Net Gain on Disposition of Interest in Unconsolidated Entities (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Net gain on disposition of interest in unconsolidated entities [Line Items]
Net gain on disposition of interest in unconsolidated entities	$ 1,009,000	$ 9,189,000	$ 20,293,000	$ 50,075,000
Mall at Stonecrest [Member]
Net gain on disposition of interest in unconsolidated entities [Line Items]
Net gain on disposition of interest in unconsolidated entities	0	7,952,000	0	7,952,000
LIberty Center [Member]
Net gain on disposition of interest in unconsolidated entities [Line Items]
Net gain on disposition of interest in unconsolidated entities	0	1,237,000	0	1,237,000
Newport Landing [Member]
Net gain on disposition of interest in unconsolidated entities [Line Items]
Net gain on disposition of interest in unconsolidated entities	0	0	5,765,000	0
Eaton Ridge [Member]
Net gain on disposition of interest in unconsolidated entities [Line Items]
Net gain on disposition of interest in unconsolidated entities	0	0	4,745,000	0
Arbor Glen [Member]
Net gain on disposition of interest in unconsolidated entities [Line Items]
Net gain on disposition of interest in unconsolidated entities	0	0	3,422,000	0
Parkwood Village [Member]
Net gain on disposition of interest in unconsolidated entities [Line Items]
Net gain on disposition of interest in unconsolidated entities	0	0	2,817,000	0
Sutton Landing [Member]
Net gain on disposition of interest in unconsolidated entities [Line Items]
Net gain on disposition of interest in unconsolidated entities	0	0	2,535,000	0
Westwood Reserve [Member]
Net gain on disposition of interest in unconsolidated entities [Line Items]
Net gain on disposition of interest in unconsolidated entities	0	0	0	8,904,000
Legacy Crossroads [Member]
Net gain on disposition of interest in unconsolidated entities [Line Items]
Net gain on disposition of interest in unconsolidated entities	0	0	0	6,216,000
Colonial Grand [Member]
Net gain on disposition of interest in unconsolidated entities [Line Items]
Net gain on disposition of interest in unconsolidated entities	0	0	0	4,904,000
Legacy Arboretum [Member]
Net gain on disposition of interest in unconsolidated entities [Line Items]
Net gain on disposition of interest in unconsolidated entities	0	0	0	3,257,000
Barrington Place [Member]
Net gain on disposition of interest in unconsolidated entities [Line Items]
Net gain on disposition of interest in unconsolidated entities	0	0	0	1,515,000
Golden Gate [Member]
Net gain on disposition of interest in unconsolidated entities [Line Items]
Net gain on disposition of interest in unconsolidated entities	0	0	0	16,440,000
Other [Member]
Net gain on disposition of interest in unconsolidated entities [Line Items]
Net gain on disposition of interest in unconsolidated entities	$ 1,009,000	$ 0	$ 1,009,000	$ (350,000)