Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Deferred financing and leasing costs, accumulated amortization	$ 158,817	$ 155,865
Limited Partners' common units outstanding	3,520,205	3,520,205
Common shares of beneficial interest, par value per share	$ 0.001	$ 0.001
Common shares of beneficial interest, shares authorized	283,987,000	283,987,000
Common shares of beneficial interest, shares issued	147,796,618	147,450,691
Common shares of beneficial interest, shares outstanding	147,796,618	147,450,691
Liberty Property Limited Partnership [Member]
Deferred financing and leasing costs, accumulated amortization	$ 158,817	$ 155,865
Limited Partners' common units outstanding	3,520,205	3,520,205
Common shares of beneficial interest, shares outstanding	147,796,618	147,450,691
Series I 2 [Member]
Noncontrolling interest - operating partnership, preferred units outstanding	301,483	301,483
Series I 2 [Member] \| Liberty Property Limited Partnership [Member]
Noncontrolling interest - operating partnership, preferred units outstanding	301,483	301,483

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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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
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-Name Accounting Standards Codification
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-Section 50
-Paragraph 2
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For an unclassified balance sheet, the accumulated amortization, as of the reporting date, which represents the periodic charge to earnings of initial direct costs which have been deferred and are being allocated over the lease term in proportion to the recognition of rental income.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 25
-Paragraph 16
-URI http://asc.fasb.org/extlink&oid=77902619&loc=d3e40588-112709

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-Name Accounting Standards Codification
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The number of limited partner units outstanding.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055

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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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