Retirement Benefit Plans - Narrative (Details) - USD ($)		9 Months Ended
	Nov. 26, 2019	Jun. 30, 2020	Jun. 30, 2019
Defined Benefit Plan Disclosure [Line Items]
Contributions amount in defined benefit pension plans		$ 604,000	$ 48,000
Additional cash contributions planned for fiscal 2020		0
Other debt withdrawal liability		$ 739,000
IAM National Pension Fund
Defined Benefit Plan Disclosure [Line Items]
Payment period	20 years