Consolidated Statement of Equity (USD $) In Thousands	Total	Common Shares Of Beneficial Interest [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income [Member]	Distributions in Excess of Net Income [Member]	Common Shares Held in Treasury [Member]	Total Liberty Property Trust Shareholders' Equity [Member]	Noncontrolling interest operating partnership-Common [Member]	Noncontrolling interest operating partnership-Preferred [Member]	Noncontrolling interest-consolidated joint ventures [Member]	Liberty Property Limited Partnership [Member]	Liberty Property Limited Partnership [Member] General Partners Equity [Member]	Liberty Property Limited Partnership [Member] Noncontrolling interest operating partnership-Common [Member]	Liberty Property Limited Partnership [Member] Noncontrolling interest operating partnership-Preferred [Member]	Liberty Property Limited Partnership [Member] Noncontrolling interest-consolidated joint ventures [Member]
Beginning Balance at Dec. 31, 2012	$ 2,217,820	$ 119	$ 2,687,701	$ 2,900	$ (547,757)	$ (51,951)	$ 2,091,012	$ 60,223	$ 63,264	$ 3,321	$ 2,217,820	$ 2,091,012	$ 60,223	$ 63,264	$ 3,321
Net proceeds from the issuance of common shares	108,852	4	108,848				108,852
Net income	117,899				111,348		111,348	3,432	3,119	0	117,899	111,348	3,432	3,119	0
Contributions from partners											115,211	115,211
Distributions	(120,624)				(114,693)		(114,693)	(3,745)	(1,883)	(303)
Distributions to partners											(120,624)	(114,693)	(3,745)	(1,883)	(303)
Share-based compensation	6,359		6,359				6,359
Foreign currency translation adjustment	(4,812)			(4,667)			(4,667)	(145)			(4,812)	(4,667)	(145)
Redemption of noncontrolling interest - preferred units	(63,264)								(63,264)		(63,264)			(63,264)
Preferred stock redemption premium	(1,236)								(1,236)		(1,236)			(1,236)
Ending Balance at Jun. 30, 2013	2,260,994	123	2,802,908	(1,767)	(551,102)	(51,951)	2,198,211	59,765	0	3,018	2,260,994	2,198,211	59,765	0	3,018
Beginning Balance at Mar. 31, 2013
Net income	43,243										43,243
Foreign currency translation adjustment	40										40
Preferred stock redemption premium	(1,236)										(1,236)
Ending Balance at Jun. 30, 2013	$ 2,260,994					$ (51,951)					$ 2,260,994