Receivables (Details) (USD $) In Thousands, unless otherwise specified			3 Months Ended
Jul. 28, 2012	Apr. 28, 2012	Jul. 28, 2012 Minimum	Jul. 28, 2012 Maximum
Receivables
Allowance for doubtful accounts	$ 2,117	$ 2,398
Long-term contracts and lease receivables, present value	19,365	18,452
Contract and lease receivables annual interest rates			5.80%	10.00%
Long-term contracts and lease receivables, face amount	19,585	21,494
Retainage on construction-type contracts, expected to be collected in one year	$ 341	$ 783

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6375948&loc=d3e4428-111522

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

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 01-6

-Paragraph 13

-Subparagraph e

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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