Equity - Reconciliation of Changes in Equity (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			$ 709,742
Consolidated net income (loss)	$ (34,318)	$ 14,748	(42,555)	$ 23,755
Distributions to noncontrolling interests			(687)
Other (primarily share-based compensation)			3,881
Ending balance	670,381		670,381
Forestar Group Inc. [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			707,202
Consolidated net income (loss)			(42,665)
Distributions to noncontrolling interests			0
Other (primarily share-based compensation)			3,881
Ending balance	668,418		668,418
Noncontrolling Interest [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			2,540
Consolidated net income (loss)			110
Distributions to noncontrolling interests			(687)
Other (primarily share-based compensation)			0
Ending balance	$ 1,963		$ 1,963