Inventory - Total Owned Inventory by Segment (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014
Segment Reporting Information [Line Items]
Projects in Progress	$ 1,297,105bzh_InventoryProjectsInProgress	$ 1,204,776bzh_InventoryProjectsInProgress
Land held for future development	312,148us-gaap_LandAvailableForDevelopment	301,048us-gaap_LandAvailableForDevelopment
Land held for sale	68,358us-gaap_InventoryLandHeldForSale	51,672us-gaap_InventoryLandHeldForSale
Total owned inventory	1,677,611us-gaap_InventoryOperativeBuilders	1,557,496us-gaap_InventoryOperativeBuilders
West Segment
Segment Reporting Information [Line Items]
Projects in Progress	479,550	462,508
Land held for future development	272,009	260,898
Land held for sale	12,446	10,026
Total owned inventory	764,005	733,432
East Segment
Segment Reporting Information [Line Items]
Projects in Progress	379,191	353,859
Land held for future development	29,215	29,239
Land held for sale	36,958	34,530
Total owned inventory	445,364	417,628
Southeast Segment
Segment Reporting Information [Line Items]
Projects in Progress	283,014	264,843
Land held for future development	10,924	10,911
Land held for sale	16,658	4,821
Total owned inventory	310,596	280,575
Unallocated and Other
Segment Reporting Information [Line Items]
Projects in Progress	155,350	123,566
Land held for future development	0	0
Land held for sale	2,296	2,295
Total owned inventory	$ 157,646	$ 125,861

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

No definition available.

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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://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.6(a))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 6

-Subparagraph a

-Article 5

+ Details

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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

+ Details

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- Definition

Carrying amount of land available for development.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.(a),1(d))

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Subparagraph d

-Article 7

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