Consolidated Statement of Equity - 6 months ended Jun. 30, 2015 - 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-consolidated joint ventures [Member]	Total Equity [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-consolidated joint ventures [Member]	Liberty Property Limited Partnership [Member] Total Equity [Member]
Beginning Balance at Dec. 31, 2014	$ 3,086,377,000	$ 150,000	$ 3,740,594,000	$ (6,252,000)	$ (654,869,000)	$ (51,951,000)	$ 3,027,672,000	$ 54,786,000	$ 3,919,000	$ 3,086,377,000	$ 3,086,377,000	$ 3,027,672,000	$ 54,786,000	$ 3,919,000	$ 3,086,377,000
Noncontrolling Interest - Operating Partnership (Mezzanine) - Beginning Balance at Dec. 31, 2014	7,537,000										7,537,000
Net proceeds from the issuance of common shares		1,000	25,226,000				25,227,000			25,227,000
Net income	68,388,000				66,464,000		66,464,000	1,575,000	113,000	68,152,000	68,388,000	66,464,000	1,575,000	113,000	68,152,000
Net income (Mezzanine)	236,000										236,000
Distributions (Mezzanine)	(236,000)										(236,000)
Redemption of limited partners common units for common shares			224,000				224,000	(224,000)		0		224,000	(224,000)		0
Contributions from partners												34,731,000			34,731,000
Distributions					(141,837,000)		(141,837,000)	(3,465,000)	(113,000)	(145,415,000)
Distributions to partners												(141,837,000)	(3,465,000)	(113,000)	(145,415,000)
Share-based compensation			9,504,000				9,504,000			9,504,000
Other comprehensive income - foreign currency translation	1,741,000			1,701,000			1,701,000	40,000		1,741,000	1,741,000	1,701,000	40,000		1,741,000
Other comprehensive loss - derivative instruments	(319,000)			(312,000)			(312,000)	(7,000)		(319,000)	(319,000)	(312,000)	(7,000)		(319,000)
Ending Balance at Jun. 30, 2015	3,045,267,000	$ 151,000	$ 3,775,548,000	$ (4,863,000)	$ (730,242,000)	$ (51,951,000)	$ 2,988,643,000	$ 52,705,000	$ 3,919,000	$ 3,045,267,000	3,045,267,000	$ 2,988,643,000	$ 52,705,000	$ 3,919,000	$ 3,045,267,000
Noncontrolling Interest - Operating Partnership (Mezzanine) - Ending Balance at Jun. 30, 2015	$ 7,537,000										$ 7,537,000