Aggregate collateral ratio (as defined by the underlying credit agreement)

No definition available.

Name:	bzh_AggregateCollateralRatio
Namespace Prefix:	bzh_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Face Amount, Modification

+ References

No definition available.

+ Details

Name:	bzh_DebtInstrumentFaceAmountModification
Namespace Prefix:	bzh_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Debt Instrument, Interest Rate, Effective Period

+ References

No definition available.

+ Details

Name:	bzh_DebtInstrumentInterestRateEffectivePeriod
Namespace Prefix:	bzh_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Percentage Outstanding after Repurchase with Equity Offerings- Percentage of original amount of debt instrument to remain outstanding after repurchase with equity offerings

+ References

No definition available.

+ Details

Name:	bzh_DebtInstrumentPercentageofDebtOutstandingafterRepurchasewithEquityOfferings
Namespace Prefix:	bzh_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Redemption Option with Equity Offerings, Percent of Par

+ References

No definition available.

+ Details

Name:	bzh_DebtInstrumentRedemptionOptionwithEquityOfferingsPercentofPar
Namespace Prefix:	bzh_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Repurchase Price upon Change of Control, Percent of Par

+ References

No definition available.

+ Details

Name:	bzh_DebtInstrumentRepurchasePriceuponChangeofControlPercentofPar
Namespace Prefix:	bzh_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line of Credit Facility, Number of Lenders

+ References

No definition available.

+ Details

Name:	bzh_LineofCreditFacilityNumberofLenders
Namespace Prefix:	bzh_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- 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.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after accumulated amortization, of debt discount.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28541-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentUnamortizedDiscount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the aggregate of total long-term debt, including current maturities and short-term debt.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtLongtermAndShorttermCombinedAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28555-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DeferredFinanceCostsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The cash outflow for the extinguishment of long-term borrowing, with the highest claim on the assets of the entity in case of bankruptcy or liquidation, before its maturity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3291-108585

+ Details

Name:	us-gaap_EarlyRepaymentOfSeniorDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12317-112629

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12355-112629

+ Details

Name:	us-gaap_GainsLossesOnExtinguishmentOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

+ Details

Name:	us-gaap_JuniorSubordinatedLongtermNotesCurrentAndNoncurrentAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ 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(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: 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(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_OtherLongtermDebtCurrentAndNoncurrentAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The carrying amount, as of the date of the latest financial statement presented, of real estate owned but transferred to serve as collateral for the payment of the related debt obligation, primarily a secured borrowing or repurchase agreement, and for which the transferee is not permitted to sell or re-pledge them to an unrelated party.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 50
-Paragraph 1A
-Subparagraph (b)(1)(i)
-URI http://asc.fasb.org/extlink&oid=64858031&loc=SL6224234-111729

+ Details

Name:	us-gaap_PledgedAssetsNotSeparatelyReportedRealEstate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_SecuredLongtermDebtCurrentAndNoncurrentAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

Name:	us-gaap_SeniorLongtermNotesCurrentAndNoncurrentAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	bzh_LongtermandShorttermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=bzh_A634SeniorNotesMaturingMarch20255Domain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=bzh_A918SeniorNotesMaturingMay2019Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=bzh_A534SeniorNotesMaturingJune2019Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	bzh_LongtermandShorttermDebtTypeAxis=bzh_TermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	bzh_LongtermandShorttermDebtTypeAxis=us-gaap_JuniorSubordinatedDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	bzh_LongtermandShorttermDebtTypeAxis=us-gaap_NotesPayableOtherPayablesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=bzh_LetterofCreditCashSecuredMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	bzh_DebtInstrumentCovenantComplianceStatusAxis=bzh_OptionalRedemptionUnderIndentureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Borrowings - Narrative (Details)		3 Months Ended			9 Months Ended
Borrowings - Narrative (Details)	Jul. 30, 2016	Jun. 30, 2017 USD ($) lender	Mar. 31, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) lender	Jun. 30, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jan. 31, 2010 USD ($)
Line of Credit Facility [Abstract]
Amount of available borrowings under the Secured Revolving Credit Facility		$ 140,100,000			$ 140,100,000		$ 106,800,000
Senior Notes [Abstract]
Loss on extinguishment of debt		0		$ (429,000)	15,563,000	$ 2,030,000
Secured Debt [Abstract]
Total debt, net		(1,334,623,000)			(1,334,623,000)		(1,331,878,000)
Senior Notes
Secured Debt [Abstract]
Total debt, net		$ (1,259,258,000)			$ (1,259,258,000)		$ (1,207,526,000)
Senior Notes \| 6 3/4% Senior Notes Maturing March 2025
Debt Instrument [Line Items]
Debt Instrument, Percentage of Debt Outstanding after Repurchase		35.00%			35.00%
Other Long-term Debt [Abstract]
Stated interest rate on debt instrument (percent)		6.75%			6.75%		6.75%
Junior Subordinated Notes [Abstract]
Stated interest rate on debt instrument (percent)		6.75%			6.75%		6.75%
Aggregate principal amount of debt		$ 250,000,000			$ 250,000,000
Secured Debt [Abstract]
Debt Instrument, Repurchase Price upon Change of Control, Percent of Par		101.00%			101.00%
Senior Notes \| 9 1/8% Senior Notes Maturing May 2019
Senior Notes [Abstract]
Call price and make-whole premiums provided for by 2018 Notes				9,300,000		19,100,000
Senior Notes \| 5 3/4% Senior Notes Maturing June 2019
Senior Notes [Abstract]
Call price and make-whole premiums provided for by 2018 Notes				$ 3,000,000		$ 3,600,000
Other Long-term Debt [Abstract]
Stated interest rate on debt instrument (percent)		5.75%			5.75%		5.75%
Junior Subordinated Notes [Abstract]
Stated interest rate on debt instrument (percent)		5.75%			5.75%		5.75%
Secured Debt [Abstract]
Total debt, net		$ (321,393,000)			$ (321,393,000)		$ (321,393,000)
Term Loan
Senior Notes [Abstract]
Call price and make-whole premiums provided for by 2018 Notes			$ 55,000,000
Other Long-term Debt [Abstract]
Debt instrument term		2 years
Junior Subordinated Notes [Abstract]
Aggregate principal amount of debt		$ 140,000,000			140,000,000
Unamortized accretion		0			0		800,000
Debt Issuance Costs, Net		0			0		1,451,000
Secured Debt [Abstract]
Total debt, net		0			0		(52,669,000)
Junior Subordinated Notes
Other Long-term Debt [Abstract]
Stated interest rate on debt instrument (percent)	7.987%
Junior Subordinated Notes [Abstract]
Stated interest rate on debt instrument (percent)	7.987%
Effective period of debt instrument interest rate	10 years
Debt Instrument, Face Amount Modification								$ 75,000,000
Unamortized accretion		39,353,000			39,353,000		40,903,000
Secured Debt [Abstract]
Total debt, net		$ (61,420,000)			$ (61,420,000)		(59,870,000)
Weighted average fixed interest rate of debt (percent)		4.09%			4.09%
Other secured notes payable
Secured Debt [Abstract]
Total debt, net		$ (13,945,000)			$ (13,945,000)		(11,813,000)
Weighted average fixed interest rate of debt (percent)		3.28%			3.28%
Revolving Credit Facility
Line of Credit Facility [Abstract]
Credit facility borrowing capacity		$ 180,000,000			$ 180,000,000		145,000,000
Inventory assets pledged as collateral		$ 800,000,000			$ 800,000,000		1,000,000,000
Number of lenders \| lender		3			3
Borrowings outstanding under facility		$ 0			$ 0		0
Letters of credit secured using cash collateral		$ 39,900,000			$ 39,900,000		$ 38,200,000
Revolving Credit Facility \| Maximum
Line of Credit Facility [Abstract]
Aggregate collateral ratio		4.00			4.00		5.00
Revolving Credit Facility \| Minimum
Line of Credit Facility [Abstract]
Aggregate collateral ratio		1.00			1.00		1.00
Letter of Credit, Cash Secured
Line of Credit Facility [Abstract]
Letters of credit secured using cash collateral		$ 11,100,000			$ 11,100,000		$ 12,100,000
Optional Redemption Under Indenture \| Senior Notes \| 6 3/4% Senior Notes Maturing March 2025
Debt Instrument [Line Items]
Debt Instrument, Percentage of Debt Outstanding after Repurchase		65.00%			65.00%
Debt Instrument, Redemption Option, Percent of Par		106.75%			106.75%