Consolidated Balance Sheets (Parentheticals) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Amortized Cost on Deferred Financing and Leasing Costs	$ 173,076,000	$ 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	283,987,000us-gaap_CommonStockSharesAuthorized	283,987,000us-gaap_CommonStockSharesAuthorized
Common Stock, Shares, Issued	150,367,813us-gaap_CommonStockSharesIssued	149,807,179us-gaap_CommonStockSharesIssued
Common Stock, Shares, Outstanding	150,367,813us-gaap_CommonStockSharesOutstanding	149,807,179us-gaap_CommonStockSharesOutstanding
Treasury Stock, Shares	1,249,909us-gaap_TreasuryStockShares	1,249,909us-gaap_TreasuryStockShares
Liberty Property Limited Partnership [Member]
Amortized Cost on Deferred Financing and Leasing Costs	$ 173,076,000	$ 169,468,000
Limited Partners' Capital Account, Units Outstanding	3,539,075	3,553,566
Common Stock, Shares, Outstanding	149,117,904	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

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Noncontrolling Interest of the Trust relating to the Operating Partnership. The amount of units owned by limited partners' which are outstanding.

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Face amount or stated value per share of common stock.

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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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The number of limited partner units outstanding.

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The number of securities classified as temporary equity that have been issued and are held by the entity's shareholders. Securities outstanding equals securities issued minus securities held in treasury. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer.

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Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends.

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