REAL ESTATE AFFILIATES (Details) (USD $)	12 Months Ended							12 Months Ended					0 Months Ended				12 Months Ended				12 Months Ended		1 Months Ended				12 Months Ended		0 Months Ended					12 Months Ended				12 Months Ended		0 Months Ended				12 Months Ended	0 Months Ended				0 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Equity method investments	Dec. 31, 2011 Equity method investments	Dec. 31, 2010 Equity method investments	Dec. 31, 2012 Other Investments	Dec. 31, 2012 Cost basis investments	Dec. 31, 2011 Cost basis investments	Dec. 31, 2011 The Woodlands Equity method investments	Dec. 31, 2010 The Woodlands Equity method investments	Jun. 30, 2011 The Woodlands Equity method investments	Oct. 30, 2012 Bridges at Mint Hill, LLC	Dec. 31, 2012 Bridges at Mint Hill, LLC	Dec. 31, 2012 Bridges at Mint Hill, LLC Equity method investments	Dec. 31, 2011 Bridges at Mint Hill, LLC Equity method investments	Dec. 31, 2010 Circle T	Dec. 31, 2011 Circle T Equity method investments	Dec. 31, 2010 Circle T Equity method investments	Dec. 31, 2012 Circle T Equity method investments	Dec. 31, 2012 Forest View Apartments Equity method investments	Dec. 31, 2011 Forest View Apartments Equity method investments	Oct. 31, 2011 HHMK Development, LLC item	Dec. 31, 2012 HHMK Development, LLC Equity method investments	Dec. 31, 2011 HHMK Development, LLC Equity method investments	May 31, 2012 Millennium Waterway Apartments	Dec. 31, 2012 Millennium Waterway Apartments Equity method investments	Dec. 31, 2011 Millennium Waterway Apartments Equity method investments	Jul. 05, 2012 Millennium Woodlands Phase II, LLC. acre	May 14, 2012 Millennium Woodlands Phase II, LLC.	Dec. 31, 2012 Millennium Woodlands Phase II, LLC. Equity method investments	Dec. 31, 2012 Parcel D Development, LLC Equity method investments	Dec. 31, 2011 Parcel D Development, LLC Equity method investments	Dec. 31, 2012 Stewart Title Equity method investments	Dec. 31, 2011 Stewart Title Equity method investments	Dec. 31, 2012 Timbermill Apartments Equity method investments	Dec. 31, 2011 Timbermill Apartments Equity method investments	Dec. 31, 2012 Woodlands Sarofim # 1 Equity method investments	Dec. 31, 2011 Woodlands Sarofim # 1 Equity method investments	Apr. 19, 2012 Forest View/Timbermill Apartments	Oct. 11, 2011 AlaMoana Condominium Development Joint Venture	Oct. 27, 2011 Columbia Parcel D Joint Venture	Dec. 31, 2012 Properties owned by real estate affiliates	Dec. 31, 2011 The Woodlands	Sep. 30, 2012 KR Holdings, LLC	Jun. 14, 2012 KR Holdings, LLC	Sep. 17, 2012 KR Holdings, LLC	Dec. 31, 2012 KR Holdings, LLC Equity method investments	Sep. 30, 2012 KR Holdings, LLC Mezzanine loan agreements	Sep. 17, 2012 KR Holdings, LLC Mezzanine loan agreements item	Dec. 31, 2012 KR Holdings, LLC Mezzanine loan agreements
Real Estate Affiliates
Number of local developers with whom the entity entered into a joint venture																							2
Investment in Real Estate Affiliates
Economic ownership (as a percent)												52.50%			90.50%	79.00%		50.00%		50.00%	0.00%	50.00%		50.00%	50.00%		100.00%	83.55%			81.43%	50.00%	50.00%	50.00%	50.00%	0.00%	50.00%	20.00%	20.00%									50.00%
Carrying Value	$ 32,179,000	$ 58,790,000		$ 23,402,000	$ 49,617,000		$ 300,000	$ 8,777,000	$ 9,173,000							$ 180,000		$ 9,004,000		$ 9,004,000		$ 5,358,000		$ 1,257,000				$ 21,998,000			$ 2,190,000	$ 4,330,000	$ 2,990,000	$ 3,871,000	$ 3,643,000		$ 3,988,000	$ 2,450,000	$ 2,456,000
Share of Earnings	3,683,000	8,578,000	9,413,000	1,307,000	4,685,000	9,413,000		2,376,000	3,893,000	3,731,000	9,417,000						(4,000)	(1,000)	(4,000)		2,000	5,000					407,000	682,000						902,000	204,000	2,000		(6,000)	64,000					3,731,000
Aggregate carrying value of unconsolidated VIEs	7,800,000	3,200,000
Ownership ratio in a joint venture																																														50.00%
Number of debt instruments																																																		2
Amount of borrowings																																																		20,000,000
Blended interest rate (as a percent)																																																		12.00%
Option to extend, term																																																	1 year
Preferred return on capital (as a percent)																																													13.00%
Committed pre-development costs																																															40,000,000			3,000,000
Funded pre-development costs																																																			2,600,000
Non-interest bearing predevelopment costs																																																			2,000,000
Amount funded in cash to joint venture	0												4,500,000
Economic interest (as a percent)													90.50%																	81.40%											50.00%	50.00%
Ownership percentage before acquiring additional interest													79.00%
Share of distributable cash		1,429,000																																						8,600,000
Consideration for acquisition of partner's interest																										6,900,000
Predevelopment costs														800,000
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
Secured debt																																											9,900,000
Share of the entity in secured debt																																											$ 3,900,000