Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2011	Dec. 31, 2010
Common shares, par value	$ 0.001	$ 0.001
Common shares, shares authorized	183,987,000	183,987,000
Common shares, shares issued	117,352,353	115,530,608
Common shares, shares outstanding	117,352,353	115,530,608
Treasury stock, shares	1,249,909	1,249,909
Noncontrolling Interest Operating Partnership Common Units Outstanding	3,808,746	3,928,733
Preferred stock, units outstanding	9,740,000	9,740,000
Limited Partners' Capital Account, Units Outstanding	3,808,746	3,928,733
Liberty Property Limited Partnership [Member]
Common shares, shares outstanding	116,102,444	114,280,699
Treasury stock, shares	1,249,909	1,249,909
Preferred stock, units outstanding	9,740,000	9,740,000
Series I-2 [Member]
Preferred stock, units outstanding	301,483	0
Series I-2 [Member] | Liberty Property Limited Partnership [Member]
Preferred stock, units outstanding	301,483	0