Secured and Unsecured Debt of the Operating Partnership - Debt Maturities (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Stated debt maturities and scheduled amortization payments, excluding debt discounts
Debt issuance discount	$ (6,500)
Kilroy Realty L.P. [Member]
Stated debt maturities and scheduled amortization payments, excluding debt discounts
2020	5,137
2021	5,342
2022	400,554
2023	305,775
2024	431,006
Thereafter	2,431,688
Total aggregate principal value	3,579,502
Unamortized debt issuance expense	$ (20,300)

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Amount, after accumulated amortization, of debt discount.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

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