Consolidated Statements of Cash Flows (KILROY REALTY, L.P.) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 2,388	$ 78,671
Adjustments to reconcile net income to net cash provided by operating activities (including discontinued operations):
Depreciation and amortization of building and improvements and leasing costs	50,011	36,464
Increase in provision for bad debts	95	2
Depreciation of furniture, fixtures and equipment	380	288
Noncash amortization of share-based compensation awards	2,234	1,287
Noncash amortization of deferred financing costs and debt discounts and premiums	1,413	2,976
Noncash amortization of net below market rents (Note 3)	(2,047)	(525)
Net gain on dispositions of discontinued operations	0	(72,809)
Noncash amortization of deferred revenue related to tenant-funded tenant improvements	(2,442)	(2,261)
Straight-line rents	(6,724)	(5,487)
Net change in other operating assets	(7,390)	(3,869)
Net change in other operating liabilities	18,581	14,956
Insurance proceeds received for property damage	0	(951)
Net cash provided by operating activities	56,499	48,742
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for acquisition of operating properties, net of cash acquired (Note 2)	(85,692)	(162,380)
Expenditures for operating properties	(25,571)	(17,307)
Expenditures for development and redevelopment properties and undeveloped land	(73,369)	(13,477)
Net proceeds received from dispositions of operating properties	0	100,765
Insurance proceeds received for property damage	0	951
Increase in acquisition-related deposits	0	(5,250)
Decrease (increase) in restricted cash (Note 1)	228,079	(386)
Net cash provided by (used in) investing activities	43,447	(97,084)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from issuance of Series G preferred units	0	96,757
Borrowings on unsecured line of credit	0	30,000
Repayments on unsecured line of credit	(185,000)	(212,000)
Principal payments on secured debt	(84,918)	(1,546)
Proceeds from the issuance of unsecured debt (Note 5)	299,901	150,000
Financing costs	(2,870)	(1,877)
Repurchase of common units and restricted stock units (Note 9)	(1,209)	(603)
Proceeds from exercise of stock options	0	129
Distributions paid to common unitholders	(26,956)	(21,191)
Distributions paid to preferred unitholders	(3,313)	(3,799)
Net cash provided by financing activities	19,030	417,933
Net increase in cash and cash equivalents	118,976	369,591
Cash and cash equivalents, beginning of period	16,700	4,777
Cash and cash equivalents, end of period	135,676	374,368
SUPPLEMENTAL CASH FLOWS INFORMATION:
Cash paid for interest, net of capitalized interest of $7,175 and $3,251 as of March 31, 2013 and 2012, respectively	11,303	4,487
NONCASH INVESTING TRANSACTIONS:
Accrual for expenditures for operating properties and development and redevelopment properties	42,140	5,421
Tenant improvements funded directly by tenants	1,426	95
Assumption of secured debt with property acquisition (Notes 2 and 5)	95,496	0
Assumption of other assets and liabilities with operating and development property acquisitions (Note 2)	422	137
Net disposition proceeds held by a qualified intermediary in connection wtih Section 1031 exchange	0	42,395
NONCASH FINANCING TRANSACTIONS:
Accrual of preferred unit issuance costs	0	602
Accrual of distributions payable to common unitholders	27,011	24,524
Accrual of distributions payable to preferred unitholders	1,694	2,431
Issuance of share-based compensation awards, net (Note 9)	8,451	29,989
Reclassification of preferred units called for redemption from equity to liabilities	0	126,500
Kilroy Realty, L.P. [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	2,388	78,671
Adjustments to reconcile net income to net cash provided by operating activities (including discontinued operations):
Depreciation and amortization of building and improvements and leasing costs	50,011	36,464
Increase in provision for bad debts	95	2
Depreciation of furniture, fixtures and equipment	380	288
Noncash amortization of share-based compensation awards	2,234	1,287
Noncash amortization of deferred financing costs and debt discounts and premiums	1,413	2,976
Noncash amortization of net below market rents (Note 3)	(2,047)	(525)
Net gain on dispositions of discontinued operations	0	(72,809)
Noncash amortization of deferred revenue related to tenant-funded tenant improvements	(2,442)	(2,261)
Straight-line rents	(6,724)	(5,487)
Net change in other operating assets	(7,390)	(3,869)
Net change in other operating liabilities	18,581	14,956
Insurance proceeds received for property damage	0	(951)
Net cash provided by operating activities	56,499	48,742
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for acquisition of operating properties, net of cash acquired (Note 2)	(85,692)	(162,380)
Expenditures for operating properties	(25,571)	(17,307)
Expenditures for development and redevelopment properties and undeveloped land	(73,369)	(13,477)
Net proceeds received from dispositions of operating properties	0	100,765
Insurance proceeds received for property damage	0	951
Increase in acquisition-related deposits	0	(5,250)
Decrease (increase) in restricted cash (Note 1)	228,079	(386)
Net cash provided by (used in) investing activities	43,447	(97,084)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from issuance of Series G preferred units	0	96,757
Net proceeds from issuance of common units (Note 8)	23,395	382,063
Borrowings on unsecured line of credit	0	30,000
Repayments on unsecured line of credit	(185,000)	(212,000)
Principal payments on secured debt	(84,918)	(1,546)
Proceeds from the issuance of unsecured debt (Note 5)	299,901	150,000
Financing costs	(2,870)	(1,877)
Repurchase of common units and restricted stock units (Note 9)	(1,209)	(603)
Proceeds from exercise of stock options	0	129
Distributions paid to common unitholders	(26,956)	(21,191)
Distributions paid to preferred unitholders	(3,313)	(3,799)
Net cash provided by financing activities	19,030	417,933
Net increase in cash and cash equivalents	118,976	369,591
Cash and cash equivalents, beginning of period	16,700	4,777
Cash and cash equivalents, end of period	135,676	374,368
SUPPLEMENTAL CASH FLOWS INFORMATION:
Cash paid for interest, net of capitalized interest of $7,175 and $3,251 as of March 31, 2013 and 2012, respectively	11,303	4,487
NONCASH INVESTING TRANSACTIONS:
Accrual for expenditures for operating properties and development and redevelopment properties	42,140	5,421
Tenant improvements funded directly by tenants	1,426	95
Assumption of secured debt with property acquisition (Notes 2 and 5)	95,496	0
Assumption of other assets and liabilities with operating and development property acquisitions (Note 2)	422	137
Net disposition proceeds held by a qualified intermediary in connection wtih Section 1031 exchange	0	42,395
NONCASH FINANCING TRANSACTIONS:
Accrual of preferred unit issuance costs	0	602
Accrual of distributions payable to common unitholders	27,011	24,524
Accrual of distributions payable to preferred unitholders	1,694	2,431
Issuance of share-based compensation awards, net (Note 9)	8,451	29,989
Reclassification of preferred units called for redemption from equity to liabilities	$ 0	$ 126,500