Refers to the amount of eligible collateral letters of credit, based on borrowing base availability.

No definition available.

Name:	syx_EligibleCollateralUnderTheCreditFacility
Namespace Prefix:	syx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The optional borrowing capacity subject to conditions 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

No definition available.

+ Details

Name:	syx_LineOfCreditFacilityOptionalBorrowingCapacitySubjectToConditions
Namespace Prefix:	syx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Refers to the amount of outstanding advances.

+ References

No definition available.

+ Details

Name:	syx_OutstandingAdvances
Namespace Prefix:	syx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The percentage of eligible accounts receivable for borrowings under the agreement.

+ References

No definition available.

+ Details

Name:	syx_PercentageOfEligibleAccountsReceivableForBorrowings
Namespace Prefix:	syx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Refers to percentage of inventory advance rate computed as the lesser of NOVL (Net Orderly Liquidation Value).

+ References

No definition available.

+ Details

Name:	syx_PercentageOfInventoryAdvanceRateComputed
Namespace Prefix:	syx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Refers to percentage of inventory advance rate computed of NOVL (Net Orderly Liquidation Value).

+ References

No definition available.

+ Details

Name:	syx_PercentageOfInventoryAdvanceRateOfNOVL
Namespace Prefix:	syx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Date the credit facility terminates, 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 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationDate1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

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

- 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

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=syx_GroupOfFinancialInstitutionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=syx_OneFinancialInstitutionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Credit Facilities and Long Term Debt (Details) - Secured Revolving Credit Facility [Member] - USD ($) $ in Millions		9 Months Ended
	Nov. 07, 2016	Sep. 30, 2016	Oct. 28, 2016
Group of Financial Institutions [Member]
Line of Credit Facility [Line Items]
Secured revolving credit agreement, maximum borrowing capacity		$ 125.0
Line of credit facility optional maximum borrowing capacity subject to conditions		$ 200.0
Credit facility maturity date		Oct. 31, 2016
Eligible collateral under the credit facility		$ 52.1
Availability under line of credit		46.6
Total outstanding letters of credit		5.5
Outstanding borrowings		$ 0.0
One Financial Institution [Member] \| Subsequent Event [Member]
Line of Credit Facility [Line Items]
Secured revolving credit agreement, maximum borrowing capacity			$ 75.0
Credit facility maturity date	Oct. 28, 2021
Term of credit facility	5 years
Percentage of inventory advance rate computed	60.00%
Percentage of inventory advance rate of net orderly liquidation value	85.00%
One Financial Institution [Member] \| Maximum [Member]
Line of Credit Facility [Line Items]
Percentage of eligible accounts receivable for borrowings	85.00%