Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Jan. 31, 2013 Customer Reporting_Segments	Jan. 31, 2012	Jan. 31, 2011
Significant Accounting Policies (Textual) [Abstract]
Other intangible asset amortization Period	3 years
Significant Accounting Policies (Additional Textual) [Abstract]
Cash and cash equivalent maturity period	3 months
Customer holding percentage of revenue	10.00%	10.00%	10.00%
License Fee Receivable Within One Year	80.00%
License Fee Receivable After One Year	20.00%
License agreement period	1 year
Number of Reporting Segments	1
Dividend yield	0.00%	0.00%	0.00%
Advertising Expense	$ 3.6	$ 3.5	$ 3.1
Cash payments period for tax	1 year
Number of customer accounted for net revenue	0
Maximum [Member]
Significant Accounting Policies (Textual) [Abstract]
Property, Plant and Equipment, Useful Life	5 years
Other intangible asset amortization Period	8 years
Minimum [Member]
Significant Accounting Policies (Textual) [Abstract]
Property, Plant and Equipment, Useful Life	3 years
Other intangible asset amortization Period	1 year 6 months

Cash and cash equivalent maturity period.

No definition available.

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Namespace Prefix:	srna_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Cash payments period for tax.

+ References

No definition available.

+ Details

Name:	srna_CashPaymentsPeriodForTax
Namespace Prefix:	srna_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

License agreement period.

+ References

No definition available.

+ Details

Name:	srna_LicenseAgreementPeriod
Namespace Prefix:	srna_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

License fee receivable after one year.

+ References

No definition available.

+ Details

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

- Definition

License fee receivable within one year.

+ References

No definition available.

+ Details

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

- Definition

Number of major customer accounted for net revenues.

+ References

No definition available.

+ Details

Name:	srna_NumberOfMajorCustomerAccountedForNetRevenues
Namespace Prefix:	srna_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	srna_SignificantAccountingPoliciesAdditionalTextualAbstract
Namespace Prefix:	srna_
Data Type:	xbrli:stringItemType
Balance Type:	na
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- Details

Name:	srna_SignificantAccountingPoliciesTextualAbstract
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- 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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 720

-SubTopic 35

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6420018&loc=d3e36677-107848

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

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 93-7

-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.

+ Details

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

- Definition

Percentage of revenue generated from a single external customer that accounts for 10 percent or more of an entity's revenues.

+ References

No definition available.

+ Details

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

- 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.

+ Details

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

- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

No definition available.

+ Details

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

- 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

No definition available.

+ Details

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Balance Type:	na
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- Definition

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (f)(2)(iii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph e(2)(c)

-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.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
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