Document and Entity Information
Apr. 21, 2021
Cover [Abstract]  
Amendment Flag false
Entity Central Index Key 0001406587
Document Type 8-K
Document Period End Date Apr. 21, 2021
Entity Registrant Name Forestar Group Inc.
Entity Incorporation State Country Code DE
Entity File Number 001-33662
Entity Tax Identification Number 26-1336998
Entity Address, Address Line One 2221 E. Lamar Blvd.
Entity Address, Address Line Two Suite 790
Entity Address, City or Town Arlington
Entity Address, State or Province TX
Entity Address, Postal Zip Code 76006
City Area Code (817)
Local Phone Number 769-1860
Written Communications false
Soliciting Material false
Pre Commencement Tender Offer false
Pre Commencement Issuer Tender Offer false
Security 12b Title Common Stock, par value $1.00 per share
Trading Symbol FOR
Security Exchange Name NYSE
Entity Emerging Growth Company false