINANCING TRANSACTIONS:
Accrual of dividends and distributions payable to common stockholders and common unitholders (Note 11)	33,336	31,243	29,378
Accrual of dividends and distributions payable to preferred stockholders and preferred unitholders (Note 11)	1,656	1,656	1,694
Exchange of common units of the Operating Partnership into shares of the Company’s common stock (Note 11)	1,223	28	450
Subsidiaries [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	238,604	183,808	44,565
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	201,482	202,108	199,558
Increase (decrease) in provision for bad debts	545	58	396
Depreciation of furniture, fixtures and equipment	2,812	2,370	1,929
Noncash amortization of share-based compensation awards (Note 13)	15,537	12,095	8,616
Noncash amortization of deferred financing costs and debt discounts and premiums	1,853	4,315	5,315
Noncash amortization of net below market rents (Note 5)	(8,449)	(8,328)	(7,777)
Disposal Group Depreciable Operating Properties, Not Discontinued Operations, Gain (Loss) on Disposal (Note 4)	(109,950)	0	0
Net gain on dispositions of discontinued operations (Note 19)	0	(121,922)	(12,252)
Gain on sale of land (Note 4)	17,116	3,490	0
Noncash amortization of deferred revenue related to tenant-funded tenant improvements (Note 9)	(13,338)	(10,979)	(10,713)
Straight-line rents	(44,383)	(31,782)	(24,135)
Net change in other operating assets	(8,085)	367	(4,615)
Net change in other operating liabilities	12,496	16,633	40,137
Insurance proceeds received for property damage and other, net	0	0	(448)
Net cash provided by operating activities	272,008	245,253	240,576
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for acquisitions of operating properties, net of cash acquired (Note 3)	0	204,546	202,682
Expenditures for acquisitions of development and redevelopment properties (Note 3)	(139,073)	(147,182)	(102,769)
Payments for Capital Improvements	99,557	132,080	129,873
Payments to Develop Real Estate Assets	407,969	417,784	320,141
Net proceeds received from dispositions of operating properties and land (Notes 4 and 19)	319,639	427,544	21,178
Issuance of Note Receivable	(3,000)	0	0
Insurance proceeds received for property damage	0	0	448
(Increase) decrease in acquisition-related deposits	1,998	(1,983)	(2,596)
(Increase) decrease in restricted cash (Note 4)	65,210	(25,405)	229,915
Net cash used in investing activities	(262,752)	(501,436)	(506,520)
CASH FLOWS FROM FINANCING ACTIVITIES:
Borrowings on unsecured line of credit	250,000	505,000	55,000
Repayments on unsecured line of credit	(390,000)	(410,000)	(195,000)
Proceeds from the issuance of unsecured debt (Note 8)	397,776	395,528	299,901
Repayments of exchangeable senior notes (Note 8)	0	(172,500)	0
Principal payments on secured debt (Note 8)	(159,766)	(9,845)	(93,688)
Borrowings on unsecured debt (Note 8)	0	39,000	0
Repayments of unsecured debt (Note 8)	325,000	83,000	0
Financing costs	(4,814)	(8,648)	(4,384)
Repurchase of common stock and restricted stock units	(7,081)	(3,533)	(2,520)
Proceeds from exercise of stock options	14,573	21,092	128
Contributions from noncontrolling interests in consolidated subsidiary (Note 2)	474	977	0
Dividends and distributions paid to common stockholders and common unitholders	(126,839)	(118,463)	(111,517)
Dividends and distributions paid to preferred stockholders and preferred unitholders	(13,250)	(13,250)	(13,250)
Net cash provided by financing activities	23,471	244,587	284,621
Net increase (decrease) in cash and cash equivalents	32,727	(11,596)	18,677
Cash and cash equivalents, beginning of period	23,781	35,377	16,700
Cash and cash equivalents, end of period	56,508	23,781	35,377
SUPPLEMENTAL CASH FLOWS INFORMATION:
Cash paid for interest, net of capitalized interest of $50,923, $44,385, and $32,742 as of December 31, 2015, 2014 and 2013, respectively	54,747	58,944	65,157
NONCASH INVESTING TRANSACTIONS:
Accrual for expenditures for operating properties and development and redevelopment properties	109,715	77,091	73,482
Tenant improvements funded directly by tenants to third parties	13,837	42,906	7,633
Assumption of secured debt with property acquisition (Note 8)	0	0	95,496
Assumption of other assets and liabilities in connection with operating and development property acquisitions, net (Note 3)	6,254	14,917	1,811
Release of Holdback Funds to Third Party	9,279	0	0
Contribution of land, net of related liabilities, by noncontrolling interest to consolidated subsidiary	0	0	4,885
NONCASH FINANCING TRANSACTIONS:
Accrual of dividends and distributions payable to common stockholders and common unitholders (Note 11)	33,353	31,243	29,378
Accrual of dividends and distributions payable to preferred stockholders and preferred unitholders (Note 11)	$ 1,656	$ 1,656	$ 1,694

Consolidated Statements of Cas8

Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Cash Flows [Abstract]
Capitalized interest	$ 50,923	$ 44,385	$ 32,742

Consolidated Balance Sheets (KI

Consolidated Balance Sheets (KILROY REALTY, L.P.) - USD ($) $ in Thousands	Dec. 31, 2015		Dec. 31, 2014
REAL ESTATE ASSETS (Notes 3 and 18):
Land and improvements	$ 875,794		$ 877,633
Buildings and improvements	4,091,012		4,059,639
Undeveloped land and construction in progress	1,361,340		1,120,660
Total real estate held for investment	6,328,146		6,057,932
Accumulated depreciation and amortization	(994,241)		(947,664)
Total real estate held for investment, net ($184,254 and $211,755 of VIE, Note 2)	5,333,905		5,110,268
REAL ESTATE ASSETS AND OTHER ASSETS HELD FOR SALE, NET (Note 4)	117,666		8,211
CASH AND CASH EQUIVALENTS	56,508		23,781
RESTRICTED CASH (Note 4)	696		75,185
MARKETABLE SECURITIES (Notes 14 and 17)	12,882		11,971
CURRENT RECEIVABLES, NET (Note 6)	11,153	[1]	7,229
DEFERRED RENT RECEIVABLES, NET (Note 6)	189,704		156,416
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Notes 3 and 5)	176,683		201,926
DEFERRED FINANCING COSTS, NET (Notes 2 and 8)	17,628		18,374
PREPAID EXPENSES AND OTHER ASSETS, NET	22,644		20,375
Total Assets	5,939,469		5,633,736
LIABILITIES:
Secured debt (Notes 3, 7, 8 and 17)	381,918		546,292
Unsecured debt, net (Notes 7, 8 and 17)	1,856,590		1,783,121
Unsecured line of credit (Notes 7, 8 and 17)	0		140,000
Accounts payable, accrued expenses and other liabilities (Note 16)	246,323		225,830
Accrued distributions (Note 11)	(34,992)		(32,899)
Deferred revenue and acquisition-related intangible liabilities, net (Notes 3, 5 and 9)	128,156		132,239
Rents received in advance and tenant security deposits	49,361		49,363
Liabilities and deferred revenue of real estate assets held for sale (Note 4)	7,543		56
Total liabilities	$ 2,704,883		$ 2,909,800
COMMITMENTS AND CONTINGENCIES (Note 16)
Partners' Capital:
TOTAL LIABILITIES AND EQUITY	$ 5,939,469		$ 5,633,736
Kilroy Realty, L.P. [Member]
REAL ESTATE ASSETS (Notes 3 and 18):
Land and improvements	875,794		877,633
Buildings and improvements	4,091,012		4,059,639
Undeveloped land and construction in progress	1,361,340		1,120,660
Total real estate held for investment	6,328,146		6,057,932
Accumulated depreciation and amortization	(994,241)		(947,664)
Total real estate held for investment, net ($184,254 and $211,755 of VIE, Note 2)	5,333,905		5,110,268
REAL ESTATE ASSETS AND OTHER ASSETS HELD FOR SALE, NET (Note 4)	117,666		8,211
CASH AND CASH EQUIVALENTS	56,508		23,781
RESTRICTED CASH (Note 4)	696		75,185
MARKETABLE SECURITIES (Notes 14 and 17)	12,882		11,971
CURRENT RECEIVABLES, NET (Note 6)	11,153		7,229
DEFERRED RENT RECEIVABLES, NET (Note 6)	189,704		156,416
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Notes 3 and 5)	176,683		201,926
DEFERRED FINANCING COSTS, NET (Notes 2 and 8)	17,628		18,374
PREPAID EXPENSES AND OTHER ASSETS, NET	22,644		20,375
Total Assets	5,939,469		5,633,736
LIABILITIES:
Secured debt (Notes 3, 7, 8 and 17)	381,918		546,292
Unsecured debt, net (Notes 7, 8 and 17)	1,856,590		1,783,121
Unsecured line of credit (Notes 7, 8 and 17)	0		140,000
Accounts payable, accrued expenses and other liabilities (Note 16)	246,323		225,830
Accrued distributions (Note 11)	(34,992)		(32,899)
Deferred revenue and acquisition-related intangible liabilities, net (Notes 3, 5 and 9)	128,156		132,239
Rents received in advance and tenant security deposits	49,361		49,363
Liabilities and deferred revenue of real estate assets held for sale (Note 4)	7,543		56
Total liabilities	$ 2,704,883		$ 2,909,800
COMMITMENTS AND CONTINGENCIES (Note 16)
Partners' Capital:
Common units, 86,259,684 and 82,153,944 held by the general partner and 1,804,200 and 1,805,200 held by common limited partners issued and outstanding, respectively	$ 3,031,609		$ 2,521,900
Total Partners' Capital	3,224,020		2,714,311
Noncontrolling interests in consolidated subsidiaries (Notes 2, 3 and 9)	10,566		9,625
Total capital	3,234,586		2,723,936
TOTAL LIABILITIES AND EQUITY	5,939,469		5,633,736
Series H Cumulative Redeemable Preferred Unit [Member] | Kilroy Realty, L.P. [Member]
Partners' Capital:
Preferred Units, Preferred Partners' Capital Accounts	96,256		96,256
Series G Cumulative Redeemable Preferred Unit [Member] | Kilroy Realty, L.P. [Member]
Partners' Capital:
Preferred Units, Preferred Partners' Capital Accounts	$ 96,155		$ 96,155
[1]	Excludes current receivables, net related to real estate held for sale.

Consolidated Balance Sheets (10

Consolidated Balance Sheets (KILROY REALTY, L.P.) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2013	Jun. 30, 2015
Kilroy Realty, L.P. [Member]
Variable Interest Entity Consolidated Carrying Amounts, Real Estate Assets, net	$ 234,532	$ 211,755
Kilroy Realty, L.P. [Member] | Capital Units [Member]
General Partners' Capital Account, Units Issued	86,259,684	92,258,690
General Partners' Capital Account, Units Outstanding	86,259,684	92,258,690
Limited Partners' Capital Account, Units Issued	1,804,200	1,764,775
Noncontrolling common units of the Operating Partnership	1,804,200	1,764,775
Kilroy Realty, L.P. [Member] | Series G Cumulative Redeemable Preferred Unit [Member]
Preferred stock dividend rate (percentage)	6.875%
Preferred Units, Issued	4,000,000	4,000,000
Preferred units outstanding	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)	6.375%
Preferred Units, Issued	4,000,000	4,000,000
Preferred units outstanding	4,000,000
Preferred stock liquidation preference	$ 100,000	$ 100,000

Consolidated Statements of Op11

Consolidated Statements of Operations (KILROY REALTY, L.P.) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
REVENUES:
Rental income	$ 525,355		$ 466,328		$ 411,899
Tenant reimbursements	53,774		46,717		38,047
Other property income (Note 15 and 17)	2,146		8,680		7,165
Total revenues	581,275		521,725		457,111
EXPENSES:
Property expenses	105,378		100,514		94,115
Real estate taxes	50,223		45,197		39,417
Provision for bad debts	545		58		396
Ground leases (Note 4 and 15)	3,096		3,075		3,504
General and administrative expenses	48,265		46,152		39,660
Acquisition-related expenses	497		1,479		1,962
Depreciation and amortization (Notes 2 and 4)	204,294		202,417		188,887
Total expenses	412,298		398,892		367,941
OTHER (EXPENSES) INCOME:
Interest income and other net investment gains (Note 16)	243		561		1,635
Interest expense (Note 7)	(57,682)		(67,571)		(75,870)
Total other (expenses) income	(57,439)		(67,010)		(74,235)
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest, Before Gain on Sale of Real Estate	111,538		55,823		14,935
Gain on sale of land (Note 18)	17,116		3,490		0
Gains on sales of depreciable operating properties (Note 4)	109,950		0		0
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	238,604		59,313		14,935
DISCONTINUED OPERATIONS (Note 18)
Income from discontinued operations	0		2,573		17,378
Net gain on dispositions of discontinued operations (Note 18)	0		121,922		12,252
Income from discontinued operations (2)	0	[1]	124,495	[1]	29,630	[2]
NET INCOME	238,604		183,808		44,565
Net income attributable to noncontrolling interests in consolidated subsidiaries	(4,523)		(3,589)		(685)
NET INCOME ATTRIBUTABLE TO KILROY REALTY	234,081		180,219		43,880
Total preferred distributions	13,250		13,250
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	$ 220,831		$ 166,969		$ 30,630
Income (Loss) from Continuing Operations, Per Basic Share	$ 2.44		$ 0.52		$ 0
Loss from continuing operations available to common unitholders per unit-diluted (Note 19)	2.42		0.51		0
Net income available to common unitholders per unit (dollars per unit)	2.44		1.99		0.37
Net income available to common unitholders per unit (dollars per unit)	$ 2.42		$ 1.95		$ 0.37
Weighted average common units outstanding - basic (Note 19)	89,854,096		83,090,235		77,343,853
Weighted average common units outstanding - diluted (Note 19)	90,395,775		84,967,720		77,343,853
Kilroy Realty, L.P. [Member]
REVENUES:
Rental income	$ 525,355		$ 466,328		$ 411,899
Tenant reimbursements	53,774		46,717		38,047
Other property income (Note 15 and 17)	2,146		8,680		7,165
Total revenues	581,275		521,725		457,111
EXPENSES:
Property expenses	105,378		100,514		94,115
Real estate taxes	50,223		45,197		39,417
Provision for bad debts	545		58		396
Ground leases (Note 4 and 15)	3,096		3,075		3,504
General and administrative expenses	48,265		46,152		39,660
Acquisition-related expenses	497		1,479		1,962
Depreciation and amortization (Notes 2 and 4)	204,294		202,417		188,887
Total expenses	412,298		398,892		367,941
OTHER (EXPENSES) INCOME:
Interest income and other net investment gains (Note 16)	243		561		1,635
Interest expense (Note 7)	(57,682)		(67,571)		(75,870)
Total other (expenses) income	(57,439)		(67,010)		(74,235)
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest, Before Gain on Sale of Real Estate	111,538		55,823		14,935
Gain on sale of land (Note 18)	17,116		3,490		0
Gains on sales of depreciable operating properties (Note 4)	109,950		0		0
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	238,604		59,313		14,935
DISCONTINUED OPERATIONS (Note 18)
Income from discontinued operations	0		2,573		17,378
Net gain on dispositions of discontinued operations (Note 18)	0		121,922		12,252
Income from discontinued operations (2)	0	[2]	124,495	[2]	29,630
NET INCOME	238,604		183,808		44,565
Net income attributable to noncontrolling interests in consolidated subsidiaries	(467)		(260)		(224)
NET INCOME ATTRIBUTABLE TO KILROY REALTY	238,137		183,548		44,341
Preferred distributions (Note 11)			(13,250)		(13,250)
Total preferred distributions	13,250		13,250		13,250
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	$ 224,887		$ 170,298		$ 31,091
Income (Loss) from Continuing Operations, Per Basic Share	$ 2.44		$ 0.52		$ 0
Loss from continuing operations available to common unitholders per unit-diluted (Note 19)	2.42		0.51		0
Net income available to common unitholders per unit (dollars per unit)	2.44		1.99		0.37
Net income available to common unitholders per unit (dollars per unit)	$ 2.42		$ 1.94		$ 0.37
Weighted average common units outstanding - basic (Note 19)	91,645,578		84,894,498		79,166,260
Weighted average common units outstanding - diluted (Note 19)	92,187,257		86,771,983		79,166,260
Distributions declared per common unit	$ 1.40		$ 1.40		$ 1.40
[1]	(2)The Company adopted ASU 2014-08 effective January 1, 2015 (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As a result, properties classified as held for sale and/or disposed of subsequent to January 1, 2015 that do not represent a strategic shift are no longer presented as discontinued operations.
[2]	The Operating Partnership adopted ASU 2014-08 effective January 1, 2015 (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As a result, properties classified as held for sale and/or disposed of subsequent to January 1, 2015 that do not represent a strategic shift are no longer presented as discontinued operations.

Consolidated Statements of Capi

Consolidated Statements of Capital (KILROY REALTY, L.P.) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015		Mar. 31, 2015		Dec. 31, 2014		Mar. 31, 2014		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 29,308	[1]	$ 44,002	[1]	$ 31,430	[1]	$ 101,932	[1]	$ 238,604	$ 183,808	$ 44,565
Stock Issued During Period, Value, New Issues									387,398	123,860	349,951
Noncontrolling Interest, Increase from Business Combination									474	977	4,885
Noncash amortization of share-based compensation									18,869	14,471	9,563
Preferred distributions									(13,250)	(13,250)	(13,250)
Stock Issued During Period, Value, in Connection with Early Exchange of Notes										223
Stock Issued During Period, Value, Restricted Stock Award, Gross									(1)	(1)	1
Noncontrolling Interest In Consolidated Subsidiaries [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income									4,523	3,589	685
Noncontrolling Interest, Increase from Business Combination									474	977	4,885
Kilroy Realty, L.P. [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			2,723,936				2,516,160		2,723,936	2,516,160	2,235,933
Net income	29,308	[2]	44,002	[2]	31,430	[2]	101,932	[2]	238,604	183,808	44,565
Issuance of common units (Note 11)									387,398	123,860	349,951
Noncontrolling Interest, Increase from Business Combination									474	977	4,885
Issuance of share-based compensation awards (Note 12)									1,692	1,692	1,448
Noncash amortization of share-based compensation									18,869	14,471	9,563
Repurchase of common units and restricted stock units (Note 12)									7,081	3,533	2,521
Preferred distributions									(13,250)	(13,250)	(13,250)
Distributions declared per common unit ($1.40 per unit)									(130,628)	(121,563)	(114,543)
Settlement of restricted stock units for shares of common stock									(1)	(1)
Stock Issued During Period, Value, in Connection with Early Exchange of Notes										$ 223
Stock Received During Period, Call Options										0
Stock Issued During Period, Value, Restricted Stock Award, Gross											1
Exercise of stock options									14,573	$ 21,092	128
Ending Balance	3,234,586				2,723,936				3,234,586	2,723,936	$ 2,516,160
Kilroy Realty, L.P. [Member] | Partners Capital Common Unit [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common units, units											7,210,838
Kilroy Realty, L.P. [Member] | Total Partners Capital [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			2,714,311				2,507,772		2,714,311	2,507,772	$ 2,232,654
Net income									238,137	183,548	44,341
Issuance of common units (Note 11)									387,398	123,860	349,951
Issuance of share-based compensation awards (Note 12)									1,692	1,692	1,448
Noncash amortization of share-based compensation									18,869	14,471	9,563
Repurchase of common units and restricted stock units (Note 12)									7,081	3,533	2,521
Preferred distributions									(13,250)	(13,250)	(13,250)
Distributions declared per common unit ($1.40 per unit)									(130,628)	(121,563)	(114,543)
Settlement of restricted stock units for shares of common stock									(1)	(1)
Stock Issued During Period, Value, in Connection with Early Exchange of Notes										$ 223
Stock Received During Period, Call Options										0
Stock Issued During Period, Value, Restricted Stock Award, Gross											1
Exercise of stock options										$ 21,092	128
Ending Balance	3,224,020				2,714,311				3,224,020	2,714,311	2,507,772
Kilroy Realty, L.P. [Member] | Partners Capital Preferred Units [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			192,411				192,411		192,411	192,411	192,411
Ending Balance	192,411				192,411				192,411	192,411	192,411
Kilroy Realty, L.P. [Member] | Partners Capital Common Unit [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			$ 2,521,900				$ 2,315,361		$ 2,521,900	$ 2,315,361	$ 2,040,243
Beginning Balance units			88,063,884				83,959,144		88,063,884	83,959,144	76,753,484
Net income									$ 238,137	$ 183,548	$ 44,341
Issuance of common units (Note 11)									$ 387,398	$ 123,860	349,951
Issuance of common units, units									5,640,033	1,950,599
Issuance of share-based compensation awards (Note 12)									$ 1,692	$ 1,692	$ 1,448
Issuance of share-based compensation awards, units (Note 12)											0
Noncash amortization of share-based compensation									18,869	14,471	$ 9,563
Repurchase of common units and restricted stock units (Note 12)									$ 7,081	$ 3,533	$ 2,521
Stock Issued During Period, Shares, Restricted Stock Award, Gross											37,245
Repurchase of common units and restricted stock units, units (Note 12)									101,389	58,045	42,896
Preferred distributions									$ (13,250)	$ (13,250)	$ (13,250)
General Partners' Capital Account, Period Distribution Amount									$ 130,628	$ 121,563
Distributions declared per common unit ($1.40 per unit)											(114,543)
Stock Issued During Period, Shares, in Connection with Early Exchange of Notes										2,091,323
Stock Issued During Period, Value, in Connection with Early Exchange of Notes										$ 223
Stock Received During Period, Call Options										515,342
Settlement of restricted stock units for shares of common stock units									78,937	141,205
Stock Issued During Period, Value, Restricted Stock Award, Gross									$ (1)	$ (1)	1
Exercise of stock options									$ 14,573	$ 21,092	$ 128
Exercise of stock options, units									342,000	495,000	473
Ending Balance	$ 3,031,609				$ 2,521,900				$ 3,031,609	$ 2,521,900	$ 2,315,361
Ending Balance units	94,023,465				88,063,884				94,023,465	88,063,884	83,959,144
Kilroy Realty, L.P. [Member] | Noncontrolling Interest In Consolidated Subsidiaries [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			$ 9,625				$ 8,388		$ 9,625	$ 8,388	$ 3,279
Net income									467	260	224
Noncontrolling Interest, Increase from Business Combination									474	977	4,885
Ending Balance	$ 10,566				$ 9,625				$ 10,566	$ 9,625	$ 8,388
[1]	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common stockholders per share does not equal the annual number reported on the consolidated statements of operations due to the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended December 31, 2015 and 2014.
[2]	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common unitholders per unit does not equal the annual number reported on the consolidated statements of operations due to the impact of the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended December 31, 2015 and 2014.

Consolidated Statements of Ca13

Consolidated Statements of Capital (KILROY REALTY, L.P.) - Parenthetical - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Kilroy Realty, L.P. [Member]
Distributions declared per common unit	$ 1.40	$ 1.40	$ 1.40

Consolidated Statements of Ca14

Consolidated Statements of Cash Flows (KILROY REALTY, L.P.) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Capitalized interest	$ 50,923	$ 44,385	$ 32,742
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	238,604	183,808	44,565
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	201,482	202,108	199,558
Increase (decrease) in provision for bad debts	545	58	396
Depreciation of furniture, fixtures and equipment	2,812	2,370	1,929
Noncash amortization of share-based compensation awards (Note 13)	15,537	12,095	8,616
Noncash amortization of deferred financing costs and debt discounts and premiums	1,853	4,315	5,315
Noncash amortization of net below market rents (Note 5)	(8,449)	(8,328)	(7,777)
Disposal Group Depreciable Operating Properties, Not Discontinued Operations, Gain (Loss) on Disposal	109,950	0	0
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax	0	(121,922)	(12,252)
Gain on sale of land (Note 4)	(17,116)	(3,490)	0
Noncash amortization of deferred revenue related to tenant-funded tenant improvements (Note 9)	(13,338)	(10,979)	(10,713)
Straight-line rents	(44,383)	(31,782)	(24,135)
Net change in other operating assets	(8,085)	367	(4,615)
Net change in other operating liabilities	12,496	16,633	40,137
Insurance proceeds received for property damage and other, net	0	0	(448)
Net cash provided by operating activities	272,008	245,253	240,576
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for acquisitions of operating properties, net of cash acquired (Note 3)	0	(204,546)	(202,682)
Expenditures for acquisitions of development and redevelopment properties (Note 3)	(139,073)	(147,182)	(102,769)
Expenditures for operating properties	(99,557)	(132,080)	(129,873)
Expenditures for development and redevelopment properties and undeveloped land	(407,969)	(417,784)	(320,141)
Net proceeds received from dispositions of operating properties and land (Notes 4 and 19)	319,639	427,544	21,178
Issuance of Note Receivable	(3,000)	0	0
Insurance proceeds received for property damage	0	0	448
(Increase) decrease in acquisition-related deposits	1,998	(1,983)	(2,596)
(Increase) decrease in restricted cash (Note 4)	65,210	(25,405)	229,915
Net cash used in investing activities	(262,752)	(501,436)	(506,520)
CASH FLOWS FROM FINANCING ACTIVITIES:
Borrowings on unsecured line of credit	250,000	505,000	55,000
Repayments on unsecured line of credit	(390,000)	(410,000)	(195,000)
Proceeds from the issuance of unsecured debt (Note 8)	397,776	395,528	299,901
Repayments of exchangeable senior notes (Note 8)	0	(172,500)	0
Principal payments on secured debt (Note 8)	(159,766)	(9,845)	(93,688)
Borrowings on unsecured debt (Note 8)	0	39,000
Repayments of unsecured debt (Note 8)	(325,000)	(83,000)
Financing costs	(4,814)	(8,648)	(4,384)
Repurchase/redemption of common units and restricted stock units	(7,081)	(3,533)	(2,520)
Proceeds from exercise of stock options	14,573	21,092	128
Contributions from noncontrolling interests in consolidated subsidiary (Note 2)	474	977
Distributions paid to common unitholders	(126,839)	(118,463)	(111,517)
Distributions paid to preferred unitholders	(13,250)	(13,250)	(13,250)
Net cash provided by financing activities	23,471	244,587	284,621
Net increase (decrease) in cash and cash equivalents	32,727	(11,596)	18,677
Cash and cash equivalents, beginning of period	23,781	35,377	16,700
Cash and cash equivalents, end of period	56,508	23,781	35,377
SUPPLEMENTAL CASH FLOWS INFORMATION:
Cash paid for interest, net of capitalized interest of $50,923, $44,385, and $32,742 as of December 31, 2015, 2014 and 2013, respectively	54,747	58,944	65,157
NONCASH INVESTING TRANSACTIONS:
Accrual for expenditures for operating properties and development and redevelopment properties	109,715	77,091	73,482
Tenant improvements funded directly by tenants to third parties	13,837	42,906	7,633
Assumption of secured debt with property acquisition (Note 8)	0	0	95,496
Assumption of other assets and liabilities in connection with operating and development property acquisitions, net (Note 3)	6,254	14,917	1,811
Release of Holdback Funds to Third Party	9,279	0	0
Contribution of land, net of related liabilities, by noncontrolling interest to consolidated subsidiary	0	0	(4,885)
NONCASH FINANCING TRANSACTIONS:
Accrual of dividends distributions payable to common unitholders (Note 11)	(33,336)	(31,243)	(29,378)
Accrual of distributions payable to preferred unitholders (Note 11)	(1,656)	(1,656)	(1,694)
Kilroy Realty, L.P. [Member]
Capitalized interest	50,923	44,385	32,742
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	238,604	183,808	44,565
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	201,482	202,108	199,558
Increase (decrease) in provision for bad debts	545	58	396
Depreciation of furniture, fixtures and equipment	2,812	2,370	1,929
Noncash amortization of share-based compensation awards (Note 13)	15,537	12,095	8,616
Noncash amortization of deferred financing costs and debt discounts and premiums	1,853	4,315	5,315
Noncash amortization of net below market rents (Note 5)	(8,449)	(8,328)	(7,777)
Disposal Group Depreciable Operating Properties, Not Discontinued Operations, Gain (Loss) on Disposal	109,950	0	0
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax	0	(121,922)	(12,252)
Gain on sale of land (Note 4)	(17,116)	(3,490)	0
Noncash amortization of deferred revenue related to tenant-funded tenant improvements (Note 9)	(13,338)	(10,979)	(10,713)
Straight-line rents	(44,383)	(31,782)	(24,135)
Net change in other operating assets	(8,085)	367	(4,615)
Net change in other operating liabilities	12,496	16,633	40,137
Insurance proceeds received for property damage and other, net	0	0	(448)
Net cash provided by operating activities	272,008	245,253	240,576
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for acquisitions of operating properties, net of cash acquired (Note 3)	0	(204,546)	(202,682)
Expenditures for acquisitions of development and redevelopment properties (Note 3)	(139,073)	(147,182)	(102,769)
Expenditures for operating properties	(99,557)	(132,080)	(129,873)
Expenditures for development and redevelopment properties and undeveloped land	(407,969)	(417,784)	(320,141)
Net proceeds received from dispositions of operating properties and land (Notes 4 and 19)	319,639	427,544	21,178
Issuance of Note Receivable	(3,000)	0	0
Insurance proceeds received for property damage	0	0	448
(Increase) decrease in acquisition-related deposits	1,998	(1,983)	(2,596)
(Increase) decrease in restricted cash (Note 4)	65,210	(25,405)	229,915
Net cash used in investing activities	(262,752)	(501,436)	(506,520)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from issuance of common units (Note 12)	387,398	102,229	349,951
Borrowings on unsecured line of credit	250,000	505,000	55,000
Repayments on unsecured line of credit	(390,000)	(410,000)	(195,000)
Proceeds from the issuance of unsecured debt (Note 8)	397,776	395,528	299,901
Repayments of exchangeable senior notes (Note 8)	0	(172,500)	0
Principal payments on secured debt (Note 8)	(159,766)	(9,845)	(93,688)
Borrowings on unsecured debt (Note 8)	0	39,000	0
Repayments of unsecured debt (Note 8)	(325,000)	(83,000)	0
Financing costs	(4,814)	(8,648)	(4,384)
Repurchase/redemption of common units and restricted stock units	(7,081)	(3,533)	(2,520)
Proceeds from exercise of stock options	14,573	21,092	128
Contributions from noncontrolling interests in consolidated subsidiary (Note 2)	474	977	0
Distributions paid to common unitholders	(126,839)	(118,463)	(111,517)
Distributions paid to preferred unitholders	(13,250)	(13,250)	(13,250)
Net cash provided by financing activities	23,471	244,587	284,621
Net increase (decrease) in cash and cash equivalents	32,727	(11,596)	18,677
Cash and cash equivalents, beginning of period	23,781	35,377	16,700
Cash and cash equivalents, end of period	56,508	23,781	35,377
SUPPLEMENTAL CASH FLOWS INFORMATION:
Cash paid for interest, net of capitalized interest of $50,923, $44,385, and $32,742 as of December 31, 2015, 2014 and 2013, respectively	54,747	58,944	65,157
NONCASH INVESTING TRANSACTIONS:
Accrual for expenditures for operating properties and development and redevelopment properties	109,715	77,091	73,482
Tenant improvements funded directly by tenants to third parties	13,837	42,906	7,633
Assumption of secured debt with property acquisition (Note 8)	0	0	95,496
Assumption of other assets and liabilities in connection with operating and development property acquisitions, net (Note 3)	6,254	14,917	1,811
Release of Holdback Funds to Third Party	9,279	0	0
Contribution of land, net of related liabilities, by noncontrolling interest to consolidated subsidiary	0	0	(4,885)
NONCASH FINANCING TRANSACTIONS:
Accrual of dividends distributions payable to common unitholders (Note 11)	(33,353)	(31,243)	(29,378)
Accrual of distributions payable to preferred unitholders (Note 11)	$ (1,656)	$ (1,656)	$ (1,694)

Supplemental Cash Flow Informat

Supplemental Cash Flow Information of the Operating Partnership Statement - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other Significant Noncash Transactions [Line Items]
Interest Paid, Net	$ 54,747	$ 58,944	$ 65,157
Capital Expenditures Incurred but Not yet Paid	109,715	77,091	73,482
Tenant improvements funded directly by tenants to third parties	13,837	42,906	7,633
Noncash or Part Noncash Acquisition, Debt Assumed	0	0	95,496
Noncash or Part Noncash Acquisition, Other Liabilities Assumed	6,254	14,917	1,811
Release of Holdback Funds to Third Party	9,279	0	0
Noncash or Part Noncash Acquisition, Land Contributed, Net of Liabilities Assumed	0	0	4,885
Common Stockholders And Unitholders Dividends And Distributions Declared But Not Paid	33,336	31,243	29,378
Preferred Stockholders And Unitholders Dividends And Distributions Declared But Not Paid	1,656	1,656	1,694
purchase price, value of shares issued to acquire land	0	21,631	0
Subsidiaries [Member]
Other Significant Noncash Transactions [Line Items]
Interest Paid, Net	54,747	58,944	65,157
Capital Expenditures Incurred but Not yet Paid	109,715	77,091	73,482
Tenant improvements funded directly by tenants to third parties	13,837	42,906	7,633
Noncash or Part Noncash Acquisition, Debt Assumed	0	0	95,496
Noncash or Part Noncash Acquisition, Other Liabilities Assumed	6,254	14,917	1,811
Release of Holdback Funds to Third Party	9,279	0	0
Noncash or Part Noncash Acquisition, Land Contributed, Net of Liabilities Assumed	0	0	4,885
Common Stockholders And Unitholders Dividends And Distributions Declared But Not Paid	33,353	31,243	29,378
Preferred Stockholders And Unitholders Dividends And Distributions Declared But Not Paid	$ 1,656	$ 1,656	$ 1,694

Organization and Ownership

Organization and Ownership	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Ownership	Organization and Ownership Kilroy Realty Corporation (the “Company”) is a self-administered real estate investment trust (“REIT”) active in premier office submarkets along the West Coast. We own, develop, acquire and manage real estate assets, consisting primarily of Class A properties in the coastal regions of Los Angeles, Orange County, San Diego County, the San Francisco Bay Area and greater Seattle, which we believe have strategic advantages and strong barriers to entry. Class A real estate encompasses attractive and efficient buildings of high quality that are attractive to tenants, are well-designed and constructed with above-average material, workmanship and finishes, and are well-maintained and managed. We qualify as a REIT under the Internal Revenue Code of 1986, as amended (the “Code”). The Company’s common stock is publicly traded on the New York Stock Exchange (“NYSE”) under the ticker symbol “KRC.” We own our interests in all of our real estate assets through Kilroy Realty, L.P. (the “Operating Partnership”) and Kilroy Realty Finance Partnership, L.P. (the “Finance Partnership”). We generally conduct substantially all of our operations through the Operating Partnership. Unless stated otherwise or the context indicates otherwise, the terms “Kilroy Realty Corporation” or the “Company,” “we,” “our,” and “us” refer to Kilroy Realty Corporation and its consolidated subsidiaries and the term “Operating Partnership” refers to Kilroy Realty, L.P. and its consolidated subsidiaries. The descriptions of our business, employees, and properties apply to both the Company and the Operating Partnership. Our stabilized portfolio of operating properties was comprised of the following office properties at December 31, 2015 : Number of Buildings Rentable Square Feet (unaudited) Number of Tenants Percentage Occupied (unaudited) Stabilized Office Properties 101 13,032,406 517 94.8 % Our stabilized portfolio includes all of our properties with the exception of development and redevelopment properties currently under construction or committed for construction, “lease-up” properties, real estate assets held for sale and undeveloped land. 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 year ended December 31, 2015 , we stabilized a development project consisting of two office buildings encompassing 108,517 rentable square feet in Hollywood, California, and a development project consisting of two office buildings encompassing 339,987 rentable square feet in Redwood City, California. These projects were included in our stabilized portfolio as of December 31, 2015 . As of December 31, 2015 , we had one office development project in the “lease-up” phase. We also had four operating properties and one land parcel classified as held for sale as of December 31, 2015 . As of December 31, 2015 , the following properties were excluded from our stabilized portfolio: Number of Properties/Projects Estimated Rentable Square Feet (unaudited) (1) Properties held for sale (2) 4 465,812 Development projects in “ lease-up" 1 73,000 Development projects under construction 5 1,910,000 _______________ (1) Estimated rentable square feet upon completion. (2) See Note 4 “Dispositions and Real Estate Assets Held for Sale” for additional information. Our stabilized portfolio also excludes our near-term and future development pipeline, which is comprised of ten potential development sites, representing approximately 99 gross acres of undeveloped land. As of December 31, 2015 , all of our real estate assets were owned and all of our business was conducted in the state of California with the exception of twelve office properties and one future development project located in the state of Washington. All of our real estate assets are 100% owned, excluding two office properties owned by Redwood City Partners, LLC (“Redwood LLC”), a consolidated subsidiary, and an undeveloped land parcel held at a qualified intermediary for potential future transactions that are intended to qualify as like-kind exchanges pursuant to Section 1031 of the Code (“Section 1031 Exchanges”) to defer taxable gains on dispositions for federal and state income tax purposes, which have been consolidated for financial reporting purposes (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As of December 31, 2015 , the Company owned a 98.1% common general partnership interest in the Operating Partnership. The remaining 1.9% common limited partnership interest in the Operating Partnership as of December 31, 2015 was owned by non-affiliated investors and certain of our executive officers and directors. Both the general and limited common partnership interests in the Operating Partnership are denominated in common units. Generally, the number of common units held by the Company is equivalent to the number of outstanding shares of the Company’s common stock, and the rights of all the common units to quarterly distributions and payments in liquidation mirror those of the Company’s common stockholders. The common limited partners have certain redemption rights as provided in the Operating Partnership’s Seventh Amended and Restated Agreement of Limited Partnership, as amended, the “Partnership Agreement” (see Note 10 “Noncontrolling Interests on the Company’s Consolidated Financial Statements” for additional information). Kilroy Realty Finance, Inc., which is a wholly owned subsidiary of the Company, is the sole general partner of the Finance Partnership and owns a 1.0% common general partnership interest in the Finance Partnership. The Operating Partnership owns the remaining 99.0% common limited partnership interest. Kilroy Services, LLC (“KSLLC”), which is a wholly owned subsidiary of the Operating Partnership, is the entity through which we generally conduct substantially all of our development activities. With the exception of the Operating Partnership and Redwood LLC, all of our subsidiaries are wholly owned.

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Basis of Presentation and Significant Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	Basis of Presentation and Significant Accounting Policies Basis of Presentation The consolidated financial statements of the Company include the consolidated financial position and results of operations of the Company, the Operating Partnership, the Finance Partnership, KSLLC, Redwood LLC and all of our wholly owned and controlled subsidiaries. The consolidated financial statements of the Operating Partnership include the consolidated financial position and results of operations of the Operating Partnership, the Finance Partnership, KSLLC, Redwood LLC and all wholly owned and controlled subsidiaries of the Operating Partnership. All intercompany balances and transactions have been eliminated in the consolidated financial statements. Partially Owned Entities and Variable Interest Entities At December 31, 2015 , the consolidated financial statements of the Company and the Operating Partnership included two variable interest entities (“VIEs”), in which we were deemed to be the primary beneficiary. One VIE, Redwood LLC, was established in the second quarter of 2013 in connection with an undeveloped land acquisition. The other VIE was established in the fourth quarter of 2015 to facilitate potential future Section 1031 Exchanges to defer taxable gains on dispositions for federal and state income tax purposes. The impact of consolidating the VIEs increased the Company’s total assets, liabilities and noncontrolling interests by approximately $203.3 million (of which $187.3 million related to real estate held for investment on our consolidated balance sheet), approximately $28.8 million and approximately $6.5 million , respectively, as of December 31, 2015 . At December 31, 2014 , the consolidated financial statements of the Company and the Operating Partnership included two VIEs, in which we were deemed to be the primary beneficiary. One of the VIEs was Redwood LLC and the remaining VIE was established during the fourth quarter of 2014 to facilitate potential Section 1031 Exchanges. During the three months ended March 31, 2015, the Section 1031 Exchange was successfully completed and the VIE was terminated. As a result, $59.2 million of our restricted cash balance at December 31, 2014 , which related to prior period disposition proceeds that were set aside to facilitate the Section 1031 Exchanges, was released from escrow. The impact of consolidating the VIEs increased the Company’s total assets, liabilities and noncontrolling interests by approximately $219.6 million (of which $211.8 million related to real estate held for investment on our consolidated balance sheet), approximately $23.4 million and approximately $5.9 million , respectively, as of December 31, 2014 . Our accounting policy is to consolidate entities in which we have a controlling financial interest and significant decision making control over the entity's operations. In determining whether we have a controlling financial interest in a partially owned entity and the requirement to consolidate the accounts of that entity, we consider factors such as ownership interest, board representation, management representation, size of our investment (including loans), authority to control decisions, and contractual and substantive participating rights of the members. In addition to evaluating control rights, we consolidate entities in which the other members have no substantive kick-out rights to remove the Company as the managing member. We also evaluate whether the entity is a variable interest entity (“VIE”) and whether we are the primary beneficiary. VIEs are entities in which the equity investors do not have sufficient equity at risk to finance their endeavors without additional financial support or the holders of the equity investment at risk do not have a controlling financial interest. We are deemed to be the primary beneficiary of a VIE when we have the power to direct the activities of the VIE that most significantly impact the VIEs’ economic performance and the obligation to absorb losses or receive benefits that could potentially be significant to the VIE. If the requirements for consolidation are not met, the Company would account for investments under the equity method of accounting if we have the ability to exercise significant influence over the entity. Equity method investments would be initially recorded at cost and subsequently adjusted for our share of net income or loss and cash contributions and distributions each period. The Company did not have any equity method investments at December 31, 2015 or December 31, 2014 . 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, 2015 , 2014 and 2013 we capitalized $1.1 million , $4.5 million and $2.3 million , respectively, in acquisition costs associated with development acquisitions. Operating Properties Operating properties are generally carried at historical cost less accumulated depreciation. Properties held for sale are reported at the lower of the carrying value or the fair value less estimated cost to sell. The cost of operating properties includes the purchase price or development costs of the properties. Costs incurred for the renovation and betterment of the operating properties are capitalized to our investment in that property. Maintenance and repairs are charged to expense as incurred. When evaluating properties to be held and used for potential impairment, we first evaluate whether there are any indicators of impairment for any of our properties. If any impairment indicators are present for a specific property, we then perform an undiscounted cash flow analysis and compare the net carrying amount of the property to the property’s estimated undiscounted future cash flow over the anticipated holding period. If the estimated undiscounted future cash flow is less than the net carrying amount of the property, we then perform an impairment loss calculation to determine if the fair value of the property is less than the net carrying value of the property. Our impairment loss calculation compares the net carrying amount of the property to the property’s estimated fair value, which may be based on estimated discounted future cash flow calculations or third-party valuations or appraisals. We would recognize an impairment loss if the asset’s net carrying amount exceeds the asset’s estimated fair value. If we were to recognize an impairment loss, the estimated fair value of the asset (less costs to sell for assets held for sale) would become its new cost basis. For a depreciable long-lived asset, the new cost basis would be depreciated (amortized) over the remaining useful life of that asset. 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, 2015 , 2014 , and 2013 was $159.5 million , $153.8 million and $145.3 million , respectively. Asset Description Depreciable Lives Buildings and improvements 25 – 40 years Tenant improvements 1 – 20 years (1) ________________________ (1) Tenant improvements are amortized over the shorter of the lease term or the estimated useful life. Real Estate Assets Held for Sale, Dispositions and Discontinued Operations A real estate asset is classified as held for sale when certain criteria are met, including but not limited to the availability of the asset for immediate sale, the existence of an active program to locate a buyer and the probable sale or transfer of the asset within one year. If such criteria are met, we present the applicable assets and liabilities related to the real estate asset held for sale, if material, separately on the balance sheet and we would cease to record depreciation and amortization expense. Real estate assets held for sale are reported at the lower of their carrying value or their estimated fair value less the estimated costs to sell. As of December 31, 2015 , we classified four operating properties and one undeveloped land parcel located in San Diego, California as held for sale. As of December 31, 2014 , we had one undeveloped land parcel classified as held for sale. Effective January 1, 2015, the Company adopted Financial Accounting Standards Board (“FASB”) Accounting Standards Update (“ASU”) No. 2014-08 (“ASU 2014-08”), which changed the criteria for reporting discontinued operations while enhancing disclosures in this area. Under the new guidance, only property disposals representing a strategic shift that has (or will have) a major effect on an entity's operations and financial results, such as a major line of business, a major geographical area or a major equity investment, are required to be presented as discontinued operations. If we were to determine that the property disposition represents a strategic shift, the revenues, expenses and net gain (loss) on dispositions of the property would be recorded in discontinued operations for all periods presented through the date of the applicable disposition. The Company adopted and applied the new guidance on a prospective basis as required by ASU 2014-08. Therefore, properties classified as held for sale and/or disposed of subsequent to January 1, 2015 that do not represent a strategic shift are presented in continuing operations for all periods presented. In accordance with this guidance, the operations of the ten properties sold during the year ended December 31, 2015 are presented in continuing operations for the year ended December 31, 2015 . Prior to January 1, 2015, 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. For the year ended December 31, 2014, discontinued operations includes the income and gains on all of the properties sold in 2014. For the year ended December 31, 2013, discontinued operations includes the income and gains on all of the properties sold in 2013 and 2014. The net gains (losses) on dispositions of non-depreciable real estate property, including land, are reported in the consolidated statements of operations as gains (losses) on sale of land within continuing operations in the period the land is sold. Revenue Recognition We recognize revenue from rent, tenant reimbursements, parking and other revenue once all of the following criteria are met: (i) the agreement has been fully executed and delivered, (ii) services have been rendered, (iii) the amount is fixed or determinable, and (iv) the collectability of the amount is reasonably assured. Minimum annual rental revenues are recognized in rental revenues on a straight-line basis over the term of the related lease. Rental revenue recognition commences when the tenant takes possession or controls the physical use of the leased space. In order for the tenant to take possession, the leased space must be substantially complete and ready for its intended use. In order to determine whether the leased space is substantially ready for its intended use, we begin by determining whether the Company 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 generally when Company owned tenant improvements are substantially complete. In certain instances, when we conclude that the Company is not the owner (the tenant is the owner) of tenant improvements, rental revenue recognition begins when the tenant takes possession of or controls the space. When we conclude that the Company is the owner of tenant improvements, we record the cost to construct the tenant improvements, including costs paid for or reimbursed by the tenants, as a capital asset. For these tenant improvements, we record the amount funded by or reimbursed by the tenants as deferred revenue, which is amortized on a straight-line basis as additional rental income over the term of the related lease. When we conclude that the tenant is the owner of tenant improvements for accounting purposes, we record our contribution towards those improvements as a lease incentive, which is included in deferred leasing costs and acquisition-related intangible assets, net on our consolidated balance sheets and amortized as a reduction to rental income on a straight-line basis over the term of the lease. Tenant Reimbursements Reimbursements from tenants, consisting of amounts due from tenants for common area maintenance, real estate taxes and other recoverable costs, are recognized as revenue in the period the recoverable costs are incurred. Tenant reimbursements are recognized and recorded on a gross basis, as we are generally the primary obligor with respect to purchasing goods and services from third-party suppliers, have discretion in selecting the supplier, and have credit risk. Other Property Income Other property income primarily includes amounts recorded in connection with lease terminations and tenant bankruptcy settlement payments. Lease termination fees are amortized over the remaining lease term, if applicable. If there is no remaining lease term, they are recognized when received and realized. Other property income also includes miscellaneous income from tenants, such as fees related to the restoration of leased premises to their original condition and fees for late rental payments. Allowances for Uncollectible Tenant and Deferred Rent Receivables We carry our current and deferred rent receivables net of allowances for uncollectible amounts. Our determination of the adequacy of these allowances is based primarily upon evaluations of individual receivables, current economic conditions, historical loss experience, and other relevant factors. The allowances are increased or decreased through the provision for bad debts on our consolidated statements of operations. Cash and Cash Equivalents We consider all highly-liquid investments with original maturities of three months or less to be cash equivalents. Restricted Cash Restricted cash consists of cash proceeds from dispositions that are temporarily held at qualified intermediaries for purposes of facilitating potential Section 1031 Exchanges and cash held in escrow related to acquisition holdbacks. Restricted cash also includes cash held as collateral to provide credit enhancement for the Operating Partnership’s mortgage debt, including cash reserves for capital expenditures, tenant improvements and property taxes. As of December 31, 2015 , we had no restricted cash held at qualified intermediaries for the purpose of facilitating Section 1031 Exchanges. As of December 31, 2014 , we had approximately $59.2 million in restricted cash held at qualified intermediaries for the purpose of facilitating Section 1031 Exchanges. 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 14 “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 do not significantly impact net income. Deferred Leasing Costs Costs incurred in connection with successful property leasing are capitalized as deferred leasing costs and classified as investment activities in the statement of cash flows. Deferred leasing costs consist primarily of leasing commissions and also include certain internal payroll costs and lease incentives, which are amortized using the straight-line method of accounting over the lives of the leases which generally range from one to 20 years. We reevaluate the remaining useful lives of leasing costs as the creditworthiness of our tenants and economic and market conditions change. If we determine that the estimated remaining life of a lease has changed, we adjust the amortization period accordingly. Fully amortized deferred leasing costs are written off each quarter. Deferred Financing Costs Financing costs related to the origination or assumption of long-term debt are deferred and generally amortized using the straight-line method of accounting, which approximates the effective interest method, over the contractual terms of the applicable financings. Fully amortized deferred financing costs are written off when the corresponding financing is repaid. As of December 31, 2015 and 2014 , deferred financing costs were reported net of accumulated amortization of $12.3 million and $12.2 million , respectively. Debt Discounts and Premiums Original issuance debt discounts and discounts/premiums related to recording debt acquired in connection with operating property acquisitions at fair value are generally amortized and accreted on a straight-line basis, which approximates the effective interest method. Discounts are recorded as additional interest expense from date of issuance or acquisition through the contractual maturity date of the related debt. Premiums are recorded as a reduction to interest expense from the date of issuance or acquisition through the contractual maturity date of the related debt. Our secured debt is presented including unamortized premiums of $6.2 million and $10.3 million as of December 31, 2015 and 2014 , respectively. Our unsecured senior notes are presented net of unamortized discounts of $7.4 million and $5.9 million , as of December 31, 2015 and 2014 , 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. A portion of this additional interest expense is capitalized to the development and redevelopment balances qualifying for interest capitalization each period. As of December 31, 2015 , we had no outstanding exchangeable debt instruments, as our exchangeable debt instruments reached their maturity in November 2014 (see Note 8 “Secured and Unsecured Debt of the Operating Partnership” for additional information). Noncontrolling Interests in the Company’s Consolidated Financial Statements Noncontrolling interests in the Company’s consolidated financial statements represent the common limited partnership interests in the Operating Partnership not held by the Company (“noncontrolling common units”) and the equity interest held by an unrelated third party in our consolidated subsidiary, Redwood LLC, which was formed during 2013 in connection with a development land acquisition. 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 10 “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. Net income attributable to noncontrolling interest in consolidated subsidiary is allocated in accordance with the terms of the related agreement. 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, 2015 and 2014 . The Series G and Series H Preferred Units are presented in the permanent equity section of the Operating Partnership’s consolidated balance sheets given that the Series G and Series H Preferred Units may only be redeemed at our option (see Note 12 “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 10 “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 equity interest in Redwood LLC held by an unrelated third party. 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 11 “Stockholders’ Equity of the Company”) are reflected as a reduction of additional paid-in capital. Issuance costs incurred in connection with preferred equity offerings are reflected as a reduction of the carrying value of the preferred equity. The Company records preferred stock issuance costs as a noncash preferred equity distribution at the time we notify the holders of preferred stock or units of our intent to redeem such shares or units. The net proceeds from any equity offering of the Company are generally contributed to the Operating Partnership in exchange for a number of common or preferred units equivalent to the number of shares of common or preferred stock issued and are reflected in the Operating Partnership’s consolidated financial statements as an increase in partners’ capital. Share-based Incentive Compensation Accounting Compensation cost for all share-based awards, including options, requires measurement at estimated fair value on the grant date. Compensation cost is recognized over the service vesting period, which represents the requisite service period, on a straight-line basis. The grant date fair value of market measure-based share-based compensation plans are calculated using a Monte Carlo simulation pricing model. The grant date fair value of stock option grants is calculated using the Black-Scholes valuation model. Equity awards settled in cash are valued at the fair value of our common stock on the period end date through the settlement date. Equity awards settled in cash are remeasured at each reporting period and are recognized as a liability in the consolidated balance sheet during the vesting period until settlement. For share-based awards in which the performance period precedes the grant date, we recognize compensation cost over the requisite service period, which

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
Acquisitions	Acquisitions Development Project Acquisitions During the years ended December 31, 2015 and 2014 , we acquired the following undeveloped land sites listed below from unrelated third parties. The acquisitions were funded with proceeds from the Company’s at-the-market stock offering program (see Note 11 “Stockholders’ Equity of the Company” for additional information), borrowings under the unsecured line of credit (see Note 8 “Secured and Unsecured Debt of the Operating Partnership” for additional information), and disposition proceeds (see Note 4 “Dispositions and Real Estate Assets Held for Sale” for additional information). Project Date of Acquisition City/Submarket Type Purchase Price (1) (in millions) 2015 Acquisitions 333 Dexter (2) February 13, 2015 Seattle, WA Land $ 49.5 100 Hooper (3) July 7, 2015 San Francisco, CA Land 78.0 Total $ 127.5 2014 Acquisitions The Exchange on 16th (4) May 23, 2014 San Francisco, CA Land $ 95.0 Flower Mart (5) October 23, 2014 San Francisco, CA Land December 19, 2014 71.0 Total $ 166.0 _______________ (1) See Note 16 “Commitments and Contingencies” for additional information on certain accrued liabilities for these acquisitions. (2) Acquisition comprised of four adjacent parcels in the South Lake Union submarket of Seattle, Washington located at 330 Dexter Avenue North, 333 Dexter Avenue North, 401 Dexter Avenue North, and 400 Aurora Avenue North. In connection with this acquisition, we also assumed $2.4 million in accrued liabilities and acquisition costs that are not included in the purchase price above. (3) In connection with this acquisition, we assumed $4.1 million in accrued liabilities and acquisition costs that are not included in the purchase price above. (4) In connection with this acquisition, we assumed $2.3 million in accrued liabilities that are not included in the purchase price above. (5) In the fourth quarter of 2014, the Company closed on two adjacent land sites for a total purchase price of $71.0 million and approximately $13.4 million in transaction costs and accrued liabilities, net. The acquisitions, which were completed through the execution of two merger transactions, were partially funded through the issuance of 351,476 shares of the Company’s common stock valued at approximately $21.6 million and the remainder was paid in cash. Operating Properties We did not acquire any operating properties during the year ended December 31, 2015 . During the year ended December 31, 2014 , we acquired the five operating office properties, listed below, from unrelated third parties. Unless otherwise noted, we funded these acquisitions with proceeds from the Company’s public offerings of common stock and the Company's at-the-market stock offering program (see Note 11 “Stockholders’ Equity of the Company”), borrowings under the unsecured line of credit (see Note 8 “Secured and Unsecured Debt of the Operating Partnership”), disposition proceeds (see Note 4 “Dispositions and Real Estate Assets Held for Sale” for additional information”), 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, 2015 (unaudited) Purchase Price (in millions) (1) 2014 Acquisitions 401 Terry Ave. N., Seattle, WA March 13, 2014 1 140,605 100.0% $ 106.1 1310, 1315, 1320-1324, 1325-1327 Chesapeake Terrace, Sunnyvale, CA (2) November 5, 2014 4 266,982 100.0% 100.5 Total (3) 5 407,587 $ 206.6 ________________________ (1) Excludes acquisition-related costs and non-lease related accrued liabilities assumed. Includes assumed unpaid leasing commissions and tenant improvements. (2) As of December 31, 2014 , these properties, together the “Chesapeake Commons” project, were temporarily being held in a separate VIE to facilitate potential Section 1031 Exchanges. During January 2015, the Company closed out the Section 1031 Exchange related to this VIE. (See Note 2 “Basis of Presentation and Significant Accounting Policies”). (3) The results of operations for the properties acquired during 2014 contributed $7.7 million and $2.8 million to revenues and net income from continuing operations, respectively, for the year ended December 31, 2014 . The related assets, liabilities and results of operations of the acquired properties are included in the consolidated financial statements as of the date of acquisition. The following table summarizes the estimated fair values of the assets acquired and liabilities assumed at the respective acquisition dates for our 2014 operating property acquisitions: Acquisitions Total 2014 Acquisitions (1) Assets Land and improvements $ 81,430 Buildings and improvements (2) 114,876 Deferred leasing costs and acquisition-related intangible assets (3) 17,259 Total assets acquired 213,565 Liabilities Deferred revenue and acquisition-related intangible liabilities (4) 6,990 Accounts payable, accrued expenses and other liabilities 2,029 Total liabilities assumed 9,019 Net assets and liabilities acquired (5) $ 204,546 _______________ (1) The purchase price of the two acquisitions completed during the year ended December 31, 2014 were individually less than 5% and in aggregate less than 10% of the Company’s total assets as of December 31, 2014 . (2) Represents buildings, building improvements and tenant improvements. (3) Represents in-place leases (approximately $12.3 million with a weighted average amortization period of 7.0 years) and leasing commissions (approximately $4.9 million with a weighted average amortization period of 7.0 years). (4) Represents below-market leases (approximately $7.0 million with a weighted average amortization period of 6.1 years). (5) Reflects the purchase price net of assumed secured debt and other lease-related obligations.

Dispositions and Real Estate As

Dispositions and Real Estate Assets Held for Sale (Notes)	12 Months Ended
	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]	4. Dispositions and Real Estate Assets Held for Sale Operating Property Dispositions The following table summarizes the properties sold during the years ended December 31, 2015 , 2014 and 2013 : Location Month of Disposition Number of Buildings Rentable Square Feet (unaudited) Sales Price (in millions) (1) 2015 Dispositions 15050 NE 36th Street, Redmond, WA April 1 122,103 $ 51.2 San Diego Properties - Tranches 1 and 2 (2) April/July 9 924,291 258.0 Total 2015 Dispositions 10 1,046,394 $ 309.2 2014 Dispositions (3) San Diego Properties, San Diego, CA (4) January 12 1,049,035 $ 294.7 9785 & 9791 Towne Centre Drive, San Diego, CA June 2 126,000 29.5 111 Pacifica, Irvine, CA September 1 67,496 15.1 4040 Civic Center Drive, San Rafael, CA October 1 130,237 34.9 999 Town & Country Road, Orange, CA December 1 98,551 25.3 Total 2014 Dispositions 17 1,471,319 $ 399.5 2013 Dispositions (3) 26541 Agoura Road, Calabasas, CA June 1 90,156 $ 14.7 8101 Kaiser Boulevard, Anaheim, CA October 1 59,790 9.6 4910 Directors Place, San Diego CA December 1 50,360 32.6 Total 2013 Dispositions 3 200,306 $ 56.9 __________________ (1) Represents gross sales price before the impact of broker commissions and closing costs. (2) The San Diego Properties - Tranche 1 includes the following properties: 10770 Wateridge Circle, 6200 Greenwich Drive, and 6220 Greenwich Drive. The San Diego Properties - Tranche 2 includes the following properties: 6260 Sequence Drive, 6290, Sequence Drive, 6310 Sequence Drive, 6340 Sequence Drive, 6350 Sequence Drive and 4921 Directors Place. (3) The Company adopted ASU 2014-08 effective January 1, 2015 (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As a result, results of operations for properties disposed of subsequent of January 1, 2015 are presented in continuing operations because they did not represent strategic shifts. Properties disposed of prior to January 1, 2015 are presented in discontinued operations. (4) The San Diego Properties included the following: 10020 Pacific Mesa Boulevard, 6055 Lusk Avenue, 5010 and 5005 Wateridge Vista Drive, 15435 and 15445 Innovation Drive, and 15051, 15073, 15231, 15253, 15333 and 15378 Avenue of Science. These properties were held for sale as of December 31, 2013. The operations of the ten properties sold during the year ended December 31, 2015 are presented in continuing operations for the year ended December 31, 2015 . The total gains on sales of the ten properties sold during the year ended December 31, 2015 was $110.0 million . For the year ended December 31, 2014 , discontinued operations includes the income and gains on all of the properties sold in 2014 . For the year ended December 31, 2013 , discontinued operations includes the income and gains on all of the properties sold in 2014 and 2013 (see Note 2 “Basis of Presentation and Significant Accounting Policies” and Note 19 “Discontinued Operations” for additional information). Operating Properties Held for Sale As of December 31, 2015 , the properties listed below were classified as held for sale. We did not have any properties classified as held for sale as of December 31, 2014 . Properties Submarket Property Type Number of Buildings Rentable Square Feet (unaudited) Torrey Santa Fe Properties (1)(2) Del Mar Office 4 465,812 __________________ (1) The Torrey Santa Fe Properties include the following properties: 7525 Torrey Santa Fe, 7535 Torrey Santa Fe, 7545 Torrey Santa Fe, and 7555 Torrey Santa Fe. (2) In January 2016, the Company completed the sale of these properties for a total sales price of $262.3 million . The major classes of assets and liabilities of the properties held for sale as of December 31, 2015 were as follows: Real estate assets and other assets held for sale (in thousands) Land and improvements $ 10,534 Buildings and improvements 144,716 Undeveloped land and construction in progress 4,824 Total real estate held for sale 160,074 Accumulated depreciation and amortization (46,191 ) Total real estate held for sale, net 113,883 Deferred rent receivables, net 2,500 Deferred leasing costs and acquisition-related intangible assets, net 1,115 Prepaid expenses and other assets, net 168 Real estate and other assets held for sale, net $ 117,666 Liabilities and deferred revenue of real estate assets held for sale Secured debt $ 561 Accounts payable, accrued expenses and other liabilities 2,497 Deferred revenue and acquisition-related intangible liabilities, net 2,899 Rents received in advance and tenant security deposits 1,586 Liabilities and deferred revenue of real estate assets held for sale $ 7,543 Land Dispositions The following table summarizes the land dispositions completed during the years ended December 31, 2015 and 2014 : Properties Submarket Month of Disposition Gross Site Acreage (unaudited) Sales Price (1) (in millions) 2015 Land Disposition 17150 Von Karman (2) Irvine January 8.5 $ 26.0 2014 Land Disposition 10850 Via Frontera (3) Rancho Bernardo April 21.0 $ 33.1 __________________ (1) Represents gross sales price before the impact of commissions and closing costs. (2) This transaction resulted in a gain on sale of $17.3 million . (3) This transaction resulted in a gain on sale of $3.5 million . Land Held for Sale As of December 31, 2015 and 2014 , the following land parcels were classified as held for sale: Properties Submarket Gross Site Acreage (unaudited) Sales Price 2015 Held for Sale Carlsbad Oaks - Lot 7 (1)(2) Carlsbad 7.6 $ 4.5 2014 Held for Sale 17150 Von Karman Irvine 8.5 $ 26.0 __________________ (1) During the year ended December 31, 2015 , the Company recognized a loss relating to selling costs of approximately $0.2 million . (2) In January 2016, the Company completed the sale of the Carlsbad Oaks - Lot 7 land parcel. Restricted Cash Related to Dispositions As of December 31, 2014 , approximately $59.2 million of net proceeds related to the land and office property dispositions during the year ended December 31, 2014 were temporarily being held at a qualified intermediary, at our direction, for the purpose of facilitating Section 1031 Exchanges. The cash proceeds were included in restricted cash on the consolidated balance sheet at December 31, 2014 . In January 2015, we successfully completed Section 1031 Exchanges and the $59.2 million of cash proceeds comprising the balances as of December 31, 2014 were released from the qualified intermediary. We did not have any restricted cash related to dispositions or Section 1031 Exchanges as of December 31, 2015 . Discontinued Operations For the years ended December 31, 2014 and 2013 , discontinued operations included the results of all properties sold in 2014 and 2013 and classified as held for sale at December 31, 2013 , except for the operations deemed immaterial related to a June 2014 office property disposition. The following table summarizes the revenue and expense components that comprise income from discontinued operations for the years ended December 31, 2014 and 2013 : 2014 2013 (in thousands) Revenues: Rental income $ 7,206 $ 31,984 Tenant reimbursements 278 3,546 Other property income 13 5,178 Total revenues 7,497 40,708 Expenses: Property expenses 2,171 7,207 Real estate taxes 692 3,523 Depreciation and amortization 2,061 12,600 Total expenses 4,924 23,330 Income from discontinued operations before net gain on dispositions of discontinued operations 2,573 17,378 Net gain on dispositions of discontinued operations 121,922 12,252 Total income from discontinued operations $ 124,495 $ 29,630

Deferred Leasing Costs and Acqu

Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, net	12 Months Ended
	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, net	he 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, 2015 and 2014 : December 31, 2015 December 31, 2014 (in thousands) Deferred Leasing Costs and Acquisition-related Intangible Assets, net: (1) Deferred leasing costs $ 205,888 $ 216,102 Accumulated amortization (72,745 ) (74,904 ) Deferred leasing costs, net 133,143 141,198 Above-market operating leases 10,989 20,734 Accumulated amortization (6,739 ) (13,952 ) Above-market operating leases, net 4,250 6,782 In-place leases 72,639 97,250 Accumulated amortization (33,810 ) (43,773 ) In-place leases, net 38,829 53,477 Below-market ground lease obligation 490 490 Accumulated amortization (29 ) (21 ) Below-market ground lease obligation, net 461 469 Total deferred leasing costs and acquisition-related intangible assets, net $ 176,683 $ 201,926 Acquisition-related Intangible Liabilities, net: (2) Below-market operating leases $ 53,502 $ 68,051 Accumulated amortization (27,074 ) (30,620 ) Below-market operating leases, net 26,428 37,431 Above-market ground lease obligation 6,320 6,320 Accumulated amortization (424 ) (324 ) Above-market ground lease obligation, net 5,896 5,996 Total acquisition-related intangible liabilities, net $ 32,324 $ 43,427 _______________ (1) Excludes deferred leasing costs and acquisition-related intangible assets, net related to properties held for sale as of December 31, 2015 . (2) Included in deferred revenue and acquisition-related intangible liabilities, net in the consolidated balance sheets. The following table sets forth amortization related to deferred leasing costs and acquisition-related intangibles for the years ended December 31, 2015 , 2014 and 2013 , including amounts attributable to discontinued operations for the years ended December 31, 2014 and 2013 . Year Ended December 31, 2015 2014 2013 (in thousands) Deferred leasing costs (1) $ 27,866 $ 27,555 $ 25,902 Above-market operating leases (2) 2,532 5,303 5,664 In-place leases (1) 14,622 21,628 29,363 Below-market ground lease obligation (3) 8 8 8 Below-market operating leases (4) (10,980 ) (13,238 ) (13,441 ) Above-market ground lease obligation (5) (101 ) (101 ) (101 ) Total $ 33,947 $ 41,155 $ 47,395 _______________ (1) The amortization of deferred leasing costs and in-place leases is recorded to depreciation and amortization expense and the amortization of lease incentives is recorded as a reduction to rental income in the consolidated statements of operations for the periods presented. (2) The amortization of above-market operating leases is recorded as a decrease to rental income in the consolidated statements of operations for the periods presented. (3) The amortization of 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, 2015 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) 2016 $ 25,637 $ 1,501 $ 10,542 $ 8 $ (7,664 ) $ (101 ) 2017 22,790 1,241 9,108 8 (7,017 ) (101 ) 2018 19,580 831 6,296 8 (5,713 ) (101 ) 2019 15,649 643 4,637 8 (3,574 ) (101 ) 2020 11,720 16 2,789 8 (2,035 ) (101 ) Thereafter 37,767 18 5,457 421 (425 ) (5,391 ) Total $ 133,143 $ 4,250 $ 38,829 $ 461 $ (26,428 ) $ (5,896 ) _______________ (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, 2015
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, 2015 and 2014 : December 31, 2015 December 31, 2014 (in thousands) Current receivables (1) $ 13,233 $ 9,228 Allowance for uncollectible tenant receivables (1) (2,080 ) (1,999 ) Current receivables, net (1) $ 11,153 $ 7,229 ______________ (1) Excludes current receivables, net related to real estate held for sale. Deferred Rent Receivables, net Deferred rent receivables, net consisted of the following as of December 31, 2015 and 2014 : December 31, 2015 December 31, 2014 (in thousands) Deferred rent receivables (1) $ 191,586 $ 158,405 Allowance for deferred rent receivables (1,882 ) (1,989 ) Deferred rent receivables, net (1) $ 189,704 $ 156,416 __________________ (1) Excludes deferred rent receivables, net related to real estate held for sale.

Secured and Unsecured Debt of t

Secured and Unsecured Debt of the Company	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Secured and Unsecured Debt of the Company	Secured and Unsecured Debt of the Company In this Note 7, the “Company” refers solely to Kilroy Realty Corporation and not to any of our subsidiaries. The Company itself does not hold any indebtedness. All of our secured and unsecured debt is held directly by the Operating Partnership. The Company generally guarantees all the Operating Partnership’s unsecured debt obligations including the unsecured revolving credit facility, the $150.0 million unsecured term loan facility, the $39.0 million unsecured term loan, the 4.800% unsecured senior notes due in 2018, the 6.625% unsecured senior notes due in 2020, the 3.80% unsecured senior notes due in 2023, the 4.375% unsecured senior notes due in 2025, and the 4.250% unsecured senior notes due in 2029. At December 31, 2015 and 2014 , the Operating Partnership had $1.9 billion outstanding in total under these unsecured debt obligations. In addition, although the remaining $0.4 billion of the Operating Partnership’s debt as of December 31, 2015 , and $0.5 billion as of December 31, 2014 is secured and non-recourse to the Company, the Company provides limited customary secured debt guarantees for items such as voluntary bankruptcy, fraud, misapplication of payments and environmental liabilities. Debt Covenants and Restrictions One of the covenants contained within the unsecured revolving credit facility, the unsecured term loan facility, and the unsecured term loan as discussed further below in Note 8 prohibits the Company from paying dividends in excess of 95% of funds from operations (“FFO”).

Secured and Unsecured Debt of23

Secured and Unsecured Debt of the Operating Partnership	12 Months Ended
	Dec. 31, 2015
Debt Instrument [Line Items]
Secured and Unsecured Debt of the Operating Partnership	Secured and Unsecured Debt of the Company In this Note 7, the “Company” refers solely to Kilroy Realty Corporation and not to any of our subsidiaries. The Company itself does not hold any indebtedness. All of our secured and unsecured debt is held directly by the Operating Partnership. The Company generally guarantees all the Operating Partnership’s unsecured debt obligations including the unsecured revolving credit facility, the $150.0 million unsecured term loan facility, the $39.0 million unsecured term loan, the 4.800% unsecured senior notes due in 2018, the 6.625% unsecured senior notes due in 2020, the 3.80% unsecured senior notes due in 2023, the 4.375% unsecured senior notes due in 2025, and the 4.250% unsecured senior notes due in 2029. At December 31, 2015 and 2014 , the Operating Partnership had $1.9 billion outstanding in total under these unsecured debt obligations. In addition, although the remaining $0.4 billion of the Operating Partnership’s debt as of December 31, 2015 , and $0.5 billion as of December 31, 2014 is secured and non-recourse to the Company, the Company provides limited customary secured debt guarantees for items such as voluntary bankruptcy, fraud, misapplication of payments and environmental liabilities. Debt Covenants and Restrictions One of the covenants contained within the unsecured revolving credit facility, the unsecured term loan facility, and the unsecured term loan as discussed further below in Note 8 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, 2015 and 2014 : Annual Stated Interest Rate (1) GAAP Effective Rate (1)(2) Maturity Date December 31, Type of Debt 2015 (3) 2014 (3) (in thousands) Mortgage note payable (5) 4.27% 4.27% February 2018 $ 128,315 $ 130,767 Mortgage note payable (5) 4.48% 4.48% July 2027 96,354 97,000 Mortgage note payable (4)(5) 6.05% 3.50% June 2019 85,890 89,242 Mortgage note payable 6.51% 6.51% February 2017 65,563 66,647 Mortgage note payable 7.15% 7.15% May 2017 3,987 6,568 Mortgage note payable (5)(6) 5.23% 3.50% January 2016 — 52,793 Mortgage note payable (5)(6) 5.57% 3.25% February 2016 — 40,258 Mortgage note payable (5) 5.09% 3.50% August 2015 — 34,311 Mortgage note payable 4.94% 4.00% April 2015 — 26,285 Other (7) Various Various Various 1,809 2,421 Total $ 381,918 $ 546,292 ______________ (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 $6.2 million and $10.3 million as of December 31, 2015 and 2014 , respectively. (4) In January 2013, in connection with the acquisition of two office buildings in Seattle, Washington, we assumed a mortgage loan that is secured by the project. The loan requires monthly principal and interest payments based on a 6.4 year amortization period. As of December 31, 2015 and 2014 , the mortgage loan had unamortized debt premiums of $6.2 million and $8.0 million , respectively. (5) The secured debt and the related properties that secure the debt are held in a special purpose entity and the properties are not available to satisfy the debts and other obligations of the Company or the Operating Partnership. (6) These mortgage notes payable were repaid during the year ended December 31, 2015 at par. (7) Excludes $0.6 million of secured debt related to real estate assets held for sale as of December 31, 2015 . The Operating Partnership’s secured debt was collateralized by operating properties with a combined net book value of approximately $614.4 million as of December 31, 2015 . 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, 2015 , five of the Operating Partnership’s six secured loans contained restrictions that would require the payment of prepayment penalties for the acceleration of outstanding debt. The mortgage notes payable are secured by deeds of trust on certain of our properties and the assignment of certain rents and leases associated with those properties. Unsecured Senior Notes In September 2015, the Operating Partnership issued $400.0 million of aggregate principal amount of unsecured senior notes in a registered public offering. The outstanding balance of the unsecured senior notes is included in unsecured debt, net of initial issuance discount of $2.2 million , on our consolidated balance sheets. The unsecured senior notes, which are scheduled to mature on October 1, 2025 , require semi-annual interest payments each April and October based on a stated annual interest rate of 4.375% . The Company used the net proceeds to repay the $325.0 million 5.000% Unsecured Senior Notes upon maturity in November 2015 and for other general corporate purposes, including the repayment of debt and funding development expenditures. In July 2014, the Operating Partnership issued $400.0 million aggregate principal amount of unsecured senior notes in a registered public offering. The outstanding balance of the unsecured senior notes is included in unsecured debt, net of initial issuance discount of $4.5 million , on our consolidated balance sheets. The unsecured senior notes, which are scheduled to mature on August 15, 2029 , require semi-annual interest payments each February and August based on a stated annual interest rate of 4.250% . The Company used a portion of the net proceeds for general corporate purposes, including the repayment of borrowings under the Operating Partnership’s unsecured revolving credit facility. The following table summarizes the balance and significant terms of the registered unsecured senior notes issued by the Operating Partnership as of December 31, 2015 and 2014 : Principal Amount as of December 31, Issuance date Maturity date Stated coupon rate Effective interest rate (1) 2015 2014 (in thousands) 4.375% Unsecured Senior Notes (2) September 2015 October 2025 4.375% 4.440% $ 400,000 $ — Unamortized discount (2,159 ) $ — Net carrying amount $ 397,841 $ — 4.250% Unsecured Senior Notes (3) July 2014 August 2029 4.250% 4.350% $ 400,000 $ 400,000 Unamortized discount (4,050 ) (4,348 ) Net carrying amount $ 395,950 $ 395,652 3.800% Unsecured Senior Notes (4) January 2013 January 2023 3.800% 3.804% $ 300,000 $ 300,000 Unamortized discount (70 ) (79 ) Net carrying amount $ 299,930 $ 299,921 4.800% Unsecured Senior Notes (4)(5) July 2011 July 2018 4.800% 4.827% $ 325,000 $ 325,000 Unamortized discount (191 ) (265 ) Net carrying amount $ 324,809 $ 324,735 6.625% Unsecured Senior Notes (6) May 2010 June 2020 6.625% 6.743% $ 250,000 $ 250,000 Unamortized discount (940 ) (1,154 ) Net carrying amount $ 249,060 $ 248,846 5.000% Unsecured Senior Notes (7) November 2010 November 2015 5.000% 5.014% $ — $ 325,000 Unamortized discount — (33 ) Net carrying amount $ — $ 324,967 Total Unsecured Senior Notes, Net $ 1,667,590 $ 1,594,121 ________________________ (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 these notes is payable semi-annually in arrears on April 1st and October 1st of each year. (3) Interest on these notes is payable semi-annually in arrears on February 15th and August 15th of each year. (4) Interest on these notes is payable semi-annually in arrears on January 15th and July 15th of each year. (5) In October 2015, certain common limited partners in the Operating Partnership that previously contributed their interests in the property at 6255 W. Sunset Blvd., Los Angeles, California to the Operating Partnership entered into an agreement with the Company. Pursuant to this agreement, such common limited partners will reimburse the Company for a portion of any amounts the Company may be required to pay pursuant to its guarantee of the Operating Partnership's 4.800% Senior Notes due 2018 or that the Company may otherwise become required to pay under applicable law with respect to such notes. (6) Interest on these notes is payable semi-annually in arrears on June 1st and December 1st of each year. (7) Interest of these notes is payable semi-annually in arrears on May 3rd and November 3rd of each year. In August 2014, upon maturity, we repaid our outstanding Series B unsecured senior notes which had an aggregate principal balance of $83.0 million and effective interest rate of 6.450% as of December 31, 2013 . Unsecured Revolving Credit Facility and Unsecured Term Loan Facility The following table summarizes the balance and terms of our unsecured revolving credit facility as of December 31, 2015 and December 31, 2014 : December 31, 2015 December 31, 2014 (in thousands) Outstanding borrowings $ — $ 140,000 Remaining borrowing capacity 600,000 460,000 Total borrowing capacity (1) $ 600,000 $ 600,000 Interest rate (2) — % 1.41 % Facility fee-annual rate (3) 0.200% 0.250% Maturity date July 2019 _______________ (1) We may elect to borrow, subject to bank approval and obtaining commitments for any additional borrowing capacity, up to an additional $311.0 million under an accordion feature under the terms of the unsecured revolving credit facility and unsecured term loan facility. (2) Our unsecured revolving credit facility interest rate was calculated based on an annual rate of LIBOR plus 1.050% and LIBOR plus 1.250% as of December 31, 2015 and December 31, 2014 , respectively. (3) Our facility fee is paid on a quarterly basis and is calculated based on the total borrowing capacity. In addition to the facility fee, we incurred debt origination and legal costs. As of December 31, 2015 , $4.6 million of deferred financing costs remains to be amortized through the amended maturity date of our unsecured revolving credit facility. The Company intends to borrow amounts under the unsecured revolving credit facility from time to time for general corporate purposes, to fund potential acquisitions, to finance development and redevelopment expenditures and to potentially repay long-term debt. The following table summarizes the balance and terms of our term loan facility, which is included in our unsecured debt, as of December 31, 2015 and December 31, 2014 : December 31, 2015 December 31, 2014 (in thousands) Outstanding borrowings $ 150,000 $ 150,000 Interest rate (1) 1.40 % 1.56 % Maturity date July 2019 July 2019 _______________ (1) Our unsecured term loan facility interest rate was calculated based on an annual rate of LIBOR plus 1.150% and LIBOR plus 1.400% as of December 31, 2015 and December 31, 2014 , respectively. Additionally, the Company has a $39.0 million unsecured term loan outstanding with an annual interest rate of LIBOR plus 1.150% and LIBOR plus 1.400% as of December 31, 2015 and December 31, 2014 , respectively, that matures in July 2019. Debt Covenants and Restrictions The unsecured revolving credit facility, the unsecured term loan facility, the unsecured term loan, the unsecured senior notes, and certain other secured debt arrangements contain covenants and restrictions requiring us to meet certain financial ratios and reporting requirements. Some of the more restrictive financial covenants include a maximum ratio of total debt to total asset value, a minimum fixed-charge coverage ratio, a minimum unsecured debt ratio and a minimum unencumbered asset pool debt service coverage ratio. Noncompliance with one or more of the covenants and restrictions could result in the full principal balance of the associated debt becoming immediately due and payable. We believe we were in compliance with all of our debt covenants as of December 31, 2015 and 2014 . Debt Maturities The following table summarizes the stated debt maturities and scheduled amortization payments as of December 31, 2015 : Year (in thousands) 2016 $ 9,734 2017 71,734 2018 451,713 2019 265,355 2020 251,962 Thereafter 1,189,198 Total aggregate principal value $ 2,239,696 Less net unamortized discounts (1,188 ) Total debt, net of unamortized discounts $ 2,238,508 4.25% Exchangeable Senior Notes due 2014 The table below summarizes the significant terms of the Company’s $172.5 million 4.25% Exchangeable Notes due November 2014 (the “4.25% Exchangeable Notes”) prior to their repayment upon maturity in November 2014. 4.25% Exchangeable Notes December 31, 2014 Issuance date November 2009 Maturity date November 2014 Stated coupon rate (1) 4.25% Effective interest rate (2) 7.13% Exchange rate per $1,000 principal value of the 4.25% Exchangeable Notes, as adjusted (3) 27.8307 Exchange price as adjusted (3) $35.93 Number of shares on which the aggregate consideration to be delivered on conversion (3) 4,800,796 _______________ (1) Interest on the 4.25% Exchangeable Notes was payable semi-annually in arrears on May 15th and November 15th of each year. (2) Represents the rate at which we record interest expense for financial reporting purposes, which reflects the amortization of the discounts on the 4.25% Exchangeable Notes. This rate represents our conventional debt borrowing rate at the date of issuance. (3) The exchange rate, exchange price, and the number of shares to be delivered upon conversation were subject to adjustment under certain circumstances, including increases in our common dividends as of December 31, 2014 . Prior to their maturity on November 15, 2014, the 4.25% Exchangeable Notes were exchangeable for shares of the Company's common stock only upon the occurrence of certain events. Upon exchange of the 4.25% Exchangeable Notes in November 2014, the holders received (i) cash up to the principal amount of the 4.25% Exchangeable Notes and (ii) to the extent the exchange value exceeded the principal amount of the 4.25% Exchangeable Notes, shares of the Company’s common stock. Shares of common stock delivered for settlement were based on a daily exchange value calculated on a proportionate basis for each day of a 30 day trading-day observation period. In connection with the 4.25% Exchangeable Notes, the Company entered into capped call option transactions (“capped calls”) that mitigated the dilutive impact of the potential conversion of the 4.25% Exchangeable Notes. The capped calls for the 4.25% Exchangeable Notes were terminated when the 4.25% Exchangeable Notes were repaid upon maturity in November 2014. The capped calls, as amended, were separate transactions entered into by us with the relevant financial institutions and were not part of the terms of the 4.25% Exchangeable Notes. The $42.81 strike prices of the capped calls, which were subject to customary anti-dilution adjustments, corresponded to the exchange prices of the applicable 4.25% Exchangeable Notes. In the third quarter of 2014, we settled early exchanges of the 4.25% Exchangeable Notes with an aggregate principal amount of $37.0 million . For the exchange settlements, the Company paid the noteholders a total of $37.0 million in cash for the principal amount and issued to the noteholders a total of 431,270 shares of our common stock for the excess exchange value. As a result of the exchange settlements, the Company exercised the equivalent proportionate amount of its capped call options and, as a result, received 111,206 shares of our common stock from the counterparties. This reduced the shares of common stock issued in connection with the exchanges to 320,064 shares. Upon maturity in November 2014, we repaid the remaining balance of the outstanding 4.25% Exchangeable Notes with an aggregate principal balance of $135.5 million . For the repayment settlement, the Company paid the noteholders a total of $135.5 million in cash for the principal amount and issued to the noteholders a total of 1,660,053 shares of our common stock for the excess exchange value. As a result of the repayment settlement, the Company exercised the equivalent proportionate amount of its capped call options and, as a result, received 404,136 shares of our common stock from the counterparties, thereby reducing the shares of common stock issued upon maturity of the 4.25% Exchangeable Notes to 1,255,917 shares. This reduced the total shares of common stock issued in connection with the exchanges and repayment settlements to 1,575,981 shares. For the respective reporting periods noted below, which preceding maturity of the 4.25% Exchangeable Notes on November 15, 2014, the per share average trading price of the Company's common stock on the NYSE was higher than the $35.93 exchange price for the 4.25% Exchangeable Notes, as presented in the table below. See Note 20 “Net Income Available to Common Stockholders Per Share of the Company” and Note 21 “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 years ended December 31, 2014 and 2013 . Period Ended November 15, 2014 (1) Year Ended December 31, 2013 Per share average trading price of the Company's common stock $ 60.04 $ 52.12 _______________ (1) Represents the maturity date of the 4.25% Exchangeable Notes. Interest Expense for the 4.25% Exchangeable Notes due 2014 The unamortized discount on the 4.25% Exchangeable Notes was accreted as additional interest expense from the date of issuance through the maturity date. The following table summarizes the total interest expense attributable to the 4.25% Exchangeable Notes prior to maturity in November 2014, based on the effective interest rates, before the effect of capitalized interest, for the years ended December 31, 2014 and 2013 : Year Ended December 31, 2014 2013 Contractual interest payments $ 5,608 $ 7,331 Amortization of discount 3,769 4,427 Interest expense attributable to the 4.25% Exchangeable Notes $ 9,377 $ 11,758 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, 2015 , 2014 and 2013 . The interest expense capitalized was recorded as a cost of development and redevelopment, and increased the carrying value of undeveloped land and construction in progress. Year Ended December 31, 2015 2014 2013 (in thousands) Gross interest expense $ 109,647 $ 114,661 $ 111,238 Capitalized interest (51,965 ) (47,090 ) (35,368 ) Interest expense $ 57,682 $ 67,571 $ 75,870

Deferred Revenue and Acquisitio

Deferred Revenue and Acquisition Related Liabilities, net	12 Months Ended
	Dec. 31, 2015
Deferred Revenue Disclosure [Abstract]
Deferred Revenue and Acquisition Related Liabilities, net	Deferred Revenue and Acquisition Related Liabilities, net Deferred revenue and acquisition-related liabilities, net consists of the following at December 31, 2015 and 2014 : December 31, 2015 2014 (in thousands) Deferred revenue related to tenant-funded tenant improvements (1) $ 90,825 $ 85,757 Other deferred revenue 5,007 3,055 Acquisition-related intangible liabilities, net (2) 32,324 43,427 Total $ 128,156 $ 132,239 ________________________ (1) Excludes deferred revenue related to tenant-funded tenant improvements related to properties held for sale at December 31, 2015 . (2) See Note 2 “Basis of Presentation and Significant Accounting Policies” and Note 5 “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, 2015 , 2014 , and 2013 , $13.3 million , $11.0 million and $10.7 million , respectively, of deferred revenue related to tenant-funded tenant improvements (including discontinued operations for the years ended December 31, 2014 and 2013 ) 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, 2015 for the next five years and thereafter: Year Ending (in thousands) 2016 $ 12,536 2017 11,924 2018 11,285 2019 9,761 2020 9,230 Thereafter 36,089 Total $ 90,825

Noncontrolling Interests on the

Noncontrolling Interests on the Company's Consolidated Financial Statements	12 Months Ended
	Dec. 31, 2015
Noncontrolling Interest [Abstract]
Noncontrolling Interests on the Company's Consolidated Financial Statements	Noncontrolling Interests on the Company’s Consolidated Financial Statements Common Units of the Operating Partnership The Company owned a 98.1% and 98.0% common general partnership interest in the Operating Partnership as of December 31, 2015 and 2014 , respectively. The remaining 1.9% and 2.0% common limited partnership interest as of December 31, 2015 and 2014 , respectively, was owned by non-affiliated investors and certain of our executive officers and directors in the form of noncontrolling common units. There were 1,764,775 and 1,804,200 common units outstanding held by these investors, executive officers and directors as of December 31, 2015 and 2014 , respectively. The noncontrolling common units may be redeemed by unitholders for cash. Except under certain circumstances, we, at our option, may satisfy the cash redemption obligation with shares of the Company’s common stock on a one-for-one basis. If satisfied in cash, the value for each noncontrolling common unit upon redemption is the amount equal to the average of the closing quoted price per share of the Company’s common stock, par value $0.01 per share, as reported on the NYSE for the ten trading days immediately preceding the applicable redemption date. The aggregate value upon redemption of the then-outstanding noncontrolling common units was $112.0 million and $126.8 million as of December 31, 2015 and 2014 , 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. This noncontrolling interest was $6.5 million and $5.9 million at December 31, 2015 and 2014 , respectively.

Stockholders' Equity of the Com

Stockholders' Equity of the Company	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Stockholders' Equity of the Company	Stockholders’ Equity of the Company Common Stock Common Stock Issuance In July 2015, the Company completed the sale and issuance of 3,773,766 shares of its common stock at a price of $66.19 per share for aggregate gross proceeds of $249.8 million and aggregate net proceeds after offering costs of $249.6 million through a registered direct placement with an institutional investor. In October 2014, the Company issued 351,476 shares of its common stock valued at approximately $21.6 million to partially fund a development acquisition (see Note 3 “Acquisitions” for additional information). In September 2013, the Company completed an underwritten public offering of 6,175,000 shares of its common stock. The net offering proceeds, after deducting underwriting discounts and offering expenses, were approximately $295.9 million . We used a portion of the net proceeds from the offering to fund acquisitions, repay borrowings under the unsecured revolving credit facility, and for general corporate purposes. At-The-Market Stock Offering Programs Under our at-the-market stock offering programs, which commenced in July 2011 and December 2014, we may offer and sell shares of our common stock from time to time in “at-the-market” offerings. During the year ended December 31, 2014 , the Company completed its existing at-the-market offering program (the “July 2011 At-The-Market Program”) under which we sold an aggregate of $200.0 million in gross sales price of shares, and in December 2014, we commenced a new at-the-market stock offering program (the “December 2014 At-The-Market Program”) under which we may offer to sell shares of our common stock with an aggregate gross sales price of up to $300.0 million . Since commencement of the December 2014 At-The-Market Program through December 31, 2015 , we have sold 2,007,767 shares of common stock having an aggregate gross sales price of $150.1 million . As of December 31, 2015 , shares of common stock having an aggregate gross sales price of up to $149.9 million remain available to be sold under this program. Actual future sales will depend upon a variety of factors, including but not limited to market conditions, the trading price of the Company’s common stock and our capital needs. We have no obligation to sell the remaining shares available for sale under this program. The following table sets forth information regarding sales of our common stock under our at-the-market offering programs for the years ended December 31, 2015 , 2014 and 2013 : Year Ended December 31, 2015 2014 2013 (in millions, except share data) Shares of common stock sold during the period 1,866,267 1,599,123 1,040,838 Aggregate gross proceeds $ 140.1 $ 104.7 $ 55.3 Aggregate net proceeds after underwriting discounts $ 138.2 $ 103.1 $ 54.4 The proceeds from sales were used to fund acquisitions, development expenditures and general corporate purposes including repayment of borrowings under the unsecured revolving credit facility. 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, 2015 , 2014 or 2013 . 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, 2015 and 2014 : December 31, 2015 2014 (in thousands) Dividends and Distributions payable to: Common stockholders $ 32,291 $ 30,191 Noncontrolling common unitholders of the Operating Partnership 618 631 RSU holders (1) 427 421 Total accrued dividends and distribution to common stockholders and noncontrolling unitholders 33,336 31,243 Preferred stockholders 1,656 1,656 Total accrued dividends and distributions $ 34,992 $ 32,899 ______________________ (1) The amount includes the value of the dividend equivalents that will be paid with additional RSUs (see Note 13 “Share-Based Compensation” for additional information). December 31, 2015 2014 Outstanding Shares and Units: Common stock (1) 92,258,690 86,259,684 Noncontrolling common units 1,764,775 1,804,200 RSUs (2) 1,269,809 1,248,352 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 425,452 and 247,089 market measure-based RSUs because not all the necessary performance conditions have been met as of December 31, 2015 and 2014 , respectively.

Preferred and Common Units of t

Preferred and Common Units of the Operating Partnership	12 Months Ended
	Dec. 31, 2015
Partners' Capital [Abstract]
Preferred and Common Units of the Operating Partnership	Preferred and Common Units of the Operating Partnership Common Units Issuance of Common Units In July 2015, the Company completed the sale and issuance of 3,773,766 shares of its common stock at a price of $66.19 per share for aggregate gross proceeds of $249.8 million and aggregate net proceeds after offering costs of $249.6 million through a registered direct placement with an institutional investor (see Note 11 “Stockholders’ Equity of the Company” for additional information). The net offering proceeds were contributed by the Company to the Operating Partnership in exchange for 3,773,766 common units. In October 2014, the Company issued 351,476 shares of its common stock to partially fund $21.6 million of a development acquisition (see Note 11 “Stockholders’ Equity of the Company” for additional information). The development acquisition property was contributed by the Company to the Operation Partnership in exchange for 351,476 common units. In September 2013, the Company completed an underwritten public offering of 6,175,000 shares of its common stock (see Note 11 “Stockholders’ Equity of the Company” for additional information). The net offering proceeds of approximately $295.9 million were contributed by the Company to the Operating Partnership in exchange for 6,175,000 common units. At-The-Market Stock Offering Program During the years ended December 31, 2015 , 2014 and 2013 , the Company utilized its at-the-market stock offering programs to issue shares of common stock (see Note 11 “Stockholders’ Equity of the Company” for additional information). The net offering proceeds and property acquired using net offering proceeds were contributed by the Company to the Operating Partnership in exchange for common units for the years ended December 31, 2015 , 2014 and 2013 are as follows: Year Ended December 31, 2015 2014 2013 (in millions, except share and per share data) Shares of common stock contributed by the Company 1,866,267 1,599,123 1,040,838 Common units exchanged for share of common stock by the Company 1,866,267 1,599,123 1,040,838 Aggregate gross proceeds $ 140.1 $ 104.7 $ 55.3 Aggregate net proceeds after underwriting discounts $ 138.2 $ 103.1 $ 54.4 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-affiliated 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, 2015 December 31, 2014 Company owned common units in the Operating Partnership 92,258,690 86,259,684 Company owned general partnership interest 98.1 % 98.0 % Noncontrolling common units of the Operating Partnership 1,764,775 1,804,200 Ownership interest of noncontrolling interest 1.9 % 2.0 % For a further discussion of the noncontrolling common units during the years ended December 31, 2015 and 2014 , refer to Note 10 “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, 2015 and 2014 : December 31, 2015 December 31, 2014 (in thousands) Distributions payable to: General partner $ 32,291 $ 30,191 Common limited partners 618 631 RSU holders (1) 427 421 Total accrued distributions to common unitholders 33,336 31,243 Preferred unitholders 1,656 1,656 Total accrued distributions $ 34,992 $ 32,899 ______________________ (1) The amount includes the value of the dividend equivalents that will be paid with additional RSUs (see Note 13 “Share-Based Compensation” for additional information). December 31, 2015 December 31, 2014 Outstanding Units: Common units held by the general partner 92,258,690 86,259,684 Common units held by the limited partners 1,764,775 1,804,200 RSUs (1) 1,269,809 1,248,352 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 425,452 and 247,089 market measure-based RSUs because not all the necessary performance conditions have been met as of December 31, 2015 and 2014 , respectively.

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	Share-Based Compensation Stockholder Approved Share-Based Incentive Compensation Plan As of December 31, 2015 , we maintained one share-based incentive compensation plan, the Kilroy Realty 2006 Incentive Award Plan, as amended (the “2006 Plan”). At our annual meeting of stockholders on May 21, 2015, stockholders approved an amendment and restatement of the 2006 Plan, which included an increase in the maximum number of shares that may be issued or awarded under the 2006 Plan to 8,320,000 shares. As of December 31, 2015 , 1,686,608 shares were available for grant under the 2006 Plan. The calculation of shares available for grant is presented after taking into account a reserve for a sufficient number of shares to cover the vesting and payment of 2006 Plan awards that were outstanding on that date, including performance-based vesting awards at (i) levels actually achieved for the performance conditions (as defined below) and (ii) at target levels for the market conditions (as defined below) applicable to these awards. The Executive Compensation Committee ( the “Compensation Committee”) of the Company's Board of Directors may grant the following share-based awards to eligible individuals, as provided under the 2006 Plan: incentive stock options, nonqualified stock options, restricted stock (nonvested shares), stock appreciation rights, performance shares, performance stock units, dividend equivalents, stock payments, deferred stock, restricted stock units (“RSUs”), profit interest units, performance bonus awards, performance-based awards and other incentive awards. For each award granted under our share-based incentive compensation programs, the Operating Partnership simultaneously issues to the Company a number of common units equal to the number of shares of common stock ultimately paid by the Company in respect of such awards. All of our outstanding share-based awards issued prior to 2007 were issued under the 1997 Stock Option and Incentive Plan (the “1997 Plan”), which was terminated by our Board of Directors in September 2006. Any awards that were outstanding upon the termination of the 1997 Plan continued in effect in accordance with the terms of such plan and the applicable award agreement following termination of the 1997 Plan. Stock Award Deferral Program We have a Stock Award Deferral Program (the “RSU Program”) under the 2006 Plan. Under the RSU Program, participants may defer receipt of awards of nonvested shares that may be granted by electing to receive an equivalent number of RSUs in lieu of such nonvested shares, or defer payment of RSU awards. Each RSU represents the right to receive one share of our common stock in the future and is subject to the same vesting conditions that would have applied if the award had been issued in nonvested shares. RSUs carry with them the right to receive dividend equivalents such that participants receive additional RSUs at the time dividends are paid equal to the value of the dividend earned on the shares underlying the participant’s RSUs. The dividend equivalents earned vest based on terms specified under the related RSU award agreement. Shares issued upon settlement of vested RSUs, including RSUs paid on dividend equivalents, are distributed in a single lump sum distribution upon the earlier of (1) the date specified by the participant when the election is made or (2) occurrence of certain other events specified under the RSU program. Share-Based Compensation Programs The Compensation Committee has historically awarded nonvested shares and RSUs under the share-based compensation programs described below. These share-based awards were valued based on the quoted closing share price of the Company’s common stock on the NYSE on the applicable grant date. Prior to 2014, the Compensation Committee awarded annual long-term equity awards based primarily on the prior year’s performance, however, starting in January 2014, such annual awards have been granted as an incentive for the year in which the awards were granted and subsequent years. Executive Officer and Key Employee Share-Based Compensation Programs The Compensation Committee has annually approved compensation programs that include the potential issuance of share-based awards to our executive officers and other key employees 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. Non-Employee Board Member 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 for the annual non-employee board awards and four years for the awards relating to newly elected non-employee board members. 2015 and 2014 Share-Based Compensation Grants On January 27, 2015 (the “2015 RSU Grant Date”), the Compensation Committee of the Company’s Board of Directors awarded 212,468 RSUs to certain officers of the Company under the 2006 Plan, which included 127,657 RSUs (at the target level of performance), or 60%, that are subject to time-based, market and performance-based vesting requirements (each a “2015 Performance-Based RSU” and collectively, the “2015 Performance-Based RSU Grant”) and 84,811 RSUs, or 40%, that are subject to time-based vesting requirements (each a “2015 Time-Based RSU” and collectively, the “2015 Time-Based RSU Grant”). On January 29, 2014 (the “2014 RSU Grant Date”), the Compensation Committee of the Company’s Board of Directors awarded 236,604 RSUs to certain officers of the Company under the 2006 Plan, which included 119,098 RSUs that are subject to time-based, market and performance-based vesting requirements (each a “2014 Performance-Based RSU” and collectively, the “2014 Performance-Based RSU Grant”) and 117,506 RSUs that are subject to time-based vesting requirements (each a “2014 Time-Based RSU” and collectively, the “2014 Time-Based RSU Grant”). As of the 2014 RSU Grant Date, an insufficient number of shares were available under the 2006 Plan to settle these RSUs in stock and the RSUs were subject to liability accounting. At our annual meeting of stockholders on May 22, 2014, we received stockholder approval for an increase in the maximum number of shares that may be issued or awarded under the 2006 Plan, which resulted in a sufficient number of shares available for issuance to cover settlement of these RSU awards. As a result, as of May 22, 2014 we reclassified these awards as equity awards and re-measured the fair value of the awards as of that date. 2015 and 2014 Performance-Based RSU Grants The 2015 Performance-Based RSUs and 2014 Performance-Based RSUs (collectively, the “Performance-Based RSUs”) are scheduled to cliff vest at the end of a three-year service period subject to the compensation committee's determination that the Company has achieved the pre-defined FFO per share goals (the “performance conditions”) and upon the average annual relative total stockholder return versus a comparator group of Companies that consist of Companies in the SNL US REIT Office Index (the “market conditions”) for the three-year periods detailed in the table below. The number of Performance-Based RSUs ultimately earned, and therefore the compensation costs for these awards, can fluctuate from the original number of RSUs granted based upon the levels of achievement for both the FFO per share and relative total stockholder return metrics. During the 2015 and 2014 performance periods, the estimate of the number of RSUs earned were evaluated quarterly based on our forecasted level of achievement of the FFO per share hurdle. As of December 31, 2015 , the FFO per share hurdle performance conditions were achieved at 1.5x target for both awards. As a result, the number of RSUs earned as of that date based on the FFO per share performance, excluding the impact of forfeitures, was as follows: 2015 Performance-Based RSU Grant 2014 Performance-Based RSU Grant Service vesting period December 31, 2017 December 31, 2016 Target RSUs granted 127,657 119,098 Estimated RSUs earned based on FFO per share performance condition 185,510 178,650 Date of fair valuation January 27, 2015 May 22, 2014 Each Performance-Based RSU represents the right to receive one share of our common stock in the future, subject to, and as modified by, the Company's level of achievement of the market condition. The fair value of the 2015 Performance-Based RSU Grant was $10.1 million at January 27, 2015 and the fair value of the 2014 Performance-Based RSU Grant was $7.7 million at May 22, 2014. The fair value for each grant was calculated using a Monte Carlo simulation pricing model based on the assumptions in the table below. The determination of the fair value of the Performance-Based RSU Grants take into consideration the likelihood of achievement of both the performance condition and the market condition discussed above. For the year ended December 31, 2015 , we recorded compensation expense for the 2015 Performance-Based RSU Grant based upon the $78.55 fair value per share at January 27, 2015 multiplied by the 185,510 RSUs estimated to be earned at December 31, 2015 (which is net of forfeitures). For the years ended December 31, 2015 and 2014 , we recorded compensation expense for the 2014 Performance-Based RSU Grant based upon the $65.03 fair value per share at May 22, 2014 multiplied by the 178,650 RSUs, excluding the impact of forfeitures, estimated to be earned at December 31, 2014 . Compensation expense for the Performance-Based RSUs is recorded on a straight-line basis over the respective three-year periods. The following table summarizes the assumptions utilized in the Monte Carlo simulation pricing models: 2015 Award Fair Value Assumptions 2014 Award Fair Value Assumptions Valuation date January 27, 2015 May 22, 2014 Fair value per share on valuation date $78.55 $65.03 Expected share price volatility 20.00% 24.00% Risk-free interest rate 0.92% 0.61% Remaining expected life 2.9 years 2.6 years The computation of expected volatility was based on a blend of the historical volatility of our shares of common stock over approximately five years, as this is expected to be most consistent with future volatility and equates to a time period twice as long as the approximate two and a half year remaining performance period of the RSUs and implied volatility data based on the observed pricing of six month publicly-traded options on shares of our common stock. The risk-free interest rate was based on the yield curve on zero-coupon U.S. Treasury STRIP securities in effect at January 27, 2015 and May 22, 2014. 2015 and 2014 Time-Based RSU Grants The 2015 and 2014 Time-Based RSUs (collectively, the “Time-Based RSUs”) are scheduled to vest in equal installments over the periods listed below. Compensation expense for the Time-Based RSUs will be recognized on a straight-line basis from the grant date through the continued service vesting periods. Each Time-Based RSUs represents the right to receive one share of our common stock in the future, subject to continued employment through the applicable vesting date. The total fair value of the Time-Based RSUs is based on the Company's closing share price on the NYSE on the respective fair valuation dates as detailed in the table below: 2015 Time-Based RSU Grant 2014 Time-Based RSU Grant Service vesting period January 5, 2016 - January 5, 2018 January 5, 2015 - January 5, 2018 Fair value on valuation date (in millions) $ 6.4 $ 7.1 Fair value per share $ 75.34 $ 60.16 Date of fair valuation January 27, 2015 May 22, 2014 Summary of Market-Measure Based RSUs A summary of our market-measure based RSU activity from January 1, 2015 through December 31, 2015 is presented below: Nonvested RSUs Vested RSUs Total RSUs Amount Weighted-Average (1) Outstanding at January 1, 2015 247,089 $ 58.77 — 247,089 Granted 191,483 79.25 — 191,483 Issuance of dividend equivalents (2) 6,347 70.47 — 6,347 Forfeited (19,467 ) 69.20 — (19,467 ) Outstanding as of December 31, 2015 (3) 425,452 $ 67.68 — 425,452 _______________ (1) Represents the grant-date fair value for all awards, excluding the 2014 Performance-Based RSU Grant. As discussed above, the 2014 Performance-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014. (2) Represents the issuance of dividend equivalents earned on the underlying RSUs. The dividend equivalents vest based on terms specified under the related RSU award agreement. (3) Outstanding RSUs as of December 31, 2015 represent the achievement of the maximum performance conditions and assumed target levels for the market conditions. The number of restricted stock units ultimately earned is subject to change based upon actual performance over the three-year vesting period. Dividend equivalents earned will vest along with the underlying award and are also subject to changes based on the number of RSUs ultimately earned for each underlying award. A summary of our market-measure based RSU activity for years ended December 31, 2015 , 2014 and 2013 is presented below: RSUs Granted RSUs Vested Years ended December 31, Non-Vested RSUs Granted Weighted-Average Fair Value Per Share (1) Vested RSUs Total Vest-Date Fair Value (in thousands) 2015 191,483 $ 79.25 — $ — 2014 183,365 64.86 (16,338 ) 1,092 2013 9,542 44.55 (16,338 ) 811 _______________ (1) Represents the grant-date fair value for all awards, excluding the 2014 Performance-Based RSU Grant. As discussed above, the 2014 Performance-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014. Summary of Time-Based RSUs A summary of our time-based RSU activity from January 1, 2015 through December 31, 2015 is presented below: Nonvested RSUs Vested RSUs Total RSUs Amount Weighted Average Fair Value Outstanding at January 1, 2015 340,997 $ 51.04 907,355 1,248,352 Granted 98,802 74.49 — 98,802 Vested (107,541 ) 49.52 107,541 — Settled (2) (78,887 ) (78,887 ) Issuance of dividend equivalents (3) 3,255 70.47 20,705 23,960 Forfeited (17,064 ) 53.50 — (17,064 ) Canceled (4) (5,354 ) (5,354 ) Outstanding as of December 31, 2015 318,449 $ 58.91 951,360 1,269,809 _______________ (1) Represents the grant-date fair value for all awards excluding the 2014 Time-Based RSU Grant. As discussed above, the 2014 Time-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014. (2) Represents vested RSUs that were settled in shares of the Company’s common stock. Total shares settled include 20,042 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. (3) Represents the issuance of dividend equivalents earned on the underlying RSUs. The dividend equivalents vest based on terms specified under the related RSU award agreement. (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 settlement or vesting of RSUs in accordance with the terms of the 2006 Plan. A summary of our time-based RSU activity for the years ended December 31, 2015 , 2014 and 2013 is presented below: RSUs Granted RSUs Vested Year ended December 31, Non-Vested RSUs Issued Weighted-Average Grant Date Fair Value Per Share Vested RSUs Total Vest-Date Fair Value (1) (in thousands) 2015 98,802 $ 74.49 (107,541 ) $ 7,528 2014 155,016 59.89 (116,447 ) 6,675 2013 173,758 49.45 (89,873 ) 4,495 _______________ (1) Total fair value of RSUs vested was calculated based on the quoted closing share price of the Company’s common stock on the NYSE on the day of vesting. Excludes the issuance of dividend equivalents earned on the underlying RSUs. The dividend equivalents vest based on terms specified under the related RSU award agreement. Summary of Nonvested Restricted Stock A summary of our nonvested restricted stock activity from January 1, 2015 through December 31, 2015 is presented below: Nonvested Weighted-Average Outstanding at January 1, 2015 85,061 $ 47.05 Vested (1) (24,264 ) 46.39 Outstanding as of December 31, 2015 60,797 $ 47.32 _______________ (1) The total shares vested includes 10,699 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 withholding obligations. A summary of our nonvested and vested restricted stock activity for years ended December 31, 2015 , 2014 and 2013 is presented below: Shares Granted Shares Vested Years ended December 31, Nonvested Shares Issued Weighted-Average Grant Date Fair Value Per Share Vested Shares Total Fair Value at Vest Date (1) (in thousands) 2015 — $ — (24,264 ) $ 1,725 2014 213 51.35 (25,899 ) 1,323 2013 — — (47,291 ) 2,290 _______________ (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 Compensation Committee of the Company granted non-qualified stock options to certain key members of our senior management team, including our Executive Officers, to purchase an aggregate 1,550,000 shares of the Company’s common stock (the “February 2012” Grant) at an exercise price per share equal to $42.61 , the closing price of the Company’s common stock on the grant date. The options will vest ratably in annual installments over a five year period, subject to continued employment through the applicable vesting date. The term of each option is ten years from the date of the grant. Dividends will not be paid on vested or unvested options. The options were granted pursuant to the 2006 Plan. The fair value of each stock option granted is estimated on the date of grant using the Black-Scholes option pricing model based on the following assumptions for the February 2012 Grant. February 2012 Option Grant Fair value of options granted per share $9.20 Expected stock price volatility 33.00% Risk-free interest rate 1.35% Dividend yield 3.80% Expected life of option 6.5 years The computation of expected volatility is based on a blend of the historical volatility of our shares of common stock over a time period longer than the expected life of the option and implied volatility data based on the observed pricing of six-month publicly traded options on our shares of common stock. The risk-free interest rate is based on the yield curve on zero-coupon U.S. Treasury STRIP securities in effect at the grant date. The expected dividend yield is estimated by examining the average of the historical dividend yield levels over the expected life of the option and the current dividend yield as of the grant date. The expected life of the options is calculated as the average of the vesting term and the contractual term. During the year ended December 31, 2015 , 298,000 stock options vested with a total fair value of $2.7 million . During the year ended December 31, 2014 , 304,000 stock options vested with a total fair value of $2.8 million . During the year ended December 31, 2013 , 308,000 stock options vested with a total fair value of $2.8 million . A summary of our stock option activity related to the February 2012 grant from January 1, 2015 through December 31, 2015 is presented below: Number of Options Exercise Price Intrinsic Value (in millions) (1) Outstanding at December 31, 2014 1,008,000 $ 42.61 $ 26.7 Exercised (342,000 ) 42.61 10.3 Forfeited (56,000 ) 42.61 1.3 Outstanding at December 31, 2015 (2) 610,000 $ 42.61 $ 12.6 Options exercisable at December 31, 2015 (3) 70,000 $ 42.61 $ 1.4 _______________ (1) The intrinsic value of a stock option is the amount by which the fair value of the underlying stock exceeds the exercise price of an option. The fair value of the underlying stock was determined by using the closing share price on the NYSE on the date of exercise, forfeiture or respective period end. (2) As of December 31, 2015 , the average remaining life of stock options outstanding was 6.2 years (3) As of December 31, 2015 , the average remaining life of stock options exercisable was approximately 6.2 years. In accordance with the provisions of the 2006 Plan, we allow shares of our common stock to be withheld to satisfy the payment of exercise price and/or minimum statutory tax withholding obligations due upon the exercise of stock options. The value of the shares withheld is calculated based on the closing market price of our common stock on the NYSE on the exercise date. During the year ended December 31, 2015 , 62,072 shares were withheld on stock option exercises with an aggregate value of $3.9 million . During the year ended December 31, 2014, 23,664 shares were withheld on stock option exercises with an aggregate value of $1.5 million. The number of shares withheld for taxes during the year ended December 31, 2013 was immaterial to the consolidated financial statements. Share-Based Compensation Cost Recorded During the Period The total compensation cost for all share-based compensation programs was $18.9 million , $14.5 million and $9.6 million for the years ended December 31, 2015 , 2014 and 2013 , respectively. Of the total share-based compensation costs, $3.3 million , $2.3 million and $0.9 million was capitalized as part of real estate assets for the years ended December 31, 2015 , 2014 and 2013 , respectively. As of December 31, 2015 , there was approximately $31.2 million of total unrecognized compensation cost related to nonvested incentive awards granted under share-based compensation arrangements that is expected to be recognized over a weighted-average period of 1.9 years. The remaining compensation cost related to these nonvested incentive awards had been recognized in periods prior to December 31, 2015 . The $31.2 million of unrecognized compensation costs does not reflect the future compensation cost related to share-based awards that were granted subsequent to December 31, 2015 .

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2015
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, 2015 , 2014 , and 2013 , we contributed $1.1 million , $1.0 million and $0.9 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 17 “Fair Value Measurements and Disclosures” for further discussion of our Deferred Compensation Plan assets as of December 31, 2015 and 2014 . Our liability of $12.8 million and $11.9 million under the Deferred Compensation Plan was fully funded as of December 31, 2015 and 2014 , respectively.

Future Minimum Rent

Future Minimum Rent	12 Months Ended
	Dec. 31, 2015
Leases [Abstract]
Future Minimum Rent	Future Minimum Rent We have operating leases with tenants that expire at various dates through 2035 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, 2015 for future periods is summarized as follows: Year Ending (in thousands) 2016 $ 495,765 2017 482,650 2018 440,367 2019 379,939 2020 311,225 Thereafter 1,458,333 Total $ 3,568,279

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies General As of December 31, 2015 , we had commitments of approximately $430.1 million , excluding our ground lease commitments, for contracts and executed leases directly related to our operating and development properties. Ground Leases The following table summarizes our properties that are held subject to long-term noncancellable ground lease obligations and the respective contractual expiration dates: Property Contractual Expiration Date (1) 601 108th Ave NE, Bellevue, WA November 2093 701, 801 and 837 N. 34th Street, Seattle, WA (2) December 2041 Kilroy Airport Center Phases I, II, and III, Long Beach, CA July 2084 ____________________ (1) Reflects the contractual expiration date prior to the impact of any extension or purchase options held by the Company. (2) The Company has three 10 year and one 45 year extension options for this ground lease, which if exercised would extend the expiration date to December 2116. The minimum commitment under our ground leases as of December 31, 2015 for five years and thereafter is as follows: Year Ending (in thousands) 2016 $ 3,144 2017 3,144 2018 3,144 2019 3,144 2020 3,144 Thereafter 151,738 Total (1)(2)(3)(4) $ 167,458 ________________________ (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, 2015 . (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, 2015 . (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, 2015 . Environmental Matters We follow the policy of monitoring all of our properties, both acquisition and existing properties, for the presence of hazardous or toxic substances. While there can be no assurance that a material environmental liability does not exist, we are not currently aware of any environmental liabilities with respect to our stabilized portfolio properties that would have a material adverse effect on our financial condition, results of operations and cash flow, or that we believe would require additional disclosure or the recording of a loss contingency. As of December 31, 2015 and 2014 , we had accrued environmental remediation liabilities of approximately $20.9 million and $15.5 million , respectively, recorded on our consolidated balance sheets in connection with certain of our development acquisitions and related development activities. The accrued environmental remediation liabilities represent the costs we estimate we will incur when we commence development at various development acquisition sites. These estimates, which we developed with the assistance of a third party expert, consist primarily of the removal of contaminated soil and other related costs since we are required to dispose of any existing contaminated soil when we develop new office properties at these sites. We record estimated environmental remediation obligations for acquisitions at the acquisition date when we are aware of such costs and when such costs are probable and reasonably estimable. Costs incurred in connection with development related environmental remediation liabilities are recorded as an increase to the cost of the development project. These accruals are adjusted as an increase or decrease to the development project costs and as an increase or decrease to the accrued environmental remediation liability if we obtain further information or circumstances change. The environmental remediation obligations recorded at December 31, 2015 and 2014 were not discounted to their present value since we expect to complete the remediation activities in the next one to five years in connection with development activities at the various sites. It is possible that we could incur additional environmental remediation costs in connection with these recent development acquisitions. However, given we are in the very early stages of development, possible additional environmental costs are not reasonably estimable at this time. Other than the accrued environmental liabilities recorded in connection with certain of our recent development acquisitions and related development activities, we are not aware of any unasserted claims and assessments with respect to an environmental liability that we believe would require additional disclosure or the recording of an additional loss contingency. Litigation We and our properties are subject to litigation arising in the ordinary course of business. To our knowledge, neither we nor any of our properties are presently subject to any litigation or threat of litigation which, if determined unfavorably to us, would have a material adverse effect on our cash flow, financial condition, or results of operations. Insurance 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. 2013 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 during the year ended December 31, 2013 and recognized this amount in other property income. 2013 Settlement 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.

Fair Value Measurements and Dis

Fair Value Measurements and Disclosures	12 Months Ended
	Dec. 31, 2015
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 14 “Employee Benefit Plans” for additional information). The following table sets forth the fair value of our marketable securities as of December 31, 2015 and 2014 : Fair Value (Level 1) (1) 2015 2014 Description (in thousands) Marketable securities (2) $ 12,882 $ 11,971 _______________ (1) Fair value calculated using Level 1 inputs based on quoted prices in active markets for identical securities. (2) The marketable securities are held in a limited rabbi trust . We report the change in the fair value of the marketable securities at the end of each accounting period in interest income and other net investment gains in the consolidated statements of operations. We also adjust the related Deferred Compensation Plan liability to fair value at the end of each accounting period based on the performance of the benchmark funds selected by each participant, which results in a corresponding increase or decrease to compensation cost for the period. The following table sets forth the net (loss) gain on marketable securities recorded during the years ended December 31, 2015 , 2014 and 2013 : December 31, 2015 2014 2013 Description (in thousands) Net (loss) gain on marketable securities $ (269 ) $ 397 $ 1,489 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, 2015 and 2014 : December 31, 2015 2014 Carrying Value Fair Value Carrying Value Fair Value (in thousands) Liabilities Secured debt (1) $ 381,918 $ 391,611 $ 546,292 $ 559,483 Unsecured debt, net (2) 1,856,590 1,898,863 1,783,121 1,858,492 Unsecured line of credit (1) — — 140,000 145,051 _______________ (1) Fair value calculated using Level II inputs, which are based on model-derived valuations in which significant inputs and significant value drivers are observable in active markets. (2) Fair value calculated using Level II inputs as of December 31, 2015 , which are based on model-derived valuations in which significant inputs and significant value drivers are observable in active markets. Fair value calculated using primarily Level I inputs as of December 31, 2014 , which are based on quoted prices for identical instruments in active markets. The carrying value and fair value of the instruments valued using Level I inputs was $1,269.4 million and $1,322.2 million , respectively, as of December 31, 2014 . The carrying value and fair value of the instruments valued using Level II inputs was $513.7 million and $536.3 million , respectively, as of December 31, 2014 .

Other Significant Events

Other Significant Events	12 Months Ended
	Dec. 31, 2015
Other Income and Expenses [Abstract]
Other Significant Events	In January 2014, a tenant at one of our San Diego, California operating properties exercised an early lease termination clause as permitted under the terms of their lease. As a result, the lease which encompasses approximately 79,000 rentable square feet and was scheduled to expire in February 2020, terminated during the year ended December 31, 2014 . The total lease termination fee of $5.7 million was recorded as other property income on a straight line basis through the early lease termination date. The Company received the cash payment of the lease termination fee of $5.7 million in September 2014. During the year ended December 31, 2014 , the Company also recognized approximately $1.3 million as a reduction to rental income due to the accelerated amortization of the deferred rent receivable and above market lease for this tenant.

Discontinued Operations

Discontinued Operations	12 Months Ended
	Dec. 31, 2015
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	4. Dispositions and Real Estate Assets Held for Sale Operating Property Dispositions The following table summarizes the properties sold during the years ended December 31, 2015 , 2014 and 2013 : Location Month of Disposition Number of Buildings Rentable Square Feet (unaudited) Sales Price (in millions) (1) 2015 Dispositions 15050 NE 36th Street, Redmond, WA April 1 122,103 $ 51.2 San Diego Properties - Tranches 1 and 2 (2) April/July 9 924,291 258.0 Total 2015 Dispositions 10 1,046,394 $ 309.2 2014 Dispositions (3) San Diego Properties, San Diego, CA (4) January 12 1,049,035 $ 294.7 9785 & 9791 Towne Centre Drive, San Diego, CA June 2 126,000 29.5 111 Pacifica, Irvine, CA September 1 67,496 15.1 4040 Civic Center Drive, San Rafael, CA October 1 130,237 34.9 999 Town & Country Road, Orange, CA December 1 98,551 25.3 Total 2014 Dispositions 17 1,471,319 $ 399.5 2013 Dispositions (3) 26541 Agoura Road, Calabasas, CA June 1 90,156 $ 14.7 8101 Kaiser Boulevard, Anaheim, CA October 1 59,790 9.6 4910 Directors Place, San Diego CA December 1 50,360 32.6 Total 2013 Dispositions 3 200,306 $ 56.9 __________________ (1) Represents gross sales price before the impact of broker commissions and closing costs. (2) The San Diego Properties - Tranche 1 includes the following properties: 10770 Wateridge Circle, 6200 Greenwich Drive, and 6220 Greenwich Drive. The San Diego Properties - Tranche 2 includes the following properties: 6260 Sequence Drive, 6290, Sequence Drive, 6310 Sequence Drive, 6340 Sequence Drive, 6350 Sequence Drive and 4921 Directors Place. (3) The Company adopted ASU 2014-08 effective January 1, 2015 (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As a result, results of operations for properties disposed of subsequent of January 1, 2015 are presented in continuing operations because they did not represent strategic shifts. Properties disposed of prior to January 1, 2015 are presented in discontinued operations. (4) The San Diego Properties included the following: 10020 Pacific Mesa Boulevard, 6055 Lusk Avenue, 5010 and 5005 Wateridge Vista Drive, 15435 and 15445 Innovation Drive, and 15051, 15073, 15231, 15253, 15333 and 15378 Avenue of Science. These properties were held for sale as of December 31, 2013. The operations of the ten properties sold during the year ended December 31, 2015 are presented in continuing operations for the year ended December 31, 2015 . The total gains on sales of the ten properties sold during the year ended December 31, 2015 was $110.0 million . For the year ended December 31, 2014 , discontinued operations includes the income and gains on all of the properties sold in 2014 . For the year ended December 31, 2013 , discontinued operations includes the income and gains on all of the properties sold in 2014 and 2013 (see Note 2 “Basis of Presentation and Significant Accounting Policies” and Note 19 “Discontinued Operations” for additional information). Operating Properties Held for Sale As of December 31, 2015 , the properties listed below were classified as held for sale. We did not have any properties classified as held for sale as of December 31, 2014 . Properties Submarket Property Type Number of Buildings Rentable Square Feet (unaudited) Torrey Santa Fe Properties (1)(2) Del Mar Office 4 465,812 __________________ (1) The Torrey Santa Fe Properties include the following properties: 7525 Torrey Santa Fe, 7535 Torrey Santa Fe, 7545 Torrey Santa Fe, and 7555 Torrey Santa Fe. (2) In January 2016, the Company completed the sale of these properties for a total sales price of $262.3 million . The major classes of assets and liabilities of the properties held for sale as of December 31, 2015 were as follows: Real estate assets and other assets held for sale (in thousands) Land and improvements $ 10,534 Buildings and improvements 144,716 Undeveloped land and construction in progress 4,824 Total real estate held for sale 160,074 Accumulated depreciation and amortization (46,191 ) Total real estate held for sale, net 113,883 Deferred rent receivables, net 2,500 Deferred leasing costs and acquisition-related intangible assets, net 1,115 Prepaid expenses and other assets, net 168 Real estate and other assets held for sale, net $ 117,666 Liabilities and deferred revenue of real estate assets held for sale Secured debt $ 561 Accounts payable, accrued expenses and other liabilities 2,497 Deferred revenue and acquisition-related intangible liabilities, net 2,899 Rents received in advance and tenant security deposits 1,586 Liabilities and deferred revenue of real estate assets held for sale $ 7,543 Land Dispositions The following table summarizes the land dispositions completed during the years ended December 31, 2015 and 2014 : Properties Submarket Month of Disposition Gross Site Acreage (unaudited) Sales Price (1) (in millions) 2015 Land Disposition 17150 Von Karman (2) Irvine January 8.5 $ 26.0 2014 Land Disposition 10850 Via Frontera (3) Rancho Bernardo April 21.0 $ 33.1 __________________ (1) Represents gross sales price before the impact of commissions and closing costs. (2) This transaction resulted in a gain on sale of $17.3 million . (3) This transaction resulted in a gain on sale of $3.5 million . Land Held for Sale As of December 31, 2015 and 2014 , the following land parcels were classified as held for sale: Properties Submarket Gross Site Acreage (unaudited) Sales Price 2015 Held for Sale Carlsbad Oaks - Lot 7 (1)(2) Carlsbad 7.6 $ 4.5 2014 Held for Sale 17150 Von Karman Irvine 8.5 $ 26.0 __________________ (1) During the year ended December 31, 2015 , the Company recognized a loss relating to selling costs of approximately $0.2 million . (2) In January 2016, the Company completed the sale of the Carlsbad Oaks - Lot 7 land parcel. Restricted Cash Related to Dispositions As of December 31, 2014 , approximately $59.2 million of net proceeds related to the land and office property dispositions during the year ended December 31, 2014 were temporarily being held at a qualified intermediary, at our direction, for the purpose of facilitating Section 1031 Exchanges. The cash proceeds were included in restricted cash on the consolidated balance sheet at December 31, 2014 . In January 2015, we successfully completed Section 1031 Exchanges and the $59.2 million of cash proceeds comprising the balances as of December 31, 2014 were released from the qualified intermediary. We did not have any restricted cash related to dispositions or Section 1031 Exchanges as of December 31, 2015 . Discontinued Operations For the years ended December 31, 2014 and 2013 , discontinued operations included the results of all properties sold in 2014 and 2013 and classified as held for sale at December 31, 2013 , except for the operations deemed immaterial related to a June 2014 office property disposition. The following table summarizes the revenue and expense components that comprise income from discontinued operations for the years ended December 31, 2014 and 2013 : 2014 2013 (in thousands) Revenues: Rental income $ 7,206 $ 31,984 Tenant reimbursements 278 3,546 Other property income 13 5,178 Total revenues 7,497 40,708 Expenses: Property expenses 2,171 7,207 Real estate taxes 692 3,523 Depreciation and amortization 2,061 12,600 Total expenses 4,924 23,330 Income from discontinued operations before net gain on dispositions of discontinued operations 2,573 17,378 Net gain on dispositions of discontinued operations 121,922 12,252 Total income from discontinued operations $ 124,495 $ 29,630

Net Income Available to Common

Net Income Available to Common Stockholders Per Share of the Company	12 Months Ended
	Dec. 31, 2015
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, 2015 , 2014 and 2013 : Year Ended December 31, 2015 2014 2013 (in thousands, except unit and per unit amounts) Numerator: Income from continuing operations $ 238,604 $ 59,313 $ 14,935 Income from continuing operations attributable to noncontrolling interests (4,523 ) (966 ) (36 ) Preferred dividends and distributions (13,250 ) (13,250 ) (13,250 ) Allocation to participating securities (1) (1,634 ) (1,699 ) (1,689 ) Numerator for basic and diluted income (loss) from continuing operations available to common stockholders 219,197 43,398 (40 ) Income from discontinued operations (2) — 124,495 29,630 Income from discontinued operations attributable to noncontrolling common units of the Operating Partnership (2) — (2,623 ) (649 ) Numerator for basic and diluted net income available to common stockholders $ 219,197 $ 165,270 $ 28,941 Denominator: Basic weighted average vested shares outstanding 89,854,096 83,090,235 77,343,853 Effect of dilutive securities – contingently issuable shares and stock options 541,679 1,877,485 — Diluted weighted average vested shares and common stock equivalents outstanding 90,395,775 84,967,720 77,343,853 Basic earnings per share: Income from continuing operations available to common stockholders per share $ 2.44 $ 0.52 $ 0.00 Income from discontinued operations per share of common stock (2) — 1.47 0.37 Net income available to common stockholders per share $ 2.44 $ 1.99 $ 0.37 Diluted earnings per share: Income from continuing operations available to common stockholders per share $ 2.42 $ 0.51 $ 0.00 Income from discontinued operations per share of common stock (2) — 1.44 0.37 Net income available to common stockholders per share $ 2.42 $ 1.95 $ 0.37 ________________________ (1) Participating securities include nonvested shares, certain time-based RSUs and vested market measure-based RSUs. (2) The Company adopted ASU 2014-08 effective January 1, 2015 (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As a result, properties classified as held for sale and/or disposed of subsequent to January 1, 2015 that do not represent a strategic shift are no longer presented as discontinued operations. Share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are considered participating securities. The impact of potentially dilutive common shares, including stock options, RSUs and other securities are considered in our diluted earnings per share calculation for the years ended December 31, 2015 and 2014 , because we reported income from continuing operations attributable to common stockholders in the respective periods and the effect was dilutive. Additionally, for the year ended December 31, 2014, contingently issuable shares included the impact of the 4.25% Exchangeable Notes prior to their maturity and settlement in November 2014. For the year ended December 31, 2013 , contingently issuable shares were not considered in our diluted earnings per share calculation because we reported losses from continuing operations attributable to common stockholders and the effect was anti dilutive. Certain market measure-based RSUs are not included in dilutive securities as of December 31, 2015 and 2014 as not all performance metrics had been met by the end of the applicable reporting periods. See Note 13 “Share-Based Compensation” for additional information regarding the stock options and other share-based compensation.

Net Income Available to Commo36

Net Income Available to Common Unitholders Per Unit of the Operating Partnership	12 Months Ended
	Dec. 31, 2015
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, 2015 , 2014 and 2013 : Year Ended December 31, 2015 2014 2013 (in thousands, except unit and per unit amounts) Numerator: Income from continuing operations $ 238,604 $ 59,313 $ 14,935 Income from continuing operations attributable to noncontrolling interests in consolidated subsidiaries (467 ) (247 ) (225 ) Preferred distributions (13,250 ) (13,250 ) (13,250 ) Allocation to participating securities (1) (1,634 ) (1,699 ) (1,689 ) Numerator for basic and diluted income (loss) from continuing operations available to common unitholders 223,253 44,117 (229 ) Income from discontinued operations (2) — 124,495 29,630 (Income) loss from discontinued operations attributable to noncontrolling interests in consolidated subsidiaries (2) — (13 ) 1 Numerator for basic and diluted net income available to common unitholders $ 223,253 $ 168,599 $ 29,402 Denominator: Basic weighted average vested units outstanding 91,645,578 84,894,498 79,166,260 Effect of dilutive securities - contingently issuable shares and stock options 541,679 1,877,485 — Diluted weighted average vested units and common unit equivalents outstanding 92,187,257 86,771,983 79,166,260 Basic earnings per unit: Income from continuing operations available to common unitholders per unit $ 2.44 $ 0.52 $ 0.00 Income from discontinued operations per common unit (2) — 1.47 0.37 Net income available to common unitholders per unit $ 2.44 $ 1.99 $ 0.37 Diluted earnings per unit: Income from continuing operations available to common unitholders per unit $ 2.42 $ 0.51 $ 0.00 Income from discontinued operations per common unit (2) — 1.43 0.37 Net income available to common unitholders per unit $ 2.42 $ 1.94 $ 0.37 ________________________ (1) Participating securities include nonvested shares, certain time-based RSUs and vested market measure-based RSUs. (2) The Operating Partnership adopted ASU 2014-08 effective January 1, 2015 (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As a result, properties classified as held for sale and/or disposed of subsequent to January 1, 2015 that do not represent a strategic shift are no longer presented as discontinued operations. Share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are considered participating securities. The impact of potentially dilutive common units, including stock options, RSUs and other securities are considered in our diluted earnings per share calculation for the years ended December 31, 2015 and 2014 , because we reported income from continuing operations attributable to common unitholders in the respective periods and the effect was dilutive. Additionally, for the year ended December 31, 2014, contingently issuable shares included the impact of the 4.25% Exchangeable Notes prior to their maturity and settlement in November 2014. For the year ended December 31, 2013 , contingently issuable shares were not considered in our diluted earnings per share calculation because we reported losses from continuing operations attributable to common stockholders and the effect was anti dilutive. Certain market measure-based RSUs are not included in dilutive securities as of December 31, 2015 and 2014 as not all performance metrics had been met by the end of the applicable reporting periods. See Note 13 “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, 2015
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, 2015 , 2014 and 2013 as follows: Year Ended December 31, Dividends 2015 2014 2013 Dividends declared per share of common stock 1.400 1.400 1.400 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 0.350 0.350 0.350 Dividends paid per share of common stock 1.400 1.400 1.400 The unaudited income tax treatment for the dividends to common stockholders reportable for the years ended December 31, 2015 , 2014 and 2013 as identified in the table above was as follows: Year Ended December 31, Shares of Common Stock 2015 2014 2013 Ordinary income $ 0.992 70.86 % $ 0.998 71.29 % $ 0.756 54.00 % Qualified dividend 0.002 0.13 0.002 0.14 0.003 0.21 Return of capital — — 0.398 28.43 0.620 44.29 Capital gains (1) 0.051 3.65 0.002 0.14 — — Unrecaptured section 1250 gains 0.355 25.36 — — 0.021 1.5 $ 1.400 100.00 % $ 1.400 100.00 % $ 1.400 100.00 % _________________ (1) Capital gains are comprised entirely of 20% rate gains. 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, 2015 , 2014 , and 2013 was as follows: Year Ended December 31, Preferred Shares 2015 2014 2013 Ordinary income $ 1.218 70.86 % $ 1.711 99.54 % $ 1.668 97.03 % Qualified dividend 0.002 0.13 0.003 0.17 0.006 0.35 Capital gains (1) 0.063 3.65 0.005 0.29 — — Unrecaptured section 1250 gains 0.436 25.36 — — 0.045 2.62 $ 1.719 100.00 % $ 1.719 100.00 % $ 1.719 100.00 % __________________ (1) Capital gains are comprised entirely of 20% rate gains. 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, 2015 , 2014 , and 2013 was as follows: Year Ended December 31, Preferred Shares 2015 2014 2013 Ordinary income $ 1.129 70.86 % $ 1.587 99.56 % $ 1.546 96.99 % Qualified dividend 0.002 0.13 0.003 0.19 0.006 0.38 Capital gains (1) 0.059 3.65 0.004 0.25 — — Unrecaptured section 1250 gains 0.404 25.36 — — 0.042 2.63 $ 1.594 100.00 % $ 1.594 100.00 % $ 1.594 100.00 % __________________ (1) Capital gains are comprised entirely of 20% rate gains.

Quarterly Financial Information

Quarterly Financial Information of the Company (Unaudited)	12 Months Ended
	Dec. 31, 2015
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, 2015 and 2014 was as follows: 2015 Quarter Ended (1) March 31, June 30, September 30, December 31, (in thousands, except per share amounts) Revenues from continuing operations $ 146,082 $ 146,227 $ 141,553 $ 147,413 Income from continuing operations 44,002 58,590 106,704 29,308 Net income 44,002 58,590 106,704 29,308 Net income attributable to Kilroy Realty Corporation 43,187 57,500 104,759 28,635 Preferred dividends and distributions (3,313 ) (3,312 ) (3,313 ) (3,312 ) Net income available to common stockholders 39,874 54,188 101,446 25,323 Net income available to common stockholders per share – basic 0.45 0.61 1.10 0.27 Net income available to common stockholders per share – diluted 0.45 0.61 1.09 0.27 2014 Quarter Ended (1) March 31, June 30, September 30, December 31, (in thousands, except per share amounts) Revenues from continuing operations $ 123,758 $ 127,178 $ 129,024 $ 141,765 Income from continuing operations 10,874 15,854 13,168 19,417 Income from discontinued operations 91,058 15,289 6,135 12,013 Net income 101,932 31,143 19,303 31,430 Net income attributable to Kilroy Realty Corporation 99,845 30,540 18,982 30,852 Preferred dividends and distributions (3,313 ) (3,312 ) (3,313 ) (3,312 ) Net income available to common stockholders 96,532 27,228 15,669 27,540 Net income available to common stockholders per share – basic 1.17 0.33 0.18 0.32 Net income available to common stockholders per share – diluted 1.14 0.32 0.18 0.32 ____________________ (1) The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common stockholders per share does not equal the annual number reported on the consolidated statements of operations due to the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended December 31, 2015 and 2014 .

Quarterly Financial Informati39

Quarterly Financial Information of the Operating Partnership (Unaudited)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information of the Operating Partnership	Quarterly Financial Information of the Company (Unaudited) Summarized quarterly financial data for the years ended December 31, 2015 and 2014 was as follows: 2015 Quarter Ended (1) March 31, June 30, September 30, December 31, (in thousands, except per share amounts) Revenues from continuing operations $ 146,082 $ 146,227 $ 141,553 $ 147,413 Income from continuing operations 44,002 58,590 106,704 29,308 Net income 44,002 58,590 106,704 29,308 Net income attributable to Kilroy Realty Corporation 43,187 57,500 104,759 28,635 Preferred dividends and distributions (3,313 ) (3,312 ) (3,313 ) (3,312 ) Net income available to common stockholders 39,874 54,188 101,446 25,323 Net income available to common stockholders per share – basic 0.45 0.61 1.10 0.27 Net income available to common stockholders per share – diluted 0.45 0.61 1.09 0.27 2014 Quarter Ended (1) March 31, June 30, September 30, December 31, (in thousands, except per share amounts) Revenues from continuing operations $ 123,758 $ 127,178 $ 129,024 $ 141,765 Income from continuing operations 10,874 15,854 13,168 19,417 Income from discontinued operations 91,058 15,289 6,135 12,013 Net income 101,932 31,143 19,303 31,430 Net income attributable to Kilroy Realty Corporation 99,845 30,540 18,982 30,852 Preferred dividends and distributions (3,313 ) (3,312 ) (3,313 ) (3,312 ) Net income available to common stockholders 96,532 27,228 15,669 27,540 Net income available to common stockholders per share – basic 1.17 0.33 0.18 0.32 Net income available to common stockholders per share – diluted 1.14 0.32 0.18 0.32 ____________________ (1) The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common stockholders per share does not equal the annual number reported on the consolidated statements of operations due to the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended December 31, 2015 and 2014 .
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, 2015 and 2014 was as follows: 2015 Quarter Ended (1) March 31, June 30, September 30, December 31, (in thousands, except per unit amounts) Revenues from continuing operations $ 146,082 $ 146,227 $ 141,553 $ 147,413 Income from continuing operations 44,002 58,590 106,704 29,308 Net income 44,002 58,590 106,704 29,308 Net income attributable to the Operating Partnership 43,927 58,518 106,640 29,052 Preferred distributions (3,313 ) (3,312 ) (3,313 ) (3,312 ) Net income available to common unitholders 40,614 55,206 103,327 25,740 Net income available to common unitholders per unit – basic 0.45 0.61 1.10 0.27 Net income available to common unitholders per unit – diluted 0.45 0.61 1.09 0.27 2014 Quarter Ended (1) March 31, June 30, September 30, December 31, (in thousands, except per unit amounts) Revenues from continuing operations $ 123,758 $ 127,178 $ 129,024 $ 141,765 Income from continuing operations 10,874 15,854 13,168 19,417 Income from discontinued operations 91,058 15,289 6,135 12,013 Net income 101,932 31,143 19,303 31,430 Net income attributable to the Operating Partnership 101,867 31,066 19,244 31,371 Preferred distributions (3,313 ) (3,312 ) (3,313 ) (3,312 ) Net income available to common unitholders 98,554 27,754 15,931 28,059 Net income available to common unitholders per unit – basic 1.17 0.33 0.18 0.32 Net income available to common unitholders per unit – diluted 1.14 0.32 0.18 0.31 ___________________ (1) The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common unitholders per unit does not equal the annual number reported on the consolidated statements of operations due to the impact of the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended December 31, 2015 and 2014 .

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2015
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On January 13, 2016, aggregate dividends, distributions and dividend equivalents of $33.4 million were paid to common stockholders, common unitholders and RSU holders of record on December 31, 2015 . On January 13, 2016, the Company completed the sale of the land parcel located in San Diego, California that was held for sale at December 31, 2015 for a gross sales price of $4.5 million . On January 21, 2016, the Company completed the sale of the four operating properties located in San Diego, California that were held for sale at December 31, 2015 for a gross sales price of $262.3 million . In January 2016, the Executive Compensation Committee granted 328,731 RSUs to Executive Officers and other key employees under the 2006 Plan. 185,032 of these RSUs are subject to market and performance-based vesting requirements, which could cause the final vested amount of RSUs to increase or decrease. The compensation cost related to both time-based and performance-based RSUs is expected to be recognized over a period of three years.

Schedule II Valuation and Quali

Schedule II Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2015
Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts	Balance at Beginning of Period Charged to Costs and Expenses Recoveries (Deductions) Balance at End of Period (1) Allowance for Uncollectible Tenant Receivables for the year ended December 31, 2015 – Allowance for uncollectible tenant receivables $ 1,999 $ 303 $ (222 ) $ 2,080 2014 – Allowance for uncollectible tenant receivables 2,134 58 (193 ) 1,999 2013 – Allowance for uncollectible tenant receivables 2,581 396 (843 ) 2,134 Allowance for Unbilled Deferred Rent for the year ended December 31, 2015 – Allowance for deferred rent $ 1,989 $ 242 $ (349 ) $ 1,882 2014 – Allowance for deferred rent 2,075 — (86 ) 1,989 2013 – Allowance for deferred rent 2,607 — (532 ) 2,075 _______________ (1) For the year ended December 31, 2013, includes amounts reported for properties classified as held for sale.

Schedule III - Real Estate and

Schedule III - Real Estate and Accumulated Depreciation	12 Months Ended
	Dec. 31, 2015
SEC Schedule III, Real Estate and Accumulated Depreciation Disclosure [Abstract]
Schedule III - Real Estate and Accumulated Depreciation	The aggregate gross cost of property included above for federal income tax purposes approximated $5.5 billion as of December 31, 2015 . The following table reconciles the historical cost of total real estate held for investment from January 1, 2013 to December 31, 2015 : Year Ended December 31, 2015 2014 2013 (in thousands) Total real estate held for investment, beginning of year $ 6,057,932 $ 5,264,947 $ 4,757,394 Additions during period: Acquisitions 139,123 340,296 384,650 Improvements, etc. 536,411 588,166 452,331 Total additions during period 675,534 928,462 836,981 Deductions during period: Cost of real estate sold (231,984 ) (113,416 ) (56,993 ) Properties held for sale (160,074 ) (14,700 ) (259,251 ) Other (13,262 ) (7,361 ) (13,184 ) Total deductions during period (405,320 ) (135,477 ) (329,428 ) Total real estate held for investment, end of year $ 6,328,146 $ 6,057,932 $ 5,264,947 The following table reconciles the accumulated depreciation from January 1, 2013 to December 31, 2015 : Year Ended December 31, 2015 2014 2013 (in thousands) Accumulated depreciation, beginning of year $ 947,664 $ 818,957 $ 756,515 Additions during period: Depreciation of real estate 159,524 153,841 145,325 Total additions during period 159,524 153,841 145,325 Deductions during period: Write-offs due to sale (66,603 ) (18,111 ) (17,144 ) Properties held for sale (46,191 ) (7,007 ) (63,110 ) Other (153 ) (16 ) (2,629 ) Total deductions during period (112,947 ) (25,134 ) (82,883 ) Accumulated depreciation, end of year $ 994,241 $ 947,664 $ 818,957

Basis of Presentation and Sig43

Basis of Presentation and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Basis of presentation and significant accounting policies [Line Items]
Basis of Presentation	The consolidated financial statements of the Company include the consolidated financial position and results of operations of the Company, the Operating Partnership, the Finance Partnership, KSLLC, Redwood LLC and all of our wholly owned and controlled subsidiaries. The consolidated financial statements of the Operating Partnership include the consolidated financial position and results of operations of the Operating Partnership, the Finance Partnership, KSLLC, Redwood LLC and all wholly owned and controlled subsidiaries of the Operating Partnership. All intercompany balances and transactions have been eliminated in the consolidated financial statements.
Partially Owned Entities and Variable Interest Entities	At December 31, 2015 , the consolidated financial statements of the Company and the Operating Partnership included two variable interest entities (“VIEs”), in which we were deemed to be the primary beneficiary. One VIE, Redwood LLC, was established in the second quarter of 2013 in connection with an undeveloped land acquisition. The other VIE was established in the fourth quarter of 2015 to facilitate potential future Section 1031 Exchanges to defer taxable gains on dispositions for federal and state income tax purposes. The impact of consolidating the VIEs increased the Company’s total assets, liabilities and noncontrolling interests by approximately $203.3 million (of which $187.3 million related to real estate held for investment on our consolidated balance sheet), approximately $28.8 million and approximately $6.5 million , respectively, as of December 31, 2015 . At December 31, 2014 , the consolidated financial statements of the Company and the Operating Partnership included two VIEs, in which we were deemed to be the primary beneficiary. One of the VIEs was Redwood LLC and the remaining VIE was established during the fourth quarter of 2014 to facilitate potential Section 1031 Exchanges. During the three months ended March 31, 2015, the Section 1031 Exchange was successfully completed and the VIE was terminated. As a result, $59.2 million of our restricted cash balance at December 31, 2014 , which related to prior period disposition proceeds that were set aside to facilitate the Section 1031 Exchanges, was released from escrow. The impact of consolidating the VIEs increased the Company’s total assets, liabilities and noncontrolling interests by approximately $219.6 million (of which $211.8 million related to real estate held for investment on our consolidated balance sheet), approximately $23.4 million and approximately $5.9 million , respectively, as of December 31, 2014 . Our accounting policy is to consolidate entities in which we have a controlling financial interest and significant decision making control over the entity's operations. In determining whether we have a controlling financial interest in a partially owned entity and the requirement to consolidate the accounts of that entity, we consider factors such as ownership interest, board representation, management representation, size of our investment (including loans), authority to control decisions, and contractual and substantive participating rights of the members. In addition to evaluating control rights, we consolidate entities in which the other members have no substantive kick-out rights to remove the Company as the managing member. We also evaluate whether the entity is a variable interest entity (“VIE”) and whether we are the primary beneficiary. VIEs are entities in which the equity investors do not have sufficient equity at risk to finance their endeavors without additional financial support or the holders of the equity investment at risk do not have a controlling financial interest. We are deemed to be the primary beneficiary of a VIE when we have the power to direct the activities of the VIE that most significantly impact the VIEs’ economic performance and the obligation to absorb losses or receive benefits that could potentially be significant to the VIE. If the requirements for consolidation are not met, the Company would account for investments under the equity method of accounting if we have the ability to exercise significant influence over the entity. Equity method investments would be initially recorded at cost and subsequently adjusted for our share of net income or loss and cash contributions and distributions each period. The Company did not have any equity method investments at December 31, 2015 or December 31, 2014 .
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, 2015 , 2014 and 2013 we capitalized $1.1 million , $4.5 million and $2.3 million , respectively, in acquisition costs associated with development acquisitions.
Operating Properties, Cost Capitalization, and Depreciations and Amortization of Buildings and IMprovements	Operating Properties Operating properties are generally carried at historical cost less accumulated depreciation. Properties held for sale are reported at the lower of the carrying value or the fair value less estimated cost to sell. The cost of operating properties includes the purchase price or development costs of the properties. Costs incurred for the renovation and betterment of the operating properties are capitalized to our investment in that property. Maintenance and repairs are charged to expense as incurred. When evaluating properties to be held and used for potential impairment, we first evaluate whether there are any indicators of impairment for any of our properties. If any impairment indicators are present for a specific property, we then perform an undiscounted cash flow analysis and compare the net carrying amount of the property to the property’s estimated undiscounted future cash flow over the anticipated holding period. If the estimated undiscounted future cash flow is less than the net carrying amount of the property, we then perform an impairment loss calculation to determine if the fair value of the property is less than the net carrying value of the property. Our impairment loss calculation compares the net carrying amount of the property to the property’s estimated fair value, which may be based on estimated discounted future cash flow calculations or third-party valuations or appraisals. We would recognize an impairment loss if the asset’s net carrying amount exceeds the asset’s estimated fair value. If we were to recognize an impairment loss, the estimated fair value of the asset (less costs to sell for assets held for sale) would become its new cost basis. For a depreciable long-lived asset, the new cost basis would be depreciated (amortized) over the remaining useful life of that asset. 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, 2015 , 2014 , and 2013 was $159.5 million , $153.8 million and $145.3 million , respectively. Asset Description Depreciable Lives Buildings and improvements 25 – 40 years Tenant improvements 1 – 20 years (1) ________________________ (1) Tenant improvements are amortized over the shorter of the lease term or the estimated useful life.
Discontinued Operations and Properties Held for Sale	eal Estate Assets Held for Sale, Dispositions and Discontinued Operations A real estate asset is classified as held for sale when certain criteria are met, including but not limited to the availability of the asset for immediate sale, the existence of an active program to locate a buyer and the probable sale or transfer of the asset within one year. If such criteria are met, we present the applicable assets and liabilities related to the real estate asset held for sale, if material, separately on the balance sheet and we would cease to record depreciation and amortization expense. Real estate assets held for sale are reported at the lower of their carrying value or their estimated fair value less the estimated costs to sell. As of December 31, 2015 , we classified four operating properties and one undeveloped land parcel located in San Diego, California as held for sale. As of December 31, 2014 , we had one undeveloped land parcel classified as held for sale. Effective January 1, 2015, the Company adopted Financial Accounting Standards Board (“FASB”) Accounting Standards Update (“ASU”) No. 2014-08 (“ASU 2014-08”), which changed the criteria for reporting discontinued operations while enhancing disclosures in this area. Under the new guidance, only property disposals representing a strategic shift that has (or will have) a major effect on an entity's operations and financial results, such as a major line of business, a major geographical area or a major equity investment, are required to be presented as discontinued operations. If we were to determine that the property disposition represents a strategic shift, the revenues, expenses and net gain (loss) on dispositions of the property would be recorded in discontinued operations for all periods presented through the date of the applicable disposition. The Company adopted and applied the new guidance on a prospective basis as required by ASU 2014-08. Therefore, properties classified as held for sale and/or disposed of subsequent to January 1, 2015 that do not represent a strategic shift are presented in continuing operations for all periods presented. In accordance with this guidance, the operations of the ten properties sold during the year ended December 31, 2015 are presented in continuing operations for the year ended December 31, 2015 . Prior to January 1, 2015, 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. For the year ended December 31, 2014, discontinued operations includes the income and gains on all of the properties sold in 2014. For the year ended December 31, 2013, discontinued operations includes the income and gains on all of the properties sold in 2013 and 2014. The net gains (losses) on dispositions of non-depreciable real estate property, including land, are reported in the consolidated statements of operations as gains (losses) on sale of land within continuing operations in the period the land is sold
Revenue Recognition, Tenant Reimbursements and Other Property Income	Revenue Recognition We recognize revenue from rent, tenant reimbursements, parking and other revenue once all of the following criteria are met: (i) the agreement has been fully executed and delivered, (ii) services have been rendered, (iii) the amount is fixed or determinable, and (iv) the collectability of the amount is reasonably assured. Minimum annual rental revenues are recognized in rental revenues on a straight-line basis over the term of the related lease. Rental revenue recognition commences when the tenant takes possession or controls the physical use of the leased space. In order for the tenant to take possession, the leased space must be substantially complete and ready for its intended use. In order to determine whether the leased space is substantially ready for its intended use, we begin by determining whether the Company 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 generally when Company owned tenant improvements are substantially complete. In certain instances, when we conclude that the Company is not the owner (the tenant is the owner) of tenant improvements, rental revenue recognition begins when the tenant takes possession of or controls the space. When we conclude that the Company is the owner of tenant improvements, we record the cost to construct the tenant improvements, including costs paid for or reimbursed by the tenants, as a capital asset. For these tenant improvements, we record the amount funded by or reimbursed by the tenants as deferred revenue, which is amortized on a straight-line basis as additional rental income over the term of the related lease. When we conclude that the tenant is the owner of tenant improvements for accounting purposes, we record our contribution towards those improvements as a lease incentive, which is included in deferred leasing costs and acquisition-related intangible assets, net on our consolidated balance sheets and amortized as a reduction to rental income on a straight-line basis over the term of the lease. Tenant Reimbursements Reimbursements from tenants, consisting of amounts due from tenants for common area maintenance, real estate taxes and other recoverable costs, are recognized as revenue in the period the recoverable costs are incurred. Tenant reimbursements are recognized and recorded on a gross basis, as we are generally the primary obligor with respect to purchasing goods and services from third-party suppliers, have discretion in selecting the supplier, and have credit risk. Other Property Income Other property income primarily includes amounts recorded in connection with lease terminations and tenant bankruptcy settlement payments. Lease termination fees are amortized over the remaining lease term, if applicable. If there is no remaining lease term, they are recognized when received and realized. Other property income also includes miscellaneous income from tenants, such as fees related to the restoration of leased premises to their original condition and fees for late rental payments.
Allowances for Uncollectible Tenant and Deferred Rent Receivables	Allowances for Uncollectible Tenant and Deferred Rent Receivables We carry our current and deferred rent receivables net of allowances for uncollectible amounts. Our determination of the adequacy of these allowances is based primarily upon evaluations of individual receivables, current economic conditions, historical loss experience, and other relevant factors. The allowances are increased or decreased through the provision for bad debts on our consolidated statements of operations.
Cash and Cash Equivalents	Cash and Cash Equivalents We consider all highly-liquid investments with original maturities of three months or less to be cash equivalents
Restricted Cash	Restricted Cash Restricted cash consists of cash proceeds from dispositions that are temporarily held at qualified intermediaries for purposes of facilitating potential Section 1031 Exchanges and cash held in escrow related to acquisition holdbacks. Restricted cash also includes cash held as collateral to provide credit enhancement for the Operating Partnership’s mortgage debt, including cash reserves for capital expenditures, tenant improvements and property taxes. As of December 31, 2015 , we had no restricted cash held at qualified intermediaries for the purpose of facilitating Section 1031 Exchanges. As of December 31, 2014 , we had approximately $59.2 million in restricted cash held at qualified intermediaries for the purpose of facilitating Section 1031 Exchanges.
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 14 “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 do not significantly impact net income.
Deferred Leasing Costs	Deferred Leasing Costs Costs incurred in connection with successful property leasing are capitalized as deferred leasing costs and classified as investment activities in the statement of cash flows. Deferred leasing costs consist primarily of leasing commissions and also include certain internal payroll costs and lease incentives, which are amortized using the straight-line method of accounting over the lives of the leases which generally range from one to 20 years. We reevaluate the remaining useful lives of leasing costs as the creditworthiness of our tenants and economic and market conditions change. If we determine that the estimated remaining life of a lease has changed, we adjust the amortization period accordingly. Fully amortized deferred leasing costs are written off each quarter.
Deferred Financing Costs, Debt Discounts and Premiums, Exchangeable Debt Instruments, and Gain and Losses on Early Extinguishment of Debt	Deferred Financing Costs Financing costs related to the origination or assumption of long-term debt are deferred and generally amortized using the straight-line method of accounting, which approximates the effective interest method, over the contractual terms of the applicable financings. Fully amortized deferred financing costs are written off when the corresponding financing is repaid. As of December 31, 2015 and 2014 , deferred financing costs were reported net of accumulated amortization of $12.3 million and $12.2 million , respectively. Debt Discounts and Premiums Original issuance debt discounts and discounts/premiums related to recording debt acquired in connection with operating property acquisitions at fair value are generally amortized and accreted on a straight-line basis, which approximates the effective interest method. Discounts are recorded as additional interest expense from date of issuance or acquisition through the contractual maturity date of the related debt. Premiums are recorded as a reduction to interest expense from the date of issuance or acquisition through the contractual maturity date of the related debt. Our secured debt is presented including unamortized premiums of $6.2 million and $10.3 million as of December 31, 2015 and 2014 , respectively. Our unsecured senior notes are presented net of unamortized discounts of $7.4 million and $5.9 million , as of December 31, 2015 and 2014 , 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. A portion of this additional interest expense is capitalized to the development and redevelopment balances qualifying for interest capitalization each period.
Noncontrolling Interest and Partnership Interests	Noncontrolling Interests in the Company’s Consolidated Financial Statements Noncontrolling interests in the Company’s consolidated financial statements represent the common limited partnership interests in the Operating Partnership not held by the Company (“noncontrolling common units”) and the equity interest held by an unrelated third party in our consolidated subsidiary, Redwood LLC, which was formed during 2013 in connection with a development land acquisition. 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 10 “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. Net income attributable to noncontrolling interest in consolidated subsidiary is allocated in accordance with the terms of the related agreement. 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, 2015 and 2014 . The Series G and Series H Preferred Units are presented in the permanent equity section of the Operating Partnership’s consolidated balance sheets given that the Series G and Series H Preferred Units may only be redeemed at our option (see Note 12 “Preferred and Common Units of the Operating Partnership”). The Company is the holder of both the Series G and Series H Preferred Units and for each Series G and Series H Preferred Unit the Company has an equivalent number of shares of the Company’s 6.875% Series G Cumulative Redeemable Preferred Stock and shares of the Company’s 6.375% Series H Cumulative Redeemable Preferred Stock publicly issued and outstanding.
Equity Offerings	Equity Offerings Underwriting commissions and offering costs incurred in connection with common equity offerings and our at-the-market stock offering program (see Note 11 “Stockholders’ Equity of the Company”) are reflected as a reduction of additional paid-in capital. Issuance costs incurred in connection with preferred equity offerings are reflected as a reduction of the carrying value of the preferred equity. The Company records preferred stock issuance costs as a noncash preferred equity distribution at the time we notify the holders of preferred stock or units of our intent to redeem such shares or units. The net proceeds from any equity offering of the Company are generally contributed to the Operating Partnership in exchange for a number of common or preferred units equivalent to the number of shares of common or preferred stock issued and are reflected in the Operating Partnership’s consolidated financial statements as an increase in partners’ capital.
Share-based Incentive Compensation Accounting	Share-based Incentive Compensation Accounting Compensation cost for all share-based awards, including options, requires measurement at estimated fair value on the grant date. Compensation cost is recognized over the service vesting period, which represents the requisite service period, on a straight-line basis. The grant date fair value of market measure-based share-based compensation plans are calculated using a Monte Carlo simulation pricing model. The grant date fair value of stock option grants is calculated using the Black-Scholes valuation model. Equity awards settled in cash are valued at the fair value of our common stock on the period end date through the settlement date. Equity awards settled in cash are remeasured at each reporting period and are recognized as a liability in the consolidated balance sheet during the vesting period until settlement. For share-based awards in which the performance period precedes the grant date, we recognize compensation cost over the requisite service period, which includes both the performance and service vesting periods, using the accelerated attribution expense method. The requisite service period begins on the date the Executive Compensation Committee authorizes the award and adopts any relevant performance measures. For programs with performance-based measures, the total estimated compensation cost is based on our most recent estimate of the probable achievement of the pre-established specific corporate performance measures. These estimates are based on our latest internal forecasts for each performance measure. For programs with market measures, the total estimated compensation cost is based on the fair value of the award at the grant date. In accordance with the provisions of our share-based incentive compensation plans, we accept the return of shares of Company common stock, at the current quoted market price, from employees to satisfy minimum statutory tax-withholding requirements related to shares that vested during the period. For share based awards granted by the Company, the Operating Partnership issues a number of common units equal to the number of shares of common stock ultimately granted by the Company in respect of such awards.
Basic and Diluted Net Income (Loss)	Basic and Diluted Net Income Available to Common Stockholders per Share Basic net income available to common stockholders per share is computed by dividing net income available to common stockholders, after preferred distributions and the allocation of income to participating securities, by the weighted-average number of shares of common stock outstanding for the period. Diluted net income available to common stockholders per share is computed by dividing net income available for common stockholders, after preferred distributions and the allocation of income to participating securities, by the sum of the weighted-average number of shares of common stock outstanding for the period plus the assumed exercise of all dilutive securities. The impact of the outstanding common units is considered in the calculation of diluted net income available to common stockholders per share. The common units are not reflected in the diluted net income available to common stockholders per share calculation because the exchange of common units into common stock is on a one for one basis, and the common units are allocated net income on a per share basis equal to the common stock (see Note 20 “Net Income Available to Common Stockholders Per Share of the Company”). Accordingly, any exchange would not have any effect on diluted net income (loss) available to common stockholders per share. Nonvested share-based payment awards (including nonvested restricted stock units (“RSUs”), vested market-measure RSUs and vested dividend equivalents issued to holders of RSUs) containing nonforfeitable rights to dividends or dividend equivalents are accounted for as participating securities and included in the computation of basic and diluted net income available to common stockholders per share pursuant to the two-class method. The dilutive effect of stock options are reflected in the weighted average diluted outstanding shares calculation by application of the treasury stock method. The dilutive effect of the outstanding nonvested shares of common stock (“nonvested shares”) and RSUs that have not yet been granted but are contingently issuable under the share-based compensation programs is reflected in the weighted average diluted shares calculation by application of the treasury stock method at the beginning of the quarterly period in which all necessary conditions have been satisfied.
Fair Value Measurements	Fair Value Measurements The fair value of our financial assets and liabilities are disclosed in Note 17, “Fair Value Measurements and Disclosures,” to our consolidated financial statements. The only financial assets recorded at fair value on a recurring basis in our consolidated financial statements are our marketable securities. We elected not to apply the fair value option for any of our eligible financial instruments or other items. We determine the estimated fair value of financial assets and liabilities utilizing a hierarchy of valuation techniques based on whether the inputs to a fair value measurement are considered to be observable or unobservable in a marketplace. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect our market assumptions. This hierarchy requires the use of observable market data when available. The following is the fair value hierarchy: • Level 1 – quoted prices for identical instruments in active markets; • Level 2 – quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active and model-derived valuations in which significant inputs and significant value drivers are observable in active markets; and • Level 3 – fair value measurements derived from valuation techniques in which one or more significant inputs or significant value drivers are unobservable. We determine the fair value for the marketable securities using quoted prices in active markets for identical assets. Our other financial instruments, which are only disclosed at fair value, are comprised of secured debt, unsecured senior notes, unsecured line of credit and unsecured term loan facility. We generally determine the fair value of our secured debt, unsecured debt, and unsecured line of credit by performing discounted cash flow analyses using an appropriate market discount rate. We calculate the market rate by obtaining period-end treasury rates for maturities that correspond to the maturities of our fixed-rate debt and then adding an appropriate credit spread based on information obtained from third-party financial institutions. These credit spreads take into account factors, including but not limited to, our credit profile, the tenure of the debt, amortization period, whether the debt is secured or unsecured, and the loan-to-value ratio of the debt to the collateral. These calculations are significantly affected by the assumptions used, including the discount rate, credit spreads and estimates of future cash flow. We calculate the market rate of our unsecured line of credit, unsecured term loan facility, and unsecured term loan by obtaining the period-end London Interbank Offered Rate (“LIBOR”) and then adding an appropriate credit spread based on our credit ratings, and the amended terms of our unsecured line of credit, unsecured term loan facility, and unsecured term loan agreement. We determine the fair value of each of our publicly traded unsecured senior notes based on their quoted trading price at the end of the reporting period, if such prices are available. Carrying amounts of our cash and cash equivalents, restricted cash and accounts payable approximate fair value due to their short-term maturities.
Income Taxes	Income Taxes We have elected to be taxed as a REIT under Sections 856 through 860 of the Code. To qualify as a REIT, we must distribute annually at least 90% of our adjusted taxable income, as defined in the Code, to our stockholders and satisfy certain other organizational and operating requirements. For distributions with respect to taxable years ended on or before December 31, 2011, Internal Revenue Service (“IRS”) guidance allows REITs to satisfy up to 90% of this requirement through the distribution of shares of common stock if certain conditions are met. We generally will not be subject to federal income taxes if we distribute 100% of our taxable income for each year to our stockholders. If we fail to qualify as a REIT in any taxable year, we will be subject to federal income taxes (including any applicable alternative minimum tax) on our taxable income at regular corporate rates and we may not be able to qualify as a REIT for four subsequent taxable years. Even if we qualify for taxation as a REIT, we may be subject to certain state and local taxes on our income and property and to federal income taxes and excise taxes on our undistributed taxable income. We believe that we have met all of the REIT distribution and technical requirements for the years ended December 31, 2015 , 2014 and 2013 , and we were not subject to any federal income taxes (see Note 24 “Tax Treatment of Distributions” for additional information). We intend to continue to adhere to these requirements and maintain the Company’s REIT status. Accordingly, no provision for income taxes has been made in the accompanying financial statements. In addition, any taxable income from our taxable REIT subsidiary, which was formed in 2002, is subject to federal, state, and local income taxes. For the years ended December 31, 2015 , 2014 and 2013 the taxable REIT subsidiary had de minimis taxable income.
Uncertain Tax Positions	Uncertain Tax Positions We include favorable tax positions in the calculation of tax liabilities if it is more likely than not that our adopted tax position will prevail if challenged by tax authorities. We evaluated the potential impact of identified uncertain tax positions for all tax years still subject to audit under state and federal income tax law and concluded that we did not have any unrecognized tax benefits or any additional tax liabilities as of December 31, 2015 or 2014 . As of December 31, 2015 , the years still subject to audit are 2011 through 2014 under the California state income tax law and 2012 through 2014 under the federal income tax law.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reported periods. Actual results could differ from those estimates.
Concentration of Credit Risk	Concentration of Credit Risk All of our properties and development and redevelopment projects are owned and all of our business is currently conducted in the state of California with the exception of the ownership and operation of twelve office properties located in the state of Washington. The ability of tenants to honor the terms of their leases is dependent upon the economic, regulatory, and social factors affecting the communities in which our tenants operate. As of December 31, 2015 , our 15 largest tenants represented approximately 36.9% 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, 2015 and 2014 , we had cash accounts in excess of FDIC insured limits.
Recent Accounting Pronouncements	Accounting Pronouncements On January 5, 2016, the FASB issued ASU No. 2016-01 to amend the accounting guidance on the classification and measurement of financial instruments. The standard requires that all investments in equity securities, including other ownership interests, are carried at fair value through net income. This requirement does not apply to investments that qualify for equity method accounting or to those that result in consolidation of the investee or for which the entity has elected the predictability exception to fair value measurement. Entities that elect the predictability exception would address the equity investment for impairment and no longer have to assess whether an impairment of such an investment is other than temporary. Additionally, the standard requires that the portion of the total fair value change caused by a change in instrument-specific credit risk for financial liabilities for which the fair value option has been elected would be recognized in other comprehensive income. Any accumulated amount remaining in other comprehensive income is reclassified to earnings when the liability is extinguished. The Company is currently assessing the impact of the guidance on our consolidated financial statements and notes to our consolidated financial statements. On August 12, 2015, the FASB issued ASU No. 2015-14 to defer the effective date of ASU No. 2014-09, which outlines a single comprehensive model for entities to use in accounting for revenues arising from contracts with customers and notes that lease contracts with customers are a scope exception. Public business entities may elect to adopt the amendments as of the original effective date; however, adoption is required for annual reporting periods beginning after December 15, 2017. The Company is currently assessing the impact of the guidance on our consolidated financial statements and notes to our consolidated financial statements. On April 7, 2015, the FASB issued ASU No. 2015-03 (“ASU 2015-03”) to amend the accounting guidance for the presentation of debt issuance costs. The standard requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. On August 18, 2015, the FASB also issued ASU No. 2015-15 (“ASU 2015-15”) to address the presentation of debt issuance costs specifically related to line-of-credit arrangements. The standard clarifies that an entity may defer and present debt issuance costs as an asset and amortize the costs ratably over the term of the line-of-credit arrangement, regardless of whether there are an outstanding borrowings on the line-of credit arrangement. ASU 2015-03 and ASU 2015-15 are effective for public business entities for fiscal years beginning after December 15, 2015 and retrospective application is required. Early adoption of the guidance is permitted. The Company adopted the guidance effective January 1, 2016 and the guidance will not have any impact on our consolidated statements of operations, equity/capital, or cash flows. In February 2015, the FASB issued ASU No. 2015-02 (“ASU 2015-02”), which affects reporting entities that are required to evaluate whether they should consolidate certain legal entities. Specifically, the amendments: (i) modify the evaluation of whether limited partnerships and similar legal entities are VIEs or voting interest entities, (ii) eliminate the presumption that a general partner should consolidate a limited partnership, (iii) affect the consolidated analysis of reporting entities that are involved with VIEs, and (iv) provide a scope exception for certain entities. ASU 2015-02 is effective for interim and annual reporting periods beginning after December 15, 2015.
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 10 “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 equity interest in Redwood LLC held by an unrelated third party. 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 Available to Common Unitholders per Unit Basic net income available to common unitholders per unit is computed by dividing net income available to common unitholders, after preferred distributions and the allocation of income to participating securities, by the weighted-average number of vested common units outstanding for the period. Diluted net income available to common unitholders per unit is computed by dividing net income available to common unitholders, after preferred distributions and the allocation of income to participating securities, by the sum of the weighted-average number of common units outstanding for the period plus the assumed exercise of all dilutive securities. The dilutive effect of stock options, outstanding nonvested shares, RSUs, and awards containing nonforfeitable rights to dividend equivalents are reflected in diluted net income available to common unitholders per unit in the same manner as noted above for net income available to common stockholders per share.

Basis of Presentation and Sig44

Basis of Presentation and Significant Accounting Policies Segment Reporting (Policies)	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Segment Reporting Disclosure [Text Block]	Segment We currently operate in one operating segment, our office properties segment.

Organization and Ownership (Tab

Organization and Ownership (Tables)	12 Months Ended
	Dec. 31, 2015
Real Estate Properties [Line Items]
Schedule of Real Estate Properties [Table Text Block]	Our stabilized portfolio of operating properties was comprised of the following office properties at December 31, 2015 : Number of Buildings Rentable Square Feet (unaudited) Number of Tenants Percentage Occupied (unaudited) Stabilized Office Properties 101 13,032,406 517 94.8 % As of December 31, 2015 , the following properties were excluded from our stabilized portfolio: Number of Properties/Projects Estimated Rentable Square Feet (unaudited) (1) Properties held for sale (2) 4 465,812 Development projects in “ lease-up" 1 73,000 Development projects under construction 5 1,910,000 _______________ (1) Estimated rentable square feet upon completion.

Basis of Presentation and Sig46

Basis of Presentation and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2015
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, 2015
Business Acquisition [Line Items]
Property, Plant and Equipment, Schedule of Significant Acquisitions and Disposals [Table Text Block]	The following table summarizes the land dispositions completed during the years ended December 31, 2015 and 2014 : Properties Submarket Month of Disposition Gross Site Acreage (unaudited) Sales Price (1) (in millions) 2015 Land Disposition 17150 Von Karman (2) Irvine January 8.5 $ 26.0 2014 Land Disposition 10850 Via Frontera (3) Rancho Bernardo April 21.0 $ 33.1 __________________ (1) Represents gross sales price before the impact of commissions and closing costs. (2) This transaction resulted in a gain on sale of $17.3 million . (3) This transaction resulted in a gain on sale of $3.5 million .
Office Properties Acquisitions
Business Acquisition [Line Items]
Acquired operating properties from unrelated third parties	During the year ended December 31, 2014 , we acquired the five operating office properties, listed below, from unrelated third parties. Unless otherwise noted, we funded these acquisitions with proceeds from the Company’s public offerings of common stock and the Company's at-the-market stock offering program (see Note 11 “Stockholders’ Equity of the Company”), borrowings under the unsecured line of credit (see Note 8 “Secured and Unsecured Debt of the Operating Partnership”), disposition proceeds (see Note 4 “Dispositions and Real Estate Assets Held for Sale” for additional information”), 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, 2015 (unaudited) Purchase Price (in millions) (1) 2014 Acquisitions 401 Terry Ave. N., Seattle, WA March 13, 2014 1 140,605 100.0% $ 106.1 1310, 1315, 1320-1324, 1325-1327 Chesapeake Terrace, Sunnyvale, CA (2) November 5, 2014 4 266,982 100.0% 100.5 Total (3) 5 407,587 $ 206.6 ________________________ (1) Excludes acquisition-related costs and non-lease related accrued liabilities assumed. Includes assumed unpaid leasing commissions and tenant improvements. (2) As of December 31, 2014 , these properties, together the “Chesapeake Commons” project, were temporarily being held in a separate VIE to facilitate potential Section 1031 Exchanges. During January 2015, the Company closed out the Section 1031 Exchange related to this VIE. (See Note 2 “Basis of Presentation and Significant Accounting Policies”). (3) The results of operations for the properties acquired during 2014 contributed $7.7 million and $2.8 million to revenues and net income from continuing operations, respectively, for the year ended December 31, 2014 . 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. Th following table summarizes the estimated fair values of the assets acquired and liabilities assumed at the respective acquisition dates for our 2014 operating property acquisitions: Acquisitions Total 2014 Acquisitions (1) Assets Land and improvements $ 81,430 Buildings and improvements (2) 114,876 Deferred leasing costs and acquisition-related intangible assets (3) 17,259 Total assets acquired 213,565 Liabilities Deferred revenue and acquisition-related intangible liabilities (4) 6,990 Accounts payable, accrued expenses and other liabilities 2,029 Total liabilities assumed 9,019 Net assets and liabilities acquired (5) $ 204,546 _______________ (1) The purchase price of the two acquisitions completed during the year ended December 31, 2014 were individually less than 5% and in aggregate less than 10% of the Company’s total assets as of December 31, 2014 . (2) Represents buildings, building improvements and tenant improvements. (3) Represents in-place leases (approximately $12.3 million with a weighted average amortization period of 7.0 years) and leasing commissions (approximately $4.9 million with a weighted average amortization period of 7.0 years). (4) Represents below-market leases (approximately $7.0 million with a weighted average amortization period of 6.1 years). (5) Reflects the purchase price net of assumed secured debt and other lease-related obligations.

Dispositions and Real Estate 48

Dispositions and Real Estate Assets Held for Sale (Tables)	12 Months Ended
	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disclosure of Long Lived Assets Held-for-sale [Table Text Block]	As of December 31, 2015 , the properties listed below were classified as held for sale. We did not have any properties classified as held for sale as of December 31, 2014 . Properties Submarket Property Type Number of Buildings Rentable Square Feet (unaudited) Torrey Santa Fe Properties (1)(2) Del Mar Office 4 465,812 __________________ (1) The Torrey Santa Fe Properties include the following properties: 7525 Torrey Santa Fe, 7535 Torrey Santa Fe, 7545 Torrey Santa Fe, and 7555 Torrey Santa Fe. (2) In January 2016, the Company completed the sale of these properties for a total sales price of $262.3 million . The major classes of assets and liabilities of the properties held for sale as of December 31, 2015 were as follows: Real estate assets and other assets held for sale (in thousands) Land and improvements $ 10,534 Buildings and improvements 144,716 Undeveloped land and construction in progress 4,824 Total real estate held for sale 160,074 Accumulated depreciation and amortization (46,191 ) Total real estate held for sale, net 113,883 Deferred rent receivables, net 2,500 Deferred leasing costs and acquisition-related intangible assets, net 1,115 Prepaid expenses and other assets, net 168 Real estate and other assets held for sale, net $ 117,666 Liabilities and deferred revenue of real estate assets held for sale Secured debt $ 561 Accounts payable, accrued expenses and other liabilities 2,497 Deferred revenue and acquisition-related intangible liabilities, net 2,899 Rents received in advance and tenant security deposits 1,586 Liabilities and deferred revenue of real estate assets held for sale $ 7,543 As of December 31, 2015 and 2014 , the following land parcels were classified as held for sale: Properties Submarket Gross Site Acreage (unaudited) Sales Price 2015 Held for Sale Carlsbad Oaks - Lot 7 (1)(2) Carlsbad 7.6 $ 4.5 2014 Held for Sale 17150 Von Karman Irvine 8.5 $ 26.0 __________________ (1) During the year ended December 31, 2015 , the Company recognized a loss relating to selling costs of approximately $0.2 million . (2) In January 2016, the Company completed the sale of the Carlsbad Oaks - Lot 7 land parcel.
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]	4. Dispositions and Real Estate Assets Held for Sale Operating Property Dispositions The following table summarizes the properties sold during the years ended December 31, 2015 , 2014 and 2013 : Location Month of Disposition Number of Buildings Rentable Square Feet (unaudited) Sales Price (in millions) (1) 2015 Dispositions 15050 NE 36th Street, Redmond, WA April 1 122,103 $ 51.2 San Diego Properties - Tranches 1 and 2 (2) April/July 9 924,291 258.0 Total 2015 Dispositions 10 1,046,394 $ 309.2 2014 Dispositions (3) San Diego Properties, San Diego, CA (4) January 12 1,049,035 $ 294.7 9785 & 9791 Towne Centre Drive, San Diego, CA June 2 126,000 29.5 111 Pacifica, Irvine, CA September 1 67,496 15.1 4040 Civic Center Drive, San Rafael, CA October 1 130,237 34.9 999 Town & Country Road, Orange, CA December 1 98,551 25.3 Total 2014 Dispositions 17 1,471,319 $ 399.5 2013 Dispositions (3) 26541 Agoura Road, Calabasas, CA June 1 90,156 $ 14.7 8101 Kaiser Boulevard, Anaheim, CA October 1 59,790 9.6 4910 Directors Place, San Diego CA December 1 50,360 32.6 Total 2013 Dispositions 3 200,306 $ 56.9 __________________ (1) Represents gross sales price before the impact of broker commissions and closing costs. (2) The San Diego Properties - Tranche 1 includes the following properties: 10770 Wateridge Circle, 6200 Greenwich Drive, and 6220 Greenwich Drive. The San Diego Properties - Tranche 2 includes the following properties: 6260 Sequence Drive, 6290, Sequence Drive, 6310 Sequence Drive, 6340 Sequence Drive, 6350 Sequence Drive and 4921 Directors Place. (3) The Company adopted ASU 2014-08 effective January 1, 2015 (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As a result, results of operations for properties disposed of subsequent of January 1, 2015 are presented in continuing operations because they did not represent strategic shifts. Properties disposed of prior to January 1, 2015 are presented in discontinued operations. (4) The San Diego Properties included the following: 10020 Pacific Mesa Boulevard, 6055 Lusk Avenue, 5010 and 5005 Wateridge Vista Drive, 15435 and 15445 Innovation Drive, and 15051, 15073, 15231, 15253, 15333 and 15378 Avenue of Science. These properties were held for sale as of December 31, 2013. The operations of the ten properties sold during the year ended December 31, 2015 are presented in continuing operations for the year ended December 31, 2015 . The total gains on sales of the ten properties sold during the year ended December 31, 2015 was $110.0 million . For the year ended December 31, 2014 , discontinued operations includes the income and gains on all of the properties sold in 2014 . For the year ended December 31, 2013 , discontinued operations includes the income and gains on all of the properties sold in 2014 and 2013 (see Note 2 “Basis of Presentation and Significant Accounting Policies” and Note 19 “Discontinued Operations” for additional information). Operating Properties Held for Sale As of December 31, 2015 , the properties listed below were classified as held for sale. We did not have any properties classified as held for sale as of December 31, 2014 . Properties Submarket Property Type Number of Buildings Rentable Square Feet (unaudited) Torrey Santa Fe Properties (1)(2) Del Mar Office 4 465,812 __________________ (1) The Torrey Santa Fe Properties include the following properties: 7525 Torrey Santa Fe, 7535 Torrey Santa Fe, 7545 Torrey Santa Fe, and 7555 Torrey Santa Fe. (2) In January 2016, the Company completed the sale of these properties for a total sales price of $262.3 million . The major classes of assets and liabilities of the properties held for sale as of December 31, 2015 were as follows: Real estate assets and other assets held for sale (in thousands) Land and improvements $ 10,534 Buildings and improvements 144,716 Undeveloped land and construction in progress 4,824 Total real estate held for sale 160,074 Accumulated depreciation and amortization (46,191 ) Total real estate held for sale, net 113,883 Deferred rent receivables, net 2,500 Deferred leasing costs and acquisition-related intangible assets, net 1,115 Prepaid expenses and other assets, net 168 Real estate and other assets held for sale, net $ 117,666 Liabilities and deferred revenue of real estate assets held for sale Secured debt $ 561 Accounts payable, accrued expenses and other liabilities 2,497 Deferred revenue and acquisition-related intangible liabilities, net 2,899 Rents received in advance and tenant security deposits 1,586 Liabilities and deferred revenue of real estate assets held for sale $ 7,543 Land Dispositions The following table summarizes the land dispositions completed during the years ended December 31, 2015 and 2014 : Properties Submarket Month of Disposition Gross Site Acreage (unaudited) Sales Price (1) (in millions) 2015 Land Disposition 17150 Von Karman (2) Irvine January 8.5 $ 26.0 2014 Land Disposition 10850 Via Frontera (3) Rancho Bernardo April 21.0 $ 33.1 __________________ (1) Represents gross sales price before the impact of commissions and closing costs. (2) This transaction resulted in a gain on sale of $17.3 million . (3) This transaction resulted in a gain on sale of $3.5 million . Land Held for Sale As of December 31, 2015 and 2014 , the following land parcels were classified as held for sale: Properties Submarket Gross Site Acreage (unaudited) Sales Price 2015 Held for Sale Carlsbad Oaks - Lot 7 (1)(2) Carlsbad 7.6 $ 4.5 2014 Held for Sale 17150 Von Karman Irvine 8.5 $ 26.0 __________________ (1) During the year ended December 31, 2015 , the Company recognized a loss relating to selling costs of approximately $0.2 million . (2) In January 2016, the Company completed the sale of the Carlsbad Oaks - Lot 7 land parcel. Restricted Cash Related to Dispositions As of December 31, 2014 , approximately $59.2 million of net proceeds related to the land and office property dispositions during the year ended December 31, 2014 were temporarily being held at a qualified intermediary, at our direction, for the purpose of facilitating Section 1031 Exchanges. The cash proceeds were included in restricted cash on the consolidated balance sheet at December 31, 2014 . In January 2015, we successfully completed Section 1031 Exchanges and the $59.2 million of cash proceeds comprising the balances as of December 31, 2014 were released from the qualified intermediary. We did not have any restricted cash related to dispositions or Section 1031 Exchanges as of December 31, 2015 . Discontinued Operations For the years ended December 31, 2014 and 2013 , discontinued operations included the results of all properties sold in 2014 and 2013 and classified as held for sale at December 31, 2013 , except for the operations deemed immaterial related to a June 2014 office property disposition. The following table summarizes the revenue and expense components that comprise income from discontinued operations for the years ended December 31, 2014 and 2013 : 2014 2013 (in thousands) Revenues: Rental income $ 7,206 $ 31,984 Tenant reimbursements 278 3,546 Other property income 13 5,178 Total revenues 7,497 40,708 Expenses: Property expenses 2,171 7,207 Real estate taxes 692 3,523 Depreciation and amortization 2,061 12,600 Total expenses 4,924 23,330 Income from discontinued operations before net gain on dispositions of discontinued operations 2,573 17,378 Net gain on dispositions of discontinued operations 121,922 12,252 Total income from discontinued operations $ 124,495 $ 29,630
Schedule of Property Dispositions [Table Text Block]	The following table summarizes the properties sold during the years ended December 31, 2015 , 2014 and 2013 : Location Month of Disposition Number of Buildings Rentable Square Feet (unaudited) Sales Price (in millions) (1) 2015 Dispositions 15050 NE 36th Street, Redmond, WA April 1 122,103 $ 51.2 San Diego Properties - Tranches 1 and 2 (2) April/July 9 924,291 258.0 Total 2015 Dispositions 10 1,046,394 $ 309.2 2014 Dispositions (3) San Diego Properties, San Diego, CA (4) January 12 1,049,035 $ 294.7 9785 & 9791 Towne Centre Drive, San Diego, CA June 2 126,000 29.5 111 Pacifica, Irvine, CA September 1 67,496 15.1 4040 Civic Center Drive, San Rafael, CA October 1 130,237 34.9 999 Town & Country Road, Orange, CA December 1 98,551 25.3 Total 2014 Dispositions 17 1,471,319 $ 399.5 2013 Dispositions (3) 26541 Agoura Road, Calabasas, CA June 1 90,156 $ 14.7 8101 Kaiser Boulevard, Anaheim, CA October 1 59,790 9.6 4910 Directors Place, San Diego CA December 1 50,360 32.6 Total 2013 Dispositions 3 200,306 $ 56.9 __________________ (1) Represents gross sales price before the impact of broker commissions and closing costs. (2) The San Diego Properties - Tranche 1 includes the following properties: 10770 Wateridge Circle, 6200 Greenwich Drive, and 6220 Greenwich Drive. The San Diego Properties - Tranche 2 includes the following properties: 6260 Sequence Drive, 6290, Sequence Drive, 6310 Sequence Drive, 6340 Sequence Drive, 6350 Sequence Drive and 4921 Directors Place. (3) The Company adopted ASU 2014-08 effective January 1, 2015 (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As a result, results of operations for properties disposed of subsequent of January 1, 2015 are presented in continuing operations because they did not represent strategic shifts. Properties disposed of prior to January 1, 2015 are presented in discontinued operations. (4) The San Diego Properties included the following: 10020 Pacific Mesa Boulevard, 6055 Lusk Avenue, 5010 and 5005 Wateridge Vista Drive, 15435 and 15445 Innovation Drive, and 15051, 15073, 15231, 15253, 15333 and 15378 Avenue of Science. These properties were held for sale as of December 31, 2013.
Property, Plant and Equipment, Schedule of Significant Acquisitions and Disposals [Table Text Block]	The following table summarizes the land dispositions completed during the years ended December 31, 2015 and 2014 : Properties Submarket Month of Disposition Gross Site Acreage (unaudited) Sales Price (1) (in millions) 2015 Land Disposition 17150 Von Karman (2) Irvine January 8.5 $ 26.0 2014 Land Disposition 10850 Via Frontera (3) Rancho Bernardo April 21.0 $ 33.1 __________________ (1) Represents gross sales price before the impact of commissions and closing costs. (2) This transaction resulted in a gain on sale of $17.3 million . (3) This transaction resulted in a gain on sale of $3.5 million .

Deferred Leasing Costs and Ac49

Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, net (Tables)	12 Months Ended
	Dec. 31, 2015
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, 2015 and 2014 : December 31, 2015 December 31, 2014 (in thousands) Deferred Leasing Costs and Acquisition-related Intangible Assets, net: (1) Deferred leasing costs $ 205,888 $ 216,102 Accumulated amortization (72,745 ) (74,904 ) Deferred leasing costs, net 133,143 141,198 Above-market operating leases 10,989 20,734 Accumulated amortization (6,739 ) (13,952 ) Above-market operating leases, net 4,250 6,782 In-place leases 72,639 97,250 Accumulated amortization (33,810 ) (43,773 ) In-place leases, net 38,829 53,477 Below-market ground lease obligation 490 490 Accumulated amortization (29 ) (21 ) Below-market ground lease obligation, net 461 469 Total deferred leasing costs and acquisition-related intangible assets, net $ 176,683 $ 201,926 Acquisition-related Intangible Liabilities, net: (2) Below-market operating leases $ 53,502 $ 68,051 Accumulated amortization (27,074 ) (30,620 ) Below-market operating leases, net 26,428 37,431 Above-market ground lease obligation 6,320 6,320 Accumulated amortization (424 ) (324 ) Above-market ground lease obligation, net 5,896 5,996 Total acquisition-related intangible liabilities, net $ 32,324 $ 43,427 _______________ (1) Excludes deferred leasing costs and acquisition-related intangible assets, net related to properties held for sale as of December 31, 2015 . (2) 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 intangibles for the years ended December 31, 2015 , 2014 and 2013 , including amounts attributable to discontinued operations for the years ended December 31, 2014 and 2013 . Year Ended December 31, 2015 2014 2013 (in thousands) Deferred leasing costs (1) $ 27,866 $ 27,555 $ 25,902 Above-market operating leases (2) 2,532 5,303 5,664 In-place leases (1) 14,622 21,628 29,363 Below-market ground lease obligation (3) 8 8 8 Below-market operating leases (4) (10,980 ) (13,238 ) (13,441 ) Above-market ground lease obligation (5) (101 ) (101 ) (101 ) Total $ 33,947 $ 41,155 $ 47,395 _______________ (1) The amortization of deferred leasing costs and in-place leases is recorded to depreciation and amortization expense and the amortization of lease incentives is recorded as a reduction to rental income in the consolidated statements of operations for the periods presented. (2) The amortization of above-market operating leases is recorded as a decrease to rental income in the consolidated statements of operations for the periods presented. (3) The amortization of 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, 2015 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) 2016 $ 25,637 $ 1,501 $ 10,542 $ 8 $ (7,664 ) $ (101 ) 2017 22,790 1,241 9,108 8 (7,017 ) (101 ) 2018 19,580 831 6,296 8 (5,713 ) (101 ) 2019 15,649 643 4,637 8 (3,574 ) (101 ) 2020 11,720 16 2,789 8 (2,035 ) (101 ) Thereafter 37,767 18 5,457 421 (425 ) (5,391 ) Total $ 133,143 $ 4,250 $ 38,829 $ 461 $ (26,428 ) $ (5,896 ) _______________ (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, 2015
Receivables [Abstract]
Current Receivables, net	Current receivables, net is primarily comprised of contractual rents and other lease-related obligations due from tenants. The balance consisted of the following as of December 31, 2015 and 2014 : December 31, 2015 December 31, 2014 (in thousands) Current receivables (1) $ 13,233 $ 9,228 Allowance for uncollectible tenant receivables (1) (2,080 ) (1,999 ) Current receivables, net (1) $ 11,153 $ 7,229 ______________ (1) Excludes current receivables, net related to real estate held for sale.
Deferred Rent Receivables, net	Deferred rent receivables, net consisted of the following as of December 31, 2015 and 2014 : December 31, 2015 December 31, 2014 (in thousands) Deferred rent receivables (1) $ 191,586 $ 158,405 Allowance for deferred rent receivables (1,882 ) (1,989 ) Deferred rent receivables, net (1) $ 189,704 $ 156,416 __________________ (1) Excludes deferred rent receivables, net related to real estate held for sale.

Secured and Unsecured Debt of51

Secured and Unsecured Debt of the Operating Partnership (Tables)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Interest Expense For Exchangeable Notes [Table Text Block]		The following table summarizes the total interest expense attributable to the 4.25% Exchangeable Notes prior to maturity in November 2014, based on the effective interest rates, before the effect of capitalized interest, for the years ended December 31, 2014 and 2013 : Year Ended December 31, 2014 2013 Contractual interest payments $ 5,608 $ 7,331 Amortization of discount 3,769 4,427 Interest expense attributable to the 4.25% Exchangeable Notes $ 9,377 $ 11,758
Per Share Average Trading Price Of Companys Common Stock On Stock Exchange [Tables Text Block]		For the respective reporting periods noted below, which preceding maturity of the 4.25% Exchangeable Notes on November 15, 2014, the per share average trading price of the Company's common stock on the NYSE was higher than the $35.93 exchange price for the 4.25% Exchangeable Notes, as presented in the table below. See Note 20 “Net Income Available to Common Stockholders Per Share of the Company” and Note 21 “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 years ended December 31, 2014 and 2013 . Period Ended November 15, 2014 (1) Year Ended December 31, 2013 Per share average trading price of the Company's common stock $ 60.04 $ 52.12 _______________ (1) Represents the maturity date of the 4.25% Exchangeable Notes.
Debt Instrument Redemption [Table Text Block]		The table below summarizes the significant terms of the Company’s $172.5 million 4.25% Exchangeable Notes due November 2014 (the “4.25% Exchangeable Notes”) prior to their repayment upon maturity in November 2014. 4.25% Exchangeable Notes December 31, 2014 Issuance date November 2009 Maturity date November 2014 Stated coupon rate (1) 4.25% Effective interest rate (2) 7.13% Exchange rate per $1,000 principal value of the 4.25% Exchangeable Notes, as adjusted (3) 27.8307 Exchange price as adjusted (3) $35.93 Number of shares on which the aggregate consideration to be delivered on conversion (3) 4,800,796 _______________ (1) Interest on the 4.25% Exchangeable Notes was payable semi-annually in arrears on May 15th and November 15th of each year. (2) Represents the rate at which we record interest expense for financial reporting purposes, which reflects the amortization of the discounts on the 4.25% Exchangeable Notes. This rate represents our conventional debt borrowing rate at the date of issuance. (3) The exchange rate, exchange price, and the number of shares to be delivered upon conversation were subject to adjustment under certain circumstances, including increases in our common dividends as of December 31, 2014 .
Kilroy Realty, L.P. [Member]
Debt Instrument [Line Items]
Schedule of Line of Credit Facilities [Table Text Block]	The following table summarizes the balance and terms of our unsecured revolving credit facility as of December 31, 2015 and December 31, 2014 : December 31, 2015 December 31, 2014 (in thousands) Outstanding borrowings $ — $ 140,000 Remaining borrowing capacity 600,000 460,000 Total borrowing capacity (1) $ 600,000 $ 600,000 Interest rate (2) — % 1.41 % Facility fee-annual rate (3) 0.200% 0.250% Maturity date July 2019 _______________ (1) We may elect to borrow, subject to bank approval and obtaining commitments for any additional borrowing capacity, up to an additional $311.0 million under an accordion feature under the terms of the unsecured revolving credit facility and unsecured term loan facility. (2) Our unsecured revolving credit facility interest rate was calculated based on an annual rate of LIBOR plus 1.050% and LIBOR plus 1.250% as of December 31, 2015 and December 31, 2014 , respectively. (3) Our facility fee is paid on a quarterly basis and is calculated based on the total borrowing capacity. In addition to the facility fee, we incurred debt origination and legal costs. As of December 31, 2015 , $4.6 million of deferred financing costs remains to be amortized through the amended maturity date of our unsecured revolving credit facility.
Schedule of Term Loan Facilities [Table Text Block]	The following table summarizes the balance and terms of our term loan facility, which is included in our unsecured debt, as of December 31, 2015 and December 31, 2014 : December 31, 2015 December 31, 2014 (in thousands) Outstanding borrowings $ 150,000 $ 150,000 Interest rate (1) 1.40 % 1.56 % Maturity date July 2019 July 2019 _______________ (1) Our unsecured term loan facility interest rate was calculated based on an annual rate of LIBOR plus 1.150% and LIBOR plus 1.400% as of December 31, 2015 and December 31, 2014 , respectively.
Stated debt maturities and scheduled amortization payments, excluding debt discounts	The following table summarizes the stated debt maturities and scheduled amortization payments as of December 31, 2015 : Year (in thousands) 2016 $ 9,734 2017 71,734 2018 451,713 2019 265,355 2020 251,962 Thereafter 1,189,198 Total aggregate principal value $ 2,239,696 Less net unamortized discounts (1,188 ) Total debt, net of unamortized discounts $ 2,238,508
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, 2015 , 2014 and 2013 . The interest expense capitalized was recorded as a cost of development and redevelopment, and increased the carrying value of undeveloped land and construction in progress. Year Ended December 31, 2015 2014 2013 (in thousands) Gross interest expense $ 109,647 $ 114,661 $ 111,238 Capitalized interest (51,965 ) (47,090 ) (35,368 ) Interest expense $ 57,682 $ 67,571 $ 75,870
Kilroy Realty, L.P. [Member] | 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, 2015 and 2014 : Annual Stated Interest Rate (1) GAAP Effective Rate (1)(2) Maturity Date December 31, Type of Debt 2015 (3) 2014 (3) (in thousands) Mortgage note payable (5) 4.27% 4.27% February 2018 $ 128,315 $ 130,767 Mortgage note payable (5) 4.48% 4.48% July 2027 96,354 97,000 Mortgage note payable (4)(5) 6.05% 3.50% June 2019 85,890 89,242 Mortgage note payable 6.51% 6.51% February 2017 65,563 66,647 Mortgage note payable 7.15% 7.15% May 2017 3,987 6,568 Mortgage note payable (5)(6) 5.23% 3.50% January 2016 — 52,793 Mortgage note payable (5)(6) 5.57% 3.25% February 2016 — 40,258 Mortgage note payable (5) 5.09% 3.50% August 2015 — 34,311 Mortgage note payable 4.94% 4.00% April 2015 — 26,285 Other (7) Various Various Various 1,809 2,421 Total $ 381,918 $ 546,292 ______________ (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 $6.2 million and $10.3 million as of December 31, 2015 and 2014 , respectively. (4) In January 2013, in connection with the acquisition of two office buildings in Seattle, Washington, we assumed a mortgage loan that is secured by the project. The loan requires monthly principal and interest payments based on a 6.4 year amortization period. As of December 31, 2015 and 2014 , the mortgage loan had unamortized debt premiums of $6.2 million and $8.0 million , respectively. (5) The secured debt and the related properties that secure the debt are held in a special purpose entity and the properties are not available to satisfy the debts and other obligations of the Company or the Operating Partnership. (6) These mortgage notes payable were repaid during the year ended December 31, 2015 at par. (7) Excludes $0.6 million of secured debt related to real estate assets held for sale as of December 31, 2015 .
Kilroy Realty, L.P. [Member] | Exchangeable Notes [Member]
Debt Instrument [Line Items]
Debt balance and significant terms	Uns
Kilroy Realty, L.P. [Member] | 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, 2015 and 2014 : Principal Amount as of December 31, Issuance date Maturity date Stated coupon rate Effective interest rate (1) 2015 2014 (in thousands) 4.375% Unsecured Senior Notes (2) September 2015 October 2025 4.375% 4.440% $ 400,000 $ — Unamortized discount (2,159 ) $ — Net carrying amount $ 397,841 $ — 4.250% Unsecured Senior Notes (3) July 2014 August 2029 4.250% 4.350% $ 400,000 $ 400,000 Unamortized discount (4,050 ) (4,348 ) Net carrying amount $ 395,950 $ 395,652 3.800% Unsecured Senior Notes (4) January 2013 January 2023 3.800% 3.804% $ 300,000 $ 300,000 Unamortized discount (70 ) (79 ) Net carrying amount $ 299,930 $ 299,921 4.800% Unsecured Senior Notes (4)(5) July 2011 July 2018 4.800% 4.827% $ 325,000 $ 325,000 Unamortized discount (191 ) (265 ) Net carrying amount $ 324,809 $ 324,735 6.625% Unsecured Senior Notes (6) May 2010 June 2020 6.625% 6.743% $ 250,000 $ 250,000 Unamortized discount (940 ) (1,154 ) Net carrying amount $ 249,060 $ 248,846 5.000% Unsecured Senior Notes (7) November 2010 November 2015 5.000% 5.014% $ — $ 325,000 Unamortized discount — (33 ) Net carrying amount $ — $ 324,967 Total Unsecured Senior Notes, Net $ 1,667,590 $ 1,594,121 ________________________ (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 these notes is payable semi-annually in arrears on April 1st and October 1st of each year. (3) Interest on these notes is payable semi-annually in arrears on February 15th and August 15th of each year. (4) Interest on these notes is payable semi-annually in arrears on January 15th and July 15th of each year. (5) In October 2015, certain common limited partners in the Operating Partnership that previously contributed their interests in the property at 6255 W. Sunset Blvd., Los Angeles, California to the Operating Partnership entered into an agreement with the Company. Pursuant to this agreement, such common limited partners will reimburse the Company for a portion of any amounts the Company may be required to pay pursuant to its guarantee of the Operating Partnership's 4.800% Senior Notes due 2018 or that the Company may otherwise become required to pay under applicable law with respect to such notes. (6) Interest on these notes is payable semi-annually in arrears on June 1st and December 1st of each year. (7) Interest of these notes is payable semi-annually in arrears on May 3rd and November 3rd of each year.

Deferred Revenue and Acquisit52

Deferred Revenue and Acquisition Related Liabilities, net (Tables)	12 Months Ended
	Dec. 31, 2015
Deferred Revenue Disclosure [Abstract]
Deferred Revenue and Acquisition-related Liabilities	Deferred revenue and acquisition-related liabilities, net consists of the following at December 31, 2015 and 2014 : December 31, 2015 2014 (in thousands) Deferred revenue related to tenant-funded tenant improvements (1) $ 90,825 $ 85,757 Other deferred revenue 5,007 3,055 Acquisition-related intangible liabilities, net (2) 32,324 43,427 Total $ 128,156 $ 132,239 ________________________ (1) Excludes deferred revenue related to tenant-funded tenant improvements related to properties held for sale at December 31, 2015 . (2) See Note 2 “Basis of Presentation and Significant Accounting Policies” and Note 5 “Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, net” for additional information.
Estimated Amortization of Deferred Revenue Related to Tenant-funded Improvements	During the years ended December 31, 2015 , 2014 , and 2013 , $13.3 million , $11.0 million and $10.7 million , respectively, of deferred revenue related to tenant-funded tenant improvements (including discontinued operations for the years ended December 31, 2014 and 2013 ) 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, 2015 for the next five years and thereafter: Year Ending (in thousands) 2016 $ 12,536 2017 11,924 2018 11,285 2019 9,761 2020 9,230 Thereafter 36,089 Total $ 90,825

Stockholders' Equity of the C53

Stockholders' Equity of the Company Stockholders' Equity of the Company (Tables)	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Schedule of Common Stock Sales Under the At-the-Market Offering	The following table sets forth information regarding sales of our common stock under our at-the-market offering programs for the years ended December 31, 2015 , 2014 and 2013 : Year Ended December 31, 2015 2014 2013 (in millions, except share data) Shares of common stock sold during the period 1,866,267 1,599,123 1,040,838 Aggregate gross proceeds $ 140.1 $ 104.7 $ 55.3 Aggregate net proceeds after underwriting discounts $ 138.2 $ 103.1 $ 54.4 The proceeds from sales were used to fund acquisitions, development expenditures and general corporate purposes including repayment of borrowings under the unsecured revolving credit facility.
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, 2015 and 2014 : December 31, 2015 2014 (in thousands) Dividends and Distributions payable to: Common stockholders $ 32,291 $ 30,191 Noncontrolling common unitholders of the Operating Partnership 618 631 RSU holders (1) 427 421 Total accrued dividends and distribution to common stockholders and noncontrolling unitholders 33,336 31,243 Preferred stockholders 1,656 1,656 Total accrued dividends and distributions $ 34,992 $ 32,899 ______________________ (1) The amount includes the value of the dividend equivalents that will be paid with additional RSUs (see Note 13 “Share-Based Compensation” for additional information)
Schedule of Outstanding Shares of Common Stock, Preferred Stock and Noncontrolling Units	December 31, 2015 2014 Outstanding Shares and Units: Common stock (1) 92,258,690 86,259,684 Noncontrolling common units 1,764,775 1,804,200 RSUs (2) 1,269,809 1,248,352 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 425,452 and 247,089 market measure-based RSUs because not all the necessary performance conditions have been met as of December 31, 2015 and 2014 , respectively.

Preferred and Common Units of54

Preferred and Common Units of the Operating Partnership (Tables)	12 Months Ended
	Dec. 31, 2015
Class of Stock [Line Items]
Schedule of Common Stock Sales Under the At-the-Market Offering	The following table sets forth information regarding sales of our common stock under our at-the-market offering programs for the years ended December 31, 2015 , 2014 and 2013 : Year Ended December 31, 2015 2014 2013 (in millions, except share data) Shares of common stock sold during the period 1,866,267 1,599,123 1,040,838 Aggregate gross proceeds $ 140.1 $ 104.7 $ 55.3 Aggregate net proceeds after underwriting discounts $ 138.2 $ 103.1 $ 54.4 The proceeds from sales were used to fund acquisitions, development expenditures and general corporate purposes including repayment of borrowings under the unsecured revolving credit facility.
Redeemable Noncontrolling Interest [Table Text Block]	The following table sets forth the number of common units held by the Company and the number of common units held by non-affiliated 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, 2015 December 31, 2014 Company owned common units in the Operating Partnership 92,258,690 86,259,684 Company owned general partnership interest 98.1 % 98.0 % Noncontrolling common units of the Operating Partnership 1,764,775 1,804,200 Ownership interest of noncontrolling interest 1.9 % 2.0 % For a further discussion of the noncontrolling common units during the years ended December 31, 2015 and 2014 , refer to Note 10 “Noncontrolling Interests on the Company’s Consolidated Financial Statements”.
Schedule of Accrued Dividends and Distributions	The following tables summarize accrued dividends and distributions for the noted outstanding shares of common stock, preferred stock, and noncontrolling units as of December 31, 2015 and 2014 : December 31, 2015 2014 (in thousands) Dividends and Distributions payable to: Common stockholders $ 32,291 $ 30,191 Noncontrolling common unitholders of the Operating Partnership 618 631 RSU holders (1) 427 421 Total accrued dividends and distribution to common stockholders and noncontrolling unitholders 33,336 31,243 Preferred stockholders 1,656 1,656 Total accrued dividends and distributions $ 34,992 $ 32,899 ______________________ (1) The amount includes the value of the dividend equivalents that will be paid with additional RSUs (see Note 13 “Share-Based Compensation” for additional information)
Schedule of Outstanding Shares of Common Stock, Preferred Stock and Noncontrolling Units	December 31, 2015 2014 Outstanding Shares and Units: Common stock (1) 92,258,690 86,259,684 Noncontrolling common units 1,764,775 1,804,200 RSUs (2) 1,269,809 1,248,352 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 425,452 and 247,089 market measure-based RSUs because not all the necessary performance conditions have been met as of December 31, 2015 and 2014 , respectively.
Kilroy Realty, L.P. [Member]
Class of Stock [Line Items]
Schedule of Common Stock Sales Under the At-the-Market Offering	During the years ended December 31, 2015 , 2014 and 2013 , the Company utilized its at-the-market stock offering programs to issue shares of common stock (see Note 11 “Stockholders’ Equity of the Company” for additional information). The net offering proceeds and property acquired using net offering proceeds were contributed by the Company to the Operating Partnership in exchange for common units for the years ended December 31, 2015 , 2014 and 2013 are as follows: Year Ended December 31, 2015 2014 2013 (in millions, except share and per share data) Shares of common stock contributed by the Company 1,866,267 1,599,123 1,040,838 Common units exchanged for share of common stock by the Company 1,866,267 1,599,123 1,040,838 Aggregate gross proceeds $ 140.1 $ 104.7 $ 55.3 Aggregate net proceeds after underwriting discounts $ 138.2 $ 103.1 $ 54.4
Schedule of Accrued Dividends and Distributions	The following tables summarize accrued distributions for the noted common and preferred units as of December 31, 2015 and 2014 : December 31, 2015 December 31, 2014 (in thousands) Distributions payable to: General partner $ 32,291 $ 30,191 Common limited partners 618 631 RSU holders (1) 427 421 Total accrued distributions to common unitholders 33,336 31,243 Preferred unitholders 1,656 1,656 Total accrued distributions $ 34,992 $ 32,899 ______________________ (1) The amount includes the value of the dividend equivalents that will be paid with additional RSUs (see Note 13 “Share-Based Compensation” for additional information).
Schedule of Outstanding Shares of Common Stock, Preferred Stock and Noncontrolling Units	December 31, 2015 December 31, 2014 Outstanding Units: Common units held by the general partner 92,258,690 86,259,684 Common units held by the limited partners 1,764,775 1,804,200 RSUs (1) 1,269,809 1,248,352 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 425,452 and 247,089 market measure-based RSUs because not all the necessary performance conditions have been met as of December 31, 2015 and 2014 , respectively.

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Restricted Stock Units Valuation Assumptions	The 2015 Performance-Based RSUs and 2014 Performance-Based RSUs (collectively, the “Performance-Based RSUs”) are scheduled to cliff vest at the end of a three-year service period subject to the compensation committee's determination that the Company has achieved the pre-defined FFO per share goals (the “performance conditions”) and upon the average annual relative total stockholder return versus a comparator group of Companies that consist of Companies in the SNL US REIT Office Index (the “market conditions”) for the three-year periods detailed in the table below. The number of Performance-Based RSUs ultimately earned, and therefore the compensation costs for these awards, can fluctuate from the original number of RSUs granted based upon the levels of achievement for both the FFO per share and relative total stockholder return metrics. During the 2015 and 2014 performance periods, the estimate of the number of RSUs earned were evaluated quarterly based on our forecasted level of achievement of the FFO per share hurdle. As of December 31, 2015 , the FFO per share hurdle performance conditions were achieved at 1.5x target for both awards. As a result, the number of RSUs earned as of that date based on the FFO per share performance, excluding the impact of forfeitures, was as follows: 2015 Performance-Based RSU Grant 2014 Performance-Based RSU Grant Service vesting period December 31, 2017 December 31, 2016 Target RSUs granted 127,657 119,098 Estimated RSUs earned based on FFO per share performance condition 185,510 178,650 Date of fair valuation January 27, 2015 May 22, 2014 Each Performance-Based RSU represents the right to receive one share of our common stock in the future, subject to, and as modified by, the Company's level of achievement of the market condition. The fair value of the 2015 Performance-Based RSU Grant was $10.1 million at January 27, 2015 and the fair value of the 2014 Performance-Based RSU Grant was $7.7 million at May 22, 2014. The fair value for each grant was calculated using a Monte Carlo simulation pricing model based on the assumptions in the table below. The determination of the fair value of the Performance-Based RSU Grants take into consideration the likelihood of achievement of both the performance condition and the market condition discussed above. For the year ended December 31, 2015 , we recorded compensation expense for the 2015 Performance-Based RSU Grant based upon the $78.55 fair value per share at January 27, 2015 multiplied by the 185,510 RSUs estimated to be earned at December 31, 2015 (which is net of forfeitures). For the years ended December 31, 2015 and 2014 , we recorded compensation expense for the 2014 Performance-Based RSU Grant based upon the $65.03 fair value per share at May 22, 2014 multiplied by the 178,650 RSUs, excluding the impact of forfeitures, estimated to be earned at December 31, 2014 . Compensation expense for the Performance-Based RSUs is recorded on a straight-line basis over the respective three-year periods. The following table summarizes the assumptions utilized in the Monte Carlo simulation pricing models: 2015 Award Fair Value Assumptions 2014 Award Fair Value Assumptions Valuation date January 27, 2015 May 22, 2014 Fair value per share on valuation date $78.55 $65.03 Expected share price volatility 20.00% 24.00% Risk-free interest rate 0.92% 0.61% Remaining expected life 2.9 years 2.6 years The computation of expected volatility was based on a blend of the historical volatility of our shares of common stock over approximately five years, as this is expected to be most consistent with future volatility and equates to a time period twice as long as the approximate two and a half year remaining performance period of the RSUs and implied volatility data based on the observed pricing of six month publicly-traded options on shares of our common stock. The risk-free interest rate was based on the yield curve on zero-coupon U.S. Treasury STRIP securities in effect at January 27, 2015 and May 22, 2014.
Summary of Nonvested Restricted Stock	A summary of our nonvested restricted stock activity from January 1, 2015 through December 31, 2015 is presented below: Nonvested Weighted-Average Outstanding at January 1, 2015 85,061 $ 47.05 Vested (1) (24,264 ) 46.39 Outstanding as of December 31, 2015 60,797 $ 47.32 _______________ (1) The total shares vested includes 10,699 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 withholding obligations.
Summary of Nonvested and Vested Restricted Stock Activity	A summary of our nonvested and vested restricted stock activity for years ended December 31, 2015 , 2014 and 2013 is presented below: Shares Granted Shares Vested Years ended December 31, Nonvested Shares Issued Weighted-Average Grant Date Fair Value Per Share Vested Shares Total Fair Value at Vest Date (1) (in thousands) 2015 — $ — (24,264 ) $ 1,725 2014 213 51.35 (25,899 ) 1,323 2013 — — (47,291 ) 2,290 _______________ (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	On February 22, 2012, the Compensation Committee of the Company granted non-qualified stock options to certain key members of our senior management team, including our Executive Officers, to purchase an aggregate 1,550,000 shares of the Company’s common stock (the “February 2012” Grant) at an exercise price per share equal to $42.61 , the closing price of the Company’s common stock on the grant date. The options will vest ratably in annual installments over a five year period, subject to continued employment through the applicable vesting date. The term of each option is ten years from the date of the grant. Dividends will not be paid on vested or unvested options. The options were granted pursuant to the 2006 Plan. The fair value of each stock option granted is estimated on the date of grant using the Black-Scholes option pricing model based on the following assumptions for the February 2012 Grant. February 2012 Option Grant Fair value of options granted per share $9.20 Expected stock price volatility 33.00% Risk-free interest rate 1.35% Dividend yield 3.80% Expected life of option 6.5 years The computation of expected volatility is based on a blend of the historical volatility of our shares of common stock over a time period longer than the expected life of the option and implied volatility data based on the observed pricing of six-month publicly traded options on our shares of common stock. The risk-free interest rate is based on the yield curve on zero-coupon U.S. Treasury STRIP securities in effect at the grant date. The expected dividend yield is estimated by examining the average of the historical dividend yield levels over the expected life of the option and the current dividend yield as of the grant date. The expected life of the options is calculated as the average of the vesting term and the contractual term. During the year ended December 31, 2015 , 298,000 stock options vested with a total fair value of $2.7 million . During the year ended December 31, 2014 , 304,000 stock options vested with a total fair value of $2.8 million . During the year ended December 31, 2013 , 308,000 stock options vested with a total fair value of $2.8 million .
Summary of Stock Options Activity	A summary of our stock option activity related to the February 2012 grant from January 1, 2015 through December 31, 2015 is presented below: Number of Options Exercise Price Intrinsic Value (in millions) (1) Outstanding at December 31, 2014 1,008,000 $ 42.61 $ 26.7 Exercised (342,000 ) 42.61 10.3 Forfeited (56,000 ) 42.61 1.3 Outstanding at December 31, 2015 (2) 610,000 $ 42.61 $ 12.6 Options exercisable at December 31, 2015 (3) 70,000 $ 42.61 $ 1.4 _______________ (1) The intrinsic value of a stock option is the amount by which the fair value of the underlying stock exceeds the exercise price of an option. The fair value of the underlying stock was determined by using the closing share price on the NYSE on the date of exercise, forfeiture or respective period end. (2) As of December 31, 2015 , the average remaining life of stock options outstanding was 6.2 years (3) As of December 31, 2015 , the average remaining life of stock options exercisable was approximately 6.2 years.
Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of Restricted Stock Units Award Activity	A summary of our market-measure based RSU activity for years ended December 31, 2015 , 2014 and 2013 is presented below: RSUs Granted RSUs Vested Years ended December 31, Non-Vested RSUs Granted Weighted-Average Fair Value Per Share (1) Vested RSUs Total Vest-Date Fair Value (in thousands) 2015 191,483 $ 79.25 — $ — 2014 183,365 64.86 (16,338 ) 1,092 2013 9,542 44.55 (16,338 ) 811 _______________ (1) Represents the grant-date fair value for all awards, excluding the 2014 Performance-Based RSU Grant. As discussed above, the 2014 Performance-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014. A summary of our market-measure based RSU activity from January 1, 2015 through December 31, 2015 is presented below: Nonvested RSUs Vested RSUs Total RSUs Amount Weighted-Average (1) Outstanding at January 1, 2015 247,089 $ 58.77 — 247,089 Granted 191,483 79.25 — 191,483 Issuance of dividend equivalents (2) 6,347 70.47 — 6,347 Forfeited (19,467 ) 69.20 — (19,467 ) Outstanding as of December 31, 2015 (3) 425,452 $ 67.68 — 425,452 _______________ (1) Represents the grant-date fair value for all awards, excluding the 2014 Performance-Based RSU Grant. As discussed above, the 2014 Performance-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014. (2) Represents the issuance of dividend equivalents earned on the underlying RSUs. The dividend equivalents vest based on terms specified under the related RSU award agreement. (3) Outstanding RSUs as of December 31, 2015 represent the achievement of the maximum performance conditions and assumed target levels for the market conditions. The number of restricted stock units ultimately earned is subject to change based upon actual performance over the three-year vesting period. Dividend equivalents earned will vest along with the underlying award and are also subject to changes based on the number of RSUs ultimately earned for each underlying award.
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, 2015 through December 31, 2015 is presented below: Nonvested RSUs Vested RSUs Total RSUs Amount Weighted Average Fair Value Outstanding at January 1, 2015 340,997 $ 51.04 907,355 1,248,352 Granted 98,802 74.49 — 98,802 Vested (107,541 ) 49.52 107,541 — Settled (2) (78,887 ) (78,887 ) Issuance of dividend equivalents (3) 3,255 70.47 20,705 23,960 Forfeited (17,064 ) 53.50 — (17,064 ) Canceled (4) (5,354 ) (5,354 ) Outstanding as of December 31, 2015 318,449 $ 58.91 951,360 1,269,809 _______________ (1) Represents the grant-date fair value for all awards excluding the 2014 Time-Based RSU Grant. As discussed above, the 2014 Time-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014. (2) Represents vested RSUs that were settled in shares of the Company’s common stock. Total shares settled include 20,042 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. (3) Represents the issuance of dividend equivalents earned on the underlying RSUs. The dividend equivalents vest based on terms specified under the related RSU award agreement. (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 settlement or vesting of RSUs in accordance with the terms of the 2006 Plan. A summary of our time-based RSU activity for the years ended December 31, 2015 , 2014 and 2013 is presented below: RSUs Granted RSUs Vested Year ended December 31, Non-Vested RSUs Issued Weighted-Average Grant Date Fair Value Per Share Vested RSUs Total Vest-Date Fair Value (1) (in thousands) 2015 98,802 $ 74.49 (107,541 ) $ 7,528 2014 155,016 59.89 (116,447 ) 6,675 2013 173,758 49.45 (89,873 ) 4,495 _______________ (1) Total fair value of RSUs vested was calculated based on the quoted closing share price of the Company’s common stock on the NYSE on the day of vesting. Excludes the issuance of dividend equivalents earned on the underlying RSUs. The dividend equivalents vest based on terms specified under the related RSU award agreement.

Future Minimum Rent (Tables)

Future Minimum Rent (Tables)	12 Months Ended
	Dec. 31, 2015
Leases [Abstract]
Future contractual minimum rent under operating lease	Future contractual minimum rent under operating leases as of December 31, 2015 for future periods is summarized as follows: Year Ending (in thousands) 2016 $ 495,765 2017 482,650 2018 440,367 2019 379,939 2020 311,225 Thereafter 1,458,333 Total $ 3,568,279 The minimum commitment under our ground leases as of December 31, 2015 for five years and thereafter is as follows: Year Ending (in thousands) 2016 $ 3,144 2017 3,144 2018 3,144 2019 3,144 2020 3,144 Thereafter 151,738 Total (1)(2)(3)(4) $ 167,458 ________________________ (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, 2015 . (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, 2015 . (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, 2015 .

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
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 November 2093 701, 801 and 837 N. 34th Street, Seattle, WA (2) December 2041 Kilroy Airport Center Phases I, II, and III, Long Beach, CA July 2084 ____________________ (1) Reflects the contractual expiration date prior to the impact of any extension or purchase options held by the Company. (2) The Company has three 10 year and one 45 year extension options for this ground lease, which if exercised would extend the expiration date to December 2116.
Schedule Of Future Minimum Rental Payments For Ground Leases	Future contractual minimum rent under operating leases as of December 31, 2015 for future periods is summarized as follows: Year Ending (in thousands) 2016 $ 495,765 2017 482,650 2018 440,367 2019 379,939 2020 311,225 Thereafter 1,458,333 Total $ 3,568,279 The minimum commitment under our ground leases as of December 31, 2015 for five years and thereafter is as follows: Year Ending (in thousands) 2016 $ 3,144 2017 3,144 2018 3,144 2019 3,144 2020 3,144 Thereafter 151,738 Total (1)(2)(3)(4) $ 167,458 ________________________ (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, 2015 . (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, 2015 . (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, 2015 .

Fair Value Measurements and D58

Fair Value Measurements and Disclosures (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair value of the company's marketable securities	The only assets we record at fair value on our consolidated financial statements are the marketable securities related to our Deferred Compensation Plan (see Note 14 “Employee Benefit Plans” for additional information). The following table sets forth the fair value of our marketable securities as of December 31, 2015 and 2014 : Fair Value (Level 1) (1) 2015 2014 Description (in thousands) Marketable securities (2) $ 12,882 $ 11,971 _______________ (1) Fair value calculated using Level 1 inputs based on quoted prices in active markets for identical securities. (2) The marketable securities are held in a limited rabbi trust . We report the change in the fair value of the marketable securities at the end of each accounting period in interest income and other net investment gains in the consolidated statements of operations. We also adjust the related Deferred Compensation Plan liability to fair value at the end of each accounting period based on the performance of the benchmark funds selected by each participant, which results in a corresponding increase or decrease to compensation cost for the period.
Fair Value Adjustment Of Marketable Securities And Deferred Compensation Plan Liability [Table Text Block]	The following table sets forth the net (loss) gain on marketable securities recorded during the years ended December 31, 2015 , 2014 and 2013 : December 31, 2015 2014 2013 Description (in thousands) Net (loss) gain on marketable securities $ (269 ) $ 397 $ 1,489
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, 2015 and 2014 : December 31, 2015 2014 Carrying Value Fair Value Carrying Value Fair Value (in thousands) Liabilities Secured debt (1) $ 381,918 $ 391,611 $ 546,292 $ 559,483 Unsecured debt, net (2) 1,856,590 1,898,863 1,783,121 1,858,492 Unsecured line of credit (1) — — 140,000 145,051 _______________ (1) Fair value calculated using Level II inputs, which are based on model-derived valuations in which significant inputs and significant value drivers are observable in active markets. (2) Fair value calculated using Level II inputs as of December 31, 2015 , which are based on model-derived valuations in which significant inputs and significant value drivers are observable in active markets. Fair value calculated using primarily Level I inputs as of December 31, 2014 , which are based on quoted prices for identical instruments in active markets. The carrying value and fair value of the instruments valued using Level I inputs was $1,269.4 million and $1,322.2 million , respectively, as of December 31, 2014 . The carrying value and fair value of the instruments valued using Level II inputs was $513.7 million and $536.3 million , respectively, as of December 31, 2014 .

Discontinued Operations (Tables

Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2015
Discontinued Operations and Disposal Groups [Abstract]
Schedule of Properties Sold	The following table summarizes the properties sold during the years ended December 31, 2015 , 2014 and 2013 : Location Month of Disposition Number of Buildings Rentable Square Feet (unaudited) Sales Price (in millions) (1) 2015 Dispositions 15050 NE 36th Street, Redmond, WA April 1 122,103 $ 51.2 San Diego Properties - Tranches 1 and 2 (2) April/July 9 924,291 258.0 Total 2015 Dispositions 10 1,046,394 $ 309.2 2014 Dispositions (3) San Diego Properties, San Diego, CA (4) January 12 1,049,035 $ 294.7 9785 & 9791 Towne Centre Drive, San Diego, CA June 2 126,000 29.5 111 Pacifica, Irvine, CA September 1 67,496 15.1 4040 Civic Center Drive, San Rafael, CA October 1 130,237 34.9 999 Town & Country Road, Orange, CA December 1 98,551 25.3 Total 2014 Dispositions 17 1,471,319 $ 399.5 2013 Dispositions (3) 26541 Agoura Road, Calabasas, CA June 1 90,156 $ 14.7 8101 Kaiser Boulevard, Anaheim, CA October 1 59,790 9.6 4910 Directors Place, San Diego CA December 1 50,360 32.6 Total 2013 Dispositions 3 200,306 $ 56.9 __________________ (1) Represents gross sales price before the impact of broker commissions and closing costs. (2) The San Diego Properties - Tranche 1 includes the following properties: 10770 Wateridge Circle, 6200 Greenwich Drive, and 6220 Greenwich Drive. The San Diego Properties - Tranche 2 includes the following properties: 6260 Sequence Drive, 6290, Sequence Drive, 6310 Sequence Drive, 6340 Sequence Drive, 6350 Sequence Drive and 4921 Directors Place. (3) The Company adopted ASU 2014-08 effective January 1, 2015 (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As a result, results of operations for properties disposed of subsequent of January 1, 2015 are presented in continuing operations because they did not represent strategic shifts. Properties disposed of prior to January 1, 2015 are presented in discontinued operations. (4) The San Diego Properties included the following: 10020 Pacific Mesa Boulevard, 6055 Lusk Avenue, 5010 and 5005 Wateridge Vista Drive, 15435 and 15445 Innovation Drive, and 15051, 15073, 15231, 15253, 15333 and 15378 Avenue of Science. These properties were held for sale as of December 31, 2013.
Schedule of Real Estate Properties [Table Text Block]	Our stabilized portfolio of operating properties was comprised of the following office properties at December 31, 2015 : Number of Buildings Rentable Square Feet (unaudited) Number of Tenants Percentage Occupied (unaudited) Stabilized Office Properties 101 13,032,406 517 94.8 % As of December 31, 2015 , the following properties were excluded from our stabilized portfolio: Number of Properties/Projects Estimated Rentable Square Feet (unaudited) (1) Properties held for sale (2) 4 465,812 Development projects in “ lease-up" 1 73,000 Development projects under construction 5 1,910,000 _______________ (1) Estimated rentable square feet upon completion.
Revenue and Expense Components Comprising Income from Discontinued Operations	For the years ended December 31, 2014 and 2013 , discontinued operations included the results of all properties sold in 2014 and 2013 and classified as held for sale at December 31, 2013 , except for the operations deemed immaterial related to a June 2014 office property disposition. The following table summarizes the revenue and expense components that comprise income from discontinued operations for the years ended December 31, 2014 and 2013 : 2014 2013 (in thousands) Revenues: Rental income $ 7,206 $ 31,984 Tenant reimbursements 278 3,546 Other property income 13 5,178 Total revenues 7,497 40,708 Expenses: Property expenses 2,171 7,207 Real estate taxes 692 3,523 Depreciation and amortization 2,061 12,600 Total expenses 4,924 23,330 Income from discontinued operations before net gain on dispositions of discontinued operations 2,573 17,378 Net gain on dispositions of discontinued operations 121,922 12,252 Total income from discontinued operations $ 124,495 $ 29,630

Net Income Available to Commo60

Net Income Available to Common Stockholders Per Share of the Company (Tables)	12 Months Ended
	Dec. 31, 2015
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, 2015 , 2014 and 2013 : Year Ended December 31, 2015 2014 2013 (in thousands, except unit and per unit amounts) Numerator: Income from continuing operations $ 238,604 $ 59,313 $ 14,935 Income from continuing operations attributable to noncontrolling interests (4,523 ) (966 ) (36 ) Preferred dividends and distributions (13,250 ) (13,250 ) (13,250 ) Allocation to participating securities (1) (1,634 ) (1,699 ) (1,689 ) Numerator for basic and diluted income (loss) from continuing operations available to common stockholders 219,197 43,398 (40 ) Income from discontinued operations (2) — 124,495 29,630 Income from discontinued operations attributable to noncontrolling common units of the Operating Partnership (2) — (2,623 ) (649 ) Numerator for basic and diluted net income available to common stockholders $ 219,197 $ 165,270 $ 28,941 Denominator: Basic weighted average vested shares outstanding 89,854,096 83,090,235 77,343,853 Effect of dilutive securities – contingently issuable shares and stock options 541,679 1,877,485 — Diluted weighted average vested shares and common stock equivalents outstanding 90,395,775 84,967,720 77,343,853 Basic earnings per share: Income from continuing operations available to common stockholders per share $ 2.44 $ 0.52 $ 0.00 Income from discontinued operations per share of common stock (2) — 1.47 0.37 Net income available to common stockholders per share $ 2.44 $ 1.99 $ 0.37 Diluted earnings per share: Income from continuing operations available to common stockholders per share $ 2.42 $ 0.51 $ 0.00 Income from discontinued operations per share of common stock (2) — 1.44 0.37 Net income available to common stockholders per share $ 2.42 $ 1.95 $ 0.37 ________________________ (1) Participating securities include nonvested shares, certain time-based RSUs and vested market measure-based RSUs.

Net Income Available to Commo61

Net Income Available to Common Unitholders Per Unit of the Operating Partnership (Tables)	12 Months Ended
	Dec. 31, 2015
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, 2015 , 2014 and 2013 : Year Ended December 31, 2015 2014 2013 (in thousands, except unit and per unit amounts) Numerator: Income from continuing operations $ 238,604 $ 59,313 $ 14,935 Income from continuing operations attributable to noncontrolling interests (4,523 ) (966 ) (36 ) Preferred dividends and distributions (13,250 ) (13,250 ) (13,250 ) Allocation to participating securities (1) (1,634 ) (1,699 ) (1,689 ) Numerator for basic and diluted income (loss) from continuing operations available to common stockholders 219,197 43,398 (40 ) Income from discontinued operations (2) — 124,495 29,630 Income from discontinued operations attributable to noncontrolling common units of the Operating Partnership (2) — (2,623 ) (649 ) Numerator for basic and diluted net income available to common stockholders $ 219,197 $ 165,270 $ 28,941 Denominator: Basic weighted average vested shares outstanding 89,854,096 83,090,235 77,343,853 Effect of dilutive securities – contingently issuable shares and stock options 541,679 1,877,485 — Diluted weighted average vested shares and common stock equivalents outstanding 90,395,775 84,967,720 77,343,853 Basic earnings per share: Income from continuing operations available to common stockholders per share $ 2.44 $ 0.52 $ 0.00 Income from discontinued operations per share of common stock (2) — 1.47 0.37 Net income available to common stockholders per share $ 2.44 $ 1.99 $ 0.37 Diluted earnings per share: Income from continuing operations available to common stockholders per share $ 2.42 $ 0.51 $ 0.00 Income from discontinued operations per share of common stock (2) — 1.44 0.37 Net income available to common stockholders per share $ 2.42 $ 1.95 $ 0.37 ________________________ (1) Participating securities include nonvested shares, certain time-based RSUs and vested market measure-based RSUs.
Kilroy Realty, L.P. [Member]
Net Income Available To Common Unitholders [Line Items]
Net income available to common unitholders	The following table reconciles the numerator and denominator in computing the Operating Partnership’s basic and diluted per-unit computations for net income available to common unitholders for the years ended December 31, 2015 , 2014 and 2013 : Year Ended December 31, 2015 2014 2013 (in thousands, except unit and per unit amounts) Numerator: Income from continuing operations $ 238,604 $ 59,313 $ 14,935 Income from continuing operations attributable to noncontrolling interests in consolidated subsidiaries (467 ) (247 ) (225 ) Preferred distributions (13,250 ) (13,250 ) (13,250 ) Allocation to participating securities (1) (1,634 ) (1,699 ) (1,689 ) Numerator for basic and diluted income (loss) from continuing operations available to common unitholders 223,253 44,117 (229 ) Income from discontinued operations (2) — 124,495 29,630 (Income) loss from discontinued operations attributable to noncontrolling interests in consolidated subsidiaries (2) — (13 ) 1 Numerator for basic and diluted net income available to common unitholders $ 223,253 $ 168,599 $ 29,402 Denominator: Basic weighted average vested units outstanding 91,645,578 84,894,498 79,166,260 Effect of dilutive securities - contingently issuable shares and stock options 541,679 1,877,485 — Diluted weighted average vested units and common unit equivalents outstanding 92,187,257 86,771,983 79,166,260 Basic earnings per unit: Income from continuing operations available to common unitholders per unit $ 2.44 $ 0.52 $ 0.00 Income from discontinued operations per common unit (2) — 1.47 0.37 Net income available to common unitholders per unit $ 2.44 $ 1.99 $ 0.37 Diluted earnings per unit: Income from continuing operations available to common unitholders per unit $ 2.42 $ 0.51 $ 0.00 Income from discontinued operations per common unit (2) — 1.43 0.37 Net income available to common unitholders per unit $ 2.42 $ 1.94 $ 0.37 ________________________ (1) Participating securities include nonvested shares, certain time-based RSUs and vested market measure-based RSUs. (2) The Operating Partnership adopted ASU 2014-08 effective January 1, 2015 (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As a result, properties classified as held for sale and/or disposed of subsequent to January 1, 2015 that do not represent a strategic shift are no longer presented as discontinued operations.

Tax Treatment of Distributions

Tax Treatment of Distributions (Tables)	12 Months Ended
	Dec. 31, 2015
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, 2015 , 2014 and 2013 as follows: Year Ended December 31, Dividends 2015 2014 2013 Dividends declared per share of common stock 1.400 1.400 1.400 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 0.350 0.350 0.350 Dividends paid per share of common stock 1.400 1.400 1.400
Common Stock
Class of Stock [Line Items]
Reconciliation of Dividends Declared to Dividends Paid [Table Text Block]	The unaudited income tax treatment for the dividends to common stockholders reportable for the years ended December 31, 2015 , 2014 and 2013 as identified in the table above was as follows: Year Ended December 31, Shares of Common Stock 2015 2014 2013 Ordinary income $ 0.992 70.86 % $ 0.998 71.29 % $ 0.756 54.00 % Qualified dividend 0.002 0.13 0.002 0.14 0.003 0.21 Return of capital — — 0.398 28.43 0.620 44.29 Capital gains (1) 0.051 3.65 0.002 0.14 — — Unrecaptured section 1250 gains 0.355 25.36 — — 0.021 1.5 $ 1.400 100.00 % $ 1.400 100.00 % $ 1.400 100.00 % _________________ (1) Capital gains are comprised entirely of 20% rate gains.
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, 2015 , 2014 , and 2013 was as follows: Year Ended December 31, Preferred Shares 2015 2014 2013 Ordinary income $ 1.218 70.86 % $ 1.711 99.54 % $ 1.668 97.03 % Qualified dividend 0.002 0.13 0.003 0.17 0.006 0.35 Capital gains (1) 0.063 3.65 0.005 0.29 — — Unrecaptured section 1250 gains 0.436 25.36 — — 0.045 2.62 $ 1.719 100.00 % $ 1.719 100.00 % $ 1.719 100.00 % __________________ (1) Capital gains are comprised entirely of 20%
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, 2015 , 2014 , and 2013 was as follows: Year Ended December 31, Preferred Shares 2015 2014 2013 Ordinary income $ 1.129 70.86 % $ 1.587 99.56 % $ 1.546 96.99 % Qualified dividend 0.002 0.13 0.003 0.19 0.006 0.38 Capital gains (1) 0.059 3.65 0.004 0.25 — — Unrecaptured section 1250 gains 0.404 25.36 — — 0.042 2.63 $ 1.594 100.00 % $ 1.594 100.00 % $ 1.594 100.00 % __________________ (1) Capital gains are comprised entirely of 20% rate gains.

Quarterly Financial Informati63

Quarterly Financial Information of the Company (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Schedule of Summarized Quarterly Financial Data	Summarized quarterly financial data for the years ended December 31, 2015 and 2014 was as follows: 2015 Quarter Ended (1) March 31, June 30, September 30, December 31, (in thousands, except per share amounts) Revenues from continuing operations $ 146,082 $ 146,227 $ 141,553 $ 147,413 Income from continuing operations 44,002 58,590 106,704 29,308 Net income 44,002 58,590 106,704 29,308 Net income attributable to Kilroy Realty Corporation 43,187 57,500 104,759 28,635 Preferred dividends and distributions (3,313 ) (3,312 ) (3,313 ) (3,312 ) Net income available to common stockholders 39,874 54,188 101,446 25,323 Net income available to common stockholders per share – basic 0.45 0.61 1.10 0.27 Net income available to common stockholders per share – diluted 0.45 0.61 1.09 0.27 2014 Quarter Ended (1) March 31, June 30, September 30, December 31, (in thousands, except per share amounts) Revenues from continuing operations $ 123,758 $ 127,178 $ 129,024 $ 141,765 Income from continuing operations 10,874 15,854 13,168 19,417 Income from discontinued operations 91,058 15,289 6,135 12,013 Net income 101,932 31,143 19,303 31,430 Net income attributable to Kilroy Realty Corporation 99,845 30,540 18,982 30,852 Preferred dividends and distributions (3,313 ) (3,312 ) (3,313 ) (3,312 ) Net income available to common stockholders 96,532 27,228 15,669 27,540 Net income available to common stockholders per share – basic 1.17 0.33 0.18 0.32 Net income available to common stockholders per share – diluted 1.14 0.32 0.18 0.32 ____________________ (1) The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common stockholders per share does not equal the annual number reported on the consolidated statements of operations due to the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended December 31, 2015 and 2014 .

Quarterly Financial Informati64

Quarterly Financial Information of the Operating Partnership (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2015
Schedule of Summarized Quarterly Financial Data	Summarized quarterly financial data for the years ended December 31, 2015 and 2014 was as follows: 2015 Quarter Ended (1) March 31, June 30, September 30, December 31, (in thousands, except per share amounts) Revenues from continuing operations $ 146,082 $ 146,227 $ 141,553 $ 147,413 Income from continuing operations 44,002 58,590 106,704 29,308 Net income 44,002 58,590 106,704 29,308 Net income attributable to Kilroy Realty Corporation 43,187 57,500 104,759 28,635 Preferred dividends and distributions (3,313 ) (3,312 ) (3,313 ) (3,312 ) Net income available to common stockholders 39,874 54,188 101,446 25,323 Net income available to common stockholders per share – basic 0.45 0.61 1.10 0.27 Net income available to common stockholders per share – diluted 0.45 0.61 1.09 0.27 2014 Quarter Ended (1) March 31, June 30, September 30, December 31, (in thousands, except per share amounts) Revenues from continuing operations $ 123,758 $ 127,178 $ 129,024 $ 141,765 Income from continuing operations 10,874 15,854 13,168 19,417 Income from discontinued operations 91,058 15,289 6,135 12,013 Net income 101,932 31,143 19,303 31,430 Net income attributable to Kilroy Realty Corporation 99,845 30,540 18,982 30,852 Preferred dividends and distributions (3,313 ) (3,312 ) (3,313 ) (3,312 ) Net income available to common stockholders 96,532 27,228 15,669 27,540 Net income available to common stockholders per share – basic 1.17 0.33 0.18 0.32 Net income available to common stockholders per share – diluted 1.14 0.32 0.18 0.32 ____________________ (1) The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common stockholders per share does not equal the annual number reported on the consolidated statements of operations due to the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended December 31, 2015 and 2014 .
Kilroy Realty, L.P. [Member]
Schedule of Summarized Quarterly Financial Data	Summarized quarterly financial data for the years ended December 31, 2015 and 2014 was as follows: 2015 Quarter Ended (1) March 31, June 30, September 30, December 31, (in thousands, except per unit amounts) Revenues from continuing operations $ 146,082 $ 146,227 $ 141,553 $ 147,413 Income from continuing operations 44,002 58,590 106,704 29,308 Net income 44,002 58,590 106,704 29,308 Net income attributable to the Operating Partnership 43,927 58,518 106,640 29,052 Preferred distributions (3,313 ) (3,312 ) (3,313 ) (3,312 ) Net income available to common unitholders 40,614 55,206 103,327 25,740 Net income available to common unitholders per unit – basic 0.45 0.61 1.10 0.27 Net income available to common unitholders per unit – diluted 0.45 0.61 1.09 0.27 2014 Quarter Ended (1) March 31, June 30, September 30, December 31, (in thousands, except per unit amounts) Revenues from continuing operations $ 123,758 $ 127,178 $ 129,024 $ 141,765 Income from continuing operations 10,874 15,854 13,168 19,417 Income from discontinued operations 91,058 15,289 6,135 12,013 Net income 101,932 31,143 19,303 31,430 Net income attributable to the Operating Partnership 101,867 31,066 19,244 31,371 Preferred distributions (3,313 ) (3,312 ) (3,313 ) (3,312 ) Net income available to common unitholders 98,554 27,754 15,931 28,059 Net income available to common unitholders per unit – basic 1.17 0.33 0.18 0.32 Net income available to common unitholders per unit – diluted 1.14 0.32 0.18 0.31 ___________________ (1) The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common unitholders per unit does not equal the annual number reported on the consolidated statements of operations due to the impact of the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended December 31, 2015 and 2014 .

Organization and Ownership (Det

Organization and Ownership (Details)		Dec. 31, 2015	Dec. 31, 2015ft²	Dec. 31, 2015building	Dec. 31, 2015project	Dec. 31, 2015tenant	Dec. 31, 2015a	Dec. 31, 2014ft²property	Jan. 31, 2014ft²	Dec. 31, 2013ft²
Real Estate Properties [Line Items]
Number of real estate properties				2				5
Net Rentable Area			1,046,394					1,471,319	79,000	200,306
Lease Up Properties [Member]
Real Estate Properties [Line Items]
Number of real estate properties				2	1
Net Rentable Area	[1]		73,000
Stabilized Office Properties [Member]
Real Estate Properties [Line Items]
Number of real estate properties | building				101
Net Rentable Area			13,032,406
Number of Tenants | tenant						517
Percentage Occupied (unaudited)		94.80%
Development Properties [Member]
Real Estate Properties [Line Items]
Number of real estate properties | project	[1]				5
Net Rentable Area	[2],[3]		1,910,000
Columbia Square [Member]
Real Estate Properties [Line Items]
Net Rentable Area			108,517
Crossing 900 [Member]
Real Estate Properties [Line Items]
Net Rentable Area			339,987
Land [Member]
Real Estate Properties [Line Items]
Area of Land | a							99
4040 Civic [Member] [Member]
Real Estate Properties [Line Items]
Net Rentable Area								130,237
Carlsbad Oaks [Member]
Real Estate Properties [Line Items]
Number of real estate properties | project					1
Washington - Land Parcel [Domain]
Real Estate Properties [Line Items]
Number of real estate properties | building				1
[1]	Estimated rentable square feet upon completion.
[2]	Excludes acquisition-related costs and non-lease related accrued liabilities assumed. Includes assumed unpaid leasing commissions and tenant improvements.
[3]	The results of operations for the properties acquired during 2014 contributed $7.7 million and $2.8 million to revenues and net income from continuing operations, respectively, for the year ended December 31, 2014.

Organization and Ownership (D66

Organization and Ownership (Details Textuals) $ in Thousands		12 Months Ended
		Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)ft²property	Dec. 31, 2013USD ($)ft²	Dec. 31, 2015ft²	Dec. 31, 2015building	Dec. 31, 2015project	Dec. 31, 2015a	Jan. 31, 2014ft²
Real Estate Properties [Line Items]
Proceeds from Sale of Real Estate Held-for-investment | $		$ 319,639	$ 427,544	$ 21,178
Stabilized occupancy		95.00%
Number of real estate properties			5			2
Percentage of general partnership interest owned by the company in the Operating Partnership		98.10%	98.00%
Ownership interest of noncontrolling interest		1.90%	2.00%
Net Rentable Area			1,471,319	200,306	1,046,394				79,000
Kilroy Realty, L.P. [Member]
Real Estate Properties [Line Items]
Proceeds from Sale of Real Estate Held-for-investment | $		$ 319,639	$ 427,544	$ 21,178
Percentage of limited partnership interest owned by Operating Partnership		99.00%
Kilroy Realty Finance, Inc. [Member]
Real Estate Properties [Line Items]
Percentage of General partnership interest owned by wholly-owned subsidiary of the Company		1.00%
Washington
Real Estate Properties [Line Items]
Number of real estate properties | building						12
Lease Up Properties [Member]
Real Estate Properties [Line Items]
Number of real estate properties						2	1
Net Rentable Area	[1]				73,000
Development Properties [Member]
Real Estate Properties [Line Items]
Number of real estate properties | project	[1]						5
Net Rentable Area	[2],[3]				1,910,000
4040 Civic [Member] [Member]
Real Estate Properties [Line Items]
Net Rentable Area			130,237
Development Properties [Domain]
Real Estate Properties [Line Items]
Number of real estate properties | a								10
[1]	Estimated rentable square feet upon completion.
[2]	Excludes acquisition-related costs and non-lease related accrued liabilities assumed. Includes assumed unpaid leasing commissions and tenant improvements.
[3]	The results of operations for the properties acquired during 2014 contributed $7.7 million and $2.8 million to revenues and net income from continuing operations, respectively, for the year ended December 31, 2014.

Basis of Presentation and Sig67

Basis of Presentation and Significant Accounting Policies (Partially Owned Entities and Variable Interest Entities (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2014USD ($)property	Dec. 31, 2015USD ($)building	Dec. 31, 2014USD ($)property	Dec. 31, 2013USD ($)
Variable Interest Entity [Line Items]
Number of real estate properties	5	2	5
VIE Asset Amount	$ 219,600	$ 203,300	$ 219,600
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	23,400	28,800	23,400
Noncontrolling interest in consolidated subsidiary	5,862	6,520	5,862
Proceeds from Sale of Real Estate Held-for-investment		319,639	427,544	$ 21,178
Real Estate Investment [Member]
Variable Interest Entity [Line Items]
VIE Asset Amount	211,800	$ 187,300	211,800
Washington
Variable Interest Entity [Line Items]
Number of real estate properties | building		12
Restricted cash [Member]
Variable Interest Entity [Line Items]
Proceeds from Sale of Real Estate Held-for-investment	$ 59,200		59,200
Undeveloped Land [Member]
Variable Interest Entity [Line Items]
Business acquisition costs capitalized		$ 1,100	$ 4,500	$ 2,300

Basis of Presentation and Sig68

Basis of Presentation and Significant Accounting Policies (Acquisitions and Building Properties) (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2012USD ($)	Dec. 31, 2015USD ($)building	Dec. 31, 2014USD ($)property	Dec. 31, 2013USD ($)
Property, Plant and Equipment [Line Items]
Disclosure of Long Lived Assets Held-for-sale [Table Text Block]		As of December 31, 2015 , the properties listed below were classified as held for sale. We did not have any properties classified as held for sale as of December 31, 2014 . Properties Submarket Property Type Number of Buildings Rentable Square Feet (unaudited) Torrey Santa Fe Properties (1)(2) Del Mar Office 4 465,812 __________________ (1) The Torrey Santa Fe Properties include the following properties: 7525 Torrey Santa Fe, 7535 Torrey Santa Fe, 7545 Torrey Santa Fe, and 7555 Torrey Santa Fe. (2) In January 2016, the Company completed the sale of these properties for a total sales price of $262.3 million . The major classes of assets and liabilities of the properties held for sale as of December 31, 2015 were as follows: Real estate assets and other assets held for sale (in thousands) Land and improvements $ 10,534 Buildings and improvements 144,716 Undeveloped land and construction in progress 4,824 Total real estate held for sale 160,074 Accumulated depreciation and amortization (46,191 ) Total real estate held for sale, net 113,883 Deferred rent receivables, net 2,500 Deferred leasing costs and acquisition-related intangible assets, net 1,115 Prepaid expenses and other assets, net 168 Real estate and other assets held for sale, net $ 117,666 Liabilities and deferred revenue of real estate assets held for sale Secured debt $ 561 Accounts payable, accrued expenses and other liabilities 2,497 Deferred revenue and acquisition-related intangible liabilities, net 2,899 Rents received in advance and tenant security deposits 1,586 Liabilities and deferred revenue of real estate assets held for sale $ 7,543 As of December 31, 2015 and 2014 , the following land parcels were classified as held for sale: Properties Submarket Gross Site Acreage (unaudited) Sales Price 2015 Held for Sale Carlsbad Oaks - Lot 7 (1)(2) Carlsbad 7.6 $ 4.5 2014 Held for Sale 17150 Von Karman Irvine 8.5 $ 26.0 __________________ (1) During the year ended December 31, 2015 , the Company recognized a loss relating to selling costs of approximately $0.2 million . (2) In January 2016, the Company completed the sale of the Carlsbad Oaks - Lot 7 land parcel.
Depreciation of real estate	$ 145,325	$ 159,524		$ 153,841
Number of real estate properties		2	5
Undeveloped Land [Member]
Property, Plant and Equipment [Line Items]
Business acquisition costs capitalized		$ 1,100	$ 4,500	$ 2,300
Building and Building Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property depreciable lives		25 years
Building and Building Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property depreciable lives		40 years
Leasehold Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property depreciable lives		1 year
Leasehold Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property depreciable lives		20 years
Lease Agreements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Deferred lease costs amortization period		1 year
Lease Agreements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Deferred lease costs amortization period		20 years

Basis of Presentation and Sig69

Basis of Presentation and Significant Accounting Policies (Deferred Finance Costs and Debt) (Details) - USD ($) $ in Millions	1 Months Ended		12 Months Ended
	Aug. 31, 2012	Mar. 31, 2012	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2015
Debt Instrument [Line Items]
Amortization of Financing Costs			$ 12.3	$ 12.2
Debt premium						$ 6.2
Secured Debt [Member]
Debt Instrument [Line Items]
Debt premium			6.2
Unamortized discount (premium), Net				(10.3)
Unsecured Debt [Member]
Debt Instrument [Line Items]
Unamortized discount (premium), Net			$ (7.4)	$ 5.9
Series G Cumulative Redeemable Preferred Stock
Debt Instrument [Line Items]
Preferred Units, Issued					4,000,000
Preferred stock dividend rate (percentage)		6.875%	6.875%		6.875%
Series H Cumulative Redeemable Preferred Stock
Debt Instrument [Line Items]
Preferred Units, Issued					4,000,000
Preferred stock dividend rate (percentage)	6.375%		6.375%		6.375%
Series G Cumulative Redeemable Preferred Unit [Member] | Series G Cumulative Redeemable Preferred Stock
Debt Instrument [Line Items]
Preferred Units, Issued			4,000,000
Series H Cumulative Redeemable Preferred Unit [Member] | Series H Cumulative Redeemable Preferred Stock
Debt Instrument [Line Items]
Preferred Units, Issued						4,000,000
Minimum [Member] | Lease Agreements [Member]
Debt Instrument [Line Items]
Finite-Lived Intangible Asset, Useful Life			1 year
Maximum [Member] | Lease Agreements [Member]
Debt Instrument [Line Items]
Finite-Lived Intangible Asset, Useful Life			20 years

Basis of Presentation and Sig70

Basis of Presentation and Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2015USD ($)buildingproject	Dec. 31, 2014USD ($)buildingproperty	Dec. 31, 2013USD ($)building	Dec. 31, 2011
Basis of presentation and significant accounting policies [Line Items]
Proceeds from Sale of Real Estate Held-for-investment	$ 319,639,000	$ 427,544,000	$ 21,178,000
Number of Real Estate Properties Sold | building	10	17	3
Amortization of Financing Costs	$ 12,300,000	$ 12,200,000
Number of real estate properties	2	5
REIT annual taxable income distribution requirement percentage	90.00%			90.00%
Company annual taxable income distribution	100.00%
Concentration Risk of Significant Tenants, Percentage	36.90%
Cash, FDIC Insured Amount	$ 250,000
Kilroy Realty Finance, Inc. [Member]
Basis of presentation and significant accounting policies [Line Items]
Percentage of General partnership interest owned by wholly-owned subsidiary of the Company	1.00%
Torrey Santa Fe Properties [Member]
Basis of presentation and significant accounting policies [Line Items]
Number of real estate properties | project	4
Carlsbad Oaks [Member]
Basis of presentation and significant accounting policies [Line Items]
Number of real estate properties | project	1

Acquisitions (Details)

Acquisitions (Details) $ in Thousands		Dec. 19, 2014	Oct. 23, 2014	Dec. 31, 2015USD ($)ft²building	Dec. 31, 2014USD ($)ft²buildingproperty	Jun. 30, 2014USD ($)	Jan. 31, 2014ft²	Dec. 31, 2013ft²
Business Acquisition [Line Items]
Number of buildings				2	5
Net Rentable Area | ft²				1,046,394	1,471,319		79,000	200,306
Liabilities
Accounts Payable				$ 246,323	$ 225,830
Dexter Project [Member] [Member]
Business Acquisition [Line Items]
Accrued Liabilities and Acquisition Costs				2,400
Liabilities
Payments to Acquire Land	[1],[2]			49,500
Hooper Project [Member] [Member] [Domain]
Business Acquisition [Line Items]
Accrued Liabilities and Acquisition Costs				4,100
Liabilities
Payments to Acquire Land	[2],[3]			78,000
2015 Total Acquisitions [Member]
Liabilities
Payments to Acquire Land	[2]			127,500
The Exchange on 16th [Member]
Business Acquisition [Line Items]
Date of Acquisition	[4]				May 23, 2014
The Exchange on 16 [Member]
Liabilities
Payments to Acquire Land	[2],[4]			95,000
Bohannon Drive Menlo Park, CA [Member]
Business Acquisition [Line Items]
Date of Acquisition	[5]	Dec. 19, 2014	Oct. 23, 2014
Liabilities
Payments to Acquire Land	[2],[5]			$ 71,000
Bohannon Drive Menlo Park, CA [Member]
Business Acquisition [Line Items]
Date of Acquisition	[3]			Jul. 7, 2015
Kilroy Mission Bay [Member]
Liabilities
Accounts Payable						$ 2,300
SFFGA [Member]
Liabilities
Accounts Payable					$ 13,400
Office Properties Acquisitions [Member]
Business Acquisition [Line Items]
Number of buildings | building					5
Net Rentable Area | ft²	[6]				407,587
Purchase Price	[6],[7]				$ 206,600
Assets
Land and improvements	[8]				81,430
Buildings and improvements	[8],[9]				114,876
Deferred leasing costs and acquisition-related intangible assets	[8],[10]				17,259
Total assets	[8]				213,565
Liabilities
Deferred revenue and acquisition-related intangible liabilities	[8],[11]				6,990
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable	[8]				2,029
Total liabilities assumed	[8]				9,019
Net assets and liabilities acquired	[8],[12]				$ 204,546
320 & 321 Westlake Terry, Seattle WA [Member]
Business Acquisition [Line Items]
Date of Acquisition					Mar. 13, 2014
Number of buildings | building					1
Net Rentable Area | ft²					140,605
Occupancy as of December 31, 2013				100.00%
Purchase Price	[7]				$ 106,100
12780 and 12790 El Camino Real, Sandiego, CA [Member]
Business Acquisition [Line Items]
Number of buildings | building	[13]				4
Net Rentable Area | ft²	[13]				266,982
Occupancy as of December 31, 2013				100.00%
Purchase Price	[7],[13]				$ 100,500
4100 - 4700 Bohannon Dr, Menlo Park, CA [Member]
Business Acquisition [Line Items]
Date of Acquisition	[1]			Feb. 13, 2015
701 and 801 N. 34th St, Seattle, WA [Member]
Business Acquisition [Line Items]
Date of Acquisition	[13]				Nov. 5, 2014
Total 2014 Acquisitions [Member]
Liabilities
Payments to Acquire Land	[2]			$ 166,000
Purchase Price Of Business Combination [Member] | Assets, Total [Member] | Office Properties Acquisitions [Member]
Business Acquisition [Line Items]
Purchase price of aggregated acquisitions as percentage of Company's assets (percentage					10.00%
Purchase Price Of Business Combination [Member] | Assets, Total [Member] | 320 & 321 Westlake Terry, Seattle WA [Member]
Business Acquisition [Line Items]
Purchase price of individual acquisition as percentage of Company's assets (percentage)					5.00%
[1]	Acquisition comprised of four adjacent parcels in the South Lake Union submarket of Seattle, Washington located at 330 Dexter Avenue North, 333 Dexter Avenue North, 401 Dexter Avenue North, and 400 Aurora Avenue North. In connection with this acquisition, we also assumed $2.4 million in accrued liabilities and acquisition costs that are not included in the purchase price above.
[2]	See Note 16 “Commitments and Contingencies” for additional information on certain accrued liabilities for these acquisitions.
[3]	In connection with this acquisition, we assumed $4.1 million in accrued liabilities and acquisition costs that are not included in the purchase price above.
[4]	In connection with this acquisition, we assumed $2.3 million in accrued liabilities that are not included in the purchase price above.
[5]	In the fourth quarter of 2014, the Company closed on two adjacent land sites for a total purchase price of $71.0 million and approximately $13.4 million in transaction costs and accrued liabilities, net. The acquisitions, which were completed through the execution of two merger transactions, were partially funded through the issuance of 351,476 shares of the Company’s common stock valued at approximately $21.6 million and the remainder was paid in cash.
[6]	The results of operations for the properties acquired during 2014 contributed $7.7 million and $2.8 million to revenues and net income from continuing operations, respectively, for the year ended December 31, 2014.
[7]	Excludes acquisition-related costs and non-lease related accrued liabilities assumed. Includes assumed unpaid leasing commissions and tenant improvements.
[8]	purchase price of the two acquisitions completed during the year ended December 31, 2014 were individually less than 5% and in aggregate less than 10% of the Company’s total assets as of December 31, 2014.(2)
[9]	esents buildings, building improvements and tenant improvements.
[10]	Represents in-place leases (approximately $12.3 million with a weighted average amortization period of 7.0 years) and leasing commissions (approximately $4.9 million with a weighted average amortization period of 7.0 years).
[11]	Represents below-market leases (approximately $7.0 million with a weighted average amortization period of 6.1 years).
[12]	Reflects the purchase price net of assumed secured debt and other lease-related obligations.
[13]	As of December 31, 2014, these properties, together the “Chesapeake Commons” project, were temporarily being held in a separate VIE to facilitate potential Section 1031 Exchanges. During January 2015, the Company closed out the Section 1031 Exchange related to this VIE.

Acquisitions (Details Textuals)

Acquisitions (Details Textuals) $ in Thousands		1 Months Ended	12 Months Ended
		Oct. 23, 2014USD ($)shares	Dec. 31, 2015USD ($)building	Dec. 31, 2014USD ($)buildingproperty	Dec. 31, 2013USD ($)	Jul. 01, 2015shares	Jun. 30, 2015USD ($)	Jun. 30, 2014USD ($)
Business Acquisition [Line Items]
Number of buildings			2	5
Outstanding principal balance				$ 172,500
Initial premium on outstanding amount of secured debt							$ 6,200
Revenues			$ 7,700
Net income			2,800
Below-market leases acquired				$ 7,000
Weighted average amortization period of below-market leases				6 years 1 month
Accounts Payable and Accrued Liabilities			246,323	$ 225,830
Common stock, shares issued | shares						3,773,766
purchase price, value of shares issued to acquire land			0	$ 21,631	$ 0
Kilroy Mission Bay [Member]
Business Acquisition [Line Items]
Accounts Payable and Accrued Liabilities								$ 2,300
Office Properties Acquisitions [Member]
Business Acquisition [Line Items]
Number of buildings | building				5
Purchase price	[1],[2]			$ 206,600
In-place leases, above-market leases, and leasing commissions acquired	[3],[4]			17,259
Deferred revenue and acquisition-related intangible liabilities	[4],[5]			$ 6,990
320 & 321 Westlake Terry, Seattle WA [Member]
Business Acquisition [Line Items]
Number of buildings | building				1
Purchase price	[1]			$ 106,100
12780 and 12790 El Camino Real, Sandiego, CA [Member]
Business Acquisition [Line Items]
Number of buildings | building	[6]			4
Purchase price	[1],[6]			$ 100,500
SFFGA [Member]
Business Acquisition [Line Items]
Accounts Payable and Accrued Liabilities				13,400
Common stock, shares issued | shares		351,476
purchase price, value of shares issued to acquire land		$ 21,600
Secured Debt [Member]
Business Acquisition [Line Items]
Initial premium on outstanding amount of secured debt			6,200
In-Place Leases [Member]
Business Acquisition [Line Items]
In-place leases, above-market leases, and leasing commissions acquired				$ 12,300
Weighted average amortization period of above-market leases in years				7 years
Deferred Leasing Costs [Member]
Business Acquisition [Line Items]
In-place leases, above-market leases, and leasing commissions acquired				$ 4,900
Weighted average amortization period of above-market leases in years				7 years
Kilroy Realty, L.P. [Member]
Business Acquisition [Line Items]
Accounts Payable and Accrued Liabilities			246,323	$ 225,830
Kilroy Realty, L.P. [Member] | 6.05% Mortgage Payable Due June 1, 2019 [Member] | Secured Debt [Member]
Business Acquisition [Line Items]
Initial premium on outstanding amount of secured debt			$ 6,200	$ 8,000
[1]	Excludes acquisition-related costs and non-lease related accrued liabilities assumed. Includes assumed unpaid leasing commissions and tenant improvements.
[2]	The results of operations for the properties acquired during 2014 contributed $7.7 million and $2.8 million to revenues and net income from continuing operations, respectively, for the year ended December 31, 2014.
[3]	Represents in-place leases (approximately $12.3 million with a weighted average amortization period of 7.0 years) and leasing commissions (approximately $4.9 million with a weighted average amortization period of 7.0 years).
[4]	purchase price of the two acquisitions completed during the year ended December 31, 2014 were individually less than 5% and in aggregate less than 10% of the Company’s total assets as of December 31, 2014.(2)
[5]	Represents below-market leases (approximately $7.0 million with a weighted average amortization period of 6.1 years).
[6]	As of December 31, 2014, these properties, together the “Chesapeake Commons” project, were temporarily being held in a separate VIE to facilitate potential Section 1031 Exchanges. During January 2015, the Company closed out the Section 1031 Exchange related to this VIE.

Dispositions and Real Estate 73

Dispositions and Real Estate Assets Held for Sale (Details) $ in Thousands		Jan. 21, 2016USD ($)	Jan. 13, 2016USD ($)	Dec. 31, 2014USD ($)ft²aproperty	Dec. 31, 2015USD ($)ft²abuildingproject	Dec. 31, 2014USD ($)ft²abuildingproperty	Dec. 31, 2013USD ($)ft²building	Jan. 31, 2014ft²
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (Loss) on Disposition of Property Plant Equipment					$ 109,950	$ 0	$ 0
Number of real estate properties				5	2	5
Number of Real Estate Properties Sold | building					10	17	3
Net Rentable Area | ft²				1,471,319	1,046,394	1,471,319	200,306	79,000
Dispositions Sales Price	[1]				$ 309,200	$ 399,500	$ 56,900
Proceeds from Sale of Real Estate Held-for-investment					$ 319,639	$ 427,544	$ 21,178
15050 N.E. 36th St., Redmond, WA [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Real Estate Properties Sold | building					1
Net Rentable Area | ft²					122,103
Dispositions Sales Price	[1]				$ 51,200
Carlsbad Oaks - Lot 7 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (Loss) on Sale of Properties					$ (200)
Area of Land | a	[2]				7.6
Dispositions Sales Price	[2],[3]				$ 4,500
Von Karman, Irvine, California [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (Loss) on Sale of Properties					17,300
Area of Land | a	[2]			8.5		8.5
Dispositions Sales Price	[2],[3]				$ 26,000	$ 26,000
Torrey Santa Fe Properties [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties | project					4
Net Rentable Area | ft²	[4]				465,812
San Diego Properties Tranches 1 & 2, San Diego, CA [Member] [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Real Estate Properties Sold | building					9
Net Rentable Area | ft²					924,291
Dispositions Sales Price	[1],[5]				$ 258,000
San Diego Properties, San Diego, CA [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Real Estate Properties Sold | building	[6]					12
Net Rentable Area | ft²	[6]			1,049,035		1,049,035
Dispositions Sales Price	[1]					$ 294,700
9785&9791 Towne Centre Drive, San Diego CA [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Real Estate Properties Sold | building						2
Net Rentable Area | ft²				126,000		126,000
Dispositions Sales Price	[1]					$ 29,500
111 Pacifica [Member] [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Real Estate Properties Sold | building						1
Net Rentable Area | ft²				67,496		67,496
Dispositions Sales Price	[1]					$ 15,100
4040 Civic [Member] [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Real Estate Properties Sold | building						1
Net Rentable Area | ft²				130,237		130,237
Dispositions Sales Price	[1]					$ 34,900
999 Town &Country[Member] [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Real Estate Properties Sold | building						1
Net Rentable Area | ft²				98,551		98,551
Dispositions Sales Price	[1]					$ 25,300
Agoura Road, 26541, Calabasas, CA [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Real Estate Properties Sold | building							1
Agoura Road Calabasas California [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Rentable Area | ft²							90,156
Dispositions Sales Price	[1]						$ 14,700
Kaiser Boulevard, Anaheim, California [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Real Estate Properties Sold | building							1
Net Rentable Area | ft²							59,790
Dispositions Sales Price	[1]						$ 9,600
Directors Place, Sorrento Mesa, California One [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Real Estate Properties Sold | building							1
Net Rentable Area | ft²							50,360
Dispositions Sales Price	[1]						$ 32,600
10850 Via Frontera San Diego CA [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (Loss) on Disposition of Property Plant Equipment						$ 3,490
Area of Land | a	[7]			21		21
Dispositions Sales Price	[3],[7]					$ 33,100
Restricted cash [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Sale of Real Estate Held-for-investment				$ 59,200		$ 59,200
Land and Land Improvements [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real Estate Held-for-sale					10,534
Building and Building Improvements [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real Estate Held-for-sale					144,716
Undeveloped Land [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real Estate Held-for-sale					4,824
Total real estate held for sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real Estate Held-for-sale					160,074
Accumulated depreciation and amortization [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real Estate Held-for-sale					(46,191)
Total real estate held for sale, net [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real Estate Held-for-sale					113,883
Deferred rent receivables, net [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real Estate Held-for-sale					2,500
Deferred Leasing Costs [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real Estate Held-for-sale					1,115
Prepaid Expenses and Other Current Assets [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real Estate Held-for-sale					168
Assets Held-for-sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real Estate Held-for-sale					117,666
Secured Debt [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real Estate Held-for-sale					561
Accounts Payable and Accrued Liabilities [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real Estate Held-for-sale					2,497
Deferred Lease Revenue [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real Estate Held-for-sale					2,899
Rents received in advance and tenant security deposits [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real Estate Held-for-sale					1,586
Liabilities and deferred revenue of real estate assets held for sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real Estate Held-for-sale					$ 7,543
Subsequent Event [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Dispositions Sales Price		$ 262,300	$ 4,500
[1]	Represents gross sales price before the impact of broker commissions and closing costs.
[2]	This transaction resulted in a gain on sale of $17.3 million.
[3]	Represents gross sales price before the impact of commissions and closing costs.
[4]	Estimated rentable square feet upon completion.
[5]	The San Diego Properties - Tranche 1 includes the following properties: 10770 Wateridge Circle, 6200 Greenwich Drive, and 6220 Greenwich Drive. The San Diego Properties - Tranche 2 includes the following properties: 6260 Sequence Drive, 6290, Sequence Drive, 6310 Sequence Drive, 6340 Sequence Drive, 6350 Sequence Drive and 4921 Directors Place.
[6]	The San Diego Properties included the following: 10020 Pacific Mesa Boulevard, 6055 Lusk Avenue, 5010 and 5005 Wateridge Vista Drive, 15435 and 15445 Innovation Drive, and 15051, 15073, 15231, 15253, 15333 and 15378 Avenue of Science. These properties were held for sale as of December 31, 2013.
[7]	This transaction resulted in a gain on sale of $3.5 million.

Deferred Leasing Costs and Ac74

Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, net (Details) - USD ($) $ in Thousands		Dec. 31, 2015		Dec. 31, 2014
Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, Net
Total deferred leasing costs and acquisition-related intangible assets, net		$ 176,683		$ 201,926
Acquisition-related Intangible Liabilities, Net [Abstract]
Total acquisitions-related intangible liabilities, net	[1]	32,324		43,427
Deferred Leasing Costs [Member]
Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, Net
Finite-lived intangible assets/liabilities, gross		205,888		216,102
Accumulated amortization		(72,745)		(74,904)
Finite-lived intangible assets/liabilities, net		133,143		141,198
Above Market Operating Leases [Member]
Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, Net
Finite-lived intangible assets/liabilities, gross		10,989		20,734
Accumulated amortization		(6,739)		(13,952)
Finite-lived intangible assets/liabilities, net		4,250	[2]	6,782
Leases, Acquired-in-Place [Member]
Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, Net
Finite-lived intangible assets/liabilities, gross		72,639		97,250
Accumulated amortization		(33,810)		(43,773)
Finite-lived intangible assets/liabilities, net		38,829		53,477
Below-Market Ground Lease Obligation [Member]
Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, Net
Finite-lived intangible assets/liabilities, gross		490		490
Accumulated amortization		(29)		(21)
Finite-lived intangible assets/liabilities, net		461	[3]	469
Below Market Operating Lease [Member]
Acquisition-related Intangible Liabilities, Net [Abstract]
Acquisition-related intangible liabilities, gross		53,502		68,051
Accumulated amortization		(27,074)		(30,620)
Acquisition-related intangible liabilities, net		26,428	[4]	37,431
Above-Market Ground Lease Obligation [Member]
Acquisition-related Intangible Liabilities, Net [Abstract]
Acquisition-related intangible liabilities, gross		6,320		6,320
Accumulated amortization		(424)		(324)
Acquisition-related intangible liabilities, net		$ 5,896	[5]	$ 5,996
[1]	See Note 2 “Basis of Presentation and Significant Accounting Policies” and Note 5 “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 Ac75

Deferred Leasing Costs and Acquisition-related Intangible Assets and Liabilities, net (Details 1) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Amortization for the period related to deferred leasing costs and acquisition-related intangibles
Amortization for the period related to deferred leasing costs and acquisition-related intangibles		$ 33,947		$ 41,155	$ 47,395
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	[1]	27,866		27,555	25,902
Estimated annual amortization related to acquisition-related intangibles
2,015		25,637
2,016		22,790
Finite-Lived Intangible Assets, Amortization Expense, Year Three		19,580
2,018		15,649
Finite-Lived Intangible Assets, Amortization Expense, Year Five		11,720
Thereafter		37,767
Finite-lived intangible assets/liabilities, net		133,143		141,198
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	[2]	2,532		5,303	5,664
Estimated annual amortization related to acquisition-related intangibles
2,015	[3]	1,501
2,016	[3]	1,241
Finite-Lived Intangible Assets, Amortization Expense, Year Three	[3]	831
2,018	[3]	643
Finite-Lived Intangible Assets, Amortization Expense, Year Five	[3]	16
Thereafter	[3]	18
Finite-lived intangible assets/liabilities, net		4,250	[3]	6,782
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	[1]	14,622		21,628	29,363
Estimated annual amortization related to acquisition-related intangibles
2,015		10,542
2,016		9,108
Finite-Lived Intangible Assets, Amortization Expense, Year Three		6,296
2,018		4,637
Finite-Lived Intangible Assets, Amortization Expense, Year Five		2,789
Thereafter		5,457
Finite-lived intangible assets/liabilities, net		38,829		53,477
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	[4]	8		8	8
Estimated annual amortization related to acquisition-related intangibles
2,015	[5]	8
2,016	[5]	8
Finite-Lived Intangible Assets, Amortization Expense, Year Three	[5]	8
2,018	[5]	8
Finite-Lived Intangible Assets, Amortization Expense, Year Five	[5]	8
Thereafter	[5]	421
Finite-lived intangible assets/liabilities, net		461	[5]	469
Below Market Operating Lease [Member]
Amortization for the period related to deferred leasing costs and acquisition-related intangibles
Amortization Of Intangible Liabilities	[6]	(10,980)		(13,238)	(13,441)
Estimated annual amortization related to acquisition-related intangibles
2,015	[7]	(7,664)
2,016	[7]	(7,017)
FiniteLivedIntangibleLiabilitiesAmortizationExpenseYearThree	[7]	5,713
2,018	[7]	(3,574)
FiniteLivedIntangibleLiabilitiesAmortizationExpenseYearFive	[7]	(2,035)
Thereafter	[7]	(425)
Total		(26,428)	[7]	(37,431)
Above-Market Ground Lease Obligation [Member]
Amortization for the period related to deferred leasing costs and acquisition-related intangibles
Amortization Of Intangible Liabilities	[8]	(101)		(101)	$ (101)
Estimated annual amortization related to acquisition-related intangibles
2,015	[9]	(101)
2,016	[9]	(101)
FiniteLivedIntangibleLiabilitiesAmortizationExpenseYearThree	[9]	101
2,018	[9]	(101)
FiniteLivedIntangibleLiabilitiesAmortizationExpenseYearFive	[9]	(101)
Thereafter	[9]	(5,391)
Total		$ (5,896)	[9]	$ (5,996)
[1]	The amortization of deferred leasing costs and in-place leases is recorded to depreciation and amortization expense and the amortization of lease incentives is recorded as a reduction to rental income in the consolidated statements of operations for the periods presented.
[2]	The amortization of above-market operating leases is recorded as a decrease to rental income in the consolidated statements of operations for the periods presented
[3]	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 ($) $ in Thousands	Dec. 31, 2015		Dec. 31, 2014
Current Receivables, net
Current receivables	$ 13,233	[1]	$ 9,228
Allowance for uncollectible tenant receivables	(2,080)	[1]	(1,999)
Current receivables, net	11,153	[1]	7,229
Deferred Rent Receivables, net
Deferred rent receivables	191,586		158,405
Allowance for deferred rent receivables	(1,882)		(1,989)
Deferred rent receivables, net	$ 189,704		$ 156,416
[1]	Excludes current receivables, net related to real estate held for sale.

Secured and Unsecured Debt of77

Secured and Unsecured Debt of the Company Secured and Unsecured Debt of the Company (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Unsecured Debt		$ 1,856,590		$ 1,783,121
Long-term Debt		2,238,508
Secured debt (Notes 3, 6, 7 and 16)		$ 381,918		546,292
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
Unsecured Debt [Member]
Debt Instrument [Line Items]
Long-term Debt		1,900,000
Unsecured Debt [Member] | Thirty Nine Million Unsecured Term Loan Due July 2019 [Member]
Debt Instrument [Line Items]
Unsecured Debt		$ 39,000
Unsecured Senior Notes [Member] | 6.625% Unsecured Senior Notes due June 1, 2020 [Member]
Debt Instrument [Line Items]
Stated interest rate		6.625%
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] | 3.800% Unsecured Senior Notes [Member]
Debt Instrument [Line Items]
Stated interest rate	[1]	3.80%
Unsecured Senior Notes [Member] | Four Point Three Eight Percent Unsecured Senior Notes Due October First Two Thousand Twenty Five [Member] [Domain]
Debt Instrument [Line Items]
Stated interest rate		4.375%
Unsecured Senior Notes [Member] | Four Point Two Five Zero Percent Unsecured Senior Notes [Member] [Domain]
Debt Instrument [Line Items]
Stated interest rate		4.25%
Subsidiaries [Member]
Debt Instrument [Line Items]
Unsecured Debt		$ 1,856,590		1,783,121
Secured debt (Notes 3, 6, 7 and 16)		381,918		546,292
Subsidiaries [Member] | Line of Credit [Member] | $150.0 Term Loan Facility [Member]
Debt Instrument [Line Items]
Unsecured Debt		150,000		150,000
Subsidiaries [Member] | Line of Credit [Member] | Thirty Nine Million Unsecured Term Loan Due July 2019 [Member]
Debt Instrument [Line Items]
Unsecured Debt			$ 39,000
Subsidiaries [Member] | Unsecured Senior Notes [Member]
Debt Instrument [Line Items]
Unsecured Debt		1,667,590		1,594,121
Subsidiaries [Member] | Unsecured Senior Notes [Member] | 6.45% Unsecured Senior Notes due Aug 4 2014 [Member]
Debt Instrument [Line Items]
Unsecured Debt					$ 83,000
Subsidiaries [Member] | Unsecured Senior Notes [Member] | 6.625% Unsecured Senior Notes due June 1, 2020 [Member]
Debt Instrument [Line Items]
Unsecured Debt		$ 249,060		248,846
Stated interest rate	[2]	6.625%
Subsidiaries [Member] | Unsecured Senior Notes [Member] | 4.80% Unsecured Senior Notes due July 15, 2018 [Member]
Debt Instrument [Line Items]
Unsecured Debt		$ 324,809		324,735
Stated interest rate	[1],[3]	4.80%
Subsidiaries [Member] | Unsecured Senior Notes [Member] | 5.00% Unsecured Senior Notes due Nov 3, 2015 [Member]
Debt Instrument [Line Items]
Unsecured Debt		$ 0		324,967
Stated interest rate	[4]	5.00%
Subsidiaries [Member] | Unsecured Senior Notes [Member] | 3.800% Unsecured Senior Notes [Member]
Debt Instrument [Line Items]
Unsecured Debt		$ 299,930		299,921
Stated interest rate	[1]	3.80%
Subsidiaries [Member] | Unsecured Senior Notes [Member] | Four Point Two Five Zero Percent Unsecured Senior Notes [Member] [Domain]
Debt Instrument [Line Items]
Unsecured Debt		$ 395,950		$ 395,652
Stated interest rate	[5]	4.25%
[1]	Interest on these notes is payable semi-annually in arrears on January 15th and July 15th of each year.
[2]	Interest on these notes is payable semi-annually in arrears on June 1st and December 1st of each year.
[3]	In October 2015, certain common limited partners in the Operating Partnership that previously contributed their interests in the property at 6255 W. Sunset Blvd., Los Angeles, California to the Operating Partnership entered into an agreement with the Company. Pursuant to this agreement, such common limited partners will reimburse the Company for a portion of any amounts the Company may be required to pay pursuant to its guarantee of the Operating Partnership's 4.800% Senior Notes due 2018 or that the Company may otherwise become required to pay under applicable law with respect to such notes.
[4]	Interest of these notes is payable semi-annually in arrears on May 3rd and November 3rd of each year.
[5]	Interest on these notes is payable semi-annually in arrears on February 15th and August 15th of each year.

Secured and Unsecured Debt of78

Secured and Unsecured Debt of the Operating Partnership Secured and Unsecured Debt of the Operating Partnership - Secured Debt (Details) $ in Thousands		12 Months Ended
		Dec. 31, 2015USD ($)loans	Jun. 30, 2015USD ($)	Dec. 31, 2014USD ($)
Debt Instrument [Line Items]
Unsecured Debt		$ 1,856,590		$ 1,783,121
Secured Debt
Debt premium			$ 6,200
Principal amount				172,500
Secured debt (Notes 3, 6, 7 and 16)		381,918		546,292
Secured Debt [Member]
Secured Debt
Debt premium		6,200
Unamortized discount (premium), Net				(10,300)
Kilroy Realty, L.P. [Member]
Debt Instrument [Line Items]
Unsecured Debt		1,856,590		1,783,121
Secured Debt
Secured debt (Notes 3, 6, 7 and 16)		381,918		546,292
Kilroy Realty, L.P. [Member] | Secured Debt [Member]
Secured Debt
Net book value of properties pledged as collateral for secured debt		$ 600,000
Number of secured loans with restrictions | loans		5
Number of secured debt | loans		6
Secured debt (Notes 3, 6, 7 and 16)	[1]	$ 381,918		546,292
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 4.27% Mortgage Payable due Feb 1, 2018 [Member]
Secured Debt
Stated interest rate	[2]	4.27%
Effective interest rate	[2],[3]	4.27%
Maturity date		Feb. 1, 2018
Secured debt (Notes 3, 6, 7 and 16)		$ 128,315		130,767
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 4.48% Mortgage Payable due July 2027
Secured Debt
Stated interest rate	[2]	4.48%
Effective interest rate	[2],[3]	4.48%
Maturity date		Jul. 1, 2027
Secured debt (Notes 3, 6, 7 and 16)	[1],[4]	$ 96,354		97,000
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 6.05% Mortgage Payable Due June 1, 2019 [Member]
Secured Debt
Stated interest rate	[2]	6.05%
Effective interest rate	[2],[3]	3.50%
Maturity date		Jun. 1, 2019
Debt premium		$ 6,200		8,000
Secured debt (Notes 3, 6, 7 and 16)	[1],[4],[5]	$ 85,890		89,242
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 6.51% Mortgage Payable due February 1, 2017 [Member]
Secured Debt
Stated interest rate	[2]	6.51%
Effective interest rate	[2],[3]	6.51%
Maturity date		Feb. 1, 2017
Secured debt (Notes 3, 6, 7 and 16)	[1]	$ 65,563		66,647
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 5.23% Mortgage Payable due January 2016 [Member]
Secured Debt
Stated interest rate	[2]	5.23%
Effective interest rate	[2],[3]	3.50%
Maturity date		Jan. 1, 2016
Secured debt (Notes 3, 6, 7 and 16)	[1],[6]	$ 0		52,793
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 5.57% Mortgage Note Payable due February 2016 [Member]
Secured Debt
Stated interest rate	[2]	5.57%
Effective interest rate	[2],[3]	3.25%
Maturity date		Feb. 11, 2016
Secured debt (Notes 3, 6, 7 and 16)	[1],[6]	$ 0		40,258
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 5.09% Mortgage Payable due August 2015 [Member] [Member]
Secured Debt
Stated interest rate	[2]	5.09%
Effective interest rate	[2],[3]	3.50%
Maturity date		Aug. 7, 2015
Secured debt (Notes 3, 6, 7 and 16)	[1]	$ 0		34,311
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | Four Point Nine four Percent Mortgage Payable due April Fifteen Two Thousand Fifteen [Member]
Secured Debt
Stated interest rate	[2]	4.94%
Effective interest rate	[2],[3]	4.00%
Maturity date		Apr. 15, 2015
Secured debt (Notes 3, 6, 7 and 16)	[1]	$ 0		26,285
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | 7.15% Mortgage Payable due May 1, 2017 [Member]
Secured Debt
Stated interest rate	[2]	7.15%
Effective interest rate	[2],[3]	7.15%
Maturity date		May 1, 2017
Secured debt (Notes 3, 6, 7 and 16)	[1]	$ 3,987		6,568
Kilroy Realty, L.P. [Member] | Secured Debt [Member] | Other [Member]
Secured Debt
Secured debt (Notes 3, 6, 7 and 16)		600
Secured debt (Notes 3, 6, 7 and 16)	[1],[7]	1,809		$ 2,421
Secured Debt [Member]
Secured Debt
Secured debt (Notes 3, 6, 7 and 16)		$ 561
[1]	Amounts reported include the amounts of unamortized debt premiums of $6.2 million and $10.3 million as of December 31, 2015 and 2014, respectively.
[2]	All interest rates presented are fixed-rate interest rates.
[3]	This represents the rate at which interest expense is recorded for financial reporting purposes, which reflects the amortization of discounts/premiums, excluding debt issuance costs.
[4]	The secured debt and the related properties that secure the debt are held in a special purpose entity and the properties are not available to satisfy the debts and other obligations of the Company or the Operating Partnership.
[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 loan requires monthly principal and interest payments based on a 6.4 year amortization period. As of December 31, 2015 and 2014, the mortgage loan had unamortized debt premiums of $6.2 million and $8.0 million, respectively.
[6]	These mortgage notes payable were repaid during the year ended December 31, 2015 at par.
[7]	Excludes $0.6 million of secured debt related to real estate assets held for sale as of December 31, 2015.

Secured and Unsecured Debt of79

Secured and Unsecured Debt of the Operating Partnership - Exchangeable Senior Notes (Details) $ / shares in Units, $ in Thousands	1 Months Ended		3 Months Ended		12 Months Ended
	Nov. 30, 2014	Nov. 30, 2009	Dec. 31, 2015shares	Dec. 31, 2014$ / sharesshares	Dec. 31, 2015USD ($)shares	Dec. 31, 2014USD ($)$ / sharesshares		Dec. 31, 2013USD ($)$ / shares	Jun. 30, 2015USD ($)	Nov. 13, 2014USD ($)
Debt Instrument [Line Items]
Average Trading Price Of The Companys Stock | $ / shares						$ 60.04	[1]	$ 52.12
Debt Instrument, Unamortized Premium									$ 6,200
Capped call transactions
Debt Instrument, Convertible, Conversion Ratio						27.8307
Conversion of Stock, Shares Converted | shares						4,800,796
Interest expense					$ 57,682	$ 67,571		$ 75,870
Exchangeable Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Issuance Date		Nov. 1, 2009
Balance and significant terms of the Exchangeable Notes outstanding
Maturity date	Nov. 1, 2014
Stated interest rate				4.00%		4.00%
Effective interest rate				7.00%		7.00%
Capped call transactions
Debt Instrument, Convertible, Conversion Price | $ / shares				$ 35.93		$ 35.93
Kilroy Realty, L.P. [Member]
Debt Instrument [Line Items]
Interest Costs Incurred					109,647	$ 114,661		111,238
Interest Costs Capitalized Adjustment					(51,965)	(47,090)		(35,368)
Capped call transactions
Interest expense					$ 57,682	$ 67,571		$ 75,870
Kilroy Realty, L.P. [Member] | Exchangeable Notes [Member]
Balance and significant terms of the Exchangeable Notes outstanding
Long-term Debt, Gross										$ 135,500
Common Stock
Debt Disclosure [Abstract]
Stock issued during period, shares, conversion of convertible securities, net of adjustments | shares					1,255,917
Debt Instrument [Line Items]
Stock Issued During Period, Shares, Conversion of Convertible Securities | shares			1,660,053	431,270
Common Stock, Issued, Net of Capped Calls | shares				320,064	1,575,981
[1]	Period Ended November 15, 2014(1) Year Ended December 31, 2013Per share average trading price of the Company's common stock$60.04 $52.12_______________(1) Represents the maturity date of the 4.25% Exchangeable Notes.

Secured and Unsecured Debt of80

Secured and Unsecured Debt of the Operating Partnership - Exchangeable Senior Notes (Details Textuals)	3 Months Ended			12 Months Ended
	Dec. 31, 2015USD ($)shares	Dec. 31, 2014$ / optionshares	Dec. 31, 2013USD ($)shares	Dec. 31, 2015USD ($)shares	Dec. 31, 2014USD ($)$ / shares$ / optionshares		Dec. 31, 2013USD ($)$ / shares	Jun. 30, 2015USD ($)	Nov. 13, 2014USD ($)
Debt Instrument [Line Items]
Average Trading Price Of The Companys Stock | $ / shares					$ 60.04	[1]	$ 52.12
Derivative, Price Risk Option Strike Price | $ / option		42.81			42.81
Convertible Notes Payable [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Interest					$ 5,608,000		$ 7,331,000
Amortization of Debt Discount (Premium)					3,769,000		4,427,000
Interest Expense, Debt					$ 9,377,000		11,758,000
Kilroy Realty, L.P. [Member] | Exchangeable Notes [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross									$ 135,500,000
Kilroy Realty, L.P. [Member] | Exchangeable Notes [Member] | Exchangeable Note Two [Member]
Debt Instrument [Line Items]
Exchangeable note repurchased prinicipal amount			$ 0				$ 0	$ 0
Kilroy Realty, L.P. [Member] | Exchangeable Notes [Member] | Notes exchanged during 2014 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 37,000,000			$ 37,000,000
Common Stock
Debt Instrument [Line Items]
Stock Issued During Period, Shares, Conversion of Convertible Securities | shares	1,660,053	431,270
Shares of Common stock exercised in the capped call option | shares			404,136		111,206
Stock issued during period, shares, conversion of convertible securities, net of adjustments | shares				1,255,917
Common Stock, Issued, Net of Capped Calls | shares		320,064		1,575,981
[1]	Period Ended November 15, 2014(1) Year Ended December 31, 2013Per share average trading price of the Company's common stock$60.04 $52.12_______________(1) Represents the maturity date of the 4.25% Exchangeable Notes.

Secured and Unsecured Debt of81

Secured and Unsecured Debt of the Operating Partnership - Unsecured Senior Notes and Term Loan Facility (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Sep. 30, 2015	Jul. 01, 2014	Dec. 31, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Principal amount			$ 172,500
Net carrying amount		$ 1,856,590	1,783,121
Unsecured Debt [Member] | Thirty Nine Million Unsecured Term Loan Due July 2019 [Member]
Debt Instrument [Line Items]
Net carrying amount		$ 39,000
Unsecured Senior Notes [Member] | Four Point Two Five Zero Percent Unsecured Senior Notes [Member] [Domain]
Debt Instrument [Line Items]
Stated interest rate		4.25%
Unsecured Senior Notes [Member] | 3.800% Unsecured Senior Notes [Member]
Debt Instrument [Line Items]
Stated interest rate	[1]	3.80%
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		6.625%
Line of Credit [Member] | $150.0 Term Loan Facility [Member]
Debt Instrument [Line Items]
Net carrying amount		$ 150,000
Kilroy Realty, L.P. [Member]
Debt Instrument [Line Items]
Net carrying amount		1,856,590	1,783,121
Kilroy Realty, L.P. [Member] | Unsecured Senior Notes [Member]
Debt Instrument [Line Items]
Net carrying amount		$ 1,667,590	1,594,121
Kilroy Realty, L.P. [Member] | Unsecured Senior Notes [Member] | Four Point Three Seven Five Percent Unsecured Senior Notes [Member] [Domain] [Domain]
Debt Instrument [Line Items]
Stated interest rate	[2]	4.375%
Effective interest rate	[3]	4.44%
Principal amount		$ 400,000	0	$ 400,000
Unamortized discount		(2,159)		2,200
Net carrying amount		$ 397,841	0
Kilroy Realty, L.P. [Member] | Unsecured Senior Notes [Member] | Four Point Two Five Zero Percent Unsecured Senior Notes [Member] [Domain]
Debt Instrument [Line Items]
Stated interest rate	[4]	4.25%
Effective interest rate	[3]	4.35%
Principal amount		$ 400,000	400,000
Unamortized discount		(4,050)	(4,348)		$ 4,472
Net carrying amount		$ 395,950	395,652
Kilroy Realty, L.P. [Member] | Unsecured Senior Notes [Member] | 3.800% Unsecured Senior Notes [Member]
Debt Instrument [Line Items]
Stated interest rate	[1]	3.80%
Effective interest rate	[3]	3.804%
Principal amount		$ 300,000	300,000
Unamortized discount		(70)	(79)
Net carrying amount		$ 299,930	299,921
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	[1],[5]	4.80%
Effective interest rate	[3]	4.827%
Principal amount		$ 325,000	325,000
Unamortized discount		(191)	(265)
Net carrying amount		$ 324,809	324,735
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]	6.625%
Effective interest rate	[3]	6.743%
Principal amount		$ 250,000	250,000
Unamortized discount		(940)	(1,154)
Net carrying amount		$ 249,060	248,846
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	[7]	5.00%
Effective interest rate	[3]	5.014%
Principal amount			325,000	0
Unamortized discount			(33)	0
Net carrying amount		$ 0	$ 324,967
Kilroy Realty, L.P. [Member] | Unsecured Senior Notes [Member] | 6.45% Unsecured Senior Notes due Aug 4 2014 [Member]
Debt Instrument [Line Items]
Effective interest rate						6.45%	6.45%
Net carrying amount						$ 83,000
Kilroy Realty, L.P. [Member] | Line of Credit [Member] | $150.0 Term Loan Facility [Member]
Debt Instrument [Line Items]
Maturity date		Jul. 1, 2019	Jul. 1, 2019
Net carrying amount		$ 150,000	$ 150,000
Spread on variable rate	[8]	1.40%	1.56%
Kilroy Realty, L.P. [Member] | Line of Credit [Member] | Thirty Nine Million Unsecured Term Loan Due July 2019 [Member]
Debt Instrument [Line Items]
Net carrying amount				$ 39,000
[1]	Interest on these notes is payable semi-annually in arrears on January 15th and July 15th of each year.
[2]	Interest on these notes is payable semi-annually in arrears on April 1st and October 1st of each year.
[3]	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.
[4]	Interest on these notes is payable semi-annually in arrears on February 15th and August 15th of each year.
[5]	In October 2015, certain common limited partners in the Operating Partnership that previously contributed their interests in the property at 6255 W. Sunset Blvd., Los Angeles, California to the Operating Partnership entered into an agreement with the Company. Pursuant to this agreement, such common limited partners will reimburse the Company for a portion of any amounts the Company may be required to pay pursuant to its guarantee of the Operating Partnership's 4.800% Senior Notes due 2018 or that the Company may otherwise become required to pay under applicable law with respect to such notes.
[6]	Interest on these notes is payable semi-annually in arrears on June 1st and December 1st of each year.
[7]	Interest of these notes is payable semi-annually in arrears on May 3rd and November 3rd of each year.
[8]	Our unsecured term loan facility interest rate was calculated based on an annual rate of LIBOR plus 1.150% and LIBOR plus 1.400% as of December 31, 2015 and December 31, 2014, respectively.

Secured and Unsecured Debt of82

Secured and Unsecured Debt of the Operating Partnership - Unsecured Revolving Credit Facility (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Line of Credit Facility [Line Items]
Unsecured Debt		$ 1,856,590	$ 1,783,121
Terms of the Credit Facility
Outstanding borrowings		0	140,000
Kilroy Realty, L.P. [Member]
Line of Credit Facility [Line Items]
Unsecured Debt		1,856,590	1,783,121
Terms of the Credit Facility
Outstanding borrowings		0	140,000
Revolving Credit Facility [Member] | Kilroy Realty, L.P. [Member]
Terms of the Credit Facility
Outstanding borrowings		0	140,000
Remaining borrowing capacity		600,000	460,000
Total borrowing capacity		$ 600,000	$ 600,000
Interest rate		0.00%	1.41%
Facility fee - annual rate		0.20%	0.25%
Maturity date		Jul. 1, 2019
Unsecured debt additional borrowing amount		$ 311,000
Spread on variable rate		1.05%	1.25%
Debt Issuance Cost		$ 4,600
$150.0 Term Loan Facility [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Unsecured Debt		150,000
$150.0 Term Loan Facility [Member] | Line of Credit [Member] | Kilroy Realty, L.P. [Member]
Line of Credit Facility [Line Items]
Unsecured Debt		$ 150,000	$ 150,000
Terms of the Credit Facility
Spread on variable rate	[1]	1.40%	1.56%
Debt Instrument, Maturity Date		Jul. 1, 2019	Jul. 1, 2019
London Interbank Offered Rate (LIBOR) [Member] | $150.0 Term Loan Facility [Member] | Line of Credit [Member] | Kilroy Realty, L.P. [Member]
Terms of the Credit Facility
Spread on variable rate		1.15%	1.40%
[1]	Our unsecured term loan facility interest rate was calculated based on an annual rate of LIBOR plus 1.150% and LIBOR plus 1.400% as of December 31, 2015 and December 31, 2014, respectively.

Secured and Unsecured Debt of83

Secured and Unsecured Debt of the Operating Partnership - Debt Maturities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Capitalized interest and loan fees
Interest expense	$ 57,682	$ 67,571	$ 75,870
Long-term Debt	2,238,508
Kilroy Realty, L.P. [Member]
Capitalized interest and loan fees
Gross interest expense	109,647	114,661	111,238
Capitalized interest	51,965	47,090	35,368
Interest expense	57,682	$ 67,571	$ 75,870
Debt [Member] | Kilroy Realty, L.P. [Member]
Stated debt maturities and scheduled amortization payments, excluding debt discounts
2,015	9,734
2,016	71,734
2,018	451,713
Long-term Debt, Maturities, Repayments of Principal in Year Four	265,355
2,019	251,962
Thereafter	1,189,198
Total	2,239,696
Capitalized interest and loan fees
Debt Instrument, Unamortized Discount	$ (1,188)

Deferred Revenue and Acquisit84

Deferred Revenue and Acquisition Related Liabilities, net (Details) - USD ($) $ in Thousands		Dec. 31, 2015	Dec. 31, 2014
Deferred Revenue Arrangement [Line Items]
Acquisition-related intangible liabilities, net	[1]	$ 32,324	$ 43,427
Deferred revenue and acquisition-related intangible liabilities, net		128,156	132,239
Tenant Funded Tenant Improvements [Member]
Deferred Revenue Arrangement [Line Items]
Deferred Revenue	[2]	90,825	85,757
Other Deferred Revenue [Member]
Deferred Revenue Arrangement [Line Items]
Deferred Revenue		$ 5,007	$ 3,055
[1]	See Note 2 “Basis of Presentation and Significant Accounting Policies” and Note 5 “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

Deferred Revenue and Acquisit85

Deferred Revenue and Acquisition Related Liabilities, net (Textuals) (Details) - Tenant Funded Tenant Improvements [Member] - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Deferred Revenue Arrangement [Line Items]
Deferred revenues amortized and recognized as rental income		$ 13,300	$ 11,000	$ 10,700
2,015		12,536
2,016		11,924
2,017		11,285
2,018		9,761
2,019		9,230
Thereafter		36,089
Deferred revenue	[1]	$ 90,825	$ 85,757
[1]	Excludes deferred revenue related to tenant-funded tenant improvements related to properties held for sale at

Noncontrolling Interests on t86

Noncontrolling Interests on the Company's Consolidated Financial Statements (Details) - USD ($) $ / shares in Units, $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Noncontrolling Interest [Line Items]
Percentage of general partnership interest owned by the company in the Operating Partnership	98.10%	98.00%
Ownership interest of noncontrolling interest	1.90%	2.00%
Noncontrolling common units	1,764,775	1,804,200
Common stock, par value	$ 0.01
Aggregate value upon redemption of outstanding noncontrolling common units	$ 112,000	$ 126,800
Noncontrolling Interest	$ 6,520	$ 5,862

Stockholders' Equity of the C87

Stockholders' Equity of the Company (Details Textuals) - USD ($) $ / shares in Units, $ in Thousands	Sep. 18, 2013	Oct. 23, 2014	Sep. 30, 2013	Aug. 31, 2012	Mar. 31, 2012	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2015	Jul. 01, 2015	Jun. 30, 2015
Class of Stock [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period							212,468
Aggregate net proceeds after sales agent compensation						$ 249,600
Aggregate gross proceeds							$ 387,398	$ 102,229	$ 349,951
Common stock, shares issued											3,773,766
Shares Issued, Price Per Share											$ 66.19
At Market Stock Aggregate Gross Sales Price of Common Stock											$ 249,800
purchase price, value of shares issued to acquire land							$ 0	$ 21,631	$ 0
Share Repurchase, remaining number of shares authorized to be repurchased						988,025	988,025
Series G Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Preferred stock, dividend rate					6.875%		6.875%		6.875%
Preferred stock (in shares)						4,000,000	4,000,000	4,000,000
Series H Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Preferred stock, dividend rate				6.375%			6.375%		6.375%
Preferred stock (in shares)						4,000,000	4,000,000	4,000,000
Common Stock
Class of Stock [Line Items]
Common stock, shares issued									86,259,684			92,258,690
December 2014 At-The-Market Program [Member]
Class of Stock [Line Items]
At Market Stock Offering Program Aggregate Value Of Common Stock							$ 300,000
Issuance of Equity under ATM Program [Member] | Common Stock
Class of Stock [Line Items]
Share of common stock sold during the period							1,866,267	1,599,123	1,040,838
Aggregate net proceeds after sales agent compensation							$ 138,200	$ 103,100	$ 54,400
Aggregate gross proceeds							140,100	$ 104,700	$ 55,300
At Market Stock Offering Program Aggregate Value Of Common Stock							$ 200,000
Issuance of Equity - equity offering [Domain] | Common Stock
Class of Stock [Line Items]
Share of common stock sold during the period			6,175,000
Market Measure-Based Restricted Stock Units (RSUs) [Member]
Class of Stock [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period							127,657	119,098
Time-Based Restricted Stock Units (RSUs) [Member]
Class of Stock [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period							84,811	117,506
Kilroy Realty, L.P. [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]
Class of Stock [Line Items]
Number of RSUs outstanding									247,089			425,452	[1]
Issuance of Equity under ATM Program [Member] | Common Stock
Class of Stock [Line Items]
At Market Stock Aggregate Gross Sales Price of Common Stock										$ 150,100
Issuance of Equity - equity offering [Domain] | Issuance of Equity - equity offering [Domain] | Common Stock
Class of Stock [Line Items]
Aggregate gross proceeds	$ 295,900
SFFGA [Member]
Class of Stock [Line Items]
Common stock, shares issued		351,476
purchase price, value of shares issued to acquire land		$ 21,600
[1]	The amount includes nonvested RSUs. Does not include the 425,452 and 247,089 market measure-based RSUs because not all the necessary performance conditions have been met as of December 31, 2015 and 2014, respectively.

Stockholders' Equity of the C88

Stockholders' Equity of the Company Stockholders' Equity of the Company (Details) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended		12 Months Ended
		Oct. 23, 2014	Dec. 31, 2015		Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013	Jul. 01, 2015	Jun. 30, 2015
Dividends Payable [Line Items]
Common Stock, Shares, Issued										3,773,766
purchase price, value of shares issued to acquire land					$ 0		$ 21,631		$ 0
Aggregate gross proceeds					387,398		102,229		349,951
Aggregate net proceeds after sales agent compensation			$ 249,600
Accrued dividend and distributions
Accrued dividends and distributions			$ 34,992		34,992		32,899
Common Stockholders And Unitholders Dividends And Distributions Declared But Not Paid					$ (33,336)		$ (31,243)		$ (29,378)
Summary of shares and units
Common stock	[1]		92,258,690		92,258,690		86,259,684
Noncontrolling common units			1,764,775		1,764,775		1,804,200
Common stockholders and noncontrolling unitholders [Member]
Accrued dividend and distributions
Accrued dividends and distributions							$ 31,243
Common Stock
Dividends Payable [Line Items]
Common Stock, Shares, Issued									86,259,684		92,258,690
Accrued dividend and distributions
Accrued dividends and distributions			$ 32,291		$ 32,291		30,191
Summary of shares and units
Common stock									86,259,684		92,258,690
Capital Units [Member]
Accrued dividend and distributions
Accrued dividends and distributions			618		618		631
Preferred Stock [Member]
Accrued dividend and distributions
Accrued dividends and distributions			$ 1,656		$ 1,656		$ 1,656
Series G Cumulative Redeemable Preferred Stock
Summary of shares and units
Preferred stock (in shares)			4,000,000		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		4,000,000
Restricted Stock Units (RSUs) [Member]
Accrued dividend and distributions
Accrued dividends and distributions			$ 427	[2]	$ 427	[2]	$ 421	[3]
Time-Based Restricted Stock Units (RSUs) [Member]
Summary of shares and units
RSUs	[4]		1,269,809		1,269,809		1,248,352
Issuance of Equity under ATM Program [Member] | Common Stock
Dividends Payable [Line Items]
Share of common stock sold during the period					1,866,267		1,599,123		1,040,838
Aggregate gross proceeds					$ 140,100		$ 104,700		$ 55,300
Aggregate net proceeds after sales agent compensation					$ 138,200		$ 103,100		$ 54,400
SFFGA [Member]
Dividends Payable [Line Items]
Common Stock, Shares, Issued		351,476
purchase price, value of shares issued to acquire land		$ 21,600
[1]	The amount includes nonvested shares.
[2]	The amount includes the value of the dividend equivalents that will be paid with additional RSUs (see Note 13 “Share-Based Compensation” for additional information).
[3]	The amount includes the value of the dividend equivalents that will be paid with additional RSUs (see Note 13 “Share-Based Compensation” for additional information)
[4]	The amount includes nonvested RSUs. Does not include the 425,452 and 247,089 market measure-based RSUs because not all the necessary performance conditions have been met as of December 31, 2015 and 2014, respectively.

Preferred and Common Units of89

Preferred and Common Units of the Operating Partnership (Details Textuals) - USD ($) $ / shares in Units, $ in Thousands	Sep. 18, 2013	Oct. 23, 2014	Sep. 30, 2013	Aug. 31, 2012	Mar. 31, 2012	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jul. 01, 2015	Jun. 30, 2015		Jan. 27, 2015
Class of Stock [Line Items]
Common Stock, Shares, Issued										3,773,766
Shares Issued, Price Per Share										$ 66.19
At Market Stock Aggregate Gross Sales Price of Common Stock										$ 249,800
Proceeds from Issuance of Common stock, net						$ 249,600
purchase price, value of shares issued to acquire land							$ 0	$ 21,631	$ 0
Net proceeds from issuance of common stock							$ 387,398	$ 102,229	$ 349,951
Share price per unit of common units issued (dollars per unit)													$ (75.34)
Series H Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Preferred units issued									4,000,000
Preferred stock, dividend rate				6.375%			6.375%		6.375%
Preferred Stock, Shares Outstanding						4,000,000	4,000,000	4,000,000
Series H Cumulative Redeemable Preferred Stock | Series H Cumulative Redeemable Preferred Unit [Member]
Class of Stock [Line Items]
Preferred units issued											4,000,000
Series G Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Preferred units issued									4,000,000
Preferred stock, dividend rate					6.875%		6.875%		6.875%
Preferred Stock, Shares Outstanding						4,000,000	4,000,000	4,000,000
Series G Cumulative Redeemable Preferred Stock | Series G Cumulative Redeemable Preferred Unit [Member]
Class of Stock [Line Items]
Preferred units issued						4,000,000	4,000,000
Common Stock
Class of Stock [Line Items]
Common Stock, Shares, Issued									86,259,684		92,258,690
Kilroy Realty, L.P. [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]
Class of Stock [Line Items]
Number of RSUs outstanding									247,089		425,452	[1]
Kilroy Realty, L.P. [Member] | Series H Cumulative Redeemable Preferred Unit [Member]
Class of Stock [Line Items]
Preferred units issued									4,000,000		4,000,000
Preferred units outstanding						4,000,000	4,000,000		4,000,000
Preferred stock, dividend rate							6.375%		6.375%
Kilroy Realty, L.P. [Member] | Series G Cumulative Redeemable Preferred Unit [Member]
Class of Stock [Line Items]
Preferred units issued									4,000,000		4,000,000
Preferred units outstanding						4,000,000	4,000,000		4,000,000
Preferred stock, dividend rate							6.875%		6.875%
Kilroy Realty, L.P. [Member] | Partners Capital Common Unit [Member]
Class of Stock [Line Items]
Issuance of common units, units			6,175,000						7,210,838
Issuance of Equity - equity offering [Domain] | Common Stock
Class of Stock [Line Items]
Share of common stock sold during the period			6,175,000
Issuance of Equity - equity offering [Domain] | Common Stock | Issuance of Equity - equity offering [Domain]
Class of Stock [Line Items]
Net proceeds from issuance of common stock	$ 295,900
SFFGA [Member]
Class of Stock [Line Items]
Common Stock, Shares, Issued		351,476
purchase price, value of shares issued to acquire land		$ 21,600
[1]	The amount includes nonvested RSUs. Does not include the 425,452 and 247,089 market measure-based RSUs because not all the necessary performance conditions have been met as of December 31, 2015 and 2014, respectively.

Preferred and Common Units of90

Preferred and Common Units of the Operating Partnership (Details) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended			12 Months Ended
		Sep. 30, 2013	Dec. 31, 2015		Dec. 31, 2012	Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Class of Stock [Line Items]
Aggregate gross proceeds						$ 387,398		$ 102,229		$ 349,951
Aggregate net proceeds after sales agent compensation			$ 249,600
Accrued distributions
Accrued dividends and distributions			$ 34,992			$ 34,992		$ 32,899
Summary of units
Company owned general partnership interest			98.10%			98.10%		98.00%
Noncontrolling common units of the Operating Partnership			1,764,775			1,764,775		1,804,200
Ownership interest of noncontrolling interest			1.90%			1.90%		2.00%
Restricted Stock Units (RSUs) [Member]
Accrued distributions
Accrued dividends and distributions			$ 427	[1]		$ 427	[1]	$ 421	[2]
Issuance of Equity under ATM Program [Member] | Partners Capital Common Unit [Member]
Class of Stock [Line Items]
Common units exchanged for share of common stock by the Company					1,040,838	1,866,267				1,599,123
Capital Units [Member]
Accrued distributions
Accrued dividends and distributions			618			$ 618		631
Common Stock
Accrued distributions
Accrued dividends and distributions			32,291			$ 32,291		$ 30,191
Common Stock | Issuance of Equity under ATM Program [Member]
Class of Stock [Line Items]
Share of common stock sold during the period						1,866,267		1,599,123		1,040,838
Aggregate gross proceeds						$ 140,100		$ 104,700		$ 55,300
Aggregate net proceeds after sales agent compensation						138,200		103,100		54,400
Kilroy Realty, L.P. [Member]
Accrued distributions
Accrued dividends and distributions			$ 34,992			$ 34,992		$ 32,899		32,899
Kilroy Realty, L.P. [Member] | Restricted Stock Units (RSUs) [Member]
Accrued distributions
Accrued dividends and distributions	[1]									$ 421
Summary of units
RSUs	[3]		1,269,809			1,269,809				1,248,352
Kilroy Realty, L.P. [Member] | Partners Capital Common Unit [Member]
Class of Stock [Line Items]
Common units exchanged for share of common stock by the Company		6,175,000								7,210,838
Accrued distributions
Accrued dividends and distributions			$ 33,336			$ 33,336				$ 31,243
Kilroy Realty, L.P. [Member] | Partners Capital General Partner [Member]
Accrued distributions
Accrued dividends and distributions			32,291			32,291				30,191
Kilroy Realty, L.P. [Member] | Partners Capital Limited Partner [Member]
Accrued distributions
Accrued dividends and distributions			618			618				631
Kilroy Realty, L.P. [Member] | Partners Capital Preferred Units [Member]
Accrued distributions
Accrued dividends and distributions			$ 1,656			$ 1,656				$ 1,656
Kilroy Realty, L.P. [Member] | Series G Cumulative Redeemable Preferred Unit [Member]
Summary of units
Preferred units outstanding			4,000,000			4,000,000				4,000,000
Kilroy Realty, L.P. [Member] | Series H Cumulative Redeemable Preferred Unit [Member]
Summary of units
Preferred units outstanding			4,000,000			4,000,000				4,000,000
Kilroy Realty, L.P. [Member] | Capital Units [Member]
Summary of units
Company owned common units in the Operating Partnership			92,258,690			92,258,690		86,259,684		86,259,684
[1]	The amount includes the value of the dividend equivalents that will be paid with additional RSUs (see Note 13 “Share-Based Compensation” for additional information).
[2]	The amount includes the value of the dividend equivalents that will be paid with additional RSUs (see Note 13 “Share-Based Compensation” for additional information)
[3]	Does not include the 425,452 and 247,089 market measure-based RSUs because not all the necessary performance conditions have been met as of December 31, 2015 and 2014, respectively.

Share-Based Compensation (Detai

Share-Based Compensation (Details Textuals) - USD ($) $ / shares in Units, $ in Millions

Jan. 27, 2015

Apr. 04, 2013

Feb. 22, 2012

Feb. 28, 2012

Dec. 31, 2012

Dec. 31, 2015

Dec. 31, 2014

Dec. 31, 2013

Sep. 30, 2015

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

Granted (in shares)

212,468

Grant date fair value per share

$ 65.03

Trading price of the company's stock

$ 75.34

Allocated Share-based Compensation Expense

$ 9.6

$ 18.9

$ 14.5

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

$ 0.9

$ 3.3

$ 2.3

Total unrecognized compensation cost weighted-average period

1 year 11 months

Total unrecognized compensation cost related to nonvested incentive awards granted

$ 31.2

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

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

Granted (in shares)

127,657

119,098

Grants in period, grant date fair value

$ 10.1

Grant date fair value per share

$ 78.55

$ 44.55

[1]

$ 79.25

[1],[2]

$ 64.86

[1]

Expected share price volatility

20.00%

24.00%

Risk-free interest rate

0.92%

0.61%

Expected life

2 years 11 months

2 years 7 months

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

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

Granted (in shares)

84,811

117,506

Grant date fair value per share

$ 49.45

$ 74.49

$ 59.89

Restricted Stock [Member]

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

Granted (in shares)

213

0

Grant date fair value per share

$ 0

$ 51.35

$ 0

Stock Options [Member]

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

Expected share price volatility

33.00%

Risk-free interest rate

1.35%

Expected life

6 years 6 months

Kilroy Realty 2006 Incentive Award Plan [Member]

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

Shares Available for Grant

1,686,608

Kilroy Realty 2006 Incentive Award Plan [Member] | Stock Options [Member]

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

Options, Withheld in Period

62,072

Options, Withheld in Period, Intrinsic Value

$ 3.9

Minimum [Member] | Executive Officer Share-Based Compensation Programs [Member]

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

Service Vesting Period

1 year

Maximum [Member] | Executive Officer Share-Based Compensation Programs [Member]

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

Service Vesting Period

5 years

Chief Executive Officer [Member] | Executive Officer Share-Based Compensation Programs [Member] | Restricted Stock Units (RSUs) [Member]

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

Granted (in shares)

236,604

Chief Executive Officer [Member] | Executive Officer Share-Based Compensation Programs [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]

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

Grants in period, grant date fair value

$ 7.7

Chief Executive Officer [Member] | Executive Officer Share-Based Compensation Programs [Member] | Time-Based Restricted Stock Units (RSUs) [Member]

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

Exercise Price

$ 60.16

Management [Member] | Stock Options [Member]

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

Award vesting period

5 years

Options granted in period

1,550,000

Trading price of the company's stock

$ 42.61

Expiration period

10 years

Nonvested Restricted Stock Units R S U [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]

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

Granted (in shares)

9,542

191,483

183,365

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

98,802

155,016

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

[3]

5,354

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 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 Restricted Stock Units R S U [Member] | Time-Based Restricted Stock Units (RSUs) [Member]

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

Granted (in shares)

0

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

20,042

Vested Restricted Stock Units R S U [Member] | Restricted Stock [Member]

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

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

10,699

Shareholder Meeting Date May 21, 2015 [Member]

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

Number of Shares Requested

8,320,000

[1]

(1)Represents the grant-date fair value for all awards, excluding the 2014 Performance-Based RSU Grant. As discussed above, the 2014 Performance-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.

[2]

Represents the grant-date fair value for all awards, excluding the 2014 Performance-Based RSU Grant. As discussed above, the 2014 Performance-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.

[3]

(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 settlement or vesting of RSUs in accordance with the terms of the 2006 Plan.

Share-Based Compensation (Det92

Share-Based Compensation (Details) - $ / shares	Jan. 27, 2015	Dec. 31, 2012		Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period				212,468
Grant date fair value per share						$ 65.03
Share Price	$ (75.34)
Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period				127,657		119,098
Grant date fair value per share	$ 78.55	$ 44.55	[1]	$ 79.25	[1],[2]		$ 64.86	[1]
Expected share price volatility				20.00%		24.00%
Risk-free interest rate				0.92%		0.61%
Expected life	2 years 11 months					2 years 7 months
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]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period				0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period		16,338		0			16,338
Market Measure-Based RSU Estimate of Probable [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance				185,510		178,650
[1]	(1)Represents the grant-date fair value for all awards, excluding the 2014 Performance-Based RSU Grant. As discussed above, the 2014 Performance-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.
[2]	Represents the grant-date fair value for all awards, excluding the 2014 Performance-Based RSU Grant. As discussed above, the 2014 Performance-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.

Share-Based Compensation (Det93

Share-Based Compensation (Details 1) - USD ($)		Jan. 27, 2015	Dec. 31, 2012		Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense			$ 9,600,000		$ 18,900,000		$ 14,500,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Granted (in shares)					212,468
Grant date fair value per share							$ 65.03
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)					$ 47.05
Granted (in shares)							213	0
Grant date fair value per share					0		$ 51.35	$ 0
Vested (in shares)							(25,899)	(47,291)
Outstanding at end of year, Weighted Average Grant Date Fair Value (in dollars per share)					$ 47.32		$ 47.05
Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement By Share-based Payment Award, Equity Instruments Other Than Options, Grants In Period, Grant Date Fair Value					$ 10,100,000
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate					20.00%		24.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate					(0.92%)		(0.61%)
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)	[1]						$ 58.77
Granted (in shares)					127,657		119,098
Grant date fair value per share		$ 78.55	$ 44.55	[2]	$ 79.25	[1],[2]		$ 64.86	[2]
Outstanding at end of year, Weighted Average Grant Date Fair Value (in dollars per share)	[1]				67.68			58.77
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term		2 years 11 months					2 years 7 months
Share Based Compensation Arrangements, Dividends, Weighted Average Grant Date Fair Value	[1]				$ 70.47
Share Based Compensation, weighted average fair value of forfeitures	[1]				$ 69.20
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)	[3]						$ 51.04
Outstanding at beginning of year, Vested RSUs	[4]				1,248,352
Granted (in shares)					84,811		117,506
Grant date fair value per share			$ 49.45		$ 74.49			59.89
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	[3]				49.52
Outstanding at end of year, Weighted Average Grant Date Fair Value (in dollars per share)					$ 58.91			$ 51.04	[3]
Outstanding at end of year, Vested RSUs	[4]				1,269,809		1,248,352
Share Based Compensation Arrangements, Dividends, Weighted Average Grant Date Fair Value	[1]				$ 70.47
Share Based Compensation, weighted average fair value of forfeitures	[3]				$ 53.50
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							247,089
Granted (in shares)					191,483
Outstanding at beginning of year, Total RSUs					425,452			247,089
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Issuance Of Dividend Equivalents In Period	[5]				6,347
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Forfeitures	[6]				(19,467)
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							1,248,352
Granted (in shares)					98,802
Vested (in shares)					0
Settled (in shares)	[7]				(78,887)
Cancelled (in shares)	[8]				(5,354)
Outstanding at beginning of year, Total RSUs					1,269,809			1,248,352
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Issuance Of Dividend Equivalents In Period	[9]				23,960
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Forfeitures					(17,064)
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)					85,061
Granted (in shares)					0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	[10]				$ 46.39
Outstanding at end of year (in shares)					60,797		85,061
Nonvested Restricted Stock Units R S U [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of year (in shares)
Granted (in shares)			9,542		191,483			183,365
Outstanding at end of year (in shares)					425,452
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Issuance Of Dividend Equivalents In Period	[5]				6,347
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Forfeitures	[6]				(19,467)
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)							340,997
Granted (in shares)			173,758		98,802			155,016
Cancelled (in shares)	[8]				(5,354)
Outstanding at end of year (in shares)					318,449			340,997
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Issuance Of Dividend Equivalents In Period	[9]				3,255
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Forfeitures					(17,064)
Vested Restricted Stock Units R S U [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Vested (in shares)	[10]				(24,264)
Cancelled (in shares)					(10,699)
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)		0			(16,338)
Outstanding at end of year, Vested RSUs					0			0
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Issuance Of Dividend Equivalents In Period	[5]				0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period					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							907,355
Granted (in shares)					0
Vested (in shares)			(89,873)		(107,541)			(116,447)
Settled (in shares)	[7]				(78,887)
Cancelled (in shares)					(20,042)
Outstanding at end of year, Vested RSUs					951,360			907,355
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Issuance Of Dividend Equivalents In Period	[9]				20,705
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period					0
[1]	Represents the grant-date fair value for all awards, excluding the 2014 Performance-Based RSU Grant. As discussed above, the 2014 Performance-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.
[2]	(1)Represents the grant-date fair value for all awards, excluding the 2014 Performance-Based RSU Grant. As discussed above, the 2014 Performance-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.
[3]	(1)Represents the grant-date fair value for all awards excluding the 2014 Time-Based RSU Grant. As discussed above, the 2014 Time-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.
[4]	The amount includes nonvested RSUs. Does not include the 425,452 and 247,089 market measure-based RSUs because not all the necessary performance conditions have been met as of December 31, 2015 and 2014, respectively.
[5]	(2)Represents the issuance of dividend equivalents earned on the underlying RSUs. The dividend equivalents vest based on terms specified under the related RSU award agreement.
[6]	(3)Outstanding RSUs as of December 31, 2015 represent the achievement of the maximum performance conditions and assumed target levels for the market conditions. The number of restricted stock units ultimately earned is subject to change based upon actual performance over the three-year vesting period. Dividend equivalents earned will vest along with the underlying award and are also subject to changes based on the number of RSUs ultimately earned for each underlying award.
[7]	(2)Represents vested RSUs that were settled in shares of the Company’s common stock. Total shares settled include 20,042 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.
[8]	(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 settlement or vesting of RSUs in accordance with the terms of the 2006 Plan.
[9]	(3)Represents the issuance of dividend equivalents earned on the underlying RSUs. The dividend equivalents vest based on terms specified under the related RSU award agreement.
[10]	The total shares vested includes 10,699 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 withholding obligations.

Share-Based Compensation (Det94

Share-Based Compensation (Details 2) - USD ($)		Jan. 27, 2015	Dec. 31, 2012		Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)					212,468
Granted, Weighted Average Grant Date Fair Value (in dollars per share)							$ 65.03
Time-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)					84,811		117,506
Granted, Weighted Average Grant Date Fair Value (in dollars per share)			$ 49.45		$ 74.49			$ 59.89
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	[1]				$ 49.52
Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)					127,657		119,098
Granted, Weighted Average Grant Date Fair Value (in dollars per share)		$ 78.55	$ 44.55	[2]	$ 79.25	[2],[3]		$ 64.86	[2]
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)							213	0
Granted, Weighted Average Grant Date Fair Value (in dollars per share)					$ 0		$ 51.35	$ 0
Vested (in shares)							(25,899)	(47,291)
Vested, Total Vest-Date Fair Value	[4]				$ 1,725,000		$ 1,323,000	$ 2,290,000
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)		(107,541)			(116,447)
Vested, Total Vest-Date Fair Value	[5]		$ 4,495,000		$ 7,528,000			$ 6,675,000
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)		0			(16,338)
Vested, Total Vest-Date Fair Value			$ 811		$ 0			$ 1,092,000
Vested Restricted Stock Units R S U [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested (in shares)	[6]				(24,264)
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		98,802			155,016
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		191,483			183,365
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
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	[6]				$ 46.39
[1]	(1)Represents the grant-date fair value for all awards excluding the 2014 Time-Based RSU Grant. As discussed above, the 2014 Time-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.
[2]	(1)Represents the grant-date fair value for all awards, excluding the 2014 Performance-Based RSU Grant. As discussed above, the 2014 Performance-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.
[3]	Represents the grant-date fair value for all awards, excluding the 2014 Performance-Based RSU Grant. As discussed above, the 2014 Performance-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.
[4]	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.
[5]	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
[6]	The total shares vested includes 10,699 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 withholding obligations.

Share-Based Compensation (Stock

Share-Based Compensation (Stock Options Activity) (Details) - USD ($) $ / shares in Units, $ in Millions		Jan. 27, 2015	Feb. 28, 2012	Dec. 31, 2015		Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Intrinsic Value [Roll Forward]
Options, outstanding, weighted average remaining contractual term				6 years 2 months
Options, exercisable, weighted average remaining contractual term				6 years 2 months
Market Measure-Based Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected share price volatility				20.00%		24.00%
Risk-free interest rate				0.92%		0.61%
Expected life		2 years 11 months				2 years 7 months
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Fair value of options granted per share			$ 9.20
Expected share price volatility			33.00%
Risk-free interest rate			1.35%
Dividend yield			3.80%
Expected life			6 years 6 months
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding, Number of Options, Beginning of Year				1,008,000
Exercised (in shares)				(342,000)
Forfeited (in shares)				(56,000)
Outstanding, Number of Options, End of Year				610,000	[1]	1,008,000
Exercisable	[2]			70,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Outstanding, Exercise Price, Beginning of Year (in dollars per share)				$ 42.61
Exercised, Exercise Price (in dollars per share)				42.61
Forfeited, Exercise Price (in dollars per share)				42.61
Outstanding, Exercise Price, End of Year (in dollars per share)				$ 42.61		$ 42.61
Share-based Compensation Arrangement by Share-based Payment Award, Options, Intrinsic Value [Roll Forward]
Outstanding at December 31, 2014	[3]			$ 26.7
Exercised	[3]			12.6		$ 26.7
Forfeited	[3]			1.3
Outstanding at December 31, 2014	[3]			10.3
Options Exercisable at December 31, 2014	[3]			$ 1.4
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, Options, Outstanding [Roll Forward]
Forfeited (in shares)				0
[1]	(2)As of December 31, 2015, the average remaining life of stock options outstanding was 6.2 years
[2]	(3)As of December 31, 2015, the average remaining life of stock options exercisable was approximately 6.2 years.
[3]	(1)The intrinsic value of a stock option is the amount by which the fair value of the underlying stock exceeds the exercise price of an option. The fair value of the underlying stock was determined by using the closing share price on the NYSE on the date of exercise, forfeiture or respective period end.

Employee Benefit Plans Employee

Employee Benefit Plans Employee Benefit Plans (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2015	Dec. 31, 2013	Dec. 31, 2007	Jun. 30, 2015
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	$ 1,100,000	$ 1,000,000
Deferred Compensation - maximum participant deferral percent				70.00%
Deferred Compensation - maximum director fees and bonuses that may be deferred (percent)				100.00%
Deferred Compensation - mandatory Company contributions as percentage of gross monthly salary (percent)				10.00%
Deferred Compensation - liability under Plan			$ 11,900,000		$ 12,800,000

Future Minimum Rent (Details)

Future Minimum Rent (Details) $ in Thousands	Dec. 31, 2015USD ($)
Future contractual minimum rent under operating lease
2,015	$ 495,765
2,016	482,650
2,017	440,367
2,018	379,939
2,019	311,225
Thereafter	1,458,333
Total	$ 3,568,279

Commitments and Contingencies98

Commitments and Contingencies (Details) $ in Thousands	Dec. 31, 2015USD ($)
Summary of minimum commitment
2,015	$ 3,144
2,016	3,144
2,017	3,144
2,018	3,144
2,019	3,144
Thereafter	151,738
Total	$ 167,458	[1],[2],[3],[4]
[1]	One of our ground lease obligations includes a component which is based on the percentage of gross income that exceeds the minimum ground rent. The minimum rent is subject to increases every five years based on 50% of the average annual percentage rent for the previous five years. Currently, gross income does not exceed the threshold requiring us to pay percentage rent. The contractual obligations for that ground lease included above assume the annual lease rental obligation in effect as of December 31, 2015.
[2]	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, 2015.
[3]	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, 2015.
[4]	Reflects the minimum ground lease obligations before the impact of ground lease extension options.

Commitments and Contingencies99

Commitments and Contingencies (Details 1) $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)Extensions	Dec. 31, 2013USD ($)	Dec. 31, 2014USD ($)
Long-term Purchase Commitment [Line Items]
Commitments for contracts and executed leases, operating and redevelopment and development properties	$ 430.1
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%
Accrued environmental remediation liabilities	$ 20.9		$ 15.5
Ten Year Ground Lease Extension Option [Member]
Long-term Purchase Commitment [Line Items]
Number of extension options | Extensions	3
Ground lease extension option term	10 years
Forty-Five Year Ground Lease Extension Option [Member]
Long-term Purchase Commitment [Line Items]
Number of extension options | Extensions	1
Ground lease extension option term	45 years
Property Damage Litigation Case [Member]
Long-term Purchase Commitment [Line Items]
Proceeds from Legal Settlements		$ 5.2
Former Tenant Litigation Case [Member]
Long-term Purchase Commitment [Line Items]
Proceeds from Legal Settlements		$ 3.7

Fair Value Measurements and 100

Fair Value Measurements and Disclosures (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair value adjustment of marketable securities and deferred compensation plan liability
Net gain on marketable securities		$ (269)	$ 397	$ 1,489
Fair Value (Level 1) [Member]
Assets and Liabilities Reported at Fair Value
Marketable securities	[1],[2]	$ 12,882	$ 11,971
[1]	Fair value calculated using Level 1 inputs based on quoted prices in active markets for identical securities.
[2]	The marketable securities are held in a limited rabbi trust.

Fair Value Measurements and 101

Fair Value Measurements and Disclosures (Details 1) - USD ($) $ in Thousands		Dec. 31, 2015	Dec. 31, 2014
Liabilities
Secured debt (Notes 3, 7, 8 and 17)		$ 381,918	$ 546,292
Unsecured Debt		1,856,590	1,783,121
Unsecured line of credit		0	140,000
Carrying Value
Liabilities
Secured debt (Notes 3, 7, 8 and 17)	[1]	381,918	546,292
Unsecured Debt	[2]	1,856,590	1,783,121
Unsecured line of credit	[1]	0	140,000
Carrying Value | Unsecured Debt [Member] | Fair Value (Level 1) [Member]
Liabilities
Unsecured Debt			1,269,400
Carrying Value | Unsecured Debt [Member] | Fair Value (Level 2) [Member]
Liabilities
Unsecured Debt			513,700
Fair Value
Liabilities
Secured debt (Notes 3, 7, 8 and 17)	[1]	391,611	559,483
Unsecured Debt	[2]	1,898,863	1,858,492
Unsecured line of credit	[1]	$ 0	145,051
Fair Value | Unsecured Debt [Member] | Fair Value (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure			1,322,200
Fair Value | Unsecured Debt [Member] | Fair Value (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure			$ 536,300
[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]	{F|ahBzfndlYmZpbGluZ3MtaHJkcmoLEgZYTUxEb2MiXlhCUkxEb2NHZW5JbmZvOjc1MzE3MDhlOTcxNTQ5YjlhODJmZmNlM2UzNTVmZTg2fFRleHRTZWxlY3Rpb246MThBMTM5MzZCOTZBOUVENDNBNThGOTkxQzlDMjhCMDgM}

Other Significant Events (Detai

Other Significant Events (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)ft²	Dec. 31, 2014USD ($)ft²	Dec. 31, 2013USD ($)ft²	Jan. 31, 2014ft²
Other Significant Noncash Transactions [Line Items]
Net Rentable Area | ft²	1,046,394	1,471,319	200,306	79,000
Lease termination fee		$ 5,700
Amortization of Intangible Assets	$ 33,947	41,155	$ 47,395
Contract Termination [Member]
Other Significant Noncash Transactions [Line Items]
Amortization of Intangible Assets		$ 1,300

Discontinued Operations Discont

Discontinued Operations Discontinued Operations (Details) $ in Millions		Jan. 21, 2016USD ($)	Jan. 13, 2016USD ($)	Dec. 31, 2015USD ($)ft²building	Dec. 31, 2014USD ($)ft²property	Dec. 31, 2013USD ($)ft²	Jan. 31, 2014ft²
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties				2	5
Net Rentable Area | ft²				1,046,394	1,471,319	200,306	79,000
Dispositions Sales Price	[1]			$ 309.2	$ 399.5	$ 56.9
Von Karman, Irvine, California [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Dispositions Sales Price	[2],[3]			$ 26	$ 26
San Diego Properties, San Diego, CA [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Rentable Area | ft²	[4]				1,049,035
Dispositions Sales Price	[1]				$ 294.7
9785&9791 Towne Centre Drive, San Diego CA [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Rentable Area | ft²					126,000
Dispositions Sales Price	[1]				$ 29.5
111 Pacifica [Member] [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Rentable Area | ft²					67,496
Dispositions Sales Price	[1]				$ 15.1
4040 Civic [Member] [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Rentable Area | ft²					130,237
Dispositions Sales Price	[1]				$ 34.9
999 Town &Country[Member] [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Rentable Area | ft²					98,551
Dispositions Sales Price	[1]				$ 25.3
Kaiser Boulevard, Anaheim, California [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Rentable Area | ft²						59,790
Dispositions Sales Price	[1]					$ 9.6
Directors Place, Sorrento Mesa, California One [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Rentable Area | ft²						50,360
Dispositions Sales Price	[1]					$ 32.6
Subsequent Event [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Dispositions Sales Price		$ 262.3	$ 4.5
[1]	Represents gross sales price before the impact of broker commissions and closing costs.
[2]	Represents gross sales price before the impact of commissions and closing costs.
[3]	This transaction resulted in a gain on sale of $17.3 million.
[4]	The San Diego Properties included the following: 10020 Pacific Mesa Boulevard, 6055 Lusk Avenue, 5010 and 5005 Wateridge Vista Drive, 15435 and 15445 Innovation Drive, and 15051, 15073, 15231, 15253, 15333 and 15378 Avenue of Science. These properties were held for sale as of December 31, 2013.

Discontinued Operations (Detail

Discontinued Operations (Details 1) $ in Thousands		3 Months Ended										12 Months Ended
		Dec. 31, 2014USD ($)ft²property		Sep. 30, 2014USD ($)	[2]	Jun. 30, 2014USD ($)	[2]	Mar. 31, 2014USD ($)	[2]	Dec. 31, 2012USD ($)	[3]	Dec. 31, 2015USD ($)ft²building		Dec. 31, 2014USD ($)ft²property		Dec. 31, 2013USD ($)ft²		Jan. 31, 2014ft²
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Assets		$ 8,211										$ 117,666		$ 8,211
Number of real estate properties		5										2		5
Net Rentable Area | ft²		1,471,319										1,046,394		1,471,319		200,306		79,000
Dispositions Sales Price	[1]											$ 309,200		$ 399,500		$ 56,900
Rental income														7,206		31,984
Tenant reimbursements														278		3,546
Other property income														13		5,178
Total revenues														7,497		40,708
Property expenses														2,171		7,207
Real estate taxes														692		3,523
Depreciation and amortization														2,061		12,600
Total expenses														4,924		23,330
Income from discontinued operations before net gain on dispositions of discontinued operations												0		2,573		17,378
Net gain on dispositions of discontinued operations (Note 19)												0		121,922		12,252
Total income from discontinued operations		$ 12,013	[2]	$ 6,135		$ 15,289		$ 91,058		$ 29,630		0	[3]	124,495	[3]	29,630	[4]
Gain (Loss) on Disposition of Property Plant Equipment												109,950		0		0
Net proceeds received from dispositions of operating properties and land (Notes 4 and 19)												319,639		427,544		$ 21,178
Disposal Group, Including Discontinued Operation, Liabilities		56										7,543		56
Von Karman, Irvine, California [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Dispositions Sales Price	[5],[6]											$ 26,000		26,000
10850 Via Frontera San Diego CA [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Dispositions Sales Price	[5],[7]													33,100
Gain (Loss) on Disposition of Property Plant Equipment														3,490
Restricted cash [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net proceeds received from dispositions of operating properties and land (Notes 4 and 19)		$ 59,200												$ 59,200
[1]	Represents gross sales price before the impact of broker commissions and closing costs.
[2]	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common stockholders per share does not equal the annual number reported on the consolidated statements of operations due to the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended December 31, 2015 and 2014.
[3]	(2)The Company adopted ASU 2014-08 effective January 1, 2015 (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As a result, properties classified as held for sale and/or disposed of subsequent to January 1, 2015 that do not represent a strategic shift are no longer presented as discontinued operations.
[4]	The Operating Partnership adopted ASU 2014-08 effective January 1, 2015 (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As a result, properties classified as held for sale and/or disposed of subsequent to January 1, 2015 that do not represent a strategic shift are no longer presented as discontinued operations.
[5]	Represents gross sales price before the impact of commissions and closing costs.
[6]	This transaction resulted in a gain on sale of $17.3 million.
[7]	This transaction resulted in a gain on sale of $3.5 million.

Net Income Available to Comm105

Net Income Available to Common Stockholders Per Share of the Company (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended																		12 Months Ended
		Dec. 31, 2015	[1]	Sep. 30, 2015	[1]	Jun. 30, 2015	[1]	Mar. 31, 2015	[1]	Dec. 31, 2014	[1]	Sep. 30, 2014	[1]	Jun. 30, 2014		Mar. 31, 2014	[1]	Dec. 31, 2012		Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Numerator:
Income from continuing operations		$ 29,308		$ 106,704		$ 58,590		$ 44,002		$ 19,417		$ 13,168		$ 15,854		$ 10,874		$ 14,935		$ 238,604		$ 59,313		$ 14,935
Income from continuing operations attributable to noncontrolling interests																		(36)		(4,523)		(966)
Preferred dividends and distributions		$ (3,312)		$ (3,313)		$ (3,312)		$ (3,313)		(3,312)		(3,313)		(3,312)	[1]	(3,313)		(13,250)		(13,250)		(13,250)
Allocation to participating securities (1)	[2]																	(1,689)		(1,634)		(1,699)
Numerator for basic and diluted income (loss) from continuing operations available to common stockholders																		(40)		219,197		43,398
Income from discontinued operations (2)										$ 12,013		$ 6,135		$ 15,289	[1]	$ 91,058		29,630	[3]	0	[3]	124,495	[3]	$ 29,630	[4]
Income from discontinued operations attributable to noncontrolling common units of the Operating Partnership (2)																		(649)		0		(2,623)
Numerator for basic and diluted net income available to common stockholders																		$ 28,941		$ 219,197		$ 165,270
Denominator:
Basic weighted average vested shares outstanding																		77,343,853		89,854,096		83,090,235		77,343,853
Effect of dilutive securities – contingently issuable shares and stock options																		0		541,679		1,877,485
Diluted weighted average vested shares and common stock equivalents outstanding																		77,343,853		90,395,775		84,967,720		77,343,853
Basic earnings per share:
Income (loss) from continuing operations available to common stockholders per share (dollars per share)																				$ 2.44		$ 0.52		$ 0
Income from discontinued operations per share of common stock (dollars per share)																		$ 0.37	[3]	0	[4]	1.47	[3]
Net income available to common stockholders per share (dollars per share)		$ 0.27		$ 1.10		$ 0.61		$ 0.45		$ 0.32		$ 0.18		$ 0.33	[1]	$ 1.17		0.37		2.44		1.99		0.37
Diluted earnings per share:
Income (loss) from continuing operations available to common stockholders per share (dollars per share)																				2.42		0.51		0
Income from discontinued operations per share of common stock (dollars per share)																		0.37	[4]	0	[4]	1.44	[3]
Net income available to common stockholders per share (dollars per share)		$ 0.27		$ 1.09		$ 0.61		$ 0.45		$ 0.32		$ 0.18		$ 0.32	[1]	$ 1.14		$ 0.37		$ 2.42		$ 1.95		$ 0.37
[1]	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common stockholders per share does not equal the annual number reported on the consolidated statements of operations due to the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended December 31, 2015 and 2014.
[2]	Participating securities include nonvested shares, certain time-based RSUs and vested market measure-based RSUs.
[3]	(2)The Company adopted ASU 2014-08 effective January 1, 2015 (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As a result, properties classified as held for sale and/or disposed of subsequent to January 1, 2015 that do not represent a strategic shift are no longer presented as discontinued operations.
[4]	The Operating Partnership adopted ASU 2014-08 effective January 1, 2015 (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As a result, properties classified as held for sale and/or disposed of subsequent to January 1, 2015 that do not represent a strategic shift are no longer presented as discontinued operations.

Net Income Available to Comm106

Net Income Available to Common Unitholders Per Unit of the Operating Partnership (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended																		12 Months Ended
		Dec. 31, 2015		Sep. 30, 2015		Jun. 30, 2015		Mar. 31, 2015		Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2012		Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Numerator:
Income from continuing operations		$ 29,308	[1]	$ 106,704	[1]	$ 58,590	[1]	$ 44,002	[1]	$ 19,417	[1]	$ 13,168	[1]	$ 15,854		$ 10,874	[1]	$ 14,935		$ 238,604		$ 59,313		$ 14,935
Income from continuing operations attributable to noncontrolling interests in consolidated subsidiaries																		(36)		(4,523)		(966)
Preferred dividends and distributions		$ (3,312)	[1]	$ (3,313)	[1]	$ (3,312)	[1]	$ (3,313)	[1]	(3,312)	[1]	(3,313)	[1]	(3,312)	[1]	(3,313)	[1]	(13,250)		(13,250)		(13,250)
Allocation to participating securities (1)	[2]																	(1,689)		(1,634)		(1,699)
Numerator for basic and diluted income (loss) from continuing operations available to common unitholders																		(40)		219,197		43,398
Income from discontinued operations (2)										$ 12,013	[1]	$ 6,135	[1]	$ 15,289	[1]	$ 91,058	[1]	29,630	[3]	0	[3]	124,495	[3]	$ 29,630	[4]
(Income) loss from discontinued operations attributable to noncontrolling interests in consolidated subsidiaries (2)																		(649)		0		(2,623)
Numerator for basic and diluted net income available to common unitholders																		$ 28,941		$ 219,197		$ 165,270
Denominator:
Basic weighted average vested shares outstanding																		77,343,853		89,854,096		83,090,235		77,343,853
Effect of dilutive securities – contingently issuable shares and stock options																		0		541,679		1,877,485
Diluted weighted average vested units and common unit equivalents outstanding																		77,343,853		90,395,775		84,967,720		77,343,853
Basic earnings per unit:
Income (loss) from continuing operations available to common stockholders per share (dollars per share)																				$ 2.44		$ 0.52		$ 0
Income from discontinued operations per common unit (dollars per unit)																		$ 0.37	[3]	0	[4]	1.47	[3]
Net income available to common unitholders per unit (dollars per unit)		$ 0.27	[1]	$ 1.10	[1]	$ 0.61	[1]	$ 0.45	[1]	$ 0.32	[1]	$ 0.18	[1]	$ 0.33	[1]	$ 1.17	[1]	0.37		2.44		1.99		0.37
Diluted earnings per unit:
Income (loss) from continuing operations available to common unitholders per unit (dollars per unit)																				2.42		0.51		0
Income from discontinued operations per common unit (dollars per unit)																		0.37	[4]	0	[4]	1.44	[3]
Net income available to common unitholders per unit (dollars per unit)		$ 0.27	[1]	$ 1.09	[1]	$ 0.61	[1]	$ 0.45	[1]	$ 0.32	[1]	$ 0.18	[1]	$ 0.32	[1]	$ 1.14	[1]	$ 0.37		$ 2.42		$ 1.95		$ 0.37
Kilroy Realty, L.P. [Member]
Numerator:
Income from continuing operations		$ 29,308	[5]	$ 106,704	[5]	$ 58,590	[5]	$ 44,002	[5]	$ 19,417	[5]	$ 13,168	[5]	$ 15,854		$ 10,874	[5]			$ 238,604		$ 59,313		$ 14,935
Income from continuing operations attributable to noncontrolling interests in consolidated subsidiaries																				(467)		(247)		(225)
Preferred dividends and distributions		$ (3,312)	[5]	$ (3,313)	[5]	$ (3,312)	[5]	$ (3,313)	[5]	(3,312)	[5]	(3,313)	[5]	(3,312)	[5]	(3,313)	[5]			(13,250)		(13,250)		(13,250)
Allocation to participating securities (1)	[6]																			(1,634)		(1,699)		(1,689)
Numerator for basic and diluted income (loss) from continuing operations available to common unitholders																				223,253		44,117		(229)
Income from discontinued operations (2)										$ 12,013	[5]	$ 6,135	[5]	$ 15,289	[5]	$ 91,058	[5]			0	[4]	124,495	[4]	29,630
(Income) loss from discontinued operations attributable to noncontrolling interests in consolidated subsidiaries (2)																				0		(13)		1
Numerator for basic and diluted net income available to common unitholders																				$ 223,253		$ 168,599		$ 29,402
Denominator:
Basic weighted average vested shares outstanding																				91,645,578		84,894,498		79,166,260
Effect of dilutive securities – contingently issuable shares and stock options																				541,679		1,877,485		0
Diluted weighted average vested units and common unit equivalents outstanding																				92,187,257		86,771,983		79,166,260
Basic earnings per unit:
Income (loss) from continuing operations available to common stockholders per share (dollars per share)																				$ 2.44		$ 0.52		$ 0
Income from discontinued operations per common unit (dollars per unit)																				0	[4]	1.47	[7]	0.37	[4]
Net income available to common unitholders per unit (dollars per unit)		$ 0.27	[5]	$ 1.10	[5]	$ 0.61	[5]	$ 0.45	[5]	$ 0.32	[5]	$ 0.18	[5]	$ 0.33	[5]	$ 1.17	[5]			2.44		1.99		0.37
Diluted earnings per unit:
Income (loss) from continuing operations available to common unitholders per unit (dollars per unit)																				2.42		0.51		0
Income from discontinued operations per common unit (dollars per unit)	[4]																			0		1.43		0.37
Net income available to common unitholders per unit (dollars per unit)		$ 0.27	[5]	$ 1.09	[5]	$ 0.61	[5]	$ 0.45	[5]	$ 0.31	[5]	$ 0.18	[5]	$ 0.32	[5]	$ 1.14	[5]			$ 2.42		$ 1.94		$ 0.37
[1]	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common stockholders per share does not equal the annual number reported on the consolidated statements of operations due to the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended December 31, 2015 and 2014.
[2]	Participating securities include nonvested shares, certain time-based RSUs and vested market measure-based RSUs.
[3]	(2)The Company adopted ASU 2014-08 effective January 1, 2015 (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As a result, properties classified as held for sale and/or disposed of subsequent to January 1, 2015 that do not represent a strategic shift are no longer presented as discontinued operations.
[4]	The Operating Partnership adopted ASU 2014-08 effective January 1, 2015 (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As a result, properties classified as held for sale and/or disposed of subsequent to January 1, 2015 that do not represent a strategic shift are no longer presented as discontinued operations.
[5]	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common unitholders per unit does not equal the annual number reported on the consolidated statements of operations due to the impact of the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended December 31, 2015 and 2014.
[6]	Participating securities include nonvested shares, certain time-based RSUs and vested market measure-based RSUs.
[7]	Capital gains are comprised entirely of 20% rate gains.

Supplemental Cash Flow Infor107

Supplemental Cash Flow Information of the Company (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other Significant Noncash Transactions [Line Items]
Interest Paid, Net	$ 54,747	$ 58,944	$ 65,157
Capital Expenditures Incurred but Not yet Paid	109,715	77,091	73,482
Tenant improvements funded directly by tenants to third parties	13,837	42,906	7,633
Noncash or Part Noncash Acquisition, Debt Assumed	0	0	95,496
Noncash or Part Noncash Acquisition, Other Liabilities Assumed	6,254	14,917	1,811
Release of Holdback Funds to Third Party	9,279	0	0
Noncash or Part Noncash Acquisition, Land Contributed, Net of Liabilities Assumed	0	0	(4,885)
Common Stockholders And Unitholders Dividends And Distributions Declared But Not Paid	(33,336)	(31,243)	(29,378)
Preferred Stockholders And Unitholders Dividends And Distributions Declared But Not Paid	1,656	1,656	1,694
purchase price, value of shares issued to acquire land	0	21,631	0
Conversion of Stock, Amount Converted	$ 1,223	$ 28	$ 450

Tax Treatment of Distributio108

Tax Treatment of Distributions (Details) - $ / shares	3 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2011
Class of Stock [Line Items]
Dividends declared per common share		$ 1.40	$ 1.40		$ 1.40
Common Stock
Class of Stock [Line Items]
Dividends declared per common share	$ 1.400	1.400	1.400
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	0.350	0.350	0.350
Dividends paid per common share	$ 1.400	$ 1.400	$ 1.400	$ 1.400

Tax Treatment of Distributio109

Tax Treatment of Distributions (Details 1) - $ / shares		1 Months Ended		3 Months Ended	12 Months Ended
		Aug. 31, 2012	Mar. 31, 2012	Dec. 31, 2012	Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Income Tax Treatment of Dividends Paid [Line Items]
Capital gains, federal statutory tax rate							20.00%		25.00%
Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per common share				$ 1.400	$ 1.400		$ 1.400		$ 1.400
Common Stock, Dividends, Per Share, Cash Paid, Percentage					100.00%		100.00%		100.00%
Series G Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred stock, dividend rate			6.875%		6.875%				6.875%
Preferred Stock, Dividends, Per Share, Cash Paid					$ 1.719		$ 1.719		$ 1.719
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage					100.00%		100.00%		100.00%
Series H Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred stock, dividend rate		6.375%			6.375%				6.375%
Preferred Stock, Dividends, Per Share, Cash Paid					$ 1.594		$ 1.594		$ 1.594
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage					100.00%		100.00%		100.00%
Series E Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid					$ 0		$ 0		$ 0.818
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage					0.00%		0.00%		100.00%
Series F Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid					$ 0		$ 0		$ 0.786
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage					0.00%		0.00%		100.00%
Tax Treatment, Ordinary Income | Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per common share					$ 0.992		$ 0.998		$ 0.756
Common Stock, Dividends, Per Share, Cash Paid, Percentage					70.86%		71.29%		54.00%
Tax Treatment, Ordinary Income | Series G Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid					$ 1.218		$ 1.711		$ 1.668
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage					70.86%		99.54%		97.03%
Tax Treatment, Ordinary Income | Series H Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid					$ 1.129		$ 1.587		$ 1.546
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage					70.86%		99.56%		96.99%
Tax Treatment, Ordinary Income | Series E Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid					$ 0		$ 0		$ 0.818
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage					0.00%		0.00%		100.00%
Tax Treatment, Ordinary Income | Series F Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid					$ 0		$ 0		$ 0.786
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage					0.00%		0.00%		100.00%
Tax Treatment, Qualified Dividend | Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per common share					$ 0.002		$ 0.002		$ 0.003
Common Stock, Dividends, Per Share, Cash Paid, Percentage					0.13%		0.14%		0.21%
Tax Treatment, Qualified Dividend | Series G Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid					$ 0.002		$ 0.003		$ 0.006
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage					0.13%		0.17%		0.35%
Tax Treatment, Qualified Dividend | Series H Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid					$ 0.002		$ 0.003		$ 0.006
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage					0.13%		0.19%		0.38%
Tax Treatment, Return of Capital | Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per common share					$ 0		$ 0.398		$ 0.620
Common Stock, Dividends, Per Share, Cash Paid, Percentage					0.00%		28.43%		44.29%
Tax Treatment, Capital Gains | Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per common share					$ 0.051		$ 0.002	[1]	$ 0	[1]
Common Stock, Dividends, Per Share, Cash Paid, Percentage	[1]				3.65%		0.14%		0.00%
Tax Treatment, Capital Gains | Series G Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid					$ 0.063		$ 0.005	[2]	$ 0	[2]
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage	[2]				3.65%		0.29%		0.00%
Tax Treatment, Capital Gains | Series H Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid					$ 0.059		$ 0.004		$ 0
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage					3.65%	[2]	0.25%		0.00%
Tax Treatment, Capital Gains | Series E Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid					$ 0		$ 0		$ 0
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage					0.00%		0.00%		0.00%
Tax Treatment, Capital Gains | Series F Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid					$ 0		$ 0		$ 0
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage					0.00%		0.00%		0.00%
Tax Treatment, Unrecaptured Section 1250 Gains | Common Stock
Income Tax Treatment of Dividends Paid [Line Items]
Dividends paid per common share					$ 0.355		$ 0		$ 0.021
Common Stock, Dividends, Per Share, Cash Paid, Percentage					25.36%		0.00%		1.50%
Tax Treatment, Unrecaptured Section 1250 Gains | Series G Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid					$ 0.436		$ 0		$ 0.045
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage					25.36%		0.00%		2.62%
Tax Treatment, Unrecaptured Section 1250 Gains | Series H Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid					$ 0.404		$ 0		$ 0.042
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage					25.36%		0.00%		2.63%
Tax Treatment, Unrecaptured Section 1250 Gains | Series E Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid					$ 0		$ 0		$ 0
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage					0.00%		0.00%		0.00%
Tax Treatment, Unrecaptured Section 1250 Gains | Series F Cumulative Redeemable Preferred Stock
Income Tax Treatment of Dividends Paid [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid					$ 0		$ 0		$ 0
Preferred Stock, Dividends, Per Share, Cash Paid, Percentage					0.00%		0.00%		0.00%
[1]	Capital gains are comprised entirely of 20% rate gains.
[2]	Capital gains are comprised entirely of 20%

Quarterly Financial Informat110

Quarterly Financial Information of the Company (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																		12 Months Ended
	Dec. 31, 2015	[1]	Sep. 30, 2015	[1]	Jun. 30, 2015	[1]	Mar. 31, 2015	[1]	Dec. 31, 2014	[1]	Sep. 30, 2014	[1]	Jun. 30, 2014		Mar. 31, 2014	[1]	Dec. 31, 2012		Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Revenues from continuing operations	$ 147,413		$ 141,553		$ 146,227		$ 146,082		$ 141,765		$ 129,024		$ 127,178	[1]	$ 123,758				$ 581,275		$ 521,725		$ 457,111
Income from continuing operations	29,308		106,704		58,590		44,002		19,417		13,168		15,854		10,874		$ 14,935		238,604		59,313		14,935
Income from discontinued operations (2)									12,013		6,135		15,289	[1]	91,058		29,630	[2]	0	[2]	124,495	[2]	29,630	[3]
Net income	29,308		106,704		58,590		44,002		31,430		19,303		31,143	[1]	101,932				238,604		183,808		44,565
Net income attributable to Kilroy Realty Corporation	28,635		104,759		57,500		43,187		30,852		18,982		30,540	[1]	99,845				234,081		180,219		43,880
Preferred dividends and distributions	(3,312)		(3,313)		(3,312)		(3,313)		(3,312)		(3,313)		(3,312)	[1]	(3,313)		$ (13,250)		(13,250)		(13,250)
Net income available to common stockholders	$ 25,323		$ 101,446		$ 54,188		$ 39,874		$ 27,540		$ 15,669		$ 27,228	[1]	$ 96,532				$ 220,831		$ 166,969		$ 30,630
Net income (loss) available to common stockholders per share—basic (dollars per share)	$ 0.27		$ 1.10		$ 0.61		$ 0.45		$ 0.32		$ 0.18		$ 0.33	[1]	$ 1.17		$ 0.37		$ 2.44		$ 1.99		$ 0.37
Net income (loss) available to common stockholders per share—diluted (dollars per share)	$ 0.27		$ 1.09		$ 0.61		$ 0.45		$ 0.32		$ 0.18		$ 0.32	[1]	$ 1.14		$ 0.37		$ 2.42		$ 1.95		$ 0.37
[1]	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common stockholders per share does not equal the annual number reported on the consolidated statements of operations due to the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended December 31, 2015 and 2014.
[2]	(2)The Company adopted ASU 2014-08 effective January 1, 2015 (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As a result, properties classified as held for sale and/or disposed of subsequent to January 1, 2015 that do not represent a strategic shift are no longer presented as discontinued operations.
[3]	The Operating Partnership adopted ASU 2014-08 effective January 1, 2015 (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As a result, properties classified as held for sale and/or disposed of subsequent to January 1, 2015 that do not represent a strategic shift are no longer presented as discontinued operations.

Quarterly Financial Informat111

Quarterly Financial Information of the Operating Partnership (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																		12 Months Ended
	Dec. 31, 2015		Sep. 30, 2015		Jun. 30, 2015		Mar. 31, 2015		Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2012		Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Revenues from continuing operations	$ 147,413	[1]	$ 141,553	[1]	$ 146,227	[1]	$ 146,082	[1]	$ 141,765	[1]	$ 129,024	[1]	$ 127,178	[1]	$ 123,758	[1]			$ 581,275		$ 521,725		$ 457,111
Income from continuing operations	29,308	[1]	106,704	[1]	58,590	[1]	44,002	[1]	19,417	[1]	13,168	[1]	15,854		10,874	[1]	$ 14,935		238,604		59,313		14,935
Income from discontinued operations (2)									12,013	[1]	6,135	[1]	15,289	[1]	91,058	[1]	29,630	[2]	0	[2]	124,495	[2]	29,630	[3]
Net income	29,308	[1]	106,704	[1]	58,590	[1]	44,002	[1]	31,430	[1]	19,303	[1]	31,143	[1]	101,932	[1]			238,604		183,808		44,565
Net income attributable to the Operating Partnership	28,635	[1]	104,759	[1]	57,500	[1]	43,187	[1]	30,852	[1]	18,982	[1]	30,540	[1]	99,845	[1]			234,081		180,219		43,880
Preferred distributions	(3,312)	[1]	(3,313)	[1]	(3,312)	[1]	(3,313)	[1]	(3,312)	[1]	(3,313)	[1]	(3,312)	[1]	(3,313)	[1]	$ (13,250)		(13,250)		(13,250)
Net income available to common stockholders	$ 25,323	[1]	$ 101,446	[1]	$ 54,188	[1]	$ 39,874	[1]	$ 27,540	[1]	$ 15,669	[1]	$ 27,228	[1]	$ 96,532	[1]			$ 220,831		$ 166,969		$ 30,630
Net income (loss) available to common stockholders per share—basic (dollars per share)	$ 0.27	[1]	$ 1.10	[1]	$ 0.61	[1]	$ 0.45	[1]	$ 0.32	[1]	$ 0.18	[1]	$ 0.33	[1]	$ 1.17	[1]	$ 0.37		$ 2.44		$ 1.99		$ 0.37
Net income (loss) available to common stockholders per share—diluted (dollars per share)	$ 0.27	[1]	$ 1.09	[1]	$ 0.61	[1]	$ 0.45	[1]	$ 0.32	[1]	$ 0.18	[1]	$ 0.32	[1]	$ 1.14	[1]	$ 0.37		$ 2.42		$ 1.95		$ 0.37
Kilroy Realty, L.P. [Member]
Revenues from continuing operations	$ 147,413	[1]	$ 141,553	[1]	$ 146,227	[1]	$ 146,082	[1]	$ 141,765	[4]	$ 129,024	[4]	$ 127,178	[4]	$ 123,758	[4]			$ 581,275		$ 521,725		$ 457,111
Income from continuing operations	29,308	[4]	106,704	[4]	58,590	[4]	44,002	[4]	19,417	[4]	13,168	[4]	15,854		10,874	[4]			238,604		59,313		14,935
Income from discontinued operations (2)									12,013	[4]	6,135	[4]	15,289	[4]	91,058	[4]			0	[3]	124,495	[3]	29,630
Net income	29,308	[4]	106,704	[4]	58,590	[4]	44,002	[4]	31,430	[4]	19,303	[4]	31,143	[4]	101,932	[4]			238,604		183,808		44,565
Net income attributable to the Operating Partnership	29,052	[4]	106,640	[4]	58,518	[4]	43,927	[4]	31,371	[4]	19,244	[4]	31,066	[4]	101,867	[4]			238,137		183,548		44,341
Preferred distributions	(3,312)	[4]	(3,313)	[4]	(3,312)	[4]	(3,313)	[4]	(3,312)	[4]	(3,313)	[4]	(3,312)	[4]	(3,313)	[4]			(13,250)		(13,250)		(13,250)
Net income available to common stockholders	$ 25,740	[4]	$ 103,327	[4]	$ 55,206	[4]	$ 40,614	[4]	$ 28,059	[4]	$ 15,931	[4]	$ 27,754	[4]	$ 98,554	[4]			$ 224,887		$ 170,298		$ 31,091
Net income (loss) available to common stockholders per share—basic (dollars per share)	$ 0.27	[4]	$ 1.10	[4]	$ 0.61	[4]	$ 0.45	[4]	$ 0.32	[4]	$ 0.18	[4]	$ 0.33	[4]	$ 1.17	[4]			$ 2.44		$ 1.99		$ 0.37
Net income (loss) available to common stockholders per share—diluted (dollars per share)	$ 0.27	[4]	$ 1.09	[4]	$ 0.61	[4]	$ 0.45	[4]	$ 0.31	[4]	$ 0.18	[4]	$ 0.32	[4]	$ 1.14	[4]			$ 2.42		$ 1.94		$ 0.37
[1]	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common stockholders per share does not equal the annual number reported on the consolidated statements of operations due to the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended December 31, 2015 and 2014.
[2]	(2)The Company adopted ASU 2014-08 effective January 1, 2015 (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As a result, properties classified as held for sale and/or disposed of subsequent to January 1, 2015 that do not represent a strategic shift are no longer presented as discontinued operations.
[3]	The Operating Partnership adopted ASU 2014-08 effective January 1, 2015 (see Note 2 “Basis of Presentation and Significant Accounting Policies” for additional information). As a result, properties classified as held for sale and/or disposed of subsequent to January 1, 2015 that do not represent a strategic shift are no longer presented as discontinued operations.
[4]	The summation of the quarterly financial data may not equal the annual number reported on the consolidated statements of operations due to rounding. The summation of the quarterly net income (loss) available to common unitholders per unit does not equal the annual number reported on the consolidated statements of operations due to the impact of the Company's public offerings of common stock and its at-the-market stock offering programs that occurred during the years ended December 31, 2015 and 2014.

Subsequent Events (Details)

Subsequent Events (Details) $ / shares in Units, $ in Thousands		Jan. 21, 2016USD ($)	Jan. 13, 2016USD ($)	Feb. 11, 2016USD ($)	Jan. 31, 2016shares	Dec. 31, 2015USD ($)building$ / sharesshares	Dec. 31, 2014USD ($)property$ / sharesshares	Dec. 31, 2013USD ($)	Dec. 31, 2011$ / shares
Subsequent Event [Line Items]
Dispositions Sales Price	[1]					$ 309,200	$ 399,500	$ 56,900
Number of real estate properties						2	5
Payments of Ordinary Dividends, Common Stock						$ 126,839	$ 118,463	111,517
Common Stock, Dividends, Per Share, Declared | $ / shares						$ 1.40	$ 1.40		$ 1.40
Dividends, Preferred Stock						$ 13,250	$ 13,250	$ 13,250
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | shares						212,468
Subsequent Event [Member]
Subsequent Event [Line Items]
Dispositions Sales Price		$ 262,300	$ 4,500
Payments of Ordinary Dividends, Common Stock				$ 33,400
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | shares					328,731
Von Karman, Irvine, California [Member]
Subsequent Event [Line Items]
Dispositions Sales Price	[2],[3]					$ 26,000	$ 26,000
Market Measure-Based Restricted Stock Units (RSUs) [Member]
Subsequent Event [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | shares						127,657	119,098
Market Measure-Based Restricted Stock Units (RSUs) [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | shares					185,032
[1]	Represents gross sales price before the impact of broker commissions and closing costs.
[2]	Represents gross sales price before the impact of commissions and closing costs.
[3]	This transaction resulted in a gain on sale of $17.3 million.

Schedule II Valuation and Qu113

Schedule II Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for Uncollectible Tenant Receivables
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period		$ 1,999	$ 2,134	$ 2,581
Charged to Costs and Expenses	[1]	303	58	396
Recoveries (Deductions)		(222)	(193)	(843)
Balance at End of Period		2,080	1,999	2,134
Allowance for Unbilled Deferred Rent
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period		1,989	2,075	2,607
Charged to Costs and Expenses	[1]	242	0	0
Recoveries (Deductions)		(349)	(86)	(532)
Balance at End of Period		$ 1,882	$ 1,989	$ 2,075
[1]	For the year ended December 31, 2013, includes amounts reported for properties classified as held for sale.

Schedule III - Real Estate a114

Schedule III - Real Estate and Accumulated Depreciation (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)ft²	Jun. 30, 2015USD ($)	Dec. 31, 2014ft²	Jan. 31, 2014ft²	Dec. 31, 2013USD ($)ft²	Dec. 31, 2012USD ($)	Dec. 31, 2010USD ($)
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Accumulated Depreciation		$ 994,241			$ 947,664	$ 818,957	$ 756,515
Net Rentable Area | ft²	1,046,394		1,471,319	79,000	200,306
Office Building [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	$ 373,886
Real Estate and Accumulated Depreciation, Initial Cost of Land	835,393
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	2,617,322
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,514,091
Real Estate and Accumulated Depreciation, Carrying Amount of Land	875,794
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	4,091,012
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	4,966,806
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 994,241
Net Rentable Area | ft²	13,032,406
Office Building [Member] | 801 N. 34th St., Lake Union, WA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 0
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	58,537
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	164
Real Estate and Accumulated Depreciation, Carrying Amount of Land	0
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	58,701
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	58,701
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 7,676
Net Rentable Area | ft²	169,412
Office Building [Member] | Westlake Avenue North [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	$ 79,667
Real Estate and Accumulated Depreciation, Initial Cost of Land	14,710
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	82,018
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,087
Real Estate and Accumulated Depreciation, Carrying Amount of Land	14,710
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	83,105
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	97,815
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 8,236
Net Rentable Area | ft²	184,643
Office Building [Member] | Pacific Center Boulevard, Sorrento Mesa, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 2,693
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	6,280
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	4,220
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,693
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	10,500
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	13,193
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 3,615
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	67,995
Office Building [Member] | Executive Drive, UTC, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 1,623
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	7,926
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	2,639
Real Estate and Accumulated Depreciation, Carrying Amount of Land	1,623
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	10,565
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	12,188
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 5,992
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	47,846
Office Building [Member] | Valley Centre Drive, Del Mar, California Two [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 4,184
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	19,352
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	18,405
Real Estate and Accumulated Depreciation, Carrying Amount of Land	5,259
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	36,682
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	41,941
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 19,372
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	130,047
Office Building [Member] | 23925 Park Sorrento, Calabasas, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	$ 3,987
Real Estate and Accumulated Depreciation, Initial Cost of Land	50
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	2,346
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	493
Real Estate and Accumulated Depreciation, Carrying Amount of Land	50
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	2,839
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	2,889
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 1,587
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	11,789
Office Building [Member] | 23975 Park Sorrento, Calabasas, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 765
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	17,720
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	6,416
Real Estate and Accumulated Depreciation, Carrying Amount of Land	765
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	24,136
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	24,901
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 13,702
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	104,797
Office Building [Member] | 24025 Park Sorrento, Calabasas, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 845
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	15,896
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	6,121
Real Estate and Accumulated Depreciation, Carrying Amount of Land	845
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	22,017
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	22,862
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 12,503
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	108,671
Office Building [Member] | Townsgate Road, Thousand Oaks, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 5,248
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	8,001
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	7,417
Real Estate and Accumulated Depreciation, Carrying Amount of Land	5,247
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	15,419
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	20,666
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 9,764
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	81,067
Office Building [Member] | 2240 E. Imperial Highway, El Segundo, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 1,044
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	11,763
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	29,448
Real Estate and Accumulated Depreciation, Carrying Amount of Land	1,048
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	41,207
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	42,255
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 21,837
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	122,870
Office Building [Member] | 2250 E. Imperial Highway, El Segundo, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 2,579
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	29,062
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	34,953
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,547
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	64,047
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	66,594
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 46,814
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	298,728
Office Building [Member] | 2260 E. Imperial Highway, El Segundo, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 2,518
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	28,370
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	36,771
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,547
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	65,112
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	67,659
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 7,312
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	298,728
Office Building [Member] | 909 Sepulveda Boulevard, El Segundo, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	$ 65,563
Real Estate and Accumulated Depreciation, Initial Cost of Land	3,577
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	34,042
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	42,869
Real Estate and Accumulated Depreciation, Carrying Amount of Land	3,577
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	76,911
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	80,488
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 29,058
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	241,607
Office Building [Member] | 999 Sepulveda Boulevard, El Segundo, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 1,407
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	34,326
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	12,238
Real Estate and Accumulated Depreciation, Carrying Amount of Land	1,407
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	46,564
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	47,971
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 18,201
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	128,592
Office Building [Member] | 6121 W. Sunset Boulevard, Los Angeles, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 11,120
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	4,256
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	73,250
Real Estate and Accumulated Depreciation, Carrying Amount of Land	8,703
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	79,923
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	88,626
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 1,040
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	82,442
Office Building [Member] | 6115 W. Sunset Boulevard, Los Angeles, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 1,313
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	3
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	25,503
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,455
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	24,364
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	26,819
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 308
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	26,075
Office Building [Member] | 3750 Kilroy Airport Way, Long Beach, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	$ 1,941
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	10,463
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	12,404
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	12,404
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 9,280
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	10,457
Office Building [Member] | 3760 Kilroy Airport Way, Long Beach, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	$ 17,467
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	10,734
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	28,201
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	28,201
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 21,954
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	165,278
Office Building [Member] | 3780 Kilroy Airport Way, Long Beach, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	$ 22,319
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	17,939
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	40,258
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	40,258
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 32,824
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	219,745
Office Building [Member] | 3800 Kilroy Airport Way, Long Beach, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	$ 19,408
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	17,263
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	36,671
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	36,671
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 20,556
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	192,476
Office Building [Member] | 3840 Kilroy Airport Way, Long Beach, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	$ 13,586
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	9,337
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	22,923
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	22,923
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 13,222
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	136,026
Office Building [Member] | 3880 Kilroy Airport Way, Long Beach, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	$ 9,704
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	11,086
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	20,790
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	20,790
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 1,722
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	96,035
Office Building [Member] | 3900 Kilroy Airport Way, Long Beach, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	$ 12,615
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	9,949
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	22,564
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	22,564
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 13,958
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	126,840
Office Building [Member] | Kilroy Airport Center, Phase IV, Long Beach, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	$ 4,997
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements		4,997
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements		4,997
Real Estate and Accumulated Depreciation, Accumulated Depreciation		$ 4,984
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Office Building [Member] | 12100 W. Olympic Boulevard, Los Angeles, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 352
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	45,611
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	16,258
Real Estate and Accumulated Depreciation, Carrying Amount of Land	9,633
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	52,588
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	62,221
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 21,521
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	150,167
Office Building [Member] | 12200 W. Olympic Boulevard, Los Angeles, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 4,329
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	35,488
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	17,561
Real Estate and Accumulated Depreciation, Carrying Amount of Land	3,977
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	53,401
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	57,378
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 31,401
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	150,117
Office Building [Member] | 12233 Olympic Blvd, Los Angeles, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 22,100
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	53,170
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,695
Real Estate and Accumulated Depreciation, Carrying Amount of Land	22,100
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	54,865
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	76,965
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 5,616
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	151,029
Office Building [Member] | 12312 W. Olympic Boulevard, Los Angeles, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 3,325
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	12,202
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	11,307
Real Estate and Accumulated Depreciation, Carrying Amount of Land	3,399
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	23,435
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	26,834
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 7,687
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	76,644
Office Building [Member] | 6255 Sunset Boulevard, Los Angeles, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 18,111
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	60,320
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	32,840
Real Estate and Accumulated Depreciation, Carrying Amount of Land	18,111
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	93,160
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	111,271
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 12,693
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	324,617
Office Building [Member] | 1633 26th Street, Santa Monica, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 2,080
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	6,672
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	2,955
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,040
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	9,667
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	11,707
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 5,996
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	44,915
Office Building [Member] | 2100 Colorado Avenue, Santa Monica, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	$ 96,354
Real Estate and Accumulated Depreciation, Initial Cost of Land	5,474
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	26,087
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	13,998
Real Estate and Accumulated Depreciation, Carrying Amount of Land	5,476
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	40,083
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	45,559
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 18,941
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	102,864
Office Building [Member] | 3130 Wilshire Boulevard, Santa Monica, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 8,921
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	6,579
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	11,929
Real Estate and Accumulated Depreciation, Carrying Amount of Land	9,188
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	18,241
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	27,429
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 12,144
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	88,340
Office Building [Member] | 501 Santa Monica Boulevard, Santa Monica, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 4,547
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	12,044
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	8,861
Real Estate and Accumulated Depreciation, Carrying Amount of Land	4,551
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	20,901
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	25,452
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 11,794
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	73,115
Office Building [Member] | Michelson Drive Irvine CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 9,319
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	82,836
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	4,163
Real Estate and Accumulated Depreciation, Carrying Amount of Land	9,319
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	86,999
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	96,318
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 17,512
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	271,556
Office Building [Member] | 12225 El Camino Real, Del Mar, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 1,700
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	9,633
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	2,969
Real Estate and Accumulated Depreciation, Carrying Amount of Land	1,660
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	12,642
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	14,302
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 7,013
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	58,401
Office Building [Member] | 12235 El Camino Real, Del Mar, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 1,507
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	8,543
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	4,943
Real Estate and Accumulated Depreciation, Carrying Amount of Land	1,554
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	13,439
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	14,993
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 8,102
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	54,673
Office Building [Member] | 12340 El Camino Real, Del Mar, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 4,201
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	13,896
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	7,981
Real Estate and Accumulated Depreciation, Carrying Amount of Land	4,201
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	21,877
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	26,078
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 8,875
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	87,774
Office Building [Member] | 12390 El Camino Real, Del Mar, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 3,453
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	11,981
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,344
Real Estate and Accumulated Depreciation, Carrying Amount of Land	3,453
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	13,325
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	16,778
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 7,920
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	72,332
Office Building [Member] | 12348 High Bluff Drive, Del Mar, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 1,629
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	3,096
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	4,686
Real Estate and Accumulated Depreciation, Carrying Amount of Land	1,629
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	7,782
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	9,411
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 5,164
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	38,806
Office Building [Member] | 12400 High Bluff Drive, Del Mar, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 15,167
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	40,497
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	12,551
Real Estate and Accumulated Depreciation, Carrying Amount of Land	15,167
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	53,048
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	68,215
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 21,723
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	209,220
Office Building [Member] | 3579 Valley Centre Drive, Del Mar, California One [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 2,167
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	6,897
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	7,400
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,858
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	13,606
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	16,464
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 7,788
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	50,677
Office Building [Member] | 3661 Valley Centre Drive, Del Mar, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 4,038
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	21,144
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	12,448
Real Estate and Accumulated Depreciation, Carrying Amount of Land	4,725
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	32,905
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	37,630
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 16,408
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	129,051
Office Building [Member] | 3721 Valley Centre Drive, Del Mar, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 4,297
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	18,967
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	12,819
Real Estate and Accumulated Depreciation, Carrying Amount of Land	4,254
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	31,829
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	36,083
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 11,283
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	114,780
Office Building [Member] | 3811 Valley Centre Drive, Del Mar, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 3,452
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	16,152
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	20,092
Real Estate and Accumulated Depreciation, Carrying Amount of Land	4,457
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	35,239
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	39,696
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 17,641
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	112,067
Office Building [Member] | 12770 El Camino Real, Del Mar, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 9,360
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	0
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	22,492
Real Estate and Accumulated Depreciation, Carrying Amount of Land	9,360
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	22,492
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	31,852
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 0
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	(9)
Office Building [Member] | El Camino Real, Del Mar, California Five [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 18,398
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	54,954
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,623
Real Estate and Accumulated Depreciation, Carrying Amount of Land	18,398
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	56,577
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	74,975
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 4,942
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	140,591
Office Building [Member] | El Camino Real, Del Mar, California Six [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 10,252
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	21,236
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,202
Real Estate and Accumulated Depreciation, Carrying Amount of Land	10,252
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	22,438
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	32,690
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 1,905
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	78,349
Office Building [Member] | 13280 Evening Creek Drive, South I-15 Corridor, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 3,701
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	8,398
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	4,590
Real Estate and Accumulated Depreciation, Carrying Amount of Land	3,701
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	12,988
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	16,689
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 3,349
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	41,196
Office Building [Member] | 13290 Evening Creek Drive, South I-15 Corridor, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 5,229
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	11,871
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	5,898
Real Estate and Accumulated Depreciation, Carrying Amount of Land	5,229
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	17,769
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	22,998
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 3,418
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	61,180
Office Building [Member] | 13480 Evening Creek Drive, North I-15 Corridor, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 7,997
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	0
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	48,103
Real Estate and Accumulated Depreciation, Carrying Amount of Land	7,997
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	48,103
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	56,100
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 13,230
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	149,817
Office Building [Member] | 13500 Evening Creek Drive, North I-15 Corridor, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 7,581
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	35,903
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	8,540
Real Estate and Accumulated Depreciation, Carrying Amount of Land	7,580
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	44,444
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	52,024
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 15,768
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	147,533
Office Building [Member] | 13520 Evening Creek Drive, North I-15 Corridor, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 7,581
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	35,903
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	10,094
Real Estate and Accumulated Depreciation, Carrying Amount of Land	7,580
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	45,998
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	53,578
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 17,422
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	141,128
Office Building [Member] | 2355 Northside Drive, Mission Valley, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 4,066
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	8,332
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	2,085
Real Estate and Accumulated Depreciation, Carrying Amount of Land	3,344
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	11,139
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	14,483
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 2,770
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	53,610
Office Building [Member] | 2365 Northside Drive, Mission Valley, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 7,359
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	15,257
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	6,324
Real Estate and Accumulated Depreciation, Carrying Amount of Land	6,015
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	22,925
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	28,940
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 4,766
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	96,437
Office Building [Member] | 2375 Northside Drive, Mission Valley, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 3,947
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	8,146
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	2,386
Real Estate and Accumulated Depreciation, Carrying Amount of Land	3,213
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	11,266
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	14,479
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 2,688
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	51,516
Office Building [Member] | 2385 Northside Drive, Mission Valley, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 2,752
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	14,513
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	5,240
Real Estate and Accumulated Depreciation, Carrying Amount of Land	5,552
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	16,953
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	22,505
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 4,410
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	89,023
Office Building [Member] | 2305 Historic Decatur Road, San Diego, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 5,240
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	22,220
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	3,278
Real Estate and Accumulated Depreciation, Carrying Amount of Land	5,240
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	25,498
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	30,738
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 4,938
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	103,900
Office Building [Member] | 4939 Directors Place, Sorrento Mesa, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 2,225
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	12,698
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	4,359
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,198
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	17,084
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	19,282
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 8,975
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	60,662
Office Building [Member] | 4955 Directors Place, Sorrento Mesa, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 2,521
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	14,122
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	3,697
Real Estate and Accumulated Depreciation, Carrying Amount of Land	3,179
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	17,161
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	20,340
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 12,998
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	76,246
Office Building [Member] | 303 Second Street, San Francisco, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	$ 128,315
Real Estate and Accumulated Depreciation, Initial Cost of Land	63,550
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	154,153
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	42,562
Real Estate and Accumulated Depreciation, Carrying Amount of Land	63,550
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	196,715
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	260,265
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 41,552
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	740,047
Office Building [Member] | 100 First Street, San Francisco, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 49,150
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	131,238
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	25,717
Real Estate and Accumulated Depreciation, Carrying Amount of Land	49,150
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	156,955
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	206,105
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 32,069
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	467,095
Office Building [Member] | 250 Brannan Street, San Francisco, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 7,630
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	22,770
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	4,324
Real Estate and Accumulated Depreciation, Carrying Amount of Land	7,630
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	27,094
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	34,724
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 6,001
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	95,008
Office Building [Member] | 201 Third Street, San Francisco, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 19,260
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	84,018
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	32,926
Real Estate and Accumulated Depreciation, Carrying Amount of Land	19,260
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	116,944
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	136,204
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 23,292
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	346,538
Office Building [Member] | 301 Brannan Street, San Francisco, California [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 5,910
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	22,450
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,843
Real Estate and Accumulated Depreciation, Carrying Amount of Land	5,910
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	24,293
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	30,203
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 4,066
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	74,430
Office Building [Member] | 360 Third St., San Francisco, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 0
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	88,235
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	111,085
Real Estate and Accumulated Depreciation, Carrying Amount of Land	28,504
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	170,816
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	199,320
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 17,936
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	429,796
Office Building [Member] | 1310 Chesapeake Terrace, Sunnyvale, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 16,700
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	11,020
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	87
Real Estate and Accumulated Depreciation, Carrying Amount of Land	16,700
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	11,107
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	27,807
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 572
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	76,244
Office Building [Member] | 1315 Chesapeake Terrace, Sunnyvale, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 12,260
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	7,930
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	235
Real Estate and Accumulated Depreciation, Carrying Amount of Land	12,260
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	8,165
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	20,425
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 534
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	55,635
Office Building [Member] | 1320-1324 Chesapeake Terrace, Sunnyvale, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 17,360
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	10,720
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	91
Real Estate and Accumulated Depreciation, Carrying Amount of Land	17,360
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	10,811
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	28,171
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 723
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	79,720
Office Building [Member] | 1325-1327 Chesapeake Terrace, Sunnyvale, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 12,610
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	8,160
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	63
Real Estate and Accumulated Depreciation, Carrying Amount of Land	12,610
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	8,223
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	20,833
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 551
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	55,383
Office Building [Member] | 505 Mathilda Ave., Sunnyvale, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 37,843
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	1,163
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	50,847
Real Estate and Accumulated Depreciation, Carrying Amount of Land	37,943
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	51,910
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	89,853
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 1,966
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	212,322
Office Building [Member] | 555 Mathilda Ave., Sunnyvale, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 37,843
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	1,163
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	50,560
Real Estate and Accumulated Depreciation, Carrying Amount of Land	37,943
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	51,623
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	89,566
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 1,966
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	212,322
Office Building [Member] | 605 Mathilda Ave., Sunnyvale, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 29,014
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	891
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	76,844
Real Estate and Accumulated Depreciation, Carrying Amount of Land	29,090
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	77,659
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	106,749
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 4,354
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	162,785
Office Building [Member] | 599 N. Mathilda Avenue, Sunnyvale, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 13,538
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	12,559
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	58
Real Estate and Accumulated Depreciation, Carrying Amount of Land	13,538
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	12,617
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	26,155
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 1,778
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	75,810
Office Building [Member] | 601 108th Avenue, Bellevue, Washington [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 0
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	214,095
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	30,538
Real Estate and Accumulated Depreciation, Carrying Amount of Land	0
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	244,633
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	244,633
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 42,168
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	488,470
Office Building [Member] | NE 4th Street 10900 Bellevue, Washington [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 25,080
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	150,877
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	20,089
Real Estate and Accumulated Depreciation, Carrying Amount of Land	25,080
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	170,966
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	196,046
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 23,731
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	416,755
Office Building [Member] | 10210 NE Points Dr., Kirkland, Washington [Member] [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 4,336
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	24,187
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	2,659
Real Estate and Accumulated Depreciation, Carrying Amount of Land	4,336
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	26,846
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	31,182
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 5,022
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	84,641
Office Building [Member] | Pacific Center Court, Sorrento Mesa, California One [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 3,267
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	5,779
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	7,501
Real Estate and Accumulated Depreciation, Carrying Amount of Land	3,267
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	13,280
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	16,547
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 5,787
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	68,400
Office Building [Member] | Pacific Center Court, Sorrento Mesa, California Two [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 2,696
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	7,134
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	(781)
Real Estate and Accumulated Depreciation, Carrying Amount of Land	1,671
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	7,378
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	9,049
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 4,033
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	59,630
Office Building [Member] | Pacific Center Court, Sorrento Mesa, California Three [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 1,947
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	5,152
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,316
Real Estate and Accumulated Depreciation, Carrying Amount of Land	1,222
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	7,193
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	8,415
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 3,874
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	43,645
Office Building [Member] | Pacific Center Court, Sorrento Mesa, California Four [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 2,926
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	7,979
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	21,885
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,926
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	29,864
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	32,790
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 16,673
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	75,899
Office Building [Member] | Pacific Center Court, Sorrento Mesa, California Five [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 2,247
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	5,945
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,832
Real Estate and Accumulated Depreciation, Carrying Amount of Land	1,809
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	8,215
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	10,024
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 4,346
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	48,709
Office Building [Member] | Pacific Center Court, Sorrento Mesa, California Six [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 4,044
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	10,701
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	(2,250)
Real Estate and Accumulated Depreciation, Carrying Amount of Land	3,780
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	8,715
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	12,495
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 4,532
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	90,000
Office Building [Member] | Bohannon Drive 4100, Menlo Park, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 4,835
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	15,526
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	468
Real Estate and Accumulated Depreciation, Carrying Amount of Land	4,835
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	15,994
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	20,829
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 2,156
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	47,379
Office Building [Member] | Bohannon Drive 4200, Menlo Park, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 4,798
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	15,406
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	2,125
Real Estate and Accumulated Depreciation, Carrying Amount of Land	4,798
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	17,531
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	22,329
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 2,406
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	45,451
Office Building [Member] | Bohannon Drive 4300, Menlo Park, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 6,527
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	20,958
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	2,803
Real Estate and Accumulated Depreciation, Carrying Amount of Land	6,527
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	23,761
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	30,288
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 3,828
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	63,079
Office Building [Member] | Bohannon Drive 4400, Menlo Park, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 4,798
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	15,406
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	2,125
Real Estate and Accumulated Depreciation, Carrying Amount of Land	4,798
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	17,531
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	22,329
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 2,637
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	48,146
Office Building [Member] | Bohannon Drive 4500, Menlo Park, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 6,527
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	20,957
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,692
Real Estate and Accumulated Depreciation, Carrying Amount of Land	6,527
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	22,649
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	29,176
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 3,090
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	63,078
Office Building [Member] | Bohannon Drive 4600, Menlo Park, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 4,798
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	15,406
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	2,180
Real Estate and Accumulated Depreciation, Carrying Amount of Land	4,798
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	17,586
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	22,384
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 2,426
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	48,147
Office Building [Member] | Bohannon Drive 4700, Menlo Park, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 6,527
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	20,958
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,468
Real Estate and Accumulated Depreciation, Carrying Amount of Land	6,527
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	22,426
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	28,953
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 3,000
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	63,078
Office Building [Member] | Fairchild Drive, 331, Mountain View, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 18,396
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	17,712
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	7,887
Real Estate and Accumulated Depreciation, Carrying Amount of Land	18,396
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	25,599
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	43,995
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 1,972
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	87,147
Office Building [Member] | 680 E Middlefield Road, Mountain View, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 34,605
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	0
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	56,464
Real Estate and Accumulated Depreciation, Carrying Amount of Land	34,605
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	56,464
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	91,069
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 2,194
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	170,090
Office Building [Member] | 690 E Middlefield Road, Mountain View, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 34,755
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	0
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	56,707
Real Estate and Accumulated Depreciation, Carrying Amount of Land	34,755
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	56,707
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	91,462
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 2,203
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	170,823
Office Building [Member] | 900 Middlefield Road, Redwood City, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 7,959
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	0
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	46,065
Real Estate and Accumulated Depreciation, Carrying Amount of Land	8,626
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	45,398
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	54,024
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 277
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	113,790
Office Building [Member] | 900 Jefferson Ave., Redwood City, CA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 16,668
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	0
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	109,303
Real Estate and Accumulated Depreciation, Carrying Amount of Land	18,063
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	107,908
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	125,971
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 858
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	226,197
Office Building [Member] | NE Points Drive, Kirkland, Washington One [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 2,554
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	12,080
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,040
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,554
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	13,120
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	15,674
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 2,414
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	49,851
Office Building [Member] | NE Points Drive, Kirkland, Washington Two [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 5,071
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	24,694
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	3,671
Real Estate and Accumulated Depreciation, Carrying Amount of Land	5,070
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	28,366
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	33,436
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 5,189
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	98,982
Office Building [Member] | 3933 Lake WA Blvd. NE, Kirkland, WA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 2,380
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	15,114
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	3,428
Real Estate and Accumulated Depreciation, Carrying Amount of Land	2,380
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	18,542
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	20,922
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 3,450
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	46,450
Office Building [Member] | Fremont Lake View Seattle WA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 0
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	37,404
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	2,541
Real Estate and Accumulated Depreciation, Carrying Amount of Land	0
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	39,945
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	39,945
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 5,397
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	111,580
Office Building [Member] | Terry Avenue North, Washington Two [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 10,430
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	60,003
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	227
Real Estate and Accumulated Depreciation, Carrying Amount of Land	10,430
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	60,230
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	70,660
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 6,294
Net Rentable Area | ft²	135,755
Office Building [Member] | 701 N. 34th St., Lake Union, WA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 0
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	48,027
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	1,393
Real Estate and Accumulated Depreciation, Carrying Amount of Land	0
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	49,420
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	49,420
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 7,717
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Net Rentable Area | ft²	138,995
Office Building [Member] | 401 Terry Avenue North, Lake Union, WA [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Initial Cost of Land	$ 22,500
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	77,046
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	0
Real Estate and Accumulated Depreciation, Carrying Amount of Land	22,500
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	77,046
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	99,546
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 4,889
Net Rentable Area | ft²	140,605
Undeveloped Land and CIP Properties [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	$ 1,810
Real Estate and Accumulated Depreciation, Initial Cost of Land	730,351
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	111
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	630,878
Real Estate and Accumulated Depreciation, Carrying Amount of Land	730,351
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	630,989
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	1,361,340
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 0
Net Rentable Area | ft²	0

Schedule III - Real Estate a115

Schedule III - Real Estate and Accumulated Depreciation (Details 2) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
		Dec. 31, 2012	Dec. 31, 2015	Dec. 31, 2013
SEC Schedule III, Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Total real estate held for investment, beginning of year			$ 6,057,932	$ 5,264,947
Acquisitions		$ 384,650	139,123	340,296
Improvements, etc.		452,331	536,411	588,166
Total additions during period		836,981	675,534	928,462
Cost of real estate sold		(56,993)	(231,984)	(113,416)
Properties held for sale		(259,251)	(160,074)	(14,700)
Other	[1]	(13,184)	(13,262)	(7,361)
Total deductions during period		(329,428)	(405,320)	(135,477)
Total real estate held for investment, end of year		$ 5,264,947	$ 6,328,146	$ 6,057,932
[1]	{F|ahBzfndlYmZpbGluZ3MtaHJkcmoLEgZYTUxEb2MiXlhCUkxEb2NHZW5JbmZvOjc1MzE3MDhlOTcxNTQ5YjlhODJmZmNlM2UzNTVmZTg2fFRleHRTZWxlY3Rpb246MUZBNjVBQUVGMzIyQkEwM0JDQkRGOTkxQzlDMzdBNTEM}

Schedule III - Real Estate a116

Schedule III - Real Estate and Accumulated Depreciation (Details 3) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
		Dec. 31, 2012	Dec. 31, 2015	Dec. 31, 2013
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Accumulated depreciation, beginning of year				$ 818,957
Depreciation of real estate		$ 145,325	$ 159,524	153,841
SEC Schedule III, Real Estate Accumulated Depreciation, Period Increase		145,325	159,524	153,841
Write-offs due to sale		(17,144)	(66,603)	(18,111)
Properties held for sale		(63,110)	(46,191)	(7,007)
Other	[1]	(2,629)	(153)	(16)
Total deductions during period		(82,883)	$ (112,947)	(25,134)
Accumulated depreciation, end of year		$ 818,957		$ 947,664
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Schedule III - Real Estate a117

Schedule III - Real Estate and Accumulated Depreciation (Details) (Textuals) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014
Real Estate and Accumulated Depreciation [Line Items]
Secured debt (Notes 3, 6, 7 and 16)	$ 381,918		$ 546,292
Debt premium		$ 6,200
Aggregate cost of property for federal income tax purposes		$ 5,500,000
Secured Debt [Member]
Real Estate and Accumulated Depreciation [Line Items]
Debt premium	$ 6,200
Building [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Life Used for Depreciation	35 years
Tenant Improvements [Member] | Minimum [Member]
Real Estate and Accumulated Depreciation [Line Items]
Property, Plant and Equipment, Useful Life	1 year
Tenant Improvements [Member] | Maximum [Member]
Real Estate and Accumulated Depreciation [Line Items]
Property, Plant and Equipment, Useful Life	20 years