Income Taxes - Additional Information (Detail) - USD ($)				12 Months Ended
	Dec. 22, 2017	Dec. 21, 2017	Oct. 05, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Loss Carryforwards [Line Items]
Federal statutory rate (benefit), percent	21.00%	35.00%		35.00%	35.00%	35.00%
AMT credits				$ 1,690,000	$ 5,900,000
Valuation allowance				39,578,000	73,405,000
Unrecognized tax benefit				1,050,000	2,499,000	$ 0	$ 0
Recognized interest accrued related to unrecognized tax benefits				0	0	$ 0
Accrued interest				0	$ 0
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Operating loss carry forwards				$ 9,200,000
Expiration date of operating loss carry forwards				Dec. 31, 2037
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating loss carry forwards				$ 69,200,000
Operating loss carry forwards attributable to states not currently doing business with				$ 45,600,000
Minimum | State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Expiration date of operating loss carry forwards				Dec. 31, 2020
Maximum | State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Expiration date of operating loss carry forwards				Dec. 31, 2037
D.R. Horton Merger Agreement | D.R. Horton, Inc.
Operating Loss Carryforwards [Line Items]
Stockholders' equity, ownership interest by shareholder			75.00%