Consolidated Balance Sheets (Parentheticals) - USD ($)	Mar. 31, 2016	Dec. 31, 2015
Deferred financing and leasing costs, accumulated amortization	$ 170,558,000	$ 175,243,000
Limited Partners' common units outstanding	3,539,075	3,539,075
Common shares of beneficial interest, par value per share	$ 0.001	$ 0.001
Common shares of beneficial interest, shares authorized	283,987,000	283,987,000
Common shares of beneficial interest, shares issued	146,603,946	147,577,984
Common shares of beneficial interest, shares outstanding	146,603,946	147,577,984
Liberty Property Limited Partnership [Member]
Deferred financing and leasing costs, accumulated amortization	$ 170,558,000	$ 175,243,000
Limited Partners' common units outstanding	3,539,075	3,539,075
Common shares of beneficial interest, shares outstanding	146,603,946	147,577,984
Series I 2 [Member]
Noncontrolling interest - operating partnership, preferred units outstanding	301,483	301,483
Series I 2 [Member] | Liberty Property Limited Partnership [Member]
Noncontrolling interest - operating partnership, preferred units outstanding	301,483	301,483