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-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]
Noncontrolling Interest - Operating Partnership (Mezzanine) - Beginning Balance at Dec. 31, 2014	$ 7,537,000										$ 7,537,000
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
Net proceeds from the issuance of common shares		0	12,579,000				12,579,000			12,579,000
Net income	31,862,000				30,951,000		30,951,000	735,000	58,000	31,744,000	31,862,000	30,951,000	735,000	58,000	31,744,000
Net income (Mezzanine)	118,000										118,000
Distributions (Mezzanine)	(118,000)										(118,000)
Redemption of limited partners common units for common shares												224,000	(224,000)		0
Contributions from partners												20,016,000			20,016,000
Distributions					(70,830,000)		(70,830,000)	(1,680,000)	(58,000)	(72,568,000)
Distributions to partners												(70,830,000)	(1,680,000)	(58,000)	(72,568,000)
Share-based compensation			7,437,000				7,437,000			7,437,000
Other comprehensive loss - foreign currency translation	(10,410,000)			(10,169,000)			(10,169,000)	(241,000)		(10,410,000)	(10,410,000)	(10,169,000)	(241,000)		(10,410,000)
Other comprehensive loss - derivative instruments	(947,000)			(925,000)			(925,000)	(22,000)		(947,000)	(947,000)	(925,000)	(22,000)		(947,000)
Redemption of noncontrolling interests - common units			224,000				224,000	(224,000)		0
Noncontrolling Interest - Operating Partnership (Mezzanine) - Ending Balance at Mar. 31, 2015	7,537,000										7,537,000
Ending Balance at Mar. 31, 2015	$ 3,054,212,000	$ 150,000	$ 3,760,834,000	$ (17,346,000)	$ (694,748,000)	$ (51,951,000)	$ 2,996,939,000	$ 53,354,000	$ 3,919,000	$ 3,054,212,000	$ 3,054,212,000	$ 2,996,939,000	$ 53,354,000	$ 3,919,000	$ 3,054,212,000