Noncontrolling Interests In Subsidiaries (Tables)
9 Months Ended
Sep. 30, 2011
Noncontrolling Interests In Subsidiaries [Abstract] 
Changes Of Noncontrolling Interests In Subsidiaries
 
Common
 
Units
Balance at January 1, 2011
13,007,668
Redemption of common units for shares of common stock
(236,563)
   
Balance at September 30, 2011
12,771,105