Schedule III - Consolidated Real Estate and Accumulated Depreciation (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 290
Land		274,241
Improvements less Cost of Sales and Other		28,727
Carrying Costs	[1]	7,659
Land & Land Improvements		310,627
Total		310,627	$ 293,003	$ 618,844	$ 607,133
Accumulated depreciation		0	0	(32,129)	$ (31,377)
Non-cash impairment charges		47,172	$ 60,939	$ 108,184
Real Estate, Net
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		290
Land		160,713
Improvements less Cost of Sales and Other		(34,076)
Carrying Costs	[2]	3,743
Land & Land Improvements		130,380
Total		130,380
Real Estate, Net | Other County | Other Property
Real Estate and Accumulated Depreciation [Line Items]
Land		0
Improvements less Cost of Sales and Other		4,742
Carrying Costs	[2]	0
Land & Land Improvements		4,742
Total		4,742
Real Estate, Net | California | Contra Costa County | San Joaquin River
Real Estate and Accumulated Depreciation [Line Items]
Land		12,225
Improvements less Cost of Sales and Other		(10,558)
Land & Land Improvements		1,667
Total		1,667
Real Estate, Net | Colorado | Douglas County | Cielo
Real Estate and Accumulated Depreciation [Line Items]
Land		3,933
Improvements less Cost of Sales and Other		3,187
Land & Land Improvements		7,120
Total		$ 7,120
Date Acquired		2016
Real Estate, Net | Florida | Broward County | The Preserves at Stonebriar
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 3,002
Improvements less Cost of Sales and Other		244
Land & Land Improvements		3,246
Total		$ 3,246
Date Acquired		2017
Real Estate, Net | Florida | Manatee County | Palisades
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 4,516
Improvements less Cost of Sales and Other		370
Land & Land Improvements		4,886
Total		$ 4,886
Date Acquired		2017
Real Estate, Net | Florida | Sarasota County | Fox Creek
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 12,257
Improvements less Cost of Sales and Other		742
Land & Land Improvements		12,999
Total		$ 12,999
Date Acquired		2017
Real Estate, Net | Georgia | Cobb County | West Oaks
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 1,669
Improvements less Cost of Sales and Other		748
Land & Land Improvements		2,417
Total		$ 2,417
Date of Construction		2015
Date Acquired		2015
Real Estate, Net | Georgia | Guinnett County | Independence
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 15,937
Improvements less Cost of Sales and Other		2,651
Land & Land Improvements		18,588
Total		$ 18,588
Date of Construction		2017
Date Acquired		2017
Real Estate, Net | Georgia | Paulding County | Harris Place
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 265
Improvements less Cost of Sales and Other		(219)
Land & Land Improvements		46
Total		$ 46
Date Acquired		2012
Real Estate, Net | Georgia | Paulding County | Seven Hills
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 2,964
Improvements less Cost of Sales and Other		1,198
Carrying Costs	[2]	61
Land & Land Improvements		4,223
Total		$ 4,223
Date Acquired		2012
Real Estate, Net | North Carolina | Cabbarus County | Moss Creek
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 1,254
Improvements less Cost of Sales and Other		116
Land & Land Improvements		1,370
Total		$ 1,370
Date of Construction		2017
Date Acquired		2016
Real Estate, Net | South Carolina | York County | Habersham
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 3,877
Improvements less Cost of Sales and Other		(948)
Carrying Costs	[2]	506
Land & Land Improvements		3,435
Total		$ 3,435
Date of Construction		2014
Date Acquired		2013
Real Estate, Net | Tennessee | Wilson County | Beckwith Crossing
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 1,294
Improvements less Cost of Sales and Other		1,070
Carrying Costs	[2]	275
Land & Land Improvements		2,639
Total		$ 2,639
Date of Construction		2015
Date Acquired		2014
Real Estate, Net | Tennessee | Williamson County | Morgan Farms
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 6,841
Improvements less Cost of Sales and Other		(4,168)
Carrying Costs	[2]	225
Land & Land Improvements		2,898
Total		$ 2,898
Date of Construction		2013
Date Acquired		2013
Real Estate, Net | Tennessee | Williamson County | Weatherford Estates
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 856
Improvements less Cost of Sales and Other		(922)
Carrying Costs	[2]	139
Land & Land Improvements		73
Total		$ 73
Date of Construction		2015
Date Acquired		2014
Real Estate, Net | Texas | Calhoun County | Caracol
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 8,603
Improvements less Cost of Sales and Other		(8,025)
Land & Land Improvements		578
Total		$ 578
Date of Construction		2006
Date Acquired		2006
Real Estate, Net | Texas | Collin County | Lakes Of Prosper
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 8,951
Improvements less Cost of Sales and Other		(9,094)
Carrying Costs	[2]	453
Land & Land Improvements		310
Total		$ 310
Date Acquired		2012
Real Estate, Net | Texas | Collin County | Parkside
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 2,177
Improvements less Cost of Sales and Other		(1,937)
Carrying Costs	[2]	307
Land & Land Improvements		547
Total		$ 547
Date of Construction		2014
Date Acquired		2013
Real Estate, Net | Texas | Collin County | Timber Creek
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 7,282
Improvements less Cost of Sales and Other		6,410
Carrying Costs	[2]	212
Land & Land Improvements		13,904
Total		$ 13,904
Date of Construction		2007
Date Acquired		2007
Real Estate, Net | Texas | Denton County | Lantana
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 27,673
Improvements less Cost of Sales and Other		(19,680)
Carrying Costs	[2]	585
Land & Land Improvements		8,578
Total		$ 8,578
Date of Construction		2000
Date Acquired		1999
Real Estate, Net | Texas | Denton County | River's Edge
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 1,227
Improvements less Cost of Sales and Other		445
Land & Land Improvements		1,672
Total		$ 1,672
Date Acquired		2014
Real Estate, Net | Texas | Denton County | The Preserve At Pecan Creek
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 5,855
Improvements less Cost of Sales and Other		(681)
Carrying Costs	[2]	256
Land & Land Improvements		5,430
Total		$ 5,430
Date of Construction		2006
Date Acquired		2005
Real Estate, Net | Texas | Kaufman County | Lakewood Trails
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 8,009
Improvements less Cost of Sales and Other		340
Land & Land Improvements		8,349
Total		$ 8,349
Date Acquired		2017
Real Estate, Net | Texas | Tarrant County | Summer Creek Ranch
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 2,887
Improvements less Cost of Sales and Other		(1,651)
Land & Land Improvements		1,236
Total		$ 1,236
Date Acquired		2012
Real Estate, Net | Texas | Tarrant County | Bar C Ranch
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 1,365
Improvements less Cost of Sales and Other		3,623
Carrying Costs	[2]	430
Land & Land Improvements		5,418
Total		$ 5,418
Date Acquired		2012
Real Estate, Net | Texas | Fort Bend County | Southern Colony
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 3,024
Improvements less Cost of Sales and Other		4,090
Land & Land Improvements		7,114
Total		$ 7,114
Date Acquired		2017
Real Estate, Net | Texas | Fort Bend County | Willow Creek Farms
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 290
Land		3,479
Improvements less Cost of Sales and Other		(1,741)
Carrying Costs	[2]	60
Land & Land Improvements		1,798
Total		$ 1,798
Date of Construction		2012
Date Acquired		2012
Real Estate, Net | Texas | Harris County | City Park
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 3,946
Improvements less Cost of Sales and Other		(3,794)
Carrying Costs	[2]	229
Land & Land Improvements		381
Total		$ 381
Date of Construction		2002
Date Acquired		2001
Real Estate, Net | Texas | Harris County | Imperial Forest
Real Estate and Accumulated Depreciation [Line Items]
Land		$ 5,345
Improvements less Cost of Sales and Other		(634)
Carrying Costs	[2]	5
Land & Land Improvements		4,716
Total		$ 4,716
Date of Construction		2015
Date Acquired		2014
Real Estate, Held For Sale
Real Estate and Accumulated Depreciation [Line Items]
Land	[3]	$ 113,528
Improvements less Cost of Sales and Other	[3]	62,803
Carrying Costs	[2],[3]	3,916
Land & Land Improvements	[3]	180,247
Total	[3]	180,247
Real Estate, Held For Sale | California | Los Angeles | Land In Entitlement Process
Real Estate and Accumulated Depreciation [Line Items]
Land	[3]	3,950
Improvements less Cost of Sales and Other	[3]	21,752
Land & Land Improvements	[3]	25,702
Total	[3]	$ 25,702
Date Acquired	[3]	1997
Real Estate, Held For Sale | Colorado | Douglas County | Pinery West
Real Estate and Accumulated Depreciation [Line Items]
Land	[3]	$ 7,308
Improvements less Cost of Sales and Other	[3]	3,849
Land & Land Improvements	[3]	11,157
Total	[3]	$ 11,157
Date of Construction	[3]	2006
Date Acquired	[3]	2006
Real Estate, Held For Sale | Colorado | Weld County | Buffalo Highlands
Real Estate and Accumulated Depreciation [Line Items]
Land	[3]	$ 3,001
Improvements less Cost of Sales and Other	[3]	(295)
Land & Land Improvements	[3]	2,706
Total	[3]	$ 2,706
Date of Construction	[3]	2006
Date Acquired	[3]	2005
Real Estate, Held For Sale | Colorado | Weld County | Johnstown Farms
Real Estate and Accumulated Depreciation [Line Items]
Land	[3]	$ 2,749
Improvements less Cost of Sales and Other	[3]	4,073
Carrying Costs	[2],[3]	100
Land & Land Improvements	[3]	6,922
Total	[3]	$ 6,922
Date of Construction	[3]	2002
Date Acquired	[3]	2002
Real Estate, Held For Sale | Colorado | Weld County | Stone Braker
Real Estate and Accumulated Depreciation [Line Items]
Land	[3]	$ 3,878
Improvements less Cost of Sales and Other	[3]	(1,786)
Land & Land Improvements	[3]	2,092
Total	[3]	$ 2,092
Date of Construction	[3]	2005
Date Acquired	[3]	2005
Real Estate, Held For Sale | North Carolina | Mechlanburg County | Walden
Real Estate and Accumulated Depreciation [Line Items]
Land	[3]	$ 12,085
Improvements less Cost of Sales and Other	[3]	5,446
Carrying Costs	[2],[3]	350
Land & Land Improvements	[3]	17,881
Total	[3]	$ 17,881
Date of Construction	[3]	2016
Date Acquired	[3]	2015
Real Estate, Held For Sale | South Carolina | Lancaster County | Ansley
Real Estate and Accumulated Depreciation [Line Items]
Land	[3]	$ 5,089
Improvements less Cost of Sales and Other	[3]	4,198
Carrying Costs	[2],[3]	315
Land & Land Improvements	[3]	9,602
Total	[3]	$ 9,602
Date of Construction	[3]	2017
Date Acquired	[3]	2015
Real Estate, Held For Sale | Tennessee | Williamson County | Scales Farmstead
Real Estate and Accumulated Depreciation [Line Items]
Land	[3]	$ 3,575
Improvements less Cost of Sales and Other	[3]	4,848
Carrying Costs	[2],[3]	455
Land & Land Improvements	[3]	8,878
Total	[3]	$ 8,878
Date Acquired	[3]	2015
Real Estate, Held For Sale | Texas | Bastrop County | Hunters Crossing
Real Estate and Accumulated Depreciation [Line Items]
Land	[3]	$ 3,613
Improvements less Cost of Sales and Other	[3]	3,970
Land & Land Improvements	[3]	7,583
Total	[3]	$ 7,583
Date of Construction	[3]	2001
Date Acquired	[3]	2001
Real Estate, Held For Sale | Texas | Bexar County | Cibolo Canyons
Real Estate and Accumulated Depreciation [Line Items]
Land	[3]	$ 17,305
Improvements less Cost of Sales and Other	[3]	22,088
Carrying Costs	[2],[3]	1,696
Land & Land Improvements	[3]	41,089
Total	[3]	$ 41,089
Date of Construction	[3]	2004
Date Acquired	[3]	1986
Real Estate, Held For Sale | Texas | Dallas County | Stoney Creek
Real Estate and Accumulated Depreciation [Line Items]
Land	[3]	$ 12,822
Improvements less Cost of Sales and Other	[3]	1,712
Carrying Costs	[2],[3]	608
Land & Land Improvements	[3]	15,142
Total	[3]	$ 15,142
Date of Construction	[3]	2007
Date Acquired	[3]	2007
Real Estate, Held For Sale | Texas | Fort Bend County | Summer Lakes
Real Estate and Accumulated Depreciation [Line Items]
Land	[3]	$ 4,269
Improvements less Cost of Sales and Other	[3]	(1,100)
Carrying Costs	[2],[3]	89
Land & Land Improvements	[3]	3,258
Total	[3]	$ 3,258
Date of Construction	[3]	2013
Date Acquired	[3]	2012
Real Estate, Held For Sale | Texas | Fort Bend County | Summer Park
Real Estate and Accumulated Depreciation [Line Items]
Land	[3]	$ 4,804
Improvements less Cost of Sales and Other	[3]	(2,490)
Carrying Costs	[2],[3]	17
Land & Land Improvements	[3]	2,331
Total	[3]	$ 2,331
Date of Construction	[3]	2013
Date Acquired	[3]	2012
Real Estate, Held For Sale | Texas | Harris County | Barrington
Real Estate and Accumulated Depreciation [Line Items]
Land	[3]	$ 8,950
Improvements less Cost of Sales and Other	[3]	(7,892)
Land & Land Improvements	[3]	1,058
Total	[3]	$ 1,058
Date Acquired	[3]	2011
Real Estate, Held For Sale | Texas | Hays County | Arrowhead Ranch
Real Estate and Accumulated Depreciation [Line Items]
Land	[3]	$ 12,856
Improvements less Cost of Sales and Other	[3]	7,639
Carrying Costs	[2],[3]	286
Land & Land Improvements	[3]	20,781
Total	[3]	$ 20,781
Date of Construction	[3]	2015
Date Acquired	[3]	2007
Real Estate, Held For Sale | Texas | Travis County | West Austin
Real Estate and Accumulated Depreciation [Line Items]
Land	[3]	$ 7,274
Improvements less Cost of Sales and Other	[3]	(1,525)
Land & Land Improvements	[3]	5,749
Total	[3]	$ 5,749
Date Acquired	[3]	2014
Real Estate, Held For Sale | Texas | Other County | Other Property
Real Estate and Accumulated Depreciation [Line Items]
Improvements less Cost of Sales and Other	[3],[4]	$ (1,684)
Land & Land Improvements	[3],[4]	(1,684)
Total	[3],[4]	(1,684)
Equity Method Investments | Cost of Real Estate Sales
Real Estate and Accumulated Depreciation [Line Items]
Non-cash impairment charges		$ 3,000

[1] Includes natural gas liquids (NGLs).

[2] We do not capitalize carrying costs until development begins.

[3] Included in the strategic asset sale to Starwood on February 8, 2018. Please read Note 22 — Subsequent Event for additional information regarding this transaction.

[4] Includes $3,000,000 in non-cash impairment charges in fourth quarter 2017 associated with the asset group sold to Starwood.