Noncontrolling Interests (Narrative) (Details)	Dec. 31, 2012
Noncontrolling Interests [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Operating Partnership (OP) Units (in shares)	16,053,497
Long-Term Incentive Plan (LTIP) Units (in shares)	1,303,296
Series Two Preferred Units (in shares)	995,997
Convertible Operating Partnership (OP) Units (in shares)	1,307,083
Series Four Preferred Units (in shares)	1,221,527
OPP Units 2011 [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Outperformance awards in LTIP Units (in shares)	400,000
OPP Units 2012 [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Outperformance awards in LTIP Units (in shares)	400,000