Note 1 - Organization and Summary of Significant Accounting Policies (Details) (USD $)	12 Months Ended
Jan. 31, 2015	Feb. 01, 2014	Feb. 02, 2013
Note 1 - Organization and Summary of Significant Accounting Policies (Details) [Line Items]
Restructuring and Related Cost, Incurred Cost	$ 1,100,000	$ 2,300,000	$ 3,300,000
Other than Temporary Impairment Losses, Investments	0us-gaap_ImpairmentOfInvestments	0us-gaap_ImpairmentOfInvestments	0us-gaap_ImpairmentOfInvestments
Sales Discounts, Returns and Allowances, Goods	1,500,000	300,000
Inventory Write-down	4,267,000us-gaap_InventoryWriteDown	758,000us-gaap_InventoryWriteDown	7,053,000us-gaap_InventoryWriteDown
Percentage of Net Revenue, Products	97.00%sigm_PercentageOfNetRevenueProducts	91.00%sigm_PercentageOfNetRevenueProducts	97.00%sigm_PercentageOfNetRevenueProducts
Percentage of Potential Returns Accrued upon Sale	100.00%
Percentage of Potential Rebates Accrued upon Sale	100.00%
Interest and Other Income, Net [Member]
Note 1 - Organization and Summary of Significant Accounting Policies (Details) [Line Items]
Foreign Currency Transaction Gain (Loss), Realized	(1,000,000)	(200,000)	800,000
Selling and Marketing Expense [Member]
Note 1 - Organization and Summary of Significant Accounting Policies (Details) [Line Items]
Advertising Expense	100,000	100,000	100,000
Intellectual Property [Member] \| Minimum [Member]
Note 1 - Organization and Summary of Significant Accounting Policies (Details) [Line Items]
Finite-Lived Intangible Asset, Useful Life	2 years
Intellectual Property [Member] \| Maximum [Member]
Note 1 - Organization and Summary of Significant Accounting Policies (Details) [Line Items]
Finite-Lived Intangible Asset, Useful Life	3 years
Inventory Valuation and Obsolescence [Member]
Note 1 - Organization and Summary of Significant Accounting Policies (Details) [Line Items]
Cost of Goods Sold	600,000	1,000,000	3,300,000
Minimum [Member]
Note 1 - Organization and Summary of Significant Accounting Policies (Details) [Line Items]
Property, Plant and Equipment, Useful Life	1 year
Maximum [Member]
Note 1 - Organization and Summary of Significant Accounting Policies (Details) [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Accounts Payable and Accrued Liabilities [Member]
Note 1 - Organization and Summary of Significant Accounting Policies (Details) [Line Items]
Deferred Revenue	$ 400,000	$ 3,000,000

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The percentage of net revenues that is attributable to product sales.

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No definition available.

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- Definition

The accrual percentage for potential rebates at the time of the sale.

+ References

No definition available.

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The accrual percentage for potential returns at the time of the sale.

+ References

No definition available.

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- Definition

Amount charged to advertising expense for the period, which are expenses incurred with the objective of increasing revenue for a specified brand, product or product line.

+ References

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- Definition

Total costs related to goods produced and sold during the reporting period.

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- Definition

Amount of deferred revenue as of balance sheet date. Deferred revenue represents collections of cash or other assets related to a revenue producing activity for which revenue has not yet been recognized. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

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-Subparagraph (SAB TOPIC 13.A.4(a).Q1 Response)

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- Definition

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

Amount before tax of foreign currency transaction realized gain (loss) recognized in the income statement.

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- Definition

The amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.

+ References

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- Definition

Charge to cost of goods sold that represents the reduction of the carrying amount of inventory, generally attributable to obsolescence or market conditions.

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- Definition

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References

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- Definition

Discloses the amount charged against the accrued restructuring reserves, or earnings if not previously accrued, during the period for the specified type of restructuring cost.

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

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-Name Staff Accounting Bulletin (SAB)

-Number Topic 5

-Section P

-Subsection 3, 4

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Aggregate of: (i) sales discounts given by the entity, including, but not limited to, early payments of accounts due, (ii) the total deduction from sales during the period arising from goods returned by customers (other than under warranty provisions), and (iii) price reductions (allowance, price protection agreements) given by the entity. Discounts, returns and allowances are a deduction from gross revenue in arriving at net revenue.

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