Retirement Plans - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	4 Months Ended
	Jan. 23, 2022		Jan. 17, 2021
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 4,517		$ 4,532
Expected return on plan assets	(5,570)		(5,951)
Actuarial loss (gain)	1,187	[1]	1,616
Amortization of unrecognized prior service cost	6	[1]	6
Net periodic benefit cost	140		203
Postretirement Healthcare Plans
Defined Benefit Plan Disclosure [Line Items]
Interest cost	150		173
Actuarial loss (gain)	(197)	[1]	(105)
Net periodic benefit cost	$ (47)		$ 68

[1] Amounts were reclassified from accumulated OCI into net earnings as a component of “Other pension and post-retirement expenses, net