Secured and Unsecured Debt of the Operating Partnership - Capitalized Interest and Loan Fees (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Capitalized Interest and Loan Fees [Line Items]
Interest expense	$ 78,555	$ 70,772	$ 48,537
Kilroy Realty L.P.
Capitalized Interest and Loan Fees [Line Items]
Gross interest expense	158,756	150,325	129,778
Capitalized interest and deferred financing costs	(80,201)	(79,553)	(81,241)
Interest expense	$ 78,555	$ 70,772	$ 48,537

Amount of the cost of borrowed funds accounted for as interest expense.

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