Defined benefit plan expected termination process period.

No definition available.

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- Definition

Defined benefit plan pre-tax settlement charge.

+ References

No definition available.

+ Details

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- Definition

Amount of contribution received by defined benefit plan from employer which increases plan assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(5)(ii)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 6
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e2709-114920

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(5)(iv)(01)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Amount of contributions expected to be received by defined benefit plan from employer in fiscal year. Excludes contributions paid by employer in current fiscal year.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 6
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e2709-114920

+ Details

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- Definition

Amount of net periodic benefit cost (credit) for defined benefit plan.

+ References

+ Details

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- Definition

Amount of contributions made to multiemployer plan by all employers who participate in plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 7
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450678-114947

+ Details

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- Details

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- Details

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- Details

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Associate Retirement Plans - Additional Information (Detail) - USD ($)		3 Months Ended	4 Months Ended
	Feb. 28, 2018	Dec. 30, 2017	Apr. 21, 2018
Defined Benefit Plan Disclosure [Line Items]
Pension contributions during last plan year		$ 4,400,000	$ 4,500,000
Pension Plan or Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
One-time, pre-tax settlement charge	$ 22,000,000
Pension Plan or Plan [Member] \| Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected termination process period			12 months
Pension Plan or Plan [Member] \| Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected termination process period			24 months
Retiree Medical Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected Company contribution for remainder of fiscal year			$ 400,000
SpartanNash Company Pension Plan [Member] \| Pension Plan or Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit (income) expense		(200,000)	(100,000)
Standard pension funding carryover			0
SpartanNash Company Pension Plan [Member] \| Pension Plan or Plan [Member] \| Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected Company contribution for remainder of fiscal year			2,000,000
SpartanNash Company Pension Plan [Member] \| Pension Plan or Plan [Member] \| Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected Company contribution for remainder of fiscal year			3,000,000
SpartanNash Retiree Medical Plan [Member] \| Retiree Medical Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit (income) expense		$ 100,000	$ 100,000