Noncontrolling Interest - Common Shares and Units Activity (Details) - shares	6 Months Ended
	Jun. 30, 2019
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)	(168,327)
Restricted share, time-based LTIP Unit grants and vested restricted stock units, net of forfeitures (in shares)	518,292
Balance as of end of period (in shares)	121,922,120
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)	2,940
Balance as of end of period (in shares)	48,660
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)	(168,327)
Restricted share, time-based LTIP Unit grants and vested restricted stock units, net of forfeitures (in shares)	521,232
Balance as of end of period (in shares)	121,970,780