Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2012	Feb. 21, 2013	Jun. 29, 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 Public Float			$ 1,293,326,650
Entity Common Stock, Shares Outstanding		188,840,892
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	false
Document Period Ended Date	Dec. 31, 2012