Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	May 03, 2019
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-Q
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		100,973,534
Entity Emerging Growth Company	false
Entity Small Business	false
Kilroy Realty L.P. [Member]
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-Q
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Emerging Growth Company	false
Entity Small Business	false