Consolidated Balance Sheets (KILROY REALTY, L.P.) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
REAL ESTATE ASSETS:
Land and improvements (Note 2)	$ 528,082	$ 491,333
Buildings and improvements (Note 2)	2,820,766	2,435,173
Undeveloped land and construction in progress	303,998	290,365
Total real estate held for investment	3,652,846	3,216,871
Accumulated depreciation and amortization	(720,864)	(672,429)
Total real estate assets, net	2,931,982	2,544,442
CASH AND CASH EQUIVALENTS	25,412	14,840
RESTRICTED CASH	1,349	1,461
MARKETABLE SECURITIES (Note 12)	5,654	4,902
CURRENT RECEIVABLES, NET (Note 4)	4,732	6,258
DEFERRED RENT RECEIVABLES, NET (Note 4)	97,958	89,052
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Notes 2 and 3)	153,231	131,066
DEFERRED FINANCING COSTS, NET (Note 5)	18,910	16,447
PREPAID EXPENSES AND OTHER ASSETS, NET	25,559	8,097
TOTAL ASSETS	3,264,787	2,816,565
LIABILITIES:
Secured debt, net (Notes 5 and 12)	475,820	313,009
Exchangeable senior notes, net (Notes 5 and 12)	303,374	299,964
Unsecured senior notes, net (Notes 5 and 12)	655,929	655,803
Unsecured line of credit (Notes 5 and 12)	245,000	159,000
Accounts payable, accrued expenses and other liabilities	66,664	68,525
Accrued distributions (Note 16)	22,563	20,385
Deferred revenue and acquisition-related intangible liabilities, net (Note 3)	90,149	79,322
Rents received in advance and tenant security deposits	28,117	29,189
Total liabilities	1,887,616	1,625,197
COMMITMENTS AND CONTINGENCIES (Note 11)
7.45% SERIES A CUMULATIVE REDEEMABLE PREFERRED UNITS	73,638	73,638
Partners' Capital (Note 8):
TOTAL LIABILITIES, NONCONTROLLING INTEREST AND EQUITY/CAPITAL	3,264,787	2,816,565
Kilroy Realty, L.P. [Member]
REAL ESTATE ASSETS:
Land and improvements (Note 2)	528,082	491,333
Buildings and improvements (Note 2)	2,820,766	2,435,173
Undeveloped land and construction in progress	303,998	290,365
Total real estate held for investment	3,652,846	3,216,871
Accumulated depreciation and amortization	(720,864)	(672,429)
Total real estate assets, net	2,931,982	2,544,442
CASH AND CASH EQUIVALENTS	25,412	14,840
RESTRICTED CASH	1,349	1,461
MARKETABLE SECURITIES (Note 12)	5,654	4,902
CURRENT RECEIVABLES, NET (Note 4)	4,732	6,258
DEFERRED RENT RECEIVABLES, NET (Note 4)	97,958	89,052
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Notes 2 and 3)	153,231	131,066
DEFERRED FINANCING COSTS, NET (Note 5)	18,910	16,447
PREPAID EXPENSES AND OTHER ASSETS, NET	25,559	8,097
TOTAL ASSETS	3,264,787	2,816,565
LIABILITIES:
Secured debt, net (Notes 5 and 12)	475,820	313,009
Exchangeable senior notes, net (Notes 5 and 12)	303,374	299,964
Unsecured senior notes, net (Notes 5 and 12)	655,929	655,803
Unsecured line of credit (Notes 5 and 12)	245,000	159,000
Accounts payable, accrued expenses and other liabilities	66,664	68,525
Accrued distributions (Note 16)	22,563	20,385
Deferred revenue and acquisition-related intangible liabilities, net (Note 3)	90,149	79,322
Rents received in advance and tenant security deposits	28,117	29,189
Total liabilities	1,887,616	1,625,197
COMMITMENTS AND CONTINGENCIES (Note 11)
7.45% SERIES A CUMULATIVE REDEEMABLE PREFERRED UNITS	73,638	73,638
Partners' Capital (Note 8):
Common units, 58,464,412 and 52,349,670 held by the general partner and 1,718,131 and 1,723,131 held by common limited partners issued and outstanding, respectively	1,180,249	994,511
Total Partners' Capital	1,301,831	1,116,093
Noncontrolling interests in consolidated subsidiaries	1,702	1,637
Total capital	1,303,533	1,117,730
TOTAL LIABILITIES, NONCONTROLLING INTEREST AND EQUITY/CAPITAL	3,264,787	2,816,565
Kilroy Realty, L.P. [Member] | Series E Cumulative Redeemable Preferred Stock
Partners' Capital (Note 8):
Cumulative Redeemable Preferred stock	38,425	38,425
Kilroy Realty, L.P. [Member] | Series F Cumulative Redeemable Preferred Stock
Partners' Capital (Note 8):
Cumulative Redeemable Preferred stock	83,157	83,157
Series E Cumulative Redeemable Preferred Stock
Partners' Capital (Note 8):
Cumulative Redeemable Preferred stock	38,425	38,425
Series F Cumulative Redeemable Preferred Stock
Partners' Capital (Note 8):
Cumulative Redeemable Preferred stock	$ 83,157	$ 83,157