Long-term Obligations - Buildout of facility (Details) - item		9 Months Ended
Jan. 01, 2015	Jun. 30, 2019
Long-term Obligations
Lease term	20 years	20 years
Number of leases		2

Term of the capital lease arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	hayn_TermOfLease
Namespace Prefix:	hayn_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration