Document and Entity Information (USD $)	9 Months Ended
	Sep. 30, 2011	Nov. 03, 2011	Sep. 30, 2010
Entity Information [Line Items]
Entity Registrant Name	LEXINGTON REALTY TRUST
Entity Central Index Key	0000910108
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned User	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 789,274,513
Entity Common Stock, Shares Outstanding		154,325,254
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	Q3
Document Type	10-Q
Amendment Flag	false
Document Period Ended Date	Sep. 30, 2011