Noncontrolling Interests (Narrative) (Detail)	Sep. 30, 2012
Noncontrolling Interests [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Operating Partnership (OP) Units	16,501,441
Long-Term Incentive Plan (LTIP) Units	1,600,324
Series Two preferred units	995,997
Series Four preferred units	1,221,527
Convertible Operating Partnership (OP) Units	1,307,083
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