REAL ESTATE AFFILIATES (Details) (USD $)	3 Months Ended		6 Months Ended			3 Months Ended		6 Months Ended			6 Months Ended			3 Months Ended	6 Months Ended						3 Months Ended	6 Months Ended					3 Months Ended	6 Months Ended		1 Months Ended					3 Months Ended	6 Months Ended		3 Months Ended	6 Months Ended		3 Months Ended	6 Months Ended		1 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011	Jun. 30, 2012 Equity method investments	Jun. 30, 2011 Equity method investments	Jun. 30, 2012 Equity method investments	Jun. 30, 2011 Equity method investments	Dec. 31, 2011 Equity method investments	Jun. 30, 2012 Cost basis investments	Jun. 30, 2011 Cost basis investments	Dec. 31, 2011 Cost basis investments	Jun. 30, 2011 The Woodlands Equity method investments	Jun. 30, 2011 The Woodlands Equity method investments	Jun. 30, 2012 Bridges at Mint Hill, LLC	Jun. 30, 2012 Bridges at Mint Hill, LLC Equity method investments	Dec. 31, 2011 Bridges at Mint Hill, LLC Equity method investments	Jun. 30, 2012 Circle T Equity method investments	Dec. 31, 2011 Circle T Equity method investments	Jun. 30, 2012 Forest View Equity method investments	Jun. 30, 2012 Forest View Equity method investments	Dec. 31, 2011 Forest View Equity method investments	Jun. 30, 2012 HHMK Development, LLC Equity method investments	Dec. 31, 2011 HHMK Development, LLC Equity method investments	May 31, 2012 Millennium Waterway Apartments	Jun. 30, 2012 Millennium Waterway Apartments Equity method investments	Jun. 30, 2012 Millennium Waterway Apartments Equity method investments	Dec. 31, 2011 Millennium Waterway Apartments Equity method investments	Jul. 31, 2012 Millennium Woodlands Phase II, LLC. Acres	May 31, 2012 Millennium Woodlands Phase II, LLC. item	Jun. 30, 2012 Millennium Woodlands Phase II, LLC. Equity method investments	Jun. 30, 2012 Parcel D Development, LLC Equity method investments	Dec. 31, 2011 Parcel D Development, LLC Equity method investments	Jun. 30, 2012 Stewart Title Equity method investments	Jun. 30, 2012 Stewart Title Equity method investments	Dec. 31, 2011 Stewart Title Equity method investments	Jun. 30, 2012 Timbermill Apartments Equity method investments	Jun. 30, 2012 Timbermill Apartments Equity method investments	Dec. 31, 2011 Timbermill Apartments Equity method investments	Jun. 30, 2012 Woodlands Sarofim # 1 Equity method investments	Jun. 30, 2012 Woodlands Sarofim # 1 Equity method investments	Dec. 31, 2011 Woodlands Sarofim # 1 Equity method investments	Apr. 30, 2012 Forest View/Timbermill Apartments	Jun. 30, 2012 Properties owned by real estate affiliates	Jun. 30, 2012 Properties owned by real estate affiliates Woodlands Sarofim # 1
Investment in Real Estate Affiliates
Economic ownership (as a percent)														52.50%	52.50%		79.00%	79.00%	50.00%	50.00%			50.00%	50.00%	50.00%	100.00%	100.00%	100.00%	83.55%			81.43%	50.00%	50.00%	50.00%	50.00%	50.00%			50.00%	20.00%	20.00%	20.00%
Carrying Value	$ 32,597,000		$ 32,597,000		$ 62,595,000	$ 19,758,000		$ 19,758,000		$ 49,617,000	$ 12,839,000		$ 12,978,000				$ 503,000	$ 180,000	$ 9,004,000	$ 9,004,000			$ 5,358,000	$ 418,000					$ 21,998,000				$ 3,673,000	$ 2,990,000	$ 3,684,000	$ 3,684,000	$ 3,643,000			$ 3,988,000	$ 2,476,000	$ 2,476,000	$ 2,456,000
Share of Earnings	446,000	2,110,000	3,122,000	7,623,000		446,000	2,110,000	746,000	3,729,000		2,376,000	3,894,000		2,110,000	3,729,000						1,000	2,000					185,000	406,000							257,000	316,000		1,000	2,000		2,000	20,000
Distributions from earnings																																												800,000
Aggregate carrying value of unconsolidated VIEs	4,600,000		4,600,000		3,200,000
Number of units in Class A multi-family unit in The Woodlands Town Center to be constructed																															314
Area of land contributed to the joint venture (in acres)																														4.8
Value of the land contributed to joint venture																														15,500,000
Cash contributed by joint venture partner																														3,000,000
Construction loan secured																														37,700,000
Ownership percentage if cash contribution made to the venture																90.50%
Amount of cash contribution which may be required to be made to the venture																4,500,000
Share of distributable cash			8,579,000																																									8,600,000
Secured debt																																													6,900,000
Share of the entity in secured debt																																														$ 1,400,000