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Represents the amount of costs contingent on rescission.

No definition available.

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The percentage of the fair market value of the reporting entity's common stock that determines the price at which employees can purchase stock.

No definition available.

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Amount of contributions made by an employer to a defined contribution plan regarding severances.

No definition available.

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Amount employees over age 50 may contribute to a defined contribution plan over the maximum.

No definition available.

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The amount of liability for the potential tax consequences on behalf of employees for issuing shares in excess of the number of shares reserved under an employee stock purchase program.

No definition available.

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Represents the share to RSU reduction ratio.

No definition available.

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Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Aggregate number of common shares reserved for future issuance.

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This represents the entire assets recognized in the balance sheet that are associated with the defined benefit plans.

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The amount of the cost recognized during the period for defined contribution plans.

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Amount of discretionary contributions made by an employer to a defined contribution plan.

No definition available.

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Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

No definition available.

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Maximum amount the employee may contribute to a defined contribution plan.

No definition available.

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Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

No definition available.

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation.

No definition available.

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Unrecognized cost of unvested options awarded to employees as compensation.

No definition available.

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Amount of cash outflow to satisfy an employee's income tax withholding obligation as part of a net-share settlement of a share-based award.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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Number of additional shares authorized for issuance under an established share-based compensation plan.

No definition available.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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Number of share instruments newly issued under a share-based compensation plan.

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Price of a single share of a number of saleable stocks of a company.

No definition available.

Name:	us-gaap_SharePrice
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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Fair value of options vested. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock.

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For net-share settlement of share-based awards when the employer settles employees' income tax withholding obligations, this element represents the number of shares the employees use to repay the employer.

No definition available.

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Number of shares issued during the period as a result of an employee stock purchase plan.

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Liability for amount due employees, in addition to wages and any other money that employers owe employees, when their employment ends through a layoff or other termination. For example, a company may provide involuntarily terminated employees with a lump sum payment equal to one week's salary for every year of employment.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Namespace Prefix:
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Name:	us-gaap_PlanNameAxis=sigm_PriorPlansMember
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