v3.26.3

Note 8 - Long-term Debt - Schedule of Amortization of Financing Costs (Details) $ in Thousands	Oct. 03, 2026 USD ($)
2027	$ 50
2028	23
2029	0
2030	0
2031	$ 0

The amount of amortization costs in the next 12 months.

No definition available.

Name:	iiin_AmortizationOfFinancingCostsNext12Months
Namespace Prefix:	iiin_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The amount of amortization costs in year 2.

No definition available.

Name:	iiin_AmortizationOfFinancingCostsYear2
Namespace Prefix:	iiin_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The amount of amortization costs in year 3.

No definition available.

Name:	iiin_AmortizationOfFinancingCostsYear3
Namespace Prefix:	iiin_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

No definition available.

Name:	iiin_AmortizationOfFinancingCostsYear4
Namespace Prefix:	iiin_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The amount of amortization costs in year 5.

No definition available.

Name:	iiin_AmortizationOfFinancingCostsYear5
Namespace Prefix:	iiin_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant