Basis of Presentation and Summary of Critical Accounting Policies	9 Months Ended
	Jan. 28, 2012
Basis of Presentation and Summary of Critical Accounting Policies [Abstract]
Basis of Presentation and Summary of Critical Accounting Policies	Note 1. Basis of Presentation and Summary of Critical Accounting Policies In the opinion of management, the accompanying unaudited consolidated financial statements contain all adjustments (consisting of normal recurring adjustments) necessary to fairly present our financial position, results of operations and cash flows for the periods presented. The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts therein. Due to the inherent uncertainty involved in making estimates, actual results in future periods may differ from those estimates. Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been condensed or omitted. The balance sheet at April 30, 2011 has been derived from the audited financial statements at that date, but it does not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. These financial statements should be read in conjunction with our financial statements and notes thereto for the year ended April 30, 2011, which are contained in our Annual Report on Form 10-K previously filed with the Securities and Exchange Commission. The results of operations for the interim periods presented are not necessarily indicative of results that may be expected for any other interim period or for the full fiscal year. Reclassifications: Certain reclassifications were made to prior year amounts to conform to the current period presentation. We reclassified certain other assets from intangibles; computer software and hardware from office furniture and equipment; and accrued expenses from obligations for warranties. These reclassifications had no effect on shareholders' equity or net income as previously reported. Revenue Recognition On May 1, 2011, we prospectively adopted the Accounting Standard Updates (ASU) 2009-13 Multiple-Deliverable Revenue Arrangements, and ASU 2009-14, Certain Revenue Arrangements that Include Software Elements, regarding revenue recognition for multiple deliverable arrangements and arrangements that include software elements. The update requires a vendor to allocate revenue in an arrangement using its best estimate of selling price if neither vendor specific objective evidence nor third party evidence of selling price exists. The residual method of revenue allocation is no longer permissible. Our adoption of ASU 2009-13 and ASU 2009-14 did not change our units of accounting for bundled arrangements, nor did they materially change how we allocate arrangement consideration to our various products and services. Accordingly, our adoption of ASU 2009-13 and ASU 2009-14 did not have a significant impact on our consolidated financial statements. Multiple-element arrangements: We generate revenue from the sale of equipment and related services, including customization, installation and maintenance services. In some instances, we provide some or all of such equipment and services to our customers under the terms of a single multiple-element sales arrangement. These arrangements typically involve the sale of equipment bundled with some or all of these services, but may also involve instances in which we have contracted to deliver multiple pieces of equipment over time, rather than at a single point in time. When a sales arrangement involves multiple elements, the items included in the arrangement (deliverables) are evaluated pursuant to Accounting Standards Codification (ASC) 605-25, Revenue Arrangements with Multiple Deliverables, to determine whether they represent separate units of accounting. We perform this evaluation at the inception of an arrangement and as we deliver each item in the arrangement. Generally, we account for a deliverable (or a group of deliverables) separately if the delivered item(s) has standalone value to the customer and if we have given the customer a general right of return relative to the delivered item(s) and delivery or performance of the undelivered item(s) or service(s) is probable and substantially in our control. When items included in a multiple-element arrangement represent separate units of accounting, we allocate the arrangement consideration to the individual items based on their relative selling values. The amount of arrangement consideration allocated to the delivered item(s) is limited to the amount that is not contingent on us delivering additional products or services. Once we have determined the amount, if any, of arrangement consideration allocable to the delivered item(s), we apply the applicable revenue recognition policy, as described in our most recent Annual Report on Form 10-K filed with the Securities and Exchange Commission, to determine when and by which method such amount may be recognized as revenue. We generally determine if objective and reliable evidence of selling prices for the items included in a multiple-element arrangement exists based on whether we have vendor-specific objective evidence of the price for which we sell an item on a standalone basis. If we do not have vendor-specific objective evidence for the item, we will use the price charged by a competitor selling a comparable product or service on a standalone basis to similarly situated customers, if available. If neither vendor-specific objective evidence nor third party evidence is available, we use our best estimate of the selling price for that deliverable. All other revenue recognition accounting policies are explained in note one of the Notes to Consolidated Financial Statements in our Annual Report on Form 10-K for the fiscal year ended April 30, 2011. Recently Issued Accounting Pronouncements In December 2010, the Financial Accounting Standards Board (FASB) issued ASU 2010-28, When to Perform Step 2 of the Goodwill Impairment Test for Reporting Units with Zero or Negative Carrying Amounts (Topic 350)-Intangibles-Goodwill and Other. ASU 2010-28 amends the criteria for performing Step 2 of the goodwill impairment test for reporting units with zero or negative carrying amounts and requires performing Step 2 if qualitative factors indicate that it is more likely than not that a goodwill impairment exists. ASU 2010-28 requires any impairment to be recorded upon adoption as an adjustment to our beginning retained earnings. The adoption of this update on May 1, 2011 did not have an impact on our consolidated financial statements, as we do not have any reporting units with zero or negative carrying amounts. In May 2011, the FASB issued ASU 2011-04, Amendments to Achieve Common Fair Value Measurements and Disclosure Requirements in U.S. GAAP and IFRS, which amends ASC 820, Fair Value Measurements and Disclosures. ASU 2011-04 provides a consistent definition of fair value and ensures that the fair value measurement and disclosure requirements are similar between U.S. generally accepted accounting principles and International Financial Reporting Standards. ASU 2011-04 also changes certain fair value measurement principles and enhances the disclosure requirements particularly for level 3 fair value measurements. ASU 2011-04 is effective during interim and annual periods beginning after December 15, 2011. These new standards will be effective for us beginning in the fourth quarter of fiscal 2012. As this update impacts presentation only, its adoption will not impact our consolidated financial statements. In June 2011, the FASB issued ASU 2011-05, Presentation of Comprehensive Income which is an update to ASC 220, Comprehensive Income. ASU 2011-05 requires the components of net income and the components of other comprehensive income to be presented either in a single continuous statement of comprehensive income or in two separate but continuous statements. ASU 2011-05 eliminates the option to present components of other comprehensive income as part of the statement of changes in shareholders' equity. In addition, ASU 2011-05 requires companies to present on the face of the financial statements reclassification adjustments for items that are reclassified from other comprehensive income to net income in the statement(s) where the components of net income and the components of other comprehensive income are presented. ASU 2011-05 is effective for annual periods beginning after December 15, 2011 and interim periods thereafter. On December 23, 2011, the FASB issued ASU 2011-12, which deferred the effective date for the changes that related to the presentation of reclassification adjustments and their presentation in the financial statements until further notice. As this update impacts presentation only, its adoption will not impact our consolidated financial statements. In September 2011, the FASB issued ASU 2011-08, Intangibles - Goodwill and Other (Topic 350) - Testing Goodwill for Impairment. ASU 2011-08 permits an entity to make a qualitative assessment of whether it is more likely than not that a reporting unit's fair value is less than its carrying value before applying the two-step goodwill impairment model that is currently in place. If it is determined through the qualitative assessment that a reporting unit's fair value is more likely than not greater than its carrying value, the remaining impairment steps would be unnecessary. The qualitative assessment is optional, allowing companies to go directly to the quantitative assessment. ASU 2011-08 will be effective for annual and interim goodwill impairment tests performed in fiscal years beginning after December 15, 2011, with early adoption permitted. This new standard will be effective for us beginning in fiscal year 2013. There will be no impact to the consolidated financial statement presentation, as ASU 2011-08 impacts the analysis to be performed only if needed.