Equity (Details) (USD $)	1 Months Ended	3 Months Ended		6 Months Ended
	Mar. 31, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Equity [Line Items]
Common shares issued during period	23,000,000
Proceeds from issuance of common shares				$ 10,861,000	$ 302,987,000
Proceeds from issuance of common stock, gross	258,336,000
Proceeds from issuance of common stock, net of issuance costs	293,855,000
OP unit equivalent in common shares				1.13
Partners capital account, shares issued for units redeemed				9,322	164,596
OP units outstanding		3,439,000		3,439,000
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax [Roll Forward]
Gains and Losses on Cash Flow Hedges, Beginning				4,439,000
Gains and Losses on Cash Flow Hedges, Ending		(66,000)		(66,000)
Transfers from noncontrolling interests:
Net income (loss) attributable to Lexington Realty Trust shareholders		14,450,000	6,732,000	15,336,000	4,112,000
Increase in additional paid-in-capital for redemption of noncontrolling OP units				(959,000)
Change from net income (loss) attributable to shareholders and transfers from noncontrolling interest				14,377,000	4,973,000
Parent [Member]
Equity [Line Items]
Partners' capital account, redemption for common shares				46,000	861,000
Transfers from noncontrolling interests:
Increase in additional paid-in-capital for redemption of noncontrolling OP units					861,000
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax [Roll Forward]
Gains and Losses on Cash Flow Hedges, Beginning				4,439,000
Other comprehensive loss before reclassifications				(7,186,000)
Amounts of loss reclassified from accumulated other comprehensive income to interest expense				2,681,000
Gains and Losses on Cash Flow Hedges, Ending		(66,000)		(66,000)
Accumulated Distributions in Excess of Net Income [Member]
Transfers from noncontrolling interests:
Net income (loss) attributable to Lexington Realty Trust shareholders				15,336,000	4,112,000
Officers [Member]
Equity [Line Items]
Deferred compensation arrangement with individual, shares issued					1,325,000
Deferred compensation arrangement with individual, fair value of shares issued					14,098,000
Trustees [Member]
Equity [Line Items]
Deferred compensation arrangement with individual, shares issued				14,000	37,500
Deferred compensation arrangement with individual, fair value of shares issued				142,000	399,000
Direct Share Purchase Plan [Member]
Equity [Line Items]
Common shares issued during period				1,168,673	690,873
Proceeds from issuance of common shares				11,522,000	7,466,000
At The Market [Member]
Equity [Line Items]
Common shares issued during period					3,409,927
Value authorized					100,000,000
Value of new stock issued during period					36,884,000
Former LCIF II Partners [Member]
Equity [Line Items]
Partners capital account, units exchanged for cash				170,193
Cash acquired from acquisition				$ 1,962,000