Consolidated Statement of Equity (USD $) In Thousands	Total	Liberty Property Limited Partnership [Member]	General Partners Equity [Member] Liberty Property Limited Partnership [Member]	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-Common [Member] Liberty Property Limited Partnership [Member]	Noncontrolling interest operating partnership-Preferred [Member]	Noncontrolling interest operating partnership-Preferred [Member] Liberty Property Limited Partnership [Member]	Noncontrolling interest-consolidated joint ventures [Member]	Noncontrolling interest-consolidated joint ventures [Member] Liberty Property Limited Partnership [Member]
Beginning Balance at Dec. 31, 2010	$ 2,438,552	$ 2,438,552	$ 2,082,186	$ 116	$ 2,560,193	$ (155)	$ (426,017)	$ (51,951)	$ 2,082,186	$ 67,621	$ 67,621	$ 287,959	$ 287,959	$ 786	$ 786
Net proceeds from the issuance of common shares	33,396			1	33,395				33,396
Net income	169,465	169,465	149,207				149,207		149,207	5,010	5,010	15,759	15,759	(511)	(511)
Contributions from partners		41,448	41,448
Distributions to partners		(185,591)	(164,332)								(5,500)		(15,759)
Distributions	(185,591)						(164,332)		(164,332)	(5,500)		(15,759)
Noncash compensation	8,052				8,052				8,052
Foreign currency translation adjustment	(63)	(63)	(64)			(64)			(64)	1	1
Redemption of noncontrolling interests - common units					2,060				2,060	(2,060)
Redemption of limited partners common units for common shares			2,060								(2,060)
Ending Balance at Sep. 30, 2011	2,463,811	2,463,811	2,110,505	117	2,603,700	(219)	(441,142)	(51,951)	2,110,505	65,072	65,072	287,959	287,959	275	275
Beginning Balance at Jun. 30, 2011
Net income	41,681	41,681
Foreign currency translation adjustment	(2,200)	(2,200)
Ending Balance at Sep. 30, 2011	$ 2,463,811	$ 2,463,811						$ (51,951)