Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Accounts receivable, allowance	$ 3,782	$ 3,467
Accrued rent receivable, allowance	$ 13,562	$ 13,645
Common Stock, Par or Stated Value Per Share (USD per share)	$ 0.01	$ 0.01
Common Stock, Shares Authorized	400,000,000	400,000,000
Common Stock, Shares, Issued	178,602,602	178,285,236
Common Stock, Shares, Outstanding	178,602,602	178,285,236
Common Shares in Grantor Trust, Issued	977,120	894,736
Common Shares in Grantor Trust, Outstanding	977,120	894,736
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Accounts receivable, allowance	$ 3,782	$ 3,467
Accrued rent receivable, allowance	$ 13,562	$ 13,645
Redeemable Limited Partnership Units Issued	1,479,799	1,479,799
Redeemable Limited Partnership Units Outstanding	1,479,799	1,479,799
General Partners' Capital Account, Units Issued	178,602,602	178,285,236
General Partners' Capital Account, Units Outstanding	178,602,602	178,285,236

Allowance for doubtful accrued rent receivable.

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Common shares in grantor trust, issued.

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Common shares in grantor trust, outstanding

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For an unclassified balance sheet, a valuation allowance for receivables due a company that are expected to be uncollectible.

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Face amount or stated value per share of common stock.

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The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

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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 general partner units issued.

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The number of securities classified as temporary equity that have been sold (or granted) to the entity's shareholders. Securities issued include securities outstanding and 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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