v3.3.1.900
Secured and Unsecured Debt of the Operating Partnership - Debt Maturities (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Capitalized interest and loan fees      
Interest expense $ 57,682 $ 67,571 $ 75,870
Long-term Debt 2,238,508    
Kilroy Realty, L.P. [Member]      
Capitalized interest and loan fees      
Gross interest expense 109,647 114,661 111,238
Capitalized interest 51,965 47,090 35,368
Interest expense 57,682 $ 67,571 $ 75,870
Debt [Member] | Kilroy Realty, L.P. [Member]      
Stated debt maturities and scheduled amortization payments, excluding debt discounts      
2015 9,734    
2016 71,734    
2018 451,713    
Long-term Debt, Maturities, Repayments of Principal in Year Four 265,355    
2019 251,962    
Thereafter 1,189,198    
Total 2,239,696    
Capitalized interest and loan fees      
Debt Instrument, Unamortized Discount $ (1,188)