Inventory - Schedule of Total Owned Inventory by Segment (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Sep. 30, 2025
Segment Reporting Information [Line Items]
Projects in progress	$ 2,167,611	$ 1,962,576
Land Held for Future Development	19,489	19,489
Land Held for Sale	65,772	47,368
Total inventory	2,252,872	2,029,433
Corporate and unallocated
Segment Reporting Information [Line Items]
Projects in progress	237,010	211,524
Land Held for Future Development	0	0
Land Held for Sale	0	0
Total inventory	237,010	211,524
West \| Operating Segments
Segment Reporting Information [Line Items]
Projects in progress	1,009,839	944,601
Land Held for Future Development	3,483	3,483
Land Held for Sale	53,135	29,052
Total inventory	1,066,457	977,136
East \| Operating Segments
Segment Reporting Information [Line Items]
Projects in progress	436,030	387,954
Land Held for Future Development	10,888	10,888
Land Held for Sale	7,200	16,086
Total inventory	454,118	414,928
Southeast \| Operating Segments
Segment Reporting Information [Line Items]
Projects in progress	484,732	418,497
Land Held for Future Development	5,118	5,118
Land Held for Sale	5,437	2,230
Total inventory	$ 495,287	$ 425,845

Carrying amount as of the balance sheet date of project in progress

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- Definition

Carrying amount as of the balance sheet date of parcels of land held for sale, and on which the entity has no intention or no further intention to perform construction activities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(6)(a))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

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- Definition

The net carrying amount as of the balance sheet date of the sum of the various components of an operative builder's inventory, including finished homes. Operative builders primarily consist of entities that develop land, construct residential homes and commercial and industrial buildings thereon, and sell them to home buyers and operators of the commercial and industrial properties.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(6)(a))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

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- Definition

Carrying amount of land available for development.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(1)(d))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(1)(6))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

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- Definition

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.

+ References

No definition available.

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