Balance Sheet Parenthetical (Parentheticals) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Amortized Cost on Deferred Financing and Leasing Costs	$ 167,045,000	$ 140,933,000
Noncontrolling Interest Operating Partnership Common Units Outstanding	3,553,566	3,556,556
Common Stock, Par or Stated Value Per Share	$ 0.001	$ 0.001
Common Stock, Shares Authorized	283,987,000	183,987,000
Common Stock, Shares, Issued	149,354,294	147,846,801
Common Stock, Shares, Outstanding	149,354,294	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	$ 167,045,000	$ 140,933,000
Limited Partners' Capital Account, Units Outstanding	3,553,566	3,556,556
Common Stock, Shares, Outstanding	148,104,385	146,596,892
Treasury Stock, Shares	1,249,909	1,249,909
Series I 2 [Member]
Temporary Equity, Shares Outstanding	301,483	301,483
Series I 2 [Member] | Liberty Property Limited Partnership [Member]
Temporary Equity, Shares Outstanding	301,483	301,483