Legal, Environmental and Other Contingencies (Details) $ in Thousands	9 Months Ended
Jun. 30, 2015 USD ($) action item	Sep. 30, 2014 USD ($)
Legal, Environmental and Other Contingencies
Accrual for post-closure monitoring and maintenance activities \| $	$ 823	$ 823
Welding rod-related injuries \| Pending litigation
Legal, Environmental and Other Contingencies
Number of actions in which the entity is involved	2
Asbestos in facilities \| Pending litigation
Legal, Environmental and Other Contingencies
Number of actions in which the entity is involved	2
Site contingency accrual
Legal, Environmental and Other Contingencies
Number of areas of concern that required investigation \| item	1
Number of solid waste management units evaluated under RCRA, as required by IDEM \| item	1

Represents the number of areas of concern for further evaluation under Facility Investigation.

No definition available.

Name:	hayn_NumberOfAreasOfConcernUnderFacilityInvestigation
Namespace Prefix:	hayn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of solid waste management units evaluated under Resource Conservation and Recovery Act, as required by Indiana Department of Environmental Management.

+ References

No definition available.

+ Details

Name:	hayn_NumberOfSolidWasteManagementUnitsForFurtherEvaluationRequirementByIDEM
Namespace Prefix:	hayn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of estimated costs accrued as of the balance sheet date to comply with regulatory requirements pertaining to the retirement of a waste management facility (such as a landfill or waste treatment facility). Represents the portion that will be paid within one year or the normal operating cycle, if longer.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 410

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section 45

-Paragraph 6

-URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6911-107765

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 410

-SubTopic 20

-Section 35

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6392603&loc=d3e7037-110846

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.20)

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

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 410

-SubTopic 20

-Section 25

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6392544&loc=d3e6290-110844

+ Details

Name:	us-gaap_AccruedCappingClosurePostClosureAndEnvironmentalCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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_LossContingenciesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of pending claims pertaining to a loss contingency.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14435-108349

+ Details

Name:	us-gaap_LossContingencyPendingClaimsNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=hayn_WeldingRodRelatedInjuriesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LitigationStatusAxis=us-gaap_PendingLitigationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=hayn_AsbestosInFacilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=hayn_SiteContingencyAccrualMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: