Secured and Unsecured Debt of the Operating Partnership - Additional Information (Details) - USD ($)	Mar. 31, 2023	Jan. 31, 2023	Dec. 31, 2022
Term Loan
Debt Instrument [Line Items]
Line of credit facility, additional borrowing capacity		$ 100,000,000
Line of credit facility, maximum borrowing capacity		$ 650,000,000
Line of credit facility, additional borrowing capacity	$ 20,000,000
Kilroy Realty L.P. | Revolving credit facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	1,100,000,000		$ 1,100,000,000
Kilroy Realty L.P. | Term Loan Facility | Unsecured Term Loan Facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 520,000,000		$ 400,000,000