Consolidated Balance Sheets (KILROY REALTY, L.P.) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
REAL ESTATE ASSETS:
Buildings and improvements (Note 2)	$ 3,527,729		$ 3,335,026
Undeveloped land and construction in progress (Note 2)	907,959		809,654
Total real estate held for investment	5,048,531		4,757,394
Accumulated depreciation and amortization	(781,580)		(756,515)
Total real estate assets held for investment, net ($119,262 and $319,770 of VIE, respectively, Note 1)	4,266,951		4,000,879
REAL ESTATE ASSETS AND OTHER ASSETS HELD FOR SALE, NET (NOTE 12)	239,411		0
CASH AND CASH EQUIVALENTS	197,150		16,700
RESTRICTED CASH (Note 1)	17,931		247,544
MARKETABLE SECURITIES (Note 11)	9,192	[1],[2]	7,435	[1],[2]
CURRENT RECEIVABLES, NET (Note 4)	11,769	[3]	9,220
DEFERRED RENT RECEIVABLES, NET (Note 4)	121,659	[4]	115,418
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Notes 2 and 3)	190,085		189,968
DEFERRED FINANCING COSTS, NET	17,809		18,971
PREPAID EXPENSES AND OTHER ASSETS, NET	17,319		9,949
TOTAL ASSETS	5,089,276		4,616,084
LIABILITIES:
Secured debt (Notes 2, 5 and 11)	563,898	[5]	561,096	[5]
Exchangeable senior notes, net (Notes 5 and 11)	167,236		163,944
Unsecured debt, net (Notes 5 and 11)	1,431,048		1,130,895
Unsecured line of credit (Notes 5 and 11)	0		185,000
Accounts payable, accrued expenses and other liabilities	210,111		154,734
Accrued distributions (Note 15)	31,479		28,924
Deferred revenue and acquisition-related intangible liabilities, net (Notes 2 and 3)	102,991		117,904
Liabilities and deferred revenue of real estate assets held for sale (Note 12)	16,751		0
Total liabilities	2,565,182		2,380,151
COMMITMENTS AND CONTINGENCIES (Note 10)
Partners' Capital (Note 8):
TOTAL LIABILITIES AND EQUITY / CAPITAL	5,089,276		4,616,084
Kilroy Realty, L.P. [Member]
REAL ESTATE ASSETS:
Land and improvements (Note 2)	612,843		612,714
Buildings and improvements (Note 2)	3,527,729		3,335,026
Undeveloped land and construction in progress (Note 2)	907,959		809,654
Total real estate held for investment	5,048,531		4,757,394
Accumulated depreciation and amortization	781,580		(756,515)
Total real estate assets held for investment, net ($119,262 and $319,770 of VIE, respectively, Note 1)	4,266,951		4,000,879
CASH AND CASH EQUIVALENTS	197,150		16,700
RESTRICTED CASH (Note 1)	17,931		247,544
MARKETABLE SECURITIES (Note 11)	9,192		7,435
CURRENT RECEIVABLES, NET (Note 4)	11,769		9,220
DEFERRED RENT RECEIVABLES, NET (Note 4)	121,659		115,418
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Notes 2 and 3)	190,085		189,968
DEFERRED FINANCING COSTS, NET	17,809		18,971
PREPAID EXPENSES AND OTHER ASSETS, NET	17,319		9,949
TOTAL ASSETS	5,089,276		4,616,084
LIABILITIES:
Secured debt (Notes 2, 5 and 11)	563,898		561,096
Exchangeable senior notes, net (Notes 5 and 11)	167,236		163,944
Unsecured debt, net (Notes 5 and 11)	1,431,048		1,130,895
Unsecured line of credit (Notes 5 and 11)	0		185,000
Accounts payable, accrued expenses and other liabilities	210,111		154,734
Accrued distributions (Note 15)	31,479		28,924
Deferred revenue and acquisition-related intangible liabilities, net (Notes 2 and 3)	102,991		117,904
Rents received in advance and tenant security deposits	41,668		37,654
Total liabilities	2,565,182		2,380,151
Partners' Capital (Note 8):
Common units, 82,113,491 and 74,926,981 held by the general partner and 1,821,503 and 1,826,503 held by common limited partners issued and outstanding, respectively	2,323,341		2,040,243
Total partners' capital	2,515,752		2,232,654
Noncontrolling interest in consolidated subsidiaries (Notes 2 and 6)	8,342		3,279
Total capital	2,524,094		2,235,933
TOTAL LIABILITIES AND EQUITY / CAPITAL	5,089,276		4,616,084
Series G Cumulative Redeemable Preferred Unit [Member] | Kilroy Realty, L.P. [Member]
Partners' Capital (Note 8):
Redeemable Preferred stock	96,155		96,155
Series H Cumulative Redeemable Preferred Unit [Member] | Kilroy Realty, L.P. [Member]
Partners' Capital (Note 8):
Redeemable Preferred stock	$ 96,256		$ 96,256

[1] Based on quoted prices in active markets for identical securities.

[2] The marketable securities are held in a limited rabbi trust.

[3] Excludes current receivables, net related to properties held for sale at September 30, 2013.

[4] Excludes deferred rent receivables, net related to properties held for sale at September 30, 2013.

[5] Amounts reported include the amounts of unamortized debt premiums and discounts for the periods presented.