Real Estate - Additional Information (Detail)	12 Months Ended			120 Months Ended
	Dec. 31, 2016 USD ($) a property room transaction community_development_project multifamily_site	Dec. 31, 2015 USD ($) property	Dec. 31, 2014 USD ($)	Dec. 31, 2016 USD ($) a property room
Real Estate Properties [Line Items]
Non-cash impairment charges	$ 60,939,000	$ 108,184,000	$ 15,934,000
Payment of debt	315,229,000	58,220,000	225,481,000
Gain of sale of assets	166,747,000	1,585,000	29,512,000
General contractor costs	392,000	1,543,000	5,111,000
Recovery of direct costs	(27,107,000)	(15,176,000)	(66,047,000)
Income Producing Properties | Land, Buildings and Improvements
Real Estate Properties [Line Items]
Depreciation expense, related to commercial and income producing properties	816,000	6,810,000	3,319,000
Utility and Improvement District
Real Estate Properties [Line Items]
Cost of asset in developed and under development projects	45,157,000	67,554,000		$ 45,157,000
Cibolo Canyons Project | San Antonio, Texas
Real Estate Properties [Line Items]
Gain of sale of assets	1,219,000	1,160,000	6,577,000
Cost of asset in developed and under development projects	14,749,000	22,302,000		14,749,000
Recovery of direct costs				45,132,000
Costs relate to water, sewer and other infrastructure assets				54,376,000
Consolidated Properties
Real Estate Properties [Line Items]
Recovery of direct costs	26,606,000
Bonds | Cibolo Canyons Project | San Antonio, Texas
Real Estate Properties [Line Items]
Payments received from special improvement district	501,000	425,000	50,550,000
Debt instrument, face amount			48,900,000
Letters of credit outstanding, amount			$ 6,846,000
Surety bond for bond trustee	$ 6,631,000			$ 6,631,000
Radisson Hotel & Suites, Austin | Austin, Texas
Real Estate Properties [Line Items]
Number of hotel rooms | room	413			413
Sales price	$ 130,000,000			$ 130,000,000
Net proceeds	128,764,000
Payment of debt	15,400,000
Gain of sale of assets	95,336,000
Eleven | Multi Family Property | Austin, Texas
Real Estate Properties [Line Items]
Sales price	60,150,000			$ 60,150,000
Net proceeds	59,719,000
Payment of debt	23,936,000
Gain of sale of assets	$ 9,116,000
Number of units of multifamily project | property	257			257
Dillon | Charlotte, North Carolina
Real Estate Properties [Line Items]
Sales price	$ 25,979,000			$ 25,979,000
Net proceeds	25,428,000
Gain of sale of assets	$ 1,223,000
Number of units of multifamily project | property	379			379
Music Row | Nashville, Tennessee
Real Estate Properties [Line Items]
Sales price	$ 15,025,000			$ 15,025,000
Net proceeds	14,703,000
Gain of sale of assets	$ 3,968,000
Number of units of multifamily project | property	230			230
Downtown Edge | Austin, Texas
Real Estate Properties [Line Items]
Sales price	$ 5,000,000			$ 5,000,000
Net proceeds	4,975,000
Gain of sale of assets	(3,870,000)
Midtown
Real Estate Properties [Line Items]
Net proceeds		$ 42,639,000
Number of units of multifamily project | property		354
Real estate property sale price		$ 42,880,000
Segment earnings from sale of multifamily property		9,265,000
Repayments of debt		$ 24,166,000
Real Estate Impairment Charges
Real Estate Properties [Line Items]
Non-cash impairment charges	$ 56,453,000
Community Development Project
Real Estate Properties [Line Items]
Number of properties impaired | community_development_project	6
Multifamily Site
Real Estate Properties [Line Items]
Number of properties impaired | multifamily_site	2
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Georgia and Alabama
Real Estate Properties [Line Items]
Sales price	$ 104,172,000			$ 104,172,000
Net proceeds	103,238,000
Gain of sale of assets	$ 48,891,000
Area of land (in acres) | a	58,300			58,300
Number of transactions | transaction	3
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Community Development Project
Real Estate Properties [Line Items]
Number of properties impaired | community_development_project	4
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Multifamily Site
Real Estate Properties [Line Items]
Number of properties impaired | multifamily_site	1