Employee Benefit Plans - Schedule of Defined Benefit Plans Disclosure (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Pension Benefits [Member]
Reconciliation of benefit obligations:
Benefit obligation at beginning of year	$ 111,701	$ 122,647
Interest cost	3,943	3,778	$ 4,164
Actuarial loss (gain)	10,429	(4,535)
Lump sum benefits paid	(3,869)	(3,373)	(20,799)
Ordinary benefits paid	(6,733)	(6,816)
Benefit obligation at end of year	115,471	111,701	122,647
Reconciliation of fair value of plan assets:
Fair value of plan assets at beginning of year	78,032	85,649
Actual gain (loss) return on plan assets	8,133	(2,192)
Employer contributions	5,350	4,764	11,523
Lump sum benefits paid	(3,869)	(3,373)
Ordinary benefits paid	(6,733)	(6,816)
Fair value of plan assets at end of year	80,913	78,032	85,649
Funded status:
Funded status at end of year	(34,558)	(33,669)
Amounts recognized in consolidated balance sheets consist of:
Net amount recognized at end of year	(34,558)	(33,669)
Less: current portion	0	0
Noncurrent benefit liability	(34,558)	(33,669)
Amounts not yet recognized in net periodic benefit cost and included in accumulated other comprehensive income (loss):
Actuarial net (loss) gain	(33,733)	(33,180)
Prior service credits	0	0
Net amount recognized in accumulated other comprehensive (loss) income	(33,733)	(33,180)
Retiree Health and Life Benefits [Member]
Reconciliation of benefit obligations:
Benefit obligation at beginning of year	7,895	9,853
Interest cost	275	277	385
Actuarial loss (gain)	(296)	(1,164)
Lump sum benefits paid	0	0
Ordinary benefits paid	(945)	(1,071)
Benefit obligation at end of year	6,929	7,895	9,853
Reconciliation of fair value of plan assets:
Fair value of plan assets at beginning of year	0	0
Actual gain (loss) return on plan assets	0	0
Employer contributions	945	1,071
Lump sum benefits paid	0	0
Ordinary benefits paid	(945)	(1,071)
Fair value of plan assets at end of year	0	0	$ 0
Funded status:
Funded status at end of year	(6,929)	(7,895)
Amounts recognized in consolidated balance sheets consist of:
Net amount recognized at end of year	(6,929)	(7,895)
Less: current portion	970	1,128
Noncurrent benefit liability	(5,959)	(6,767)
Amounts not yet recognized in net periodic benefit cost and included in accumulated other comprehensive income (loss):
Actuarial net (loss) gain	5,296	5,762
Prior service credits	2,251	2,748
Net amount recognized in accumulated other comprehensive (loss) income	$ 7,547	$ 8,510