Employee Benefit Plans - Components of Net Periodic Benefit Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 27, 2025	Sep. 28, 2024	Sep. 30, 2023
Components of net periodic benefit costs included in operating expenses [Abstract]
Settlement charge	$ 528	$ 638	$ 0
Pension Benefits [Member]
Components of net periodic benefit costs included in operating expenses [Abstract]
Interest cost	2,577	3,129	3,306
Expected return on plan assets	(1,289)	(1,260)	(1,355)
Amortization of prior service credit	0	0	0
Settlement charge	528	638	0
Recognized net actuarial loss (gain)	245	1,489	1,927
Net periodic benefit costs	2,061	3,996	3,878
Retiree Health and Life Benefits [Member]
Components of net periodic benefit costs included in operating expenses [Abstract]
Interest cost	100	143	166
Expected return on plan assets	0	0	0
Amortization of prior service credit	(25)	(284)	(498)
Settlement charge	0	0	0
Recognized net actuarial loss (gain)	(687)	(741)	(775)
Net periodic benefit costs	$ (612)	$ (882)	$ (1,107)