CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 603,784	$ 123,841
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of real estate assets and leasing costs	218,171	218,841
Depreciation of non-real estate furniture, fixtures and equipment	4,563	7,477
Revenue reversals for doubtful accounts, net (Note 10)	2,830	14,205
Non-cash amortization of share-based compensation awards	26,486	24,290
Non-cash amortization of deferred financing costs and debt discounts	2,232	2,252
Non-cash amortization of net below market rents	(3,704)	(6,269)
Gain on sale of depreciable operating property (Note 3)	(457,831)	0
Non-cash amortization of deferred revenue related to tenant-funded tenant improvements	(12,982)	(13,114)
Straight-line rents	(41,238)	(51,890)
Amortization of right of use ground lease assets	886	615
Net change in other operating assets	(5,767)	(4,245)
Net change in other operating liabilities	70,130	47,977
Net cash provided by operating activities	407,560	363,980
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for acquisition of development properties and undeveloped land (Note 2)	(586,927)	0
Expenditures for development properties and undeveloped land	(436,839)	(386,237)
Expenditures for acquisitions of operating properties (Note 2)	(537,429)	0
Expenditures for operating properties and other capital assets	(90,280)	(89,464)
Net proceeds received from dispositions (Note 3)	1,013,359	0
Net decrease in acquisition-related deposits	1,000	0
Net cash used in investing activities	(637,116)	(475,701)
CASH FLOWS FROM FINANCING ACTIVITIES:
Financing costs (Note 5)	(7,801)	(6,216)
Repurchase of common stock and restricted stock units	(21,419)	(13,887)
Distributions to noncontrolling interests in consolidated property partnerships	(24,303)	(8,363)
Dividends and distributions paid to common stockholders and common unitholders	(176,196)	(165,986)
Principal payments and repayments of secured debt	(3,987)	(3,834)
Contributions from noncontrolling interests in consolidated property partnerships	1,591	0
Repayments of unsecured debt	0	(150,000)
Net proceeds from issuance of common stock	0	721,675
Proceeds from the issuance of unsecured debt	0	772,297
Borrowings on unsecured revolving credit facility	0	190,000
Repayments on unsecured revolving credit facility	0	(435,000)
Net cash (used in) provided by financing activities	(232,115)	900,686
Net (decrease) increase in cash and cash equivalents and restricted cash	(461,671)	788,965
Cash and cash equivalents and restricted cash, beginning of period	823,130	76,344
Cash and cash equivalents and restricted cash, end of period	361,459	865,309
Kilroy Realty L.P. [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	603,784	123,841
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of real estate assets and leasing costs	218,171	218,841
Depreciation of non-real estate furniture, fixtures and equipment	4,563	7,477
Revenue reversals for doubtful accounts, net (Note 10)	2,830	14,205
Non-cash amortization of share-based compensation awards	26,486	24,290
Non-cash amortization of deferred financing costs and debt discounts	2,232	2,252
Non-cash amortization of net below market rents	(3,704)	(6,269)
Gain on sale of depreciable operating property (Note 3)	(457,831)	0
Non-cash amortization of deferred revenue related to tenant-funded tenant improvements	(12,982)	(13,114)
Straight-line rents	(41,238)	(51,890)
Amortization of right of use ground lease assets	886	615
Net change in other operating assets	(5,767)	(4,245)
Net change in other operating liabilities	70,130	47,977
Net cash provided by operating activities	407,560	363,980
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for acquisition of development properties and undeveloped land (Note 2)	(586,927)	0
Expenditures for development properties and undeveloped land	(436,839)	(386,237)
Expenditures for acquisitions of operating properties (Note 2)	(537,429)	0
Expenditures for operating properties and other capital assets	(90,280)	(89,464)
Net proceeds received from dispositions (Note 3)	1,013,359	0
Net decrease in acquisition-related deposits	1,000	0
Net cash used in investing activities	(637,116)	(475,701)
CASH FLOWS FROM FINANCING ACTIVITIES:
Financing costs (Note 5)	(7,801)	(6,216)
Repurchase of common stock and restricted stock units	(21,419)	(13,887)
Distributions to noncontrolling interests in consolidated property partnerships	(24,303)	(8,363)
Dividends and distributions paid to common stockholders and common unitholders	(176,196)	(165,986)
Principal payments and repayments of secured debt	(3,987)	(3,834)
Contributions from noncontrolling interests in consolidated property partnerships	1,591	0
Repayments of unsecured debt	0	(150,000)
Net proceeds from issuance of common stock	0	721,675
Proceeds from the issuance of unsecured debt	0	772,297
Borrowings on unsecured revolving credit facility	0	190,000
Repayments on unsecured revolving credit facility	0	(435,000)
Net cash (used in) provided by financing activities	(232,115)	900,686
Net (decrease) increase in cash and cash equivalents and restricted cash	(461,671)	788,965
Cash and cash equivalents and restricted cash, beginning of period	823,130	76,344
Cash and cash equivalents and restricted cash, end of period	$ 361,459	$ 865,309