Cover - shares	3 Months Ended
	Mar. 31, 2021	May 05, 2021
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period Ended Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	1-12386
Entity Registrant Name	LEXINGTON REALTY TRUST
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	13-3717318
Entity Address, Address Line One	One Penn Plaza, Suite 4015
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10119-4015
City Area Code	212
Local Phone Number	692-7200
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)		277,628,373
Entity Central Index Key	0000910108
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false
Common Shares
Document Information [Line Items]
Title of 12(b) Security	Shares of beneficial interest, par value $0.0001 per share, classified as Common Stock
Trading Symbol	LXP
Security Exchange Name	NYSE
Series C Cumulative Convertible Preferred Stock
Document Information [Line Items]
Title of 12(b) Security	6.50% Series C Cumulative Convertible Preferred Stock, par value $0.0001 per share
Trading Symbol	LXPPRC
Security Exchange Name	NYSE