Net Income per Share - Earnings Attributable to Common Shareholders and Weighted Average Common Shares Outstanding (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Earnings available to common shareholders:
Consolidated net income	$ 14,748	$ 1,198	$ 23,755	$ 6,240
Less: Net loss (income) attributable to noncontrolling interests	74	(657)	(599)	(1,748)
NET INCOME ATTRIBUTABLE TO FORESTAR GROUP INC.	14,822	541	23,156	4,492
Less: Undistributed net income allocated to participating securities	(2,689)	0	(4,205)	0
Earnings available to common shareholders for basic earnings per share	$ 12,133	$ 541	$ 18,951	$ 4,492
Weighted average common shares outstanding - basic	35,458	35,351	35,407	35,305
Weighted average common shares upon conversion of participating securities	7,857	0	7,857	0
Dilutive effect of stock options, restricted stock and equity-settled awards	373	701	426	629
Weighted average common shares outstanding - diluted	43,688	36,052	43,690	35,934
Anti-dilutive awards excluded from diluted weighted average shares	2,503	1,854	2,277	1,837