Long-term debt - Summary of Long Term Debt (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 30, 2013	Mar. 31, 2012
Proforma Debt Instrument [Line Items]
Long-term debt and Capital lease obligations	$ 41,895	$ 50,965
Current portion of long-term debt	3,795	5,567
Long-term debt	38,100	45,398
Capital leasing arrangements [Member] \| Land and Building [Member]
Proforma Debt Instrument [Line Items]
Obligation under capital leases	13,767	14,346
Term Loan From Investissement Of Quebec Prime Plus Five Point Five Percent [Member]
Proforma Debt Instrument [Line Items]
Long-term debt	7,590	10,009
Revolving credit facility [Member]
Proforma Debt Instrument [Line Items]
Long-term debt	18,000	18,000
Leasehold improvements [Member] \| Furniture and equipment [Member]
Proforma Debt Instrument [Line Items]
Obligation under capital leases	388	2,289
Cash contribution [Member]
Proforma Debt Instrument [Line Items]
Long-term debt	1,500	5,000
Term Loan From Investissement Of Quebec Prime Plus Three Point Five Percent [Member]
Proforma Debt Instrument [Line Items]
Long-term debt	$ 650	$ 1,321

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Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

+ References

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- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 7

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22)

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 210

-Section S99

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

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-Section 02

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- Definition

Sum of the carrying values as of the balance sheet date of all long-term debt, which is debt initially having maturities due after one year from the balance sheet date or beyond the operating cycle, if longer, but excluding the portions thereof scheduled to be repaid within one year or the normal operating cycle, if longer plus capital lease obligations due to be paid more than one year after the balance sheet date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

-Section H

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Obligation related to long-term debt (excluding convertible debt) and capital leases, the portion which is due in one year or less in the future.

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Carrying amount of long-term debt, net of unamortized discount or premium, excluding amounts to be repaid within one year or the normal operating cycle, if longer (current maturities). Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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