Capitalized Interest (Details) - USD ($) $ in Millions	3 Months Ended
Dec. 31, 2024	Dec. 31, 2023
Rollforward of capitalized interest
Capitalized interest, beginning of period	$ 355.1	$ 286.4
Interest incurred	46.7	42.6
Interest charged to cost of sales	(30.3)	(28.0)
Capitalized interest, end of period	371.5	301.0
Financial Services [Member]
Rollforward of capitalized interest
Interest incurred	8.1	14.9
Forestar Group [Member]
Rollforward of capitalized interest
Interest incurred	8.3	8.1
Rental
Rollforward of capitalized interest
Interest incurred	$ 12.4	$ 8.2

Total interest costs incurred during the period and either capitalized or charged against earnings.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 835
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483013/835-20-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 835
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483013/835-20-50-1

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- Definition

Carrying amount as of the balance sheet date of interest costs that were capitalized to properties under development during the land development and construction period of a project, and which are included in inventory.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 835
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483013/835-20-50-1

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- Definition

Amount of interest cost charged to cost of sales that had been previously capitalized to inventory.

+ References

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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