Amounts Reclassified Out of Accumulated Other Comprehensive Income - Reclassification out of accumulated other comprehensive (loss) income (Details) - USD ($) $ in Thousands		3 Months Ended
		Dec. 29, 2018	Dec. 30, 2017
Accumulated Other Comprehensive Income Loss [Line Items]
Balance beginning		$ (24,670)	$ (28,812)
Amortization of net loss		552	757
Other comprehensive income		552	757
Balance ending		(24,118)	(28,055)
Pension Benefits [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance beginning		(33,180)	(37,311)
Amortization of net loss	[1]	866	921
Other comprehensive income		866	921
Balance ending		(32,314)	(36,390)
Post-Retirement Benefits [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance beginning		8,510	8,499
Amortization of net gain and prior service credits	[1]	(314)	(164)
Other comprehensive income		(314)	(164)
Balance ending		$ 8,196	$ 8,335

[1] These amounts are included in the computation of net periodic benefit cost. See Note 13, “Pension Plans and Other Postretirement Benefits.”