Represents the income tax expense or benefit pertaining to continuing operations per diluted share.

No definition available.

Name:	slab_IncomeTaxBenefitPerDilutedShare
Namespace Prefix:	slab_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	slab_OperatingLossAndTaxCreditCarryforwardLineItems
Namespace Prefix:	slab_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the provision for undistributed foreign earnings, upon which no federal or state taxes have been provided, that are considered to be permanently reinvested abroad, as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	slab_ProvisionForUndistributedEarningsFromForeignSubsidiaries
Namespace Prefix:	slab_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards, net of deferred tax liability attributable to taxable temporary differences.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319

+ Details

Name:	us-gaap_DeferredTaxAssetsLiabilitiesNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(h))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph h

-Article 4

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Income Tax Expense (or Benefit)

-URI http://asc.fasb.org/extlink&oid=6515339

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (a),(b)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32639-109319

+ Details

Name:	us-gaap_IncomeTaxExpenseBenefit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

+ References

+ Details

Name:	us-gaap_OperatingLossCarryforwards
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of the tax credit carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32559-109319

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Carryforwards

-URI http://asc.fasb.org/extlink&oid=6506874

+ Details

Name:	us-gaap_TaxCreditCarryforwardAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_BusinessAcquisitionAxis=slab_CygnalIntegratedProductsAndSiliconClocksIncSpectraLinearAndEmberMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=slab_EnergyMicroMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeTaxAuthorityAxis=us-gaap_StateAndLocalJurisdictionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementGeographicalAxis=country_SG
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Income Taxes (Details 2) (USD $)	12 Months Ended
Income Taxes (Details 2) (USD $)	Jan. 03, 2015	Dec. 28, 2013	Dec. 29, 2012
Operating loss and tax credit carryforwards
Net deferred tax assets (Liabilities)	$ 27,590,000us-gaap_DeferredTaxAssetsLiabilitiesNet	$ 31,336,000us-gaap_DeferredTaxAssetsLiabilitiesNet
Provision for U.S. federal and state income taxes	0
Income tax benefit reflected in earnings	(11,019,000)us-gaap_IncomeTaxExpenseBenefit	(12,208,000)us-gaap_IncomeTaxExpenseBenefit	(22,800,000)us-gaap_IncomeTaxExpenseBenefit
Singapore
Operating loss and tax credit carryforwards
Income tax benefit reflected in earnings	2,000,000	(2,200,000)	(13,300,000)
The income tax benefit per diluted share (in dollars per share)	$ 0.05	$ 0.05	$ (0.31)
State
Operating loss and tax credit carryforwards
Operating loss carryforwards	57,900,000
Research and development tax credit carryforwards	11,800,000
Cygnal Integrated Products, Silicon Clocks, Spectra Linear and Ember \| Federal
Operating loss and tax credit carryforwards
Operating loss carryforwards	64,900,000
Research and development tax credit carryforwards	2,000,000
Energy Micro \| Foreign
Operating loss and tax credit carryforwards
Operating loss carryforwards	$ 21,600,000