XML 123 R102.htm IDEA: XBRL DOCUMENT v3.20.4

Reporting Segment Information - Additional Information (Detail)	12 Months Ended
	Jan. 02, 2021 Segment Distribution_Centers Supermarkets PharmacyServices Fuel_Center	Dec. 28, 2019	Dec. 29, 2018
Segment Reporting Information [Line Items]
Number of Reportable Segment | Segment	3
Number of distribution centers	12
Number of military distribution centers	7
Number of corporate-owned retail stores | Supermarkets	156
Number of retail stores offered pharmacy services | PharmacyServices	97
Number of fuel centers operated | Fuel_Center	37
Food Distribution [Member]
Segment Reporting Information [Line Items]
Number of military distribution centers	2
Concentration of Credit Risk [Member] | Net Sales [Member] | Food Distribution [Member] | Customer One [Member] | Minimum [Member]
Segment Reporting Information [Line Items]
Percentage of consolidated net sales	15.00%	15.00%	15.00%
Concentration of Credit Risk [Member] | Net Sales [Member] | Food Distribution [Member] | Other Customers [Member] | Maximum [Member]
Segment Reporting Information [Line Items]
Percentage of consolidated net sales	10.00%	10.00%	10.00%

X

- Definition

Number of corporate-owned retail stores.

+ References

No definition available.

+ Details

Name:	sptn_NumberOfCorporateOwnedRetailStores
Namespace Prefix:	sptn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Number of food distribution centers.

+ References

No definition available.

+ Details

Name:	sptn_NumberOfFoodDistributionCenters
Namespace Prefix:	sptn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Number of fuel centers operated.

+ References

No definition available.

+ Details

Name:	sptn_NumberOfFuelCentersOperated
Namespace Prefix:	sptn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Number of military distribution centers.

+ References

No definition available.

+ Details

Name:	sptn_NumberOfMilitaryDistributionCenters
Namespace Prefix:	sptn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Number of retail stores offered pharmacy services.

+ References

No definition available.

+ Details

Name:	sptn_NumberOfRetailStoresOfferedPharmacyServices
Namespace Prefix:	sptn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 42
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9054-108599

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=121572278&loc=d3e13531-108611

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121572278&loc=d3e13537-108611

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

+ Details

Name:	us-gaap_ConcentrationRiskPercentage1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8672-108599

+ Details

Name:	us-gaap_NumberOfReportableSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- 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

Name:	us-gaap_SegmentReportingInformationLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=sptn_DistributionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ConcentrationRiskByTypeAxis=us-gaap_CreditConcentrationRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_SalesRevenueNetMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_MajorCustomersAxis=sptn_CustomerOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_MajorCustomersAxis=sptn_OtherCustomersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: