Marketable Securities [Abstract] Marketable Securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Commitments and Contingencies Disclosure [Abstract] Schedule of Guarantor Obligations [Table] Schedule of Guarantor Obligations [Table] Products and Services [Axis] Products and Services [Axis] Products and Services [Domain] Products and Services [Domain] Out-of-Home Product Application Out-of-Home Product Application [Member] Out-of-Home Product Application [Member] Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Domain] Guarantor Obligations, Nature [Domain] Performance guarantees Performance Guarantee [Member] Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Letter of credit and bank guarantees agreements Financial Standby Letter of Credit [Member] Surety bonds Surety Bond [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Guarantor Obligations Guarantor Obligations [Line Items] Guarantees: Guarantees [Abstract] Performance guarantees outstanding Loss Contingency Accrual Warranties: Product Warranties Disclosures [Abstract] Standard parts warranty period Product Warranty Accrual, Standard Parts Warranty Coverage Term Product Warranty Accrual, Standard Parts Warranty Coverage Term Installation warranty period Product Warranty Accrual, Installation Warranty Coverage Term Product Warranty Accrual, Installation Warranty Coverage Term Identified warranty obligations accrued Standard and Extended Product Warranty Accrual, Increase (Decrease) for Preexisting Warranties Remaining accrual Standard and Extended Product Warranty Accrual Movement in Standard Product Warranty Accrual Movement in Standard Product Warranty Accrual [Roll Forward] Beginning accrued warranty costs Warranties issued during the period Standard and Extended Product Warranty Accrual, Increase for Warranties Issued Settlements made during the period Standard and Extended Product Warranty Accrual, Decrease for Payments Changes in accrued warranty costs for pre-existing warranties during the period, including expirations Ending accrued warranty costs Income Tax Disclosure [Abstract] Unrecognized tax benefits that would affect our effective tax rate if recognized Unrecognized Tax Benefits that Would Impact Effective Tax Rate Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Deferred Tax Asset, Provisional Income Tax Expense Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Deferred Tax Asset, Provisional Income Tax Expense Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Deferred Tax Asset, Provisional Income Tax Expense Tax Cuts And Jobs Act of 2017, Incomplete Accounting, Transition Tax for Accumulated Foreign Earnings, Provisional Income Tax Expense Tax Cuts And Jobs Act of 2017, Incomplete Accounting, Transition Tax for Accumulated Foreign Earnings, Provisional Income Tax Expense Tax Cuts And Jobs Act of 2017, Incomplete Accounting, Transition Tax for Accumulated Foreign Earnings, Provisional Income Tax Expense Segment Reporting [Abstract] Segment Disclosure Segment Reporting Disclosure [Text Block] Statement of Comprehensive Income [Abstract] Net (loss) income Net Income (Loss) Attributable to Parent Other comprehensive income (loss): Other Comprehensive Income (Loss), Net of Tax [Abstract] Cumulative translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Unrealized loss on available-for-sale securities, net of tax Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax Total other comprehensive income (loss), net of tax Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Comprehensive (loss) income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Discontinued Operations and Disposal Groups [Abstract] Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative [Table] Derivative [Table] Position [Axis] Position [Axis] Position [Domain] Position [Domain] Short [Member] Short [Member] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Estimate of Fair Value Measurement [Member] Estimate of Fair Value Measurement [Member] Derivative, by Nature [Axis] Derivative Instrument [Axis] Derivative, Name [Domain] Derivative Contract [Domain] U.S. Dollars/Australian Dollars USD to AUD [Member] USD to AUD [Member] U.S. Dollars/Canadian Dollars USD to CAD [Member] USD to CAD [Member] U.S. Dollars/British Pounds USD to GBP [Member] [Member] USD to GBP [Member] [Member] U.S. Dollars/Singapore Dollars USD to SGD [Member] USD to SGD [Member] U.S. Dollars/Euros USD to EUR [Member] USD to EUR [Member] U.S. Dollars/Swiss Franc USD to CHF [Member] [Member] USD to CHF [Member] [Domain] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Recurring Basis Fair Value, Measurements, Recurring [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Level 2 Fair Value, Inputs, Level 2 [Member] Derivative Derivative [Line Items] Foreign Currency Exchange Forward Contracts: Derivative, Notional Amount Derivatives - currency forward contract, asset Foreign Currency Contract, Asset, Fair Value Disclosure Derivatives - currency forward contracts, liability Foreign Currency Contracts, Liability, Fair Value Disclosure Earnings Per Share [Abstract] Schedule of Earnings Per Share Reconciliation Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Net (loss) income Net Income (Loss) Attributable to Parent [Abstract] Basic (loss) earnings per share Dilution associated with stock compensation plans Dilutive Securities, Effect on Basic Earnings Per Share, Options and Restrictive Stock Units Diluted (loss) earnings per share Net Income (Loss) Available to Common Stockholders, Diluted Shares Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Basic (loss) earnings per share (in shares) Weighted Average Number of Shares Outstanding, Basic Dilution associated with stock compensation plans (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Diluted (loss) earnings per share (in shares) Weighted Average Number of Shares Outstanding, Diluted Per share (loss) income Earnings Per Share Reconciliation [Abstract] Basic (loss) earnings per share (in dollars per share) Earnings Per Share, Basic Dilution associated with stock compensation plans (in dollars per share) Incremental Common Shares Attributable to Share-based Payment Arrangements, Per Share Amount Incremental Common Shares Attributable to Share-based Payment Arrangements, Per Share Amount Diluted (loss) earnings per share (in dollars per share) Earnings Per Share, Diluted Receivables [Abstract] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Receivable Type [Axis] Receivable Type [Axis] Receivable Type [Domain] Receivable [Domain] Financing Receivable Financing Receivable [Member] Receivables Accounts, Notes, Loans and Financing Receivable [Line Items] Allowance for doubtful accounts Allowance for Doubtful Accounts Receivable, Current Long-term contracts and lease receivables, present value Financing Receivable, Net Contract and lease receivables annual interest rates Loans and Leases Receivable, Interest Rate Loans and Leases Receivable, Interest Rate Long-term contracts and lease receivables, face amount Financing Receivable, Gross Retainage on construction-type contracts, expected to be collected in one year Contract Receivable Retainage, Next Twelve Months Inventory Disclosure [Abstract] Schedule of Inventories Schedule of Inventory, Current [Table Text Block] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Operating Segments Operating Segments [Member] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Commerical Commerical [Member] Commerical [Member] Live Events Live Events [Member] Live Events [Member] High School Park and Recreation High School Park and Recreation [Member] High School Park and Recreation [Member] Transportation Transportation [Member] Transportation [Member] International International [Member] International [Member] Unallocated Segment Reconciling Items [Member] Segment Reporting Information Segment Reporting Information [Line Items] Number of business units Number of Reportable Segments Net sales Revenue, Net Gross profit Gross Profit Selling expense Selling Expense Depreciation and amortization Depreciation, Depletion and Amortization [Abstract] Depreciation, amortization, and impairment Depreciation, Depletion and Amortization Non-allocated operating expenses: Operating Expenses [Abstract] General and administrative General and Administrative Expense Product design and development Research and Development Expense Operating (loss) income Operating Income (Loss) Nonoperating income (expense): Nonoperating Income (Expense) [Abstract] Interest income Investment Income, Net Interest expense Interest Expense Other (expense) income, net Other Nonoperating Income (Expense) (Loss) income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income tax expense (benefit) Income Tax Expense (Benefit) Organization, Consolidation and Presentation of Financial Statements [Abstract] Recently Issued Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Available-for-sale Securities Available-for-sale Securities [Table Text Block] Investments Classified by Contractual Maturity Date Investments Classified by Contractual Maturity Date [Table Text Block] Receivables Financing Receivables [Text Block] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Stock Options Employee Stock Option [Member] Antidilutive Securities Excluded from Computation of Earnings Per Share Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive securities excluded from computation of earnings per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Antidilutive securities excluded from computation of earnings per share, weighted average exercise price (dollars per share) Antidilutive Securities Excluded from Computation of Earnings Per Share, Weighted Average Exercise Price Antidilutive Securities Excluded from Computation of Earnings Per Share, Weighted Average Exercise Price Raw materials Inventory, Raw Materials, Net of Reserves Work-in-process Inventory, Work in Process, Net of Reserves Finished goods Inventory, Finished Goods, Net of Reserves Inventories Inventory, Net Schedule of Notional Amounts of Outstanding Derivative Positions Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block] Business Combinations [Abstract] Business Combination Business Combination Disclosure [Text Block] Schedule of Product Warranty Liability Schedule of Product Warranty Liability [Table Text Block] Schedule of Future Minimum Rental Payments for Operating Leases Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Long-term Purchase Commitment Long-term Purchase Commitment [Table Text Block] Fair Value Disclosures [Abstract] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Level 3 Fair Value, Inputs, Level 3 [Member] Liability Class [Axis] Liability Class [Axis] Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Contingent Consideration Liability Contingent Consideration Liability [Member] Contingent Consideration Liability [Member] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Contingent liability as of April 29, 2017 Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value Settlements Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements Interest Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings Foreign currency translation Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Other Comprehensive Income (Loss) Contingent liability as of January 27, 2018 Subsequent Events [Abstract] Subsequent Event [Table] Subsequent Event [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event [Member] Subsequent Event [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Cash dividend declared per share (in dollars per share) Common Stock, Dividends, Per Share, Declared Goodwill and Intangible Assets Disclosure [Abstract] Schedule of Goodwill Schedule of Goodwill [Table Text Block] Basis of Presentation and Summary of Critical Accounting Policies Significant Accounting Policies [Text Block] Schedule of Operating Leased Assets [Table] Schedule of Operating Leased Assets [Table] Leases, Purchase Price Option [Axis] Leases, Purchase Price Option [Axis] Leases, Purchase Price Option [Axis] Leases, Purchase Price Option [Domain] Leases, Purchase Price Option [Domain] Leases, Purchase Price Option [Domain] March 31, 2017 to March 31, 2022 March 31, 2017 to March 31, 2022 [Member] March 31, 2017 to March 31, 2022 [Member] April 1, 2022 to March 31, 2023 April 1, 2022 to March 31, 2023 [Member] April 1, 2022 to March 31, 2023 [Member] April 1, 2023 to March 31, 2024 April 1, 2023 to March 31, 2024 [Member] April 1, 2023 to March 31, 2024 [Member] Operating Leased Assets Operating Leased Assets [Line Items] Operating leases, purchase option price Operating Leases, Purchase Option Price Operating Leases, Purchase Option Price Operating leases, rent expense Operating Leases, Rent Expense, Net Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] 2018 Operating Leases, Future Minimum Payments, Remainder of Fiscal Year 2019 Operating Leases, Future Minimum Payments, Due in Two Years 2020 Operating Leases, Future Minimum Payments, Due in Three Years 2021 Operating Leases, Future Minimum Payments, Due in Four Years 2022 Operating Leases, Future Minimum Payments, Due in Five Years Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Total Operating Leases, Future Minimum Payments Due Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Table] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Domain] Major Types of Debt and Equity Securities [Domain] Certificates of deposit Certificates of Deposit [Member] U.S. Government securities US Government Agencies Debt Securities [Member] U.S. Government sponsored entities US Government-sponsored Enterprises Debt Securities [Member] Municipal bonds US States and Political Subdivisions Debt Securities [Member] Schedule of Available-for-sale Securities Schedule of Available-for-sale Securities [Line Items] Less than 12 months Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value Greater than 12 months Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value Total Available-for-sale Securities, Debt Securities Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Disposal Group Name [Axis] Disposal Group Name [Axis] Disposal Group Name [Domain] Disposal Group Name [Domain] Non-Digital Division [Member] Non-Digital Division [Member] Non-Digital Division [Member] Disposal Group Classification [Axis] Disposal Group Classification [Axis] Disposal Group Classification [Domain] Disposal Group Classification [Domain] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Gain from sale of non-digital division Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal Assets sold Disposal Group, Including Discontinued Operation, Assets Schedule of Fair Value Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Rollforward of Level 3 Contingent Consideration Liabilities Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Subsequent Events [Text Block] Subsequent Events [Text Block] Income Statement [Abstract] Cost of goods sold Cost of Revenue Gross profit Operating expenses: Total operating expenses Operating Expenses Other (expense) income, net Weighted average shares outstanding: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Basic (in shares) Diluted (in shares) (Loss) earnings per share: Basic (in dollars per share) Diluted (in dollars per share) Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Business Acquisition [Line Items] Business Acquisition [Line Items] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Reported Value Measurement [Member] Reported Value Measurement [Member] Level 1 Fair Value, Inputs, Level 1 [Member] Municipal bonds Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Cash and cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Restricted cash Restricted Cash and Cash Equivalents, Fair Value Disclosure Restricted Cash and Cash Equivalents, Fair Value Disclosure Available-for-sale securities: Available-for-sale Securities Derivatives - currency forward contract, asset Derivatives - currency forward contracts, liability Contingent liability Business Combination, Contingent Consideration, Liability Assets (Liabilities), net Fair Value, Net Asset (Liability) Amortized Cost Available-for-sale Debt Securities, Amortized Cost Basis Unrealized Gains Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax Unrealized Losses Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax Fair Value Inventories Inventory Disclosure [Text Block] Fair Value Measurement Fair Value Disclosures [Text Block] Income Taxes Income Tax Disclosure [Text Block] Derivative Financial Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Schedule of Goodwill [Table] Schedule of Goodwill [Table] Goodwill Goodwill [Line Items] Goodwill Goodwill [Roll Forward] Balance as of April 29, 2017 Goodwill Foreign currency translation Goodwill, Foreign Currency Translation Gain (Loss) Balance as of January 27, 2018 Conditional purchase commitment Conditional Purchase Commitment, Amount Conditional Purchase Commitment, Amount Purchase Obligation, Fiscal Year Maturity Purchase Obligation, Fiscal Year Maturity [Abstract] 2018 Purchase Obligation, Due in Next Twelve Months 2019 Purchase Obligation, Due in Second Year 2020 Purchase Obligation, Due in Third Year 2021 Purchase Obligation, Due in Fourth Year 2022 Purchase Obligation, Due in Fifth Year Thereafter Purchase Obligation, Due after Fifth Year Total Purchase Obligation Schedule of Segment Reporting Information, by Segment Schedule of Segment Reporting Information, by Segment [Table Text Block] Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Table Text Block] Document and Entity Information [Abstract] Document and Entity Information [Abstract] Entities [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Entity Information [Line Items] Entity Information [Line Items] Entity Registrant Name Entity Central Index Key Current Fiscal Year End Date Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Current Reporting Status Entity Filer Category Entity Common Stock, Shares Outstanding Document Fiscal Year Focus Document Fiscal Period Focus Document Type Amendment Flag Document Period End Date Statement of Cash Flows [Abstract] Statement [Table] Statement [Table] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Statement [Line Items] Statement [Line Items] CASH FLOWS FROM OPERATING ACTIVITIES: Net Cash Provided by (Used in) Operating Activities [Abstract] Net income Adjustments to reconcile net income to net cash provided by operating activities: Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and amortization Depreciation, Amortization and Accretion, Net Impairment of intangible assets Impairment of Intangible Assets, Finite-lived (Gain) loss on sale of property, equipment and other assets Gain (Loss) on Disposition of Property Plant Equipment Share-based compensation Share-based Compensation Equity in loss of affiliate Income (Loss) from Equity Method Investments Provision for doubtful accounts Provision for Doubtful Accounts Deferred income taxes, net Deferred Income Tax Expense (Benefit) Change in operating assets and liabilities Increase (Decrease) in Other Operating Assets and Liabilities, Net Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities CASH FLOWS FROM INVESTING ACTIVITIES: Net Cash Provided by (Used in) Investing Activities [Abstract] Purchases of property and equipment Payments to Acquire Property, Plant, and Equipment Proceeds from sale of property, equipment and other assets Proceeds from Sale of Property, Plant, and Equipment Purchases of marketable securities Payments to Acquire Marketable Securities Proceeds from sales or maturities of marketable securities Proceeds from Sale and Maturity of Marketable Securities Purchases of equity investment Payments to Acquire Equity Method Investments Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities CASH FLOWS FROM FINANCING ACTIVITIES: Net Cash Provided by (Used in) Financing Activities [Abstract] Payments on notes payable Repayments of Notes Payable Proceeds from exercise of stock options Proceeds from Stock Options Exercised Principal payments on long-term obligations Repayments of Long-term Debt Dividends paid Payments of Ordinary Dividends, Common Stock Payments for common shares repurchased Payments for Repurchase of Common Stock Tax payments related to RSU issuances Payments Related to Tax Withholding for Share-based Compensation Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities EFFECT OF EXCHANGE RATE CHANGES Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents NET INCREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect CASH, CASH EQUIVALENTS AND RESTRICTED CASH: Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract] Beginning of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents End of period Cash payments for: Cash payments for: [Abstract] Interest Interest Paid Income taxes, net of refunds Income Taxes Paid, Net Supplemental schedule of non-cash investing and financing activities: Noncash Investing and Financing Items [Abstract] Demonstration equipment transferred to inventory Demonstration equipment transferred to inventory Value of demonstration equipment transferred to inventory in noncash transaction during the reporting period. Purchase of property and equipment included in accounts payable Capital Expenditures Incurred but Not yet Paid Contributions of common stock under the ESPP Stock Issued Equity Method Investments Equity Method Investments Cost Method Investments Cost Method Investments Class of Stock Disclosures [Abstract] Class of Treasury Stock [Table] Class of Treasury Stock [Table] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Share Repurchase Program [Axis] Share Repurchase Program [Axis] Share Repurchase Program [Domain] Share Repurchase Program [Domain] Equity, Class of Treasury Stock [Line Items] Equity, Class of Treasury Stock [Line Items] Stock Repurchase Program, Authorized Amount Stock Repurchase Program, Authorized Amount Stock Repurchased During Period, Shares Stock Repurchased During Period, Shares Stock Repurchased During Period, Value Stock Repurchased During Period, Value Stock Repurchase Program, Remaining Authorized Repurchase Amount Stock Repurchase Program, Remaining Authorized Repurchase Amount Treasury Stock [Text Block] Treasury Stock [Text Block] Goodwill Goodwill Disclosure [Text Block] Statement of Financial Position [Abstract] LIABILITIES AND SHAREHOLDERS' EQUITY Liabilities and Equity [Abstract] SHAREHOLDERS' EQUITY: Stockholders' Equity Attributable to Parent [Abstract] Common stock, no par value (in dollars per share) Common Stock, No Par Value Common stock, authorized (in shares) Common Stock, Shares Authorized Common stock, issued (in shares) Common Stock, Shares, Issued Treasury stock, at cost (in shares) Treasury Stock, Shares Earnings Per Share EPS Earnings Per Share [Text Block] Schedule of Revenues from External Customers and Long-Lived Assets [Table] Schedule of Revenues from External Customers and Long-Lived Assets [Table] Geographical [Axis] Geographical [Axis] Geographical [Domain] Geographical [Domain] United States UNITED STATES Outside United States Non-US [Member] Revenues from External Customers and Long-Lived Assets [Line Items] Revenues from External Customers and Long-Lived Assets [Line Items] Net sales: Geographic Areas, Revenues from External Customers [Abstract] Sales Revenues Long-lived assets: Geographic Areas, Long-Lived Assets [Abstract] Long-lived assets Long-Lived Assets ASSETS Assets [Abstract] CURRENT ASSETS: Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Restricted cash Restricted Cash and Cash Equivalents, Current Marketable securities Available-for-sale Securities, Current Accounts receivable, net Accounts Receivable, Net, Current Inventories, net Costs and estimated earnings in excess of billings Costs in Excess of Billings, Current Current maturities of long-term receivables Notes, Loans and Financing Receivable, Net, Current Prepaid expenses and other assets Prepaid Expense and Other Assets, Current Income tax receivables Income Taxes Receivable, Current Total current assets Assets, Current Long-term receivables, less current maturities Notes, Loans and Financing Receivable, Net, Noncurrent Goodwill Intangibles, net Finite-Lived Intangible Assets, Net Investments in affiliates and other assets Investments and Other Noncurrent Assets Deferred income taxes Deferred Tax Assets, Net of Valuation Allowance, Noncurrent Total noncurrent assets Noncurrent Assets Excluding Property Plant and Equipment Sum of the carrying amounts as of the balance sheet date of all assets excluding property, plant, and equipment that are expected to be realized in cash, sold or consumed after one year or beyond the normal operating cycle, if longer. PROPERTY AND EQUIPMENT: Property, Plant and Equipment, Net [Abstract] Land Land Buildings Buildings and Improvements, Gross Machinery and equipment Machinery and Equipment, Gross Office furniture and equipment Furniture and Fixtures, Gross Computer software and hardware Capitalized Computer Software And Equipment Gross Gross amount, at the balance sheet date, capitalized computer software and equipment costs. Equipment held for rental Equipment held for rental Gross amount, as of the balance sheet date, of long-lived, depreciable equipment held for rental. Demonstration equipment Demonstration equipment Gross amount, as of the balance sheet date, of long-lived, depreciable equipment used for demonstration. Transportation equipment Transportation equipment Gross amount, as of the balance sheet date, of long-lived, depreciable equipment used for transportation. Property and equipment, gross Property, Plant and Equipment, Gross Less accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Property and equipment, net Property, Plant and Equipment, Net TOTAL ASSETS Assets CURRENT LIABILITIES: Liabilities, Current [Abstract] Accounts payable Accounts Payable, Current Accrued expenses Accrued Liabilities, Current Warranty obligations Product Warranty Accrual, Current Billings in excess of costs and estimated earnings Billings in Excess of Cost, Current Customer deposits (billed or collected) Customer Deposits, Current Deferred revenue (billed or collected) Deferred Revenue, Current Current portion of other long-term obligations Other Long-term Debt, Current Income taxes payable Accrued Income Taxes, Current Total current liabilities Liabilities, Current Long-term warranty obligations Product Warranty Accrual, Noncurrent Long-term deferred revenue (billed or collected) Deferred Revenue, Noncurrent Other long-term obligations Other Liabilities, Noncurrent Long-term income tax payable Liability for Uncertainty in Income Taxes, Noncurrent Deferred income taxes Deferred Tax Liabilities, Net, Noncurrent Total long-term liabilities Liabilities, Noncurrent TOTAL LIABILITIES Liabilities Common Stock, no par value, authorized 120,000,000 shares; 44,778,945 and 44,372,357 shares issued and outstanding at January 27, 2018 and April 29, 2017, respectively Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital Retained earnings Retained Earnings (Accumulated Deficit) Treasury Stock, at cost, 303,957 shares at January 27, 2018 and April 29, 2017, respectively Treasury Stock, Value Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax TOTAL SHAREHOLDERS' EQUITY Stockholders' Equity Attributable to Parent TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY Liabilities and Equity