Other Retirement Plans - Other Retirement Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 25, 2022	Sep. 26, 2021	Sep. 27, 2020
GCIU- Employer Retirement Fund
Multiemployer Plan [Line Items]
Contribution to multiemployer plan	$ 0	$ 10	$ 87
District No. 9, International Association of Machinists and Aerospace Workers Pension Trust
Multiemployer Plan [Line Items]
Contribution to multiemployer plan	0	15	31
CWA/ITU negotiated Pension Plan
Multiemployer Plan [Line Items]
Contribution to multiemployer plan	0	81	456
IAM National Pension Fund
Multiemployer Plan [Line Items]
Contribution to multiemployer plan	57	67	86
Operating Engineers Central Pension Fund of the International Union of Operating Engineers and Participating Employers(2)
Multiemployer Plan [Line Items]
Contribution to multiemployer plan	$ 50	$ 49	$ 52