Noncontrolling Interests on the Company’s Consolidated Financial Statements (Details) $ / shares in Units, $ in Millions	12 Months Ended
Dec. 31, 2025 USD ($) trading_day $ / shares shares	Dec. 31, 2024 USD ($) trading_day $ / shares shares
Noncontrolling Interest [Line Items]
Conversion ratio	1
Common stock, par value ( in dollars per share) \| $ / shares	$ 0.01	$ 0.01
Number of trading days \| trading_day	10	10
Redeemable noncontrolling interest, equity, common, fair value \| $	$ 43.2	$ 46.8
Non-Affiliated Investors and Certain Executive Officer and Directors \| Common Units
Noncontrolling Interest [Line Items]
Non-affiliated investors and other common units of the Operating Partnership (in shares)	1,133,562	1,150,574
Kilroy Realty L.P. \| Common Units
Noncontrolling Interest [Line Items]
Conversion ratio	1
Kilroy Realty L.P. \| Common Units
Noncontrolling Interest [Line Items]
Non-affiliated investors and other common units of the Operating Partnership (in shares)	1,133,562	1,150,574
Operating Partnership
Noncontrolling Interest [Line Items]
Ownership interest (percent)	99.10%	99.00%
Operating Partnership \| Non-Affiliated Investors and Certain Executive Officer and Directors
Noncontrolling Interest [Line Items]
Ownership interest (percent)	0.90%	1.00%

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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+ References

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 272
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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
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The fair value as of the reporting date of noncontrolling interests which are redeemable by the (parent) entity (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the (parent) entity. The noncontrolling interest holder's ownership (or holders' ownership) may be in the form of common shares (regardless of class), limited partnership units (regardless of class), non-preferential membership interests, or any other form of common equity regardless of investee entity legal form.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 480
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