Maximum balance of foreign currency obligations allowed under the credit facility.

No definition available.

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Period Type:	instant

- Definition

Percentage of stand by commission.

+ References

No definition available.

+ Details

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Namespace Prefix:	sli_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Standby and commercial letter of credit sublimit.

+ References

No definition available.

+ Details

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Namespace Prefix:	sli_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

For an unclassified balance sheet, the amount as of the balance sheet date of capitalized costs associated with the issuance of debt instruments (for example, legal, accounting, underwriting, printing, and registration costs) that will be charged against earnings over the life of the debt instruments to which such costs pertain. Such amount is before the consideration of accumulated amortization.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28555-108399

+ Details

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

- 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

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)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 20, 22

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

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

- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

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

- 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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

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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

+ Details

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

- Details

Name:	us-gaap_LineOfCreditFacilityLineItems
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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

Debt - Additional Information (Detail) (USD $)	9 Months Ended			3 Months Ended			9 Months Ended		9 Months Ended			9 Months Ended
Debt - Additional Information (Detail) (USD $)	Sep. 30, 2013 2012 Credit Facility [Member]	Mar. 11, 2013 2012 Credit Facility [Member]	Dec. 31, 2012 2012 Credit Facility [Member]	Aug. 31, 2012 2012 Credit Facility [Member] PNC Bank, National Association (PNC Bank) [Member]	Jun. 20, 2013 2012 Credit Facility [Member] PNC Bank, National Association (PNC Bank) [Member]	Aug. 09, 2012 2012 Credit Facility [Member] PNC Bank, National Association (PNC Bank) [Member]	Sep. 30, 2013 2012 Credit Facility [Member] Standby Letters of Credit Due May 28, 2014 [Member]	Aug. 09, 2012 2012 Credit Facility [Member] Letter of Credit [Member] PNC Bank, National Association (PNC Bank) [Member]	Sep. 30, 2013 Minimum [Member] London Interbank Offered Rate (LIBOR) [Member]	Sep. 30, 2013 Minimum [Member] Base Rate [Member]	Mar. 11, 2013 Maximum [Member] 2012 Credit Facility [Member]	Sep. 30, 2013 Maximum [Member] London Interbank Offered Rate (LIBOR) [Member]	Sep. 30, 2013 Maximum [Member] Base Rate [Member]	Sep. 30, 2013 Maximum [Member] Federal Funds Open Rate [Member]	Sep. 30, 2013 Maximum [Member] Daily Libor Rate [Member]
Line of Credit Facility [Line Items]
Maximum borrowings	$ 40,000,000			$ 40,000,000		$ 40,000,000
Maximum borrowings under certain conditions				70,000,000		70,000,000
Standby and commercial letter of credit sublimit		5,000,000				5,000,000		10,700,000			25,000,000
Maturity date of expiration	Aug. 09, 2016			Aug. 09, 2016			May 28, 2014
Margin rate range									1.25%	0.25%		2.00%	1.00%	0.50%	1.00%
Foreign currency obligations maximum											3,500,000
Fees and expenses in connection with Credit Facility		14,000			28,000
Balance of letters of credit under credit facility							8,564,000
Annual commitment fee							0.125%
Standby commission							1.00%
Credit Availability under credit Facility	36,026,000		39,510,000
Balance under the credit facility	$ 3,500,000