v3.26.1
Segment Information (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2026
Mar. 31, 2025
Sep. 30, 2025
Assets [Abstract]          
Cash and cash equivalents $ 1,917.9   $ 1,917.9   $ 2,985.4
Restricted cash 56.3   56.3   47.9
Inventories:          
Construction in progress and finished homes 8,551.7   8,551.7   7,648.5
Residential land and lots — developed and under development 14,516.9   14,516.9   14,695.8
Land held for development 195.6   195.6   218.3
Land held for sale 39.1   39.1   21.4
Rental properties 3,000.5   3,000.5   2,703.3
Total inventories 26,303.8   26,303.8   25,287.3
Mortgage loans held for sale 2,680.8   2,680.8   2,566.5
Deferred tax asset, net 0.0   0.0   44.5
Property and equipment, net 593.1   593.1   578.9
Other assets 3,851.5   3,851.5   3,797.2
Goodwill 163.5   163.5   163.5
Total assets 35,566.9   35,566.9   35,471.2
Liabilities [Abstract]          
Accounts payable 1,323.5   1,323.5   1,221.9
Deferred tax liability, net 8.4   8.4   0.0
Accrued expenses and other liabilities 3,472.2   3,472.2   3,541.6
Notes payable 6,563.8   6,563.8   5,965.5
Total liabilities 11,367.9   11,367.9   10,729.0
Revenues          
Total revenues 7,558.1 $ 7,734.0 14,445.0 $ 15,347.0  
Inventory and land option charges 32.1 30.0 43.4 46.6  
Cost of sales 5,854.8 5,833.8 11,147.0 11,536.6  
Selling, General and Administrative Expense (903.3) (898.7) (1,768.4) (1,776.8)  
Other (income) expense (67.4) (65.6) (135.8) (143.4)  
Income (loss) before income taxes 867.4 1,067.1 1,665.4 2,177.0  
Depreciation and amortization     55.8 48.7  
Net cash provided by operating activities     441.5 210.5  
HomeBuildingOps          
Revenues          
Home sales 7,045.5 7,180.9 13,558.2 14,327.0  
Cost of Product and Service Sold 5,565.2 5,564.9 10,694.5 11,033.6  
Land [Member]          
Revenues          
Home sales 108.0 103.6 188.1 170.5  
Cost of Product and Service Sold 75.0 56.1 134.0 94.2  
Rental          
Revenues          
Home sales 211.8 236.6 321.3 454.3  
Cost of Product and Service Sold 182.5 182.8 275.1 362.2  
Financial Services [Member]          
Revenues          
Home sales 192.8 212.9 377.4 395.2  
HomeBuildingOps          
Assets [Abstract]          
Cash and cash equivalents 1,139.3   1,139.3   2,210.5
Restricted cash 26.1   26.1   25.5
Inventories:          
Construction in progress and finished homes 8,682.5   8,682.5   7,743.7
Residential land and lots — developed and under development 12,209.1   12,209.1   12,513.1
Land held for development 38.6   38.6   38.3
Land held for sale 39.1   39.1   21.4
Rental properties 0.0   0.0   0.0
Total inventories 20,969.3   20,969.3   20,316.5
Mortgage loans held for sale 0.0   0.0   0.0
Deferred tax asset, net 70.8   70.8   125.7
Property and equipment, net 557.1   557.1   543.0
Other assets 3,553.5   3,553.5   3,344.1
Goodwill 134.3   134.3   134.3
Total assets 26,450.4   26,450.4   26,699.6
Liabilities [Abstract]          
Accounts payable 1,153.4   1,153.4   1,016.8
Deferred tax liability, net 0.0   0.0    
Accrued expenses and other liabilities 3,038.7   3,038.7   3,122.1
Notes payable 3,427.1   3,427.1   3,154.4
Total liabilities 7,619.2   7,619.2   7,293.3
Revenues          
Total revenues 7,063.2 7,202.9 13,592.1 14,370.2  
Inventory and land option charges 25.5 29.4 35.7 41.3  
Cost of sales 5,667.5 5,647.1 10,873.0 11,194.7  
Selling, General and Administrative Expense (648.9) (637.8) (1,281.4) (1,274.5)  
Other (income) expense (11.1) (17.0) (28.3) (46.9)  
Income (loss) before income taxes 757.9 935.0 1,466.0 1,947.9  
Depreciation and amortization     51.9 44.8  
Net cash provided by operating activities     618.8 876.0  
HomeBuildingOps | HomeBuildingOps          
Revenues          
Home sales 7,045.5 7,180.9 13,558.2 14,327.0  
Cost of Product and Service Sold 5,628.7 5,614.7 10,810.6 11,136.7  
HomeBuildingOps | Land [Member]          
Revenues          
Home sales 17.7 22.0 33.9 43.2  
Cost of Product and Service Sold 13.3 3.0 26.7 16.7  
HomeBuildingOps | Rental          
Revenues          
Home sales 0.0 0.0 0.0 0.0  
Cost of Product and Service Sold 0.0 0.0 0.0 0.0  
HomeBuildingOps | Financial Services [Member]          
Revenues          
Home sales 0.0 0.0 0.0 0.0  
Rental          
Assets [Abstract]          
Cash and cash equivalents 142.5   142.5   140.8
Restricted cash 3.5   3.5   2.5
Inventories:          
Construction in progress and finished homes 0.0   0.0   0.0
Residential land and lots — developed and under development 0.0   0.0   0.0
Land held for development 0.0   0.0   0.0
Land held for sale 0.0   0.0   0.0
Rental properties 3,011.1   3,011.1   2,710.4
Total inventories 3,011.1   3,011.1   2,710.4
Mortgage loans held for sale 0.0   0.0   0.0
Deferred tax asset, net (42.2)   (42.2)   (42.2)
Property and equipment, net 0.6   0.6   0.6
Other assets 51.7   51.7   38.9
Goodwill 0.0   0.0   0.0
Total assets 3,167.2   3,167.2   2,851.0
Liabilities [Abstract]          
Accounts payable 203.3   203.3   230.6
Deferred tax liability, net 0.0   0.0    
Accrued expenses and other liabilities 41.2   41.2   34.7
Notes payable 865.0   865.0   600.0
Total liabilities 1,109.5   1,109.5   865.3
Revenues          
Total revenues 211.8 236.6 321.3 454.3  
Inventory and land option charges 0.3 0.3 0.4 3.9  
Cost of sales 183.2 183.1 276.1 366.1  
Selling, General and Administrative Expense (52.0) (58.0) (98.9) (104.3)  
Other (income) expense (35.7) (27.3) (66.2) (50.8)  
Income (loss) before income taxes 12.3 22.8 12.5 34.7  
Depreciation and amortization     0.8 1.0  
Net cash provided by operating activities     (321.0) (381.6)  
Rental | HomeBuildingOps          
Revenues          
Home sales 0.0 0.0 0.0 0.0  
Cost of Product and Service Sold 0.0 0.0 0.0 0.0  
Rental | Land [Member]          
Revenues          
Home sales 0.0 0.0 0.0 0.0  
Cost of Product and Service Sold 0.0 0.0 0.0 0.0  
Rental | Rental          
Revenues          
Home sales 211.8 236.6 321.3 454.3  
Cost of Product and Service Sold 182.9 182.8 275.7 362.2  
Rental | Financial Services [Member]          
Revenues          
Home sales 0.0 0.0 0.0 0.0  
Forestar Group [Member]          
Assets [Abstract]          
Cash and cash equivalents 362.2   362.2   379.2
Restricted cash 0.0   0.0   0.0
Inventories:          
Construction in progress and finished homes 0.0   0.0   0.0
Residential land and lots — developed and under development 2,552.7   2,552.7   2,465.1
Land held for development 157.0   157.0   180.0
Land held for sale 0.0   0.0   0.0
Rental properties 0.0   0.0   0.0
Total inventories 2,709.7   2,709.7   2,645.1
Mortgage loans held for sale 0.0   0.0   0.0
Deferred tax asset, net 0.0   0.0   0.0
Property and equipment, net 7.7   7.7   8.1
Other assets 93.0   93.0   104.6
Goodwill 0.0   0.0   0.0
Total assets 3,172.6   3,172.6   3,137.0
Liabilities [Abstract]          
Accounts payable 73.3   73.3   71.0
Deferred tax liability, net 84.3   84.3    
Accrued expenses and other liabilities 401.6   401.6   494.3
Notes payable 793.5   793.5   802.8
Total liabilities 1,352.7   1,352.7   1,368.1
Revenues          
Total revenues 374.3 351.0 647.3 601.3  
Inventory and land option charges 6.3 0.9 7.1 2.0  
Cost of sales 294.1 271.8 512.1 467.2  
Selling, General and Administrative Expense (37.9) (38.4) (74.3) (74.3)  
Other (income) expense (1.6) 0.1 (3.9) (2.8)  
Income (loss) before income taxes 43.9 40.7 64.8 62.6  
Depreciation and amortization     1.6 1.7  
Net cash provided by operating activities     (5.1) (469.8)  
Forestar Group [Member] | HomeBuildingOps          
Revenues          
Home sales 0.0 0.0 0.0 0.0  
Cost of Product and Service Sold 0.0 0.0 0.0 0.0  
Forestar Group [Member] | Land [Member]          
Revenues          
Home sales 374.3 351.0 647.3 601.3  
Cost of Product and Service Sold 287.8 270.9 505.0 465.2  
Forestar Group [Member] | Rental          
Revenues          
Home sales 0.0 0.0 0.0 0.0  
Cost of Product and Service Sold 0.0 0.0 0.0 0.0  
Forestar Group [Member] | Financial Services [Member]          
Revenues          
Home sales 0.0 0.0 0.0 0.0  
Financial Services [Member]          
Assets [Abstract]          
Cash and cash equivalents 242.4   242.4   244.5
Restricted cash 26.7   26.7   19.9
Inventories:          
Construction in progress and finished homes 0.0   0.0   0.0
Residential land and lots — developed and under development 0.0   0.0   0.0
Land held for development 0.0   0.0   0.0
Land held for sale 0.0   0.0   0.0
Rental properties 0.0   0.0   0.0
Total inventories 0.0   0.0   0.0
Mortgage loans held for sale 2,680.8   2,680.8   2,566.5
Deferred tax asset, net 0.0   0.0   0.0
Property and equipment, net 4.2   4.2   4.3
Other assets 177.7   177.7   220.6
Goodwill 0.0   0.0   0.0
Total assets 3,131.8   3,131.8   3,055.8
Liabilities [Abstract]          
Accounts payable 0.4   0.4   0.7
Deferred tax liability, net 0.0   0.0    
Accrued expenses and other liabilities 414.2   414.2   294.7
Notes payable 1,478.2   1,478.2   1,408.3
Total liabilities 1,892.8   1,892.8   1,703.7
Revenues          
Total revenues 192.8 212.9 377.4 395.2  
Inventory and land option charges 0.0 0.0 0.0 0.0  
Cost of sales 0.0 0.0 0.0 0.0  
Selling, General and Administrative Expense (159.8) (160.3) (304.8) (314.5)  
Other (income) expense (18.7) (20.4) (37.1) (40.9)  
Income (loss) before income taxes 51.7 73.0 109.7 121.6  
Depreciation and amortization     1.0 0.9  
Net cash provided by operating activities     136.6 197.2  
Financial Services [Member] | HomeBuildingOps          
Revenues          
Home sales 0.0 0.0 0.0 0.0  
Cost of Product and Service Sold 0.0 0.0 0.0 0.0  
Financial Services [Member] | Land [Member]          
Revenues          
Home sales 0.0 0.0 0.0 0.0  
Cost of Product and Service Sold 0.0 0.0 0.0 0.0  
Financial Services [Member] | Rental          
Revenues          
Home sales 0.0 0.0 0.0 0.0  
Cost of Product and Service Sold 0.0 0.0 0.0 0.0  
Financial Services [Member] | Financial Services [Member]          
Revenues          
Home sales 192.8 212.9 377.4 395.2  
Eliminations and Other          
Assets [Abstract]          
Cash and cash equivalents 31.5   31.5   10.4
Restricted cash 0.0   0.0   0.0
Inventories:          
Construction in progress and finished homes (130.8)   (130.8)   (95.2)
Residential land and lots — developed and under development (244.9)   (244.9)   (282.4)
Land held for development 0.0   0.0   0.0
Land held for sale 0.0   0.0   0.0
Rental properties (10.6)   (10.6)   (7.1)
Total inventories (386.3)   (386.3)   (384.7)
Mortgage loans held for sale 0.0   0.0   0.0
Deferred tax asset, net (28.6)   (28.6)   (39.0)
Property and equipment, net 23.5   23.5   22.9
Other assets (24.4)   (24.4)   89.0
Goodwill 29.2   29.2   29.2
Total assets (355.1)   (355.1)   (272.2)
Liabilities [Abstract]          
Accounts payable (106.9)   (106.9)   (97.2)
Deferred tax liability, net (75.9)   (75.9)    
Accrued expenses and other liabilities (423.5)   (423.5)   (404.2)
Notes payable 0.0   0.0   0.0
Total liabilities (606.3)   (606.3)   (501.4)
Revenues          
Total revenues (284.0) (269.4) (493.1) (474.0)  
Inventory and land option charges 0.0 (0.6) 0.2 (0.6)  
Cost of sales (290.0) (268.2) (514.2) (491.4)  
Selling, General and Administrative Expense (4.7) (4.2) (9.0) (9.2)  
Other (income) expense (0.3) (1.0) (0.3) (2.0)  
Income (loss) before income taxes 1.6 (4.4) 12.4 10.2  
Depreciation and amortization     0.5 0.3  
Net cash provided by operating activities     12.2 (11.3)  
Eliminations and Other | HomeBuildingOps          
Revenues          
Home sales 0.0 0.0 0.0 0.0  
Cost of Product and Service Sold (63.5) (49.8) (116.1) (103.1)  
Eliminations and Other | Land [Member]          
Revenues          
Home sales (284.0) (269.4) (493.1) (474.0)  
Cost of Product and Service Sold (226.1) (217.8) (397.7) (387.7)  
Eliminations and Other | Rental          
Revenues          
Home sales 0.0 0.0 0.0 0.0  
Cost of Product and Service Sold (0.4) 0.0 (0.6) 0.0  
Eliminations and Other | Financial Services [Member]          
Revenues          
Home sales 0.0 0.0 0.0 0.0  
Northwest | HomeBuildingOps          
Inventories:          
Total inventories 1,947.5   1,947.5   1,891.8
Revenues          
Total revenues 539.7 660.4 1,086.4 1,193.6  
Inventory and land option charges 0.5 2.6 0.6 3.1  
Cost of sales 432.3 511.1 868.7 918.2  
Selling, General and Administrative Expense (53.7) (57.2) (106.1) (109.8)  
Other (income) expense (0.9) (1.6) (2.3) (4.3)  
Income (loss) before income taxes 54.6 93.7 113.9 169.9  
Northwest | HomeBuildingOps | HomeBuildingOps          
Revenues          
Home sales 539.6 660.4 1,086.0 1,193.5  
Cost of Product and Service Sold 432.0 508.5 868.0 915.1  
Northwest | HomeBuildingOps | Land [Member]          
Revenues          
Home sales 0.1 0.0 0.4 0.1  
Cost of Product and Service Sold (0.2) 0.0 0.1 0.0  
Southwest [Member] | HomeBuildingOps          
Inventories:          
Total inventories 3,055.9   3,055.9   3,068.5
Revenues          
Total revenues 1,035.2 1,063.7 1,929.9 2,203.8  
Inventory and land option charges 3.4 5.9 4.1 6.3  
Cost of sales 834.7 851.1 1,559.8 1,735.9  
Selling, General and Administrative Expense (88.1) (92.1) (171.8) (183.2)  
Other (income) expense (1.8) (2.8) (4.5) (7.0)  
Income (loss) before income taxes 114.2 123.3 202.8 291.7  
Southwest [Member] | HomeBuildingOps | HomeBuildingOps          
Revenues          
Home sales 1,025.1 1,063.6 1,915.0 2,203.6  
Cost of Product and Service Sold 822.9 845.2 1,543.4 1,729.6  
Southwest [Member] | HomeBuildingOps | Land [Member]          
Revenues          
Home sales 10.1 0.1 14.9 0.2  
Cost of Product and Service Sold 8.4 0.0 12.3 0.0  
South Central [Member] | HomeBuildingOps          
Inventories:          
Total inventories 4,033.7   4,033.7   3,931.9
Revenues          
Total revenues 1,511.7 1,530.7 2,901.2 3,017.6  
Inventory and land option charges 14.1 4.4 15.8 5.6  
Cost of sales 1,210.0 1,197.5 2,295.7 2,338.1  
Selling, General and Administrative Expense (137.4) (128.2) (270.7) (260.3)  
Other (income) expense (2.0) (3.4) (4.9) (10.5)  
Income (loss) before income taxes 166.3 208.4 339.7 429.7  
South Central [Member] | HomeBuildingOps | HomeBuildingOps          
Revenues          
Home sales 1,511.4 1,530.0 2,900.7 3,016.5  
Cost of Product and Service Sold 1,195.9 1,192.9 2,279.9 2,332.1  
South Central [Member] | HomeBuildingOps | Land [Member]          
Revenues          
Home sales 0.3 0.7 0.5 1.1  
Cost of Product and Service Sold 0.0 0.2 0.0 0.4  
Southeast [Member] | HomeBuildingOps          
Inventories:          
Total inventories 4,189.9   4,189.9   4,061.8
Revenues          
Total revenues 1,558.5 1,613.8 3,016.5 3,363.6  
Inventory and land option charges 4.4 7.3 6.3 12.9  
Cost of sales 1,254.4 1,266.2 2,433.2 2,649.8  
Selling, General and Administrative Expense (141.4) (140.4) (281.3) (289.7)  
Other (income) expense (2.7) (4.1) (6.8) (10.0)  
Income (loss) before income taxes 165.4 211.3 308.8 434.1  
Southeast [Member] | HomeBuildingOps | HomeBuildingOps          
Revenues          
Home sales 1,552.3 1,593.0 3,004.6 3,332.2  
Cost of Product and Service Sold 1,245.0 1,256.1 2,417.1 2,627.9  
Southeast [Member] | HomeBuildingOps | Land [Member]          
Revenues          
Home sales 6.2 20.8 11.9 31.4  
Cost of Product and Service Sold 5.0 2.8 9.8 9.0  
East [Member] | HomeBuildingOps          
Inventories:          
Total inventories 4,599.3   4,599.3   4,397.7
Revenues          
Total revenues 1,381.9 1,360.0 2,632.4 2,674.6  
Inventory and land option charges 1.9 8.0 6.7 10.7  
Cost of sales 1,116.3 1,064.0 2,115.6 2,064.7  
Selling, General and Administrative Expense (132.8) (127.0) (263.8) (252.1)  
Other (income) expense (2.0) (2.8) (5.3) (8.4)  
Income (loss) before income taxes 134.8 171.8 258.3 366.2  
East [Member] | HomeBuildingOps | HomeBuildingOps          
Revenues          
Home sales 1,381.9 1,359.8 2,632.2 2,668.3  
Cost of Product and Service Sold 1,114.4 1,056.0 2,108.9 2,049.3  
East [Member] | HomeBuildingOps | Land [Member]          
Revenues          
Home sales 0.0 0.2 0.2 6.3  
Cost of Product and Service Sold 0.0 0.0 0.0 4.7  
North | HomeBuildingOps          
Inventories:          
Total inventories 2,783.7   2,783.7   2,637.6
Revenues          
Total revenues 1,036.2 974.3 2,025.7 1,917.0  
Inventory and land option charges 1.2 1.2 2.2 2.7  
Cost of sales 819.8 757.2 1,600.0 1,488.0  
Selling, General and Administrative Expense (95.5) (92.9) (187.7) (179.4)  
Other (income) expense (1.7) (2.3) (4.5) (6.7)  
Income (loss) before income taxes 122.6 126.5 242.5 256.3  
North | HomeBuildingOps | HomeBuildingOps          
Revenues          
Home sales 1,035.2 974.1 2,019.7 1,912.9  
Cost of Product and Service Sold 818.5 756.0 1,593.3 1,482.7  
North | HomeBuildingOps | Land [Member]          
Revenues          
Home sales 1.0 0.2 6.0 4.1  
Cost of Product and Service Sold 0.1 $ 0.0 4.5 $ 2.6  
Corporate, Non-Segment [Member] | HomeBuildingOps          
Inventories:          
Total inventories $ 359.3   $ 359.3   $ 327.2