v3.26.1
Secured and Unsecured Debt of the Operating Partnership - Schedule of Unsecured Revolving Credit Facility (Details)
 3 Months Ended 12 Months Ended
Mar. 31, 2026
USD ($)
extension_option
Dec. 31, 2025
USD ($)
extension_option
Line of Credit Facility [Line Items]    
Unamortized deferred financing costs $ 8,264,000 $ 9,150,000
Unsecured Revolving Credit Facility | Revolving credit facility | Kilroy Realty L.P.    
Line of Credit Facility [Line Items]    
Outstanding borrowings 0 0
Borrowing facility, remaining borrowing capacity 1,100,000,000 1,100,000,000
Total borrowing capacity $ 1,100,000,000 $ 1,100,000,000
Interest rate (percent) 4.88% 5.07%
Facility fee-annual rate (percent) 0.25% 0.25%
Unamortized deferred financing costs $ 8,264,000 $ 9,150,000
Outstanding letters of credit 5,200,000 5,200,000
Contingent additional borrowings $ 500,000,000.0 $ 500,000,000.0
Reduction interest rate 0.01%  
Number of extension options | extension_option 2 2
Extension period (in months) 6 months 6 months
Unsecured Revolving Credit Facility | Revolving credit facility | Kilroy Realty L.P. | SOFR    
Line of Credit Facility [Line Items]    
Variable rate (percent) 1.10% 1.10%
Unsecured Revolving Credit Facility | Revolving Credit Facility and Term Loan Facility | Kilroy Realty L.P. | Adjusted SOFR    
Line of Credit Facility [Line Items]    
Variable rate (percent) 0.10% 0.10%
2024 Term Loan Facility | Term Loan Facility | Kilroy Realty L.P.    
Line of Credit Facility [Line Items]    
Outstanding borrowings $ 200,000,000 $ 200,000,000
Interest rate (percent) 4.97% 5.02%
Unamortized deferred financing costs $ 186,000 $ 277,000
Contingent additional borrowings $ 130,000,000.0 $ 130,000,000.0
2024 Term Loan Facility | Term Loan Facility | Kilroy Realty L.P. | SOFR    
Line of Credit Facility [Line Items]    
Variable rate (percent) 1.20% 1.20%
2024 Term Loan Facility | Unsecured debt, net | Kilroy Realty L.P.    
Line of Credit Facility [Line Items]    
Extension period (in months) 12 months