Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred income tax assets:
Net operating loss carryforward and credits	$ 32,829	$ 47,529
Impairment charges	28,926	48,311
Other inventory valuation adjustments	7,929	13,819
Other reserves and accruals	3,366	5,028
Land development reserves	3,180	5,270
Executive incentive compensation	1,875	2,352
Total deferred income tax assets	78,105	122,309
Net deferred income tax assets	78,105	122,309
Deferred income tax liabilities:
Deferred gain	(3,495)	(6,246)
Goodwill	(1,524)	(1,013)
State taxes	(1,426)	(2,800)
Depreciation	(844)	(1,222)
Capitalized expenses	(451)	(771)
Total deferred income tax liabilities	(7,740)	(12,052)
Deferred tax assets, net	$ 70,365	$ 110,257