Consolidated Statements of Operations (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Net gain on property dispositions included in discontinued operation	$ 1,540	$ 4,095	$ 2,505	$ 54,722
Liberty Property Limited Partnership [Member]
Net gain on property dispositions included in discontinued operation	$ 1,540	$ 4,095	$ 2,505	$ 54,722