Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Accrued rent receivable, allowance	$ 4,133	$ 5,086
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	400,000,000	400,000,000
Common stock, shares issued (in shares)	171,126,257	170,572,964
Common stock, shares outstanding (in shares)	171,126,257	170,572,964
Common shares in grantor trust, issued and outstanding (in shares)	1,169,703	1,160,494
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Accrued rent receivable, allowance	$ 4,133	$ 5,086
Redeemable limited partnership units issued (in units)	823,983	981,634
Redeemable limited partnership units outstanding (in units)	823,983	981,634
General partners' capital account, units issued (in units)	171,126,257	170,572,964
General partners' capital account, units outstanding (in units)	171,126,257	170,572,964

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Common shares in grantor trust issued and outstanding.

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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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