Noncontrolling Interests (Narrative) (Details)	Mar. 31, 2012
Noncontrolling Interests [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Operating Partnership (OP) Units	16,527,994
Long-Term Incentive Plan (LTIP) Units	1,690,649
Series Two Preferred Units	1,030,748
Convertible Operating Partnership (OP) Units	1,352,688
OPP Units 2011 [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Outperformance awards in LTIP Units	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	400,000