Consolidated Statement of Equity (USD $)	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, 2010	$ 2,438,552,000	$ 116,000	$ 2,560,193,000	$ (155,000)	$ (426,017,000)	$ (51,951,000)	$ 2,082,186,000	$ 67,621,000	$ 287,959,000	$ 786,000	$ 2,438,552,000	$ 2,082,186,000	$ 67,621,000	$ 287,959,000	$ 786,000
Units Outstanding - Begining of Period at Dec. 31, 2010												3,928,733
Common shares, shares outstanding - Beginning of Period at Dec. 31, 2010		115,530,608
Contributions from partners											55,103,000	55,103,000
Distributions to partners											(247,829,000)	(219,480,000)	(7,280,000)	(21,069,000)	0
Net proceeds from the issuance of common shares	44,548,000	1,000	44,547,000	0	0	0	44,548,000	0	0	0
Net income	210,710,000	0	0	0	183,999,000	0	183,999,000	6,153,000	21,069,000	(511,000)	210,710,000	183,999,000	6,153,000	21,069,000	(511,000)
Contributions	3,500,000	0	0	0	0	0	0	0	0	3,500,000
Redemption of limited partners common units for common shares												2,060,000	(2,060,000)
Distributions	(247,829,000)	0	0	0	(219,480,000)	0	(219,480,000)	(7,280,000)	(21,069,000)	0
Noncash compensation	10,555,000	0	10,555,000	0	0	0	10,555,000	0	0	0
Foreign currency translation adjustment	(280,000)	0	0	(274,000)	0	0	(274,000)	(6,000)	0	0	(280,000)	(274,000)	(6,000)
Other comprehensive income - change in net unrealized gain on derivatives	0										0
Partners' Capital, Other											3,500,000	0	0	0
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests, Common Units	0	0	2,060,000	0	0	0	2,060,000	(2,060,000)	0	0
Excess of preferred unit carrying amount over redemption											0
Number of Common Shares [Roll Forward]
Stock Issued During Period, Shares, New Issues		1,701,758
Redemption of noncontrolling interests - common units	119,987										119,987
Number of Common Units [Roll Forward]
Redemption of noncontrolling interests - common units	(119,987)										(119,987)
Ending Balance at Dec. 31, 2011	2,459,756,000	117,000	2,617,355,000	(429,000)	(461,498,000)	(51,951,000)	2,103,594,000	64,428,000	287,959,000	3,775,000	2,459,756,000	2,103,594,000	64,428,000	287,959,000	3,775,000
Units Outstanding - End of Period at Dec. 31, 2011												3,808,746
Common shares, shares outstanding - End of Period at Dec. 31, 2011		117,352,353
Contributions from partners											68,767,000	68,767,000
Distributions to partners											(240,885,000)	(223,695,000)	(7,109,000)	(9,902,000)	(179,000)
Net proceeds from the issuance of common shares	58,710,000	2,000	58,708,000	0	0	0	58,710,000	0	0	0
Net income	147,751,000	0	0	0	137,436,000	0	137,436,000	4,378,000	6,212,000	(275,000)	147,751,000	137,436,000	4,378,000	6,212,000	(275,000)
Redemption of limited partners common units for common shares												1,581,000	(1,581,000)
Distributions	(240,885,000)	0	0	0	(223,695,000)	0	(223,695,000)	(7,109,000)	(9,902,000)	(179,000)
Noncash compensation	10,057,000	0	10,057,000	0	0	0	10,057,000	0	0	0
Foreign currency translation adjustment	3,436,000	0	0	3,329,000	0	0	3,329,000	107,000	0	0	3,436,000	3,329,000	107,000
Other comprehensive income - change in net unrealized gain on derivatives	0										0
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests, Common Units	0	0	1,581,000	0	0	0	1,581,000	(1,581,000)	0	0
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests, Preferred Units	(224,694,000)	0	0	0	0	0	0	0	(224,694,000)	0
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests											(224,694,000)			(224,694,000)
Excess of preferred unit carrying amount over redemption	3,689,000	0	0	0	0	0	0	0	3,689,000	0	3,689,000			3,689,000
Number of Common Shares [Roll Forward]
Stock Issued During Period, Shares, New Issues		2,273,528
Redemption of noncontrolling interests - common units	94,895										94,895
Number of Common Units [Roll Forward]
Redemption of noncontrolling interests - common units	(94,895)										(94,895)
Ending Balance at Dec. 31, 2012	2,217,820,000	119,000	2,687,701,000	2,900,000	(547,757,000)	(51,951,000)	2,091,012,000	60,223,000	63,264,000	3,321,000	2,217,820,000	2,091,012,000	60,223,000	63,264,000	3,321,000
Units Outstanding - End of Period at Dec. 31, 2012											3,713,851	3,713,851
Common shares, shares outstanding - End of Period at Dec. 31, 2012	119,720,776	119,720,776									118,470,867
Contributions from partners											979,444,000	979,444,000
Distributions to partners											(263,160,000)	(253,694,000)	(6,995,000)	(2,119,000)	(352,000)
Net proceeds from the issuance of common shares	969,468,000	29,000	969,439,000	0	0	0	969,468,000	0	0	0
Net income	219,594,000	0	0	0	209,738,000	0	209,738,000	5,848,000	3,355,000	653,000	219,594,000	209,738,000	5,848,000	3,355,000	653,000
Redemption of limited partners common units for common shares											0	2,502,000	(2,502,000)
Distributions	(263,160,000)	0	0	0	(253,694,000)	0	(253,694,000)	(6,995,000)	(2,119,000)	(352,000)
Noncash compensation	9,976,000	0	9,976,000	0	0	0	9,976,000	0	0	0
Foreign currency translation adjustment	5,397,000	0	0	5,296,000	0	0	5,296,000	101,000	0	0	5,397,000	5,296,000	101,000
Other comprehensive income - change in net unrealized gain on derivatives	1,584,000	0	0	1,546,000	0	0	1,546,000	38,000	0	0	1,584,000	1,546,000	38,000
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests, Common Units	0	0	2,502,000	0	0	0	2,502,000	(2,502,000)	0	0
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests, Preferred Units	(63,264,000)	0	0	0	0	0	0	0	(63,264,000)	0
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests											(63,264,000)			(63,264,000)
Excess of preferred unit carrying amount over redemption	(1,236,000)	0	0	0	0	0	0	0	(1,236,000)	0	(1,236,000)			(1,236,000)
Number of Common Shares [Roll Forward]
Stock Issued During Period, Shares, New Issues		27,968,740
Redemption of noncontrolling interests - common units	157,285											157,285
Number of Common Units [Roll Forward]
Redemption of noncontrolling interests - common units	(157,285)											(157,285)
Ending Balance at Dec. 31, 2013	$ 3,096,179,000	$ 148,000	$ 3,669,618,000	$ 9,742,000	$ (591,713,000)	$ (51,951,000)	$ 3,035,844,000	$ 56,713,000	$ 0	$ 3,622,000	$ 3,096,179,000	$ 3,035,844,000	$ 56,713,000	$ 0	$ 3,622,000
Units Outstanding - End of Period at Dec. 31, 2013											3,556,566	3,556,566
Common shares, shares outstanding - End of Period at Dec. 31, 2013	147,846,801	147,846,801									146,596,892