Summary of Significant Accounting Policies and Basis of Presentation - Schedule of Computation of Basic and Diluted Earnings Per Share For Continuing Operations (Detail) (USD $)
In Thousands, except Per Share data, unless otherwise specified

3 Months Ended

4 Months Ended

3 Months Ended

9 Months Ended

12 Months Ended

Jan. 03, 2015

Oct. 04, 2014

Jul. 12, 2014

Sep. 14, 2013

Jun. 22, 2013

Apr. 19, 2014

Dec. 28, 2013

Jan. 05, 2013

Jan. 03, 2015

Mar. 30, 2013

Numerator:

Earnings from continuing operation

$ 12,037us-gaap_IncomeLossFromContinuingOperations

$ 17,169us-gaap_IncomeLossFromContinuingOperations

$ 17,395us-gaap_IncomeLossFromContinuingOperations

$ 10,115us-gaap_IncomeLossFromContinuingOperations

$ 4,784us-gaap_IncomeLossFromContinuingOperations

$ 12,519us-gaap_IncomeLossFromContinuingOperations

$ (13,670)us-gaap_IncomeLossFromContinuingOperations

$ 1,229us-gaap_IncomeLossFromContinuingOperations

$ 19,903us-gaap_IncomeLossFromContinuingOperations

$ 59,120us-gaap_IncomeLossFromContinuingOperations

$ 27,842us-gaap_IncomeLossFromContinuingOperations

Adjustment for earnings attributable to participating securities

(26)sptn_AdjustmentToNetIncomeLossForEarningsPerShareCalculation

(1,015)sptn_AdjustmentToNetIncomeLossForEarningsPerShareCalculation

(709)sptn_AdjustmentToNetIncomeLossForEarningsPerShareCalculation

Earnings from continuing operations used in calculating earnings per share

$ 1,203sptn_AdjustedNetIncomeLossFromContinuingOperationsForEarningsPerShareCalculation

$ 58,105sptn_AdjustedNetIncomeLossFromContinuingOperationsForEarningsPerShareCalculation

$ 27,133sptn_AdjustedNetIncomeLossFromContinuingOperationsForEarningsPerShareCalculation

Denominator:

Weighted average shares outstanding, including participating securities

24,137us-gaap_WeightedAverageNumberOfSharesOutstandingBasic

37,641us-gaap_WeightedAverageNumberOfSharesOutstandingBasic

21,773us-gaap_WeightedAverageNumberOfSharesOutstandingBasic

Adjustment for participating securities

(519)sptn_WeightedAverageNumberOfSharesAdjustmentBasic

(646)sptn_WeightedAverageNumberOfSharesAdjustmentBasic

(554)sptn_WeightedAverageNumberOfSharesAdjustmentBasic

Shares used in calculating basic earnings per share

23,618sptn_WeightedAverageNumberOfSharesOutstandingBasicAsAdjustedForParticipatingSecurities

36,995sptn_WeightedAverageNumberOfSharesOutstandingBasicAsAdjustedForParticipatingSecurities

21,219sptn_WeightedAverageNumberOfSharesOutstandingBasicAsAdjustedForParticipatingSecurities

Effect of dilutive stock options

92us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment

69us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment

75us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment

Shares used in calculating diluted earnings per share

23,710us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding

37,064us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding

21,294us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding

Basic earnings per share from continuing operations

$ 0.32us-gaap_IncomeLossFromContinuingOperationsPerBasicShare

$ 0.46us-gaap_IncomeLossFromContinuingOperationsPerBasicShare

$ 0.22us-gaap_IncomeLossFromContinuingOperationsPerBasicShare

$ 0.33us-gaap_IncomeLossFromContinuingOperationsPerBasicShare

$ (0.49)us-gaap_IncomeLossFromContinuingOperationsPerBasicShare

$ 0.05us-gaap_IncomeLossFromContinuingOperationsPerBasicShare

$ 0.91us-gaap_IncomeLossFromContinuingOperationsPerBasicShare

$ 1.57us-gaap_IncomeLossFromContinuingOperationsPerBasicShare

$ 1.28us-gaap_IncomeLossFromContinuingOperationsPerBasicShare

Diluted earnings per share from continuing operations

$ 0.32us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare

$ 0.45us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare

$ 0.46us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare

$ 0.22us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare

$ 0.33us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare

$ (0.49)us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare

$ 0.05us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare

$ 0.91us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare

$ 1.57us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare

$ 1.27us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare

- Definition

Adjusted net income loss from continuing operations for earnings per share calculation.

+ References

No definition available.

+ Details

Name:	sptn_AdjustedNetIncomeLossFromContinuingOperationsForEarningsPerShareCalculation
Namespace Prefix:	sptn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Adjustment to net income loss for earnings per share calculation.

+ References

No definition available.

+ Details

Name:	sptn_AdjustmentToNetIncomeLossForEarningsPerShareCalculation
Namespace Prefix:	sptn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Weighted average number of shares adjustment basic.

+ References

No definition available.

+ Details

Name:	sptn_WeightedAverageNumberOfSharesAdjustmentBasic
Namespace Prefix:	sptn_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average number of basic shares outstanding, as adjusted for participating securities.

+ References

No definition available.

+ Details

Name:	sptn_WeightedAverageNumberOfSharesOutstandingBasicAsAdjustedForParticipatingSecurities
Namespace Prefix:	sptn_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of income (loss) from continuing operations attributable to the parent. Also defined as revenue less expenses and taxes from ongoing operations before extraordinary items but after deduction of those portions of income or loss from continuing operations that are allocable to noncontrolling interests.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 45

-Paragraph 18

-URI http://asc.fasb.org/extlink&oid=7656940&loc=SL4613673-111683

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.13)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

+ Details

Name:	us-gaap_IncomeLossFromContinuingOperations
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of net income (loss) from continuing operations per each share of common stock or unit outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=7655603&loc=d3e1252-109256

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.21)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-04.19)

-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.23)

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 18

-Article 7

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 20

-Article 5

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 21

-Article 9

+ Details

Name:	us-gaap_IncomeLossFromContinuingOperationsPerBasicShare
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of net income (loss) derived from continuing operations during the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=7655603&loc=d3e1252-109256

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.21)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 18

-Article 7

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 20

-Article 5

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 21

-Article 9

+ Details

Name:	us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Details

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

- Definition

The sum of dilutive potential common shares or units used in the calculation of the diluted per-share or per-unit computation.

+ References

+ Details

Name:	us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

+ References

+ Details

Name:	us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

+ References

+ Details

Name:	us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Details

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