Segment Information - Company's Combined Shopping and Office Properties Portfolios (Detail)	Dec. 31, 2012 Property Store	Dec. 31, 2011 Store Property	Dec. 31, 2010 Store Property
Segment Reporting, Asset Reconciling Item [Line Items]
Shopping centers owned	452	432	478
Office properties	0	5	6
Unconsolidated Joint Ventures [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Shopping centers owned	206	177	189
Consolidated Joint Ventures [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Shopping centers owned	3	2	3
States [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Shopping centers owned	39	38	39
Office properties	0	3	4