Preferred Shares Of Beneficial Interest	6 Months Ended
Jun. 30, 2013
Class of Stock Disclosures [Abstract]
Preferred Shares Of Beneficial Interest	Preferred Shares of Beneficial Interest We issued $150 million and $200 million of depositary shares on June 6, 2008 and January 30, 2007, respectively. Each depositary share represents one-hundredth of a Series F Cumulative Redeemable Preferred Share. The depositary shares are redeemable at our option, in whole or in part, for cash at a redemption price of $25 per depositary share, plus any accrued and unpaid dividends thereon. The depositary shares are not convertible or exchangeable for any of our other property or securities. The Series F Preferred Shares pay a 6.5% annual dividend and have a liquidation value of $2,500 per share. The Series F Preferred Shares issued in June 2008 were issued at a discount, resulting in an effective rate of 8.25%. A portion of the Series F depositary shares were redeemed on June 5, 2013, at our option, for cash with the redemption value totaling $200 million. Upon the redemption of these shares, a portion of the related original issuance costs totaling $15.7 million were reported as a deduction in arriving at net income attributable to common shareholders. The remaining Series F Preferred Shares totaling $150 million pay a 6.5% annual dividend and have a liquidation value of $2,500 per share. Of these outstanding shares, $64.3 million of the Series F Preferred Shares were issued at a discount and have an effective rate of 8.25%. In April 2003, we issued $75 million of depositary shares with each share representing one-thirtieth of a Series D Cumulative Redeemable Preferred Share. The depositary shares were redeemed on March 18, 2013, at our option, for cash at a redemption price of $25 per depositary share or $75 million, plus accrued and unpaid dividends thereon. Upon the redemption of these shares, the related original issuance costs of $2.2 million were reported as a deduction in arriving at net income attributable to common shareholders. The Series D Preferred Shares paid a 6.75% annual dividend, had a liquidation value of $750 per share and were not convertible or exchangeable for any of our property or securities.

Preferred Shares of Beneficial Interest

We issued $150 million and $200 million of depositary shares on June 6, 2008 and January 30, 2007, respectively. Each depositary share represents one-hundredth of a Series F Cumulative Redeemable Preferred Share. The depositary shares are redeemable at our option, in whole or in part, for cash at a redemption price of $25 per depositary share, plus any accrued and unpaid dividends thereon. The depositary shares are not convertible or exchangeable for any of our other property or securities. The Series F Preferred Shares pay a 6.5% annual dividend and have a liquidation value of $2,500 per share. The Series F Preferred Shares issued in June 2008 were issued at a discount, resulting in an effective rate of 8.25%.

A portion of the Series F depositary shares were redeemed on June 5, 2013, at our option, for cash with the redemption value totaling $200 million. Upon the redemption of these shares, a portion of the related original issuance costs totaling $15.7 million were reported as a deduction in arriving at net income attributable to common shareholders. The remaining Series F Preferred Shares totaling $150 million pay a 6.5% annual dividend and have a liquidation value of $2,500 per share. Of these outstanding shares, $64.3 million of the Series F Preferred Shares were issued at a discount and have an effective rate of 8.25%.

In April 2003, we issued $75 million of depositary shares with each share representing one-thirtieth of a Series D Cumulative Redeemable Preferred Share. The depositary shares were redeemed on March 18, 2013, at our option, for cash at a redemption price of $25 per depositary share or $75 million, plus accrued and unpaid dividends thereon. Upon the redemption of these shares, the related original issuance costs of $2.2 million were reported as a deduction in arriving at net income attributable to common shareholders. The Series D Preferred Shares paid a 6.75% annual dividend, had a liquidation value of $750 per share and were not convertible or exchangeable for any of our property or securities.