Noncontrolling Interest - Common Shares and Units Activity (Details)	3 Months Ended
Mar. 31, 2019 shares
Increase (Decrease) in Stockholders' Equity
Noncontrolling ownership interest in the Operating Trust	0.04%
Common Shares
Increase (Decrease) in Stockholders' Equity
Balance as of beginning of period (in shares)	121,572,155
Repurchase of shares (in shares)	(163,913)
Restricted share, time-based LTIP Unit grants and vested restricted stock units, net of forfeitures (in shares)	491,383
Balance as of end of period (in shares)	121,899,625
OP Units and LTIP Units \| Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity
Balance as of beginning of period (in shares)	45,720
Repurchase of shares (in shares)	0
Restricted share, time-based LTIP Unit grants and vested restricted stock units, net of forfeitures (in shares)	0
Balance as of end of period (in shares)	45,720
Common Stock, OP Units, and LTIP Units
Increase (Decrease) in Stockholders' Equity
Balance as of beginning of period (in shares)	121,617,875
Repurchase of shares (in shares)	(163,913)
Restricted share, time-based LTIP Unit grants and vested restricted stock units, net of forfeitures (in shares)	491,383
Balance as of end of period (in shares)	121,945,345

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

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Number of shares issued which are neither cancelled nor held in the treasury.

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Number of shares (or other type of equity) issued during the period as a result of any equity-based compensation plan other than an employee stock ownership plan (ESOP), net of any shares forfeited. Shares issued could result from the issuance of restricted stock, the exercise of stock options, stock issued under employee stock purchase plans, and/or other employee benefit plans.

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Number of shares that have been repurchased and retired during the period.

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