Face (par) amount of debt instrument at time of issuance.

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

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Gross amount of debt extinguished.

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Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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Amount of cash outflow for cost from early extinguishment and prepayment of debt. Includes, but is not limited to, third-party cost, premium paid, and other fee paid to lender directly for debt extinguishment or debt prepayment. Excludes accrued interest.

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Cash outflow in the form of capital distributions and dividends to common shareholders, preferred shareholders and noncontrolling interests.

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Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

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Write-off of amounts previously capitalized as debt issuance cost in an extinguishment of debt.

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Subsequent Events (Details) - Subsequent event [Member] - USD ($)	Oct. 25, 2021	Oct. 13, 2021	Oct. 07, 2021
Subsequent Event [Line Items]
Payment of dividends		$ 61,800,000
Unsecured Senior Notes - Registered Offering [Member] \| Senior Notes [Member] \| Kilroy Realty L.P. [Member]
Subsequent Event [Line Items]
Principal amount of debt			$ 450,000,000
Stated interest rate on debt (percent)			2.65%
3.800% Unsecured Senior Notes due January 2023 [Member] \| Senior Notes [Member] \| Kilroy Realty L.P. [Member]
Subsequent Event [Line Items]
Stated interest rate on debt (percent)	3.80%
Repayment of debt	$ 300,000,000
Loss on extinguishment of debt	12,400,000
Premium paid at redemption date	12,100,000
Write off of unamortized discount and unamortized deferred financing costs	$ 300,000