Secured and Unsecured Debt of the Operating Partnership - Secured Debt and Additional Information (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Secured Debt
Total secured debt	$ 598,199	$ 603,225
Kilroy Realty L.P.
Secured Debt
Long-term debt, gross	4,631,688
Total secured debt	598,199	603,225
Kilroy Realty L.P. \| 3.57% Mortgage Payable due December 2026
Secured Debt
Long-term debt, gross	152,700
Kilroy Realty L.P. \| 5.90% Mortgage Payable due August 2034
Secured Debt
Long-term debt, gross	375,000
Kilroy Realty L.P. \| Secured debt
Secured Debt
Total secured debt	606,688	612,694
Unamortized deferred financing costs	(8,489)	(9,469)
Total secured debt, net	$ 598,199	603,225
Kilroy Realty L.P. \| Secured debt \| 3.57% Mortgage Payable due December 2026
Secured Debt
Stated interest rate	3.57%
Effective interest rate	3.57%
Long-term debt, gross	$ 152,668	156,386
Kilroy Realty L.P. \| Secured debt \| 4.48% Mortgage Payable due July 2027
Secured Debt
Stated interest rate	4.48%
Effective interest rate	4.48%
Long-term debt, gross	$ 79,020	81,308
Kilroy Realty L.P. \| Secured debt \| 5.90% Mortgage Payable due August 2034
Secured Debt
Stated interest rate	5.90%
Effective interest rate	5.90%
Long-term debt, gross	$ 375,000	$ 375,000

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

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Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.

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The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

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