Long-term Obligations - Buildout of facility (Details)		6 Months Ended
Jan. 01, 2015	Mar. 31, 2019
Long-term Obligations
Lease term	20 years	20 years

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