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Associate Retirement Plans - Effect of Assumed Health Care Cost Rate on Post Retirement Plan Reported (Detail) | 9 Months Ended | 12 Months Ended
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Dec. 28, 2013 | Jan. 02, 2016 | Jan. 03, 2015
Defined Benefit Plan Assumed Health Care Cost Trend Rates [Abstract] |  |  |
Pre-65 | 8.00% | 7.50% | 7.75%
Post-65 | 7.00% | 8.40% | 6.85%

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- Definition Defined benefit plan health care cost trend rate assumed for post sixty five year age. + References No definition available. + Details
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- Definition Defined benefit plan health care cost trend rate assumed for pre sixty five year age. + References No definition available. + Details
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Namespace Prefix: | sptn_
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- References No definition available. + Details
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