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Associate Retirement Plans - Additional Information (Detail) - USD ($) $ in Millions |  |  |  | 3 Months Ended | 6 Months Ended
--- | --- | --- | --- | --- | ---
Jun. 28, 2024 | Jul. 01, 2023 | Jun. 30, 2022 | Jul. 13, 2024 | Jul. 15, 2023 | Jul. 13, 2024 | Jul. 15, 2023
Retiree Medical Plan [Member] |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Net periodic benefit (income) expense |  |  |  | $ 0.7 | $ 0.8 | $ 1.7 | $ 1.8
Increase (Decrease) in obligations |  |  | $ 6.6 |  |  |  |
SpartanNash Retiree Medical Plan [Member] |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Net periodic benefit (income) expense | $ 0.1 | $ 0.3 |  | 0.5 | 0.6 | 1.4 | 1.5
Payment to retired participants | $ 1.3 | $ 1.3 |  |  |  |  |
Central States, Southeast and Southwest Areas Pension Plan [Member] |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Pension contributions during last plan year |  |  |  | $ 3.3 | $ 3.3 | $ 7.9 | $ 7.6

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