Balance Sheet Parenthetical (Parentheticals) (USD $)	Mar. 31, 2014	Dec. 31, 2013
Amortized Cost on Deferred Financing and Leasing Costs	$ 150,476,000	$ 140,958,000
Noncontrolling Interest Operating Partnership Common Units Outstanding	3,553,566	3,556,556
Preferred Units, Outstanding	0	0
Common Stock, Par or Stated Value Per Share	$ 0.001	$ 0.001
Common Stock, Shares Authorized	183,987,000	183,987,000
Common Stock, Shares, Issued	148,541,749	147,846,801
Common Stock, Shares, Outstanding	148,541,749	147,846,801
Treasury Stock, Shares	1,249,909	1,249,909
Liberty Property Limited Partnership [Member]
Amortized Cost on Deferred Financing and Leasing Costs	$ 150,476,000	$ 140,958,000
Limited Partners' Capital Account, Units Outstanding	3,553,566	3,556,556
Preferred Units, Outstanding	0	0
Common Stock, Shares, Outstanding	147,291,840	146,596,892
Treasury Stock, Shares	1,249,909	1,249,909
Series I 2 [Member]
Preferred Units, Outstanding	301,483	301,483
Series I 2 [Member] | Liberty Property Limited Partnership [Member]
Preferred Units, Outstanding	301,483	301,483