v3.25.4
Secured and Unsecured Debt of the Operating Partnership - Unsecured Senior Notes (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Aug. 31, 2025
Dec. 31, 2024
Jan. 31, 2024
Debt Instrument [Line Items]        
Total Unsecured Senior Notes, Net $ 3,996,774   $ 3,999,566  
Unamortized deferred financing costs (9,150)   (12,692)  
Kilroy Realty L.P.        
Debt Instrument [Line Items]        
Long-term debt, gross 4,625,442      
Less: Unamortized Net Discounts and Deferred Financing costs (35,983)      
Total Unsecured Senior Notes, Net 3,996,774   3,999,566  
Unsecured debt | Kilroy Realty L.P.        
Debt Instrument [Line Items]        
Long-term debt, gross 3,825,000   3,825,000  
Less: Unamortized Net Discounts and Deferred Financing costs (27,949)   (24,205)  
Total Unsecured Senior Notes, Net $ 3,797,051   3,800,795  
4.300% Unsecured Senior Notes | Unsecured debt | Kilroy Realty L.P.        
Debt Instrument [Line Items]        
Stated Coupon Rate 4.30%      
Effective Interest Rate 4.389%      
Long-term debt, gross $ 50,000   50,000  
4.350% Unsecured Senior Notes | Unsecured debt | Kilroy Realty L.P.        
Debt Instrument [Line Items]        
Stated Coupon Rate 4.35%      
Effective Interest Rate 4.437%      
Long-term debt, gross $ 200,000   200,000  
3.350% Unsecured Senior Notes | Unsecured debt | Kilroy Realty L.P.        
Debt Instrument [Line Items]        
Stated Coupon Rate 3.35%      
Effective Interest Rate 3.416%      
Long-term debt, gross $ 175,000   175,000  
3.450% Unsecured Senior Notes | Unsecured debt | Kilroy Realty L.P.        
Debt Instrument [Line Items]        
Stated Coupon Rate 3.45%      
Effective Interest Rate 3.507%      
Long-term debt, gross $ 75,000   75,000  
4.270% Unsecured Senior Notes | Unsecured debt | Kilroy Realty L.P.        
Debt Instrument [Line Items]        
Stated Coupon Rate 4.27%      
Effective Interest Rate 4.322%      
Long-term debt, gross $ 350,000   350,000  
4.375% Unsecured Senior Notes | Unsecured debt | Kilroy Realty L.P.        
Debt Instrument [Line Items]        
Stated Coupon Rate 4.375%      
Effective Interest Rate 4.444%      
Long-term debt, gross $ 0   400,000  
4.750% Unsecured Senior Notes | Unsecured debt | Kilroy Realty L.P.        
Debt Instrument [Line Items]        
Stated Coupon Rate 4.75%      
Effective Interest Rate 4.874%      
Long-term debt, gross $ 400,000   400,000  
4.250% Unsecured Senior Notes | Unsecured debt | Kilroy Realty L.P.        
Debt Instrument [Line Items]        
Stated Coupon Rate 4.25%      
Effective Interest Rate 4.383%      
Long-term debt, gross $ 400,000   400,000  
3.050% Unsecured Senior Notes | Unsecured debt | Kilroy Realty L.P.        
Debt Instrument [Line Items]        
Stated Coupon Rate 3.05%      
Effective Interest Rate 3.168%      
Long-term debt, gross $ 500,000   500,000  
2.500% Unsecured Senior Notes | Unsecured debt | Kilroy Realty L.P.        
Debt Instrument [Line Items]        
Stated Coupon Rate 2.50%      
Effective Interest Rate 2.626%      
Long-term debt, gross $ 425,000   425,000  
2.650% Unsecured Senior Notes | Unsecured debt | Kilroy Realty L.P.        
Debt Instrument [Line Items]        
Stated Coupon Rate 2.65%      
Effective Interest Rate 2.727%      
Long-term debt, gross $ 450,000   450,000  
5.875% Unsecured Senior Notes Due 2035 | Unsecured debt | Kilroy Realty L.P.        
Debt Instrument [Line Items]        
Stated Coupon Rate 5.875% 5.875%    
Effective Interest Rate 6.076%      
Long-term debt, gross $ 400,000 $ 400,000 0  
Less: Unamortized Net Discounts and Deferred Financing costs   $ (4,000)    
6.250% Unsecured Senior Notes | Unsecured debt | Kilroy Realty L.P.        
Debt Instrument [Line Items]        
Stated Coupon Rate 6.25%     6.25%
Effective Interest Rate 6.412%      
Long-term debt, gross $ 400,000   400,000 $ 400,000
Unamortized discount (premium), net       $ (4,500)
Unsecured Senior Notes | Unsecured debt        
Debt Instrument [Line Items]        
Unamortized discount (premium), net (11,000)   (8,400)  
Unamortized deferred financing costs $ (16,900)   $ (15,800)