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, 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
Net proceeds from the issuance of common shares	31,588,000	1,000	31,587,000				31,588,000
Net income	104,213,000				101,149,000		101,149,000	2,438,000	236,000	390,000	104,213,000	101,149,000	2,438,000	236,000	390,000
Redemption of limited partners common units for common shares											0	48,000	(48,000)
Contributions from partners											40,088,000	40,088,000
Distributions	(143,956,000)				(140,142,000)		(140,142,000)	(3,485,000)	(236,000)	(93,000)
Distributions to partners											(143,956,000)	(140,142,000)	(3,485,000)	(236,000)	(93,000)
Share-based compensation	8,500,000		8,500,000				8,500,000
Foreign currency translation adjustment	7,811,000			7,627,000			7,627,000	184,000			7,811,000	7,627,000	184,000
Other comprehensive loss - change in net unrealized gain on derivative instruments	(1,656,000)		0	(1,617,000)	0	0	(1,617,000)	(39,000)	0	0	(1,656,000)	(1,617,000)	(39,000)
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests, Common Units	0		48,000				48,000	(48,000)
Ending Balance at Jun. 30, 2014	3,102,679,000	149,000	3,709,753,000	15,752,000	(630,706,000)	(51,951,000)	3,042,997,000	55,763,000	0	3,919,000	3,102,679,000	3,042,997,000	55,763,000	0	3,919,000
Beginning Balance at Mar. 31, 2014
Net income	30,107,000										30,107,000
Foreign currency translation adjustment	6,464,000										6,464,000
Other comprehensive loss - change in net unrealized gain on derivative instruments	(1,145,000)										(1,145,000)
Ending Balance at Jun. 30, 2014	$ 3,102,679,000										$ 3,102,679,000