Capitalized Interest (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Mar. 31, 2026	Mar. 31, 2025	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025	Sep. 30, 2025	Dec. 31, 2024	Sep. 30, 2024
Statement [Line Items]
Real Estate Inventory, Capitalized Interest Costs	$ 91.5	$ 71.9	$ 91.5	$ 71.9	$ 86.0	$ 77.8	$ 67.7	$ 63.0
Interest incurred	12.5	10.6	25.0	18.8
Interest charged to cost of sales	$ (7.0)	$ (6.4)	$ (11.3)	$ (9.9)

Capitalized Interest

No definition available.

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- Definition

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

+ References

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

+ Details

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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

+ Details

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- Definition

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

+ References

+ Details

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