Secured and Unsecured Debt of the Operating Partnership - Debt Maturities (Details) - Kilroy Realty L.P. [Member] $ in Thousands	Jun. 30, 2018 USD ($)
Stated debt maturities and scheduled amortization payments, excluding debt discounts
Remaining 2018	$ 1,816
2019	76,309
2020	255,137
2021	5,342
2022	450,554
Thereafter	2,018,469
Total debt	2,807,627
Unamortized deferred financing costs	13,700
Unsecured senior notes [Member]
Stated debt maturities and scheduled amortization payments, excluding debt discounts
Unamortized discount	5,900
Secured debt [Member]
Stated debt maturities and scheduled amortization payments, excluding debt discounts
Unamortized premium	$ 1,700

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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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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