Derivative Financial Instruments (Details) (USD $)	9 Months Ended
Oct. 01, 2011
Derivative Financial Instruments
Description of variable rate	three-month LIBOR
Notional value of interest rate swap agreement hedging headquarters lease through March 2011	$ 44,300,000
Notional value of interest rate swap agreement hedging headquarters lease through March 2013	50,100,000
Long-term obligations and other liabilities
Derivative financial instrument
Fair value of interest rate swap	$ 2,526,000

Aggregate notional amount of interest rate derivatives entered into, for future lease payments to be made through March 2011, which are designated as hedging instruments in cash flow hedges.

Name:	slab_NotionalAmountOfInterestRateCashFlowHedgeDerivativesForLeasePaymentsSwap1
Namespace Prefix:	slab
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Aggregate notional amount of interest rate derivatives entered into, for future lease payments to be made through March 2013, which are designated as hedging instruments in cash flow hedges.

+ Details

Name:	slab_NotionalAmountOfInterestRateCashFlowHedgeDerivativesForLeasePaymentsSwap2
Namespace Prefix:	slab
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The reference rate for the variable rate of the interest rate derivative, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ Details

Name:	us-gaap_DerivativeDescriptionOfVariableRateBasis
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
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.

+ Details

Name:	us-gaap_DerivativesFairValueLineItems
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value as of the balance sheet date of all interest rate derivative liabilities designated as cash flow hedging instruments.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 17

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4B

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5624163-113959

+ Details

Name:	us-gaap_InterestRateCashFlowHedgeLiabilityAtFairValue
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant