Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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- Definition

The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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- Definition

Amount of inventory used in the development of real estate classified as other.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Property, Plant, and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Property and Equipment [Line Items]
Property, Plant and Equipment, Net	$ 392.9	$ 683.7
Depreciation	73.3	69.4	$ 66.1
Rental properties	821.8	0.0
Segment Reconciling Items [Member]
Property and Equipment [Line Items]
Property, Plant and Equipment, Net	0.0	(3.0)
Home Building
Property and Equipment [Line Items]
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(276.6)	(256.2)
Property, Plant and Equipment, Net	303.3	286.7
Rental properties	0.0	0.0
Other Segments [Member]
Property and Equipment [Line Items]
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(28.4)	(28.2)
Property, Plant and Equipment, Net	82.6	308.9
Forestar Group [Member]
Property and Equipment [Line Items]
Property, Plant and Equipment, Net	2.9	1.1
Rental properties	0.0	0.0
Financial Services [Member]
Property and Equipment [Line Items]
Property, Plant and Equipment, Net	3.5	3.9
Rental properties	0.0	0.0
Rental
Property and Equipment [Line Items]
Property, Plant and Equipment, Net	0.6	0.0
Rental properties	840.9	316.0
Rental \| Single Family
Property and Equipment [Line Items]
Property, Plant and Equipment, Gross	0.0	87.2
Rental properties	415.8
Rental \| Multifamily
Property and Equipment [Line Items]
Property, Plant and Equipment, Gross	0.0	232.1
Rental properties	425.1
HomeBuildingOps GAAP FY2020
Property and Equipment [Line Items]
Property, Plant and Equipment, Net		372.8
Building and Building Improvements [Member] \| Home Building
Property and Equipment [Line Items]
Property, Plant and Equipment, Gross	299.5	267.4
2510 Household Furniture [Member] \| Home Building
Property and Equipment [Line Items]
Property, Plant and Equipment, Gross	134.1	134.0
Furniture and Fixtures \| Home Building
Property and Equipment [Line Items]
Property, Plant and Equipment, Gross	113.7	108.1
Furniture and Fixtures \| Other Segments [Member]
Property and Equipment [Line Items]
Property, Plant and Equipment, Gross	15.9	15.6
Rental Property \| Rental \| Single Family
Property and Equipment [Line Items]
Property, Plant and Equipment, Gross	0.0	68.1
Rental Property \| Rental \| Multifamily
Property and Equipment [Line Items]
Property, Plant and Equipment, Gross	0.0	173.8
Land [Member] \| Home Building
Property and Equipment [Line Items]
Property, Plant and Equipment, Gross	32.6	32.3
Land [Member] \| Other Segments [Member]
Property and Equipment [Line Items]
Property, Plant and Equipment, Gross	16.1	19.7
Land [Member] \| Rental \| Single Family
Property and Equipment [Line Items]
Property, Plant and Equipment, Gross	0.0	19.1
Land [Member] \| Rental \| Multifamily
Property and Equipment [Line Items]
Property, Plant and Equipment, Gross	0.0	58.3
Other Assets \| Other Segments [Member]
Property and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 79.0	$ 69.7