Advance rate, real estate.

No definition available.

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Period Type:	duration

- Definition

Credit facility increase in term loan capacity.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Expected redemption premium and write-off of unamortized issuance costs.

+ References

No definition available.

+ Details

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Balance Type:	debit
Period Type:	duration

- Definition

Line of credit facility additional borrowing capacity.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of credit facility percentage of maintenance of excess borrowing base.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Number of tiers.

+ References

No definition available.

+ Details

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Balance Type:	na
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- Definition

Number of tranches.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ 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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Balance Type:	na
Period Type:	duration

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Balance Type:	na
Period Type:	duration

- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph e
-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

+ Details

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- Definition

Amount of unused borrowing capacity under the long-term financing arrangement that is available to the entity as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.16)
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-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
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-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19, 20, 22
-Article 5

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average interest rate of long-term debt outstanding.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

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- Details

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Balance Type:
Period Type:

- Details

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- Details

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Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=sptn_TrancheATwoMember
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Balance Type:
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- Details

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Long-Term Debt - Additional Information (Detail)	1 Months Ended		12 Months Ended
Long-Term Debt - Additional Information (Detail)	Dec. 31, 2016 USD ($) Tier Tranche	Nov. 30, 2015 USD ($)	Dec. 31, 2016 USD ($)	Jan. 02, 2016 USD ($)
Debt Instrument [Line Items]
Unused portion of loan commitments rate			0.25%
Maintenance of excess borrowing base			10.00%
Current borrowing available under credit facility	$ 415,800,000		$ 415,800,000	$ 334,300,000
Weighted average interest rate of convertible senior notes	3.70%		3.70%
Amended Credit Facility [Member]
Debt Instrument [Line Items]
Number of tiers in pricing grid \| Tier	2
Credit Agreement [Member]
Debt Instrument [Line Items]
Advance rate on real estate	75.00%
Credit facility increase in term loan	$ 33,000,000		$ 33,000,000
Available borrowings under credit facility	$ 1,000,000,000		1,000,000,000
Number of tranches \| Tranche	3
Additional borrowings available under credit facility	$ 400,000,000		$ 400,000,000
Notes maturity date			Dec. 20, 2021
6.625% Senior Notes Due December 2016 [Member]
Debt Instrument [Line Items]
Principal amount of senior notes		$ 50,000,000
Senior notes, rate		6.625%
Redemption price (expressed as percentage of the principal amount)		101.65625%
Expected redemption premium and write-off unamortized issuance costs		$ 1,200,000
Tranche A [Member]
Debt Instrument [Line Items]
Secured revolving credit facility	325,000		$ 325,000
Tranche A-1 [Member]
Debt Instrument [Line Items]
Secured revolving credit facility	34,127		34,127
Tranche A-2 [Member]
Debt Instrument [Line Items]
Secured revolving credit facility	26,954		26,954
Revolving credit agreement [Member]
Debt Instrument [Line Items]
Secured revolving credit facility	386,100,000		386,100,000	429,800,000
Revolving credit agreement [Member] \| Tranche A [Member] \| Credit Agreement [Member]
Debt Instrument [Line Items]
Available borrowings under credit facility	900,000,000		900,000,000
Revolving credit agreement [Member] \| Tranche A-1 [Member]
Debt Instrument [Line Items]
Available borrowings under credit facility	40,000,000		40,000,000
Revolving credit agreement [Member] \| Tranche A-2 [Member]
Debt Instrument [Line Items]
Secured revolving credit facility	60,000,000		60,000,000
Letter of credit [Member]
Debt Instrument [Line Items]
Unused borrowing capacity	$ 9,600,000		$ 9,600,000	$ 11,100,000