v3.3.1.900
Document and Entity Information Document - USD ($)
 12 Months Ended
Dec. 31, 2015
Feb. 05, 2016
Jun. 30, 2015
Entity Information [Line Items]      
Entity Registrant Name KILROY REALTY CORP    
Entity Central Index Key 0001025996    
Current Fiscal Year End Date --12-31    
Entity Filer Category Large Accelerated Filer    
Document Type 10-K    
Document Period End Date Dec. 31, 2015    
Document Fiscal Year Focus 2015    
Document Fiscal Period Focus FY    
Amendment Flag false    
Entity Common Stock, Shares Outstanding   92,275,561  
Entity Public Float     $ 5,926,241,394
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Kilroy Realty, L.P. [Member]      
Entity Information [Line Items]      
Entity Registrant Name Kilroy Realty, L.P.    
Entity Central Index Key 0001493976    
Current Fiscal Year End Date --12-31    
Entity Filer Category Non-accelerated Filer    
Document Type 10-K    
Document Period End Date Dec. 31, 2015    
Document Fiscal Year Focus 2015    
Document Fiscal Period Focus FY    
Amendment Flag false    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes