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Income Tax - Summary of Deferred Tax Assets and Liabilities (Parenthetical) (Detail) | 12 Months Ended
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Dec. 28, 2019
Income Tax Expense Benefit Continuing Operations [Line Items] |
Federal credit carryforwards expire year | 2040
State and Local Jurisdiction |
Income Tax Expense Benefit Continuing Operations [Line Items] |
Net operating losses, expiration date, description | expire in tax years 2021 through 2040 if not utilized

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- Definition Deferred tax assets, federal tax credit carryforwards, expiration year. + References No definition available. + Details
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Balance Type: | na
Period Type: | duration

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- Definition Income tax expense benefit continuing operations. + References No definition available. + Details
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Namespace Prefix: | sptn_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Definition Operating loss carryforwards expiration date description. + References No definition available. + Details
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Namespace Prefix: | sptn_
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Balance Type: | na
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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |