Document and Entity Information	9 Months Ended
	Sep. 30, 2012	Nov. 06, 2012
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 Common Stock, Shares Outstanding		176,591,477
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q3
Document Type	10-Q
Amendment Flag	false
Document Period Ended Date	Sep. 30, 2012