Consolidated Statements of Operations (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Net gain on property dispositions included in discontinued operation	$ 2,981	$ 50,157	$ 4,045	$ 50,627
Liberty Property Limited Partnership [Member]
Net gain on property dispositions included in discontinued operation	$ 2,981	$ 50,157	$ 4,045	$ 50,627