Secured and Unsecured Debt of the Operating Partnership - Capitalized Interest and Loan Fees (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Capitalized Interest and Loan Fees [Line Items]
Interest expense	$ 25,671	$ 20,625
Kilroy Realty L.P.
Capitalized Interest and Loan Fees [Line Items]
Gross interest expense	43,402	39,723
Capitalized interest and deferred financing costs	(17,731)	(19,098)
Interest expense	$ 25,671	$ 20,625