Leases - Schedule of Supplemental Balance Sheet Information Related to Leases (Detail) $ in Thousands	Apr. 20, 2019 USD ($)
Operating leases:
Operating lease assets	$ 273,537
Current portion of operating lease liabilities	41,425
Noncurrent operating lease liabilities	279,599
Total operating lease liabilities	321,024
Finance leases:
Property and equipment, at cost	62,103
Accumulated amortization	(28,271)
Property and equipment, net	$ 33,832
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:PropertyPlantAndEquipmentNet
Current portion of finance lease liabilities	$ 6,109
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	sptn:LongTermDebtAndFinanceLeaseLiabilityCurrent
Noncurrent finance lease liabilities	$ 33,838
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	sptn:LongTermDebtAndFinanceLeaseLiabilityNoncurrent
Total finance lease liabilities	$ 39,947
Weighted average remaining lease term:
Operating leases	9 years 2 months 12 days
Finance leases	10 years
Weighted average discount rate:
Operating leases	5.70%
Finance leases	8.20%