v2.4.0.6
Noncontrolling Interests (Redeemable Preferred Units) (Narrative) (Details) (USD $)
3 Months Ended 3 Months Ended 3 Months Ended
Mar. 31, 2013
Noncontrolling Interests [Member]
Mar. 31, 2013
Series Two Preferred Units [Member]
Mar. 31, 2013
Series Two Preferred Units [Member]
Noncontrolling Interests [Member]
May 14, 2013
Series Two Preferred Units [Member]
Noncontrolling Interests [Member]
Feb. 15, 2013
Series Two Preferred Units [Member]
Noncontrolling Interests [Member]
Dec. 31, 2012
Series Two Preferred Units [Member]
Noncontrolling Interests [Member]
Dec. 31, 2011
Series Two Preferred Units [Member]
Noncontrolling Interests [Member]
Dec. 31, 2010
Series Two Preferred Units [Member]
Noncontrolling Interests [Member]
Dec. 31, 2009
Series Two Preferred Units [Member]
Noncontrolling Interests [Member]
Mar. 31, 2013
series four preferred units [Member]
Mar. 31, 2013
series four preferred units [Member]
Noncontrolling Interests [Member]
Feb. 15, 2013
series four preferred units [Member]
Noncontrolling Interests [Member]
Mar. 31, 2013
Redemption Year Two Thousand Fourteen [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]                          
Maximum Redeemable On Redemption Dates Preferred Units                         1,007,662
Series Two Preferred Units (in shares) 995,997   995,997                    
Liquidation preference percentage     6.00%                    
Preferred Units Liquidation Preference   $ 50.00 $ 50.00             $ 50.00 $ 50.00    
Operating Units liquidation preference (in dollars per share)     $ 38.10                    
OP Units for each Preferred Unit (in shares)   1.312336 1.312336                    
Series Two Preferred Units Redemption Price                         $ 50.00
Dates Series Two Preferred Unit Holders Can Require Redemption From Operating Partnership                         May 12, 2014
Maximum portion that may be required for redemption of total                         0.1666666667
Distributions to Series Two Preferred Units (in dollars per share)         $ 0.85302             $ 0.25  
Series Four Preferred Units (in shares) 1,221,527                   1,221,527    
Series Four Preferred Units Annual Dividend Payable Rate                   2.00% 2.00%    
Number Of Holders Exercises       0   0 0 0 0