XML 92 R77.htm IDEA: XBRL DOCUMENT
v3.22.4

Associate Retirement Plans - Assumed Current Healthcare Cost Trend Rates Used to Determine Net Periodic Benefit Cost (Income) (Detail) | 12 Months Ended
--- | ---
Jan. 01, 2022 | Jan. 02, 2021
Defined Benefit Plan, Assumed Health Care Cost Trend Rates [Abstract] |  |
Post-65 | 7.00% | 7.50%

X
- Definition Defined benefit plan health care cost trend rate assumed for post sixty five year age. + References No definition available. + Details
Name: | sptn_DefinedBenefitPlanHealthCareCostTrendRateAssumedForPostSixtyFiveYearAge
Namespace Prefix: | sptn_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlanAssumedHealthCareCostTrendRatesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration