Consolidated Balance Sheets (Parentheticals) - USD ($)	Jun. 30, 2015	Dec. 31, 2014
Amortized Cost on Deferred Financing and Leasing Costs	$ 176,671,000	$ 169,468,000
Noncontrolling Interest Operating Partnership Common Units Outstanding	3,539,075	3,553,566
Common Stock, Par or Stated Value Per Share	$ 0.001	$ 0.001
Common Stock, Shares Authorized	283,987,000	283,987,000
Common Stock, Shares, Issued	150,737,328	149,807,179
Common Stock, Shares, Outstanding	150,737,328	149,807,179
Treasury Stock, Shares	1,249,909	1,249,909
Liberty Property Limited Partnership [Member]
Amortized Cost on Deferred Financing and Leasing Costs	$ 176,671,000	$ 169,468,000
Limited Partners' Capital Account, Units Outstanding	3,539,075	3,553,566
Common Stock, Shares, Outstanding	149,487,419	148,557,270
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