CONSOLIDATED STATEMENT OF SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss	Treasury Stock, at Cost	Non-controlling Interest
Beginning balance (in shares) at Dec. 31, 2014		23,083
Beginning balance, treasury shares (in shares) at Dec. 31, 2014						78
Beginning balance at Dec. 31, 2014	$ 511,545	$ 23	$ 491,662	$ (69,508)	$ 4,717	$ (1,413)	$ 86,064
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	3,616		2,882				734
Exercise of restricted stock units (in shares)		33
Exercise of restricted stock units	0
Withholding taxes paid on vested restricted stock units	(496)		(337)				(159)
Distribution to noncontrolling interest	(26)						(26)
Net income (loss)	(80,879)			(81,858)			979
Unrealized gain (loss) on securities, net of deferred income tax and reclassification adjustments	292				292
Foreign currency translation	(48)				(48)
Ending balance (in shares) at Dec. 31, 2015		23,116
Ending balance, treasury shares (in shares) at Dec. 31, 2015						78
Ending balance at Dec. 31, 2015	434,004	$ 23	494,207	(151,366)	4,961	$ (1,413)	87,592
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	4,005		3,507				498
Exercise of restricted stock units (in shares)		9
Exercise of restricted stock units	0
Withholding taxes paid on vested restricted stock units	(46)		(26)				(20)
Changes in ownership of noncontrolling interest	0		(1,951)				1,951
UCP, Inc.’s acquisition of its class A common stock	(1,250)						(1,250)
Distribution of treasury stock to deferred compensation plan participants (in shares)						(23)
Distribution of treasury stock to deferred compensation plan participants	217		(269)			$ 486
Abandonment of consolidated subsidiary	1,968						1,968
Net income (loss)	(13,029)			(21,865)			8,836
Unrealized gain (loss) on securities, net of deferred income tax and reclassification adjustments	1,671				1,671
Foreign currency translation	$ 29				29
Ending balance (in shares) at Dec. 31, 2016	23,125	23,125
Ending balance, treasury shares (in shares) at Dec. 31, 2016	55					55
Ending balance at Dec. 31, 2016	$ 427,569	$ 23	495,468	(173,231)	6,661	$ (927)	99,575
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	2,171		1,872				299
Exercise of restricted stock units (in shares)		76
Exercise of restricted stock units	0
Withholding taxes paid on vested restricted stock units	(952)		(831)				(121)
Changes in ownership of noncontrolling interest	0		(465)				465
Distribution to noncontrolling interest	(26)						(26)
Purchases of treasury stock (in shares)						47
Purchases of treasury stock	(690)					$ (690)
Retirement of treasury stock (in shares)		(47)				(47)
Retirement of treasury stock	0		(690)			$ (690)
Distribution of treasury stock to deferred compensation plan participants (in shares)						(54)
Distribution of treasury stock to deferred compensation plan participants	796		(106)			$ 902
Deconsolidation of noncontrolling interest in conjunction with sale of consolidated subsidiary	(101,342)						(101,342)
Special dividend paid	(115,860)		(115,860)
Net income (loss)	1,614			464			1,150
Unrealized gain (loss) on securities, net of deferred income tax and reclassification adjustments	(6,193)				(6,193)
Foreign currency translation	$ 76				76
Ending balance (in shares) at Dec. 31, 2017	23,153	23,154
Ending balance, treasury shares (in shares) at Dec. 31, 2017	1					1
Ending balance at Dec. 31, 2017	$ 207,163	$ 23	$ 379,388	$ (172,767)	$ 544	$ (25)	$ 0