Stockholders' Equity of the Company - At-The-Market Offering and Derivatives and Distributions (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Dividends and Distributions payable to:
Accrued distributions (Notes 14 and 25)	$ 64,285	$ 61,850
Outstanding Shares and Units:
Common stock (in shares)	116,878,031	116,464,169
Restricted Stock Units (RSUs)
Outstanding Shares and Units:
RSUs (in shares)	984,006	1,292,802
Kilroy Realty L.P.
Dividends and Distributions payable to:
Accrued distributions (Notes 14 and 25)	$ 64,285	$ 61,850
Kilroy Realty L.P. | Restricted Stock Units (RSUs)
Dividends and Distributions payable to:
Accrued distributions (Notes 14 and 25)	$ 550	$ 691
Kilroy Realty L.P. | Market measure-based Restricted Stock Units (RSUs)
Outstanding Shares and Units:
Number of RSUs outstanding (in shares)	1,123,554	976,464
Kilroy Realty L.P. | Common Units
Outstanding Shares and Units:
Non-affiliated investors and other common units of the Operating Partnership (in shares)	1,150,574	1,150,574
Noncontrolling common units | Common Units
Outstanding Shares and Units:
Non-affiliated investors and other common units of the Operating Partnership (in shares)	1,150,574	1,150,574
Common stockholders and noncontrolling unitholders
Dividends and Distributions payable to:
Accrued distributions (Notes 14 and 25)	$ 64,285	$ 61,850
Common Stock
Dividends and Distributions payable to:
Accrued distributions (Notes 14 and 25)	$ 63,114	$ 60,561
Outstanding Shares and Units:
Common stock (in shares)	116,878,031	116,464,169
Common Units
Dividends and Distributions payable to:
Accrued distributions (Notes 14 and 25)	$ 621	$ 598