Organization, Consolidation and Presentation of Financial Statements [Abstract] Allowance for Doubtful Accounts Receivable [Roll Forward] Allowance for Doubtful Accounts Receivable [Roll Forward] Balance at beginning of period Allowance for Doubtful Accounts Receivable, Current Bad debt expense (recovery) Provision for Doubtful Accounts Uncollectible accounts written off, net of recoveries Allowance For Doubtful Accounts Receivable Write Offs Recoveries Allowance for doubtful accounts receivable write offs (recoveries). Change due to foreign currency translation Increase (Decrease) Due To Foreign Currency Translation Increase (decrease) due to foreign currency translation. Balance at end of period Income Tax Disclosure [Abstract] Income Tax Contingency [Table] Income Tax Contingency [Table] Tax Credit Carryforward Tax Credit Carryforward [Axis] Tax Credit Carryforward, Name Tax Credit Carryforward, Name [Domain] R&D Tax Credit Research And Development Tax Credit [Member] Research and development tax credit. Income Tax Contingency [Line Items] Income Tax Contingency [Line Items] Effective tax rate Effective Income Tax Rate Reconciliation, Percent Retroactive tax benefit Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions Release of a FIN 48 reserve related to the federal research and development tax credit Unrecognized Tax Benefits Undistributed earnings of foreign subsidiaries Undistributed Earnings of Foreign Subsidiaries Operating loss carryforwards, valuation allowance Operating Loss Carryforwards, Valuation Allowance Valuation allowance related to deferred tax assets Deferred Tax Assets, Valuation Allowance Tax benefit Effective Income Tax Rate Reconciliation, Tax Settlement, Domestic, Amount Decrease in unrecognized tax benefits due to expiration of certain federal statutes of limitations Unrecognized Tax Benefits Percentage Reductions Resulting From Lapse Of Applicable Statute Of Limitations Unrecognized tax benefits percentage reductions resulting from lapse of applicable statute of limitations. Income Taxes Income Tax Disclosure [Text Block] Segment Reporting [Abstract] Geographic Information Segment Reporting Disclosure [Text Block] Fair Value Disclosures [Abstract] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair Value, Measurements, Recurring Fair Value, Measurements, Recurring [Member] Fair Value, Hierarchy Fair Value, Hierarchy [Axis] Fair Value Hierarchy Fair Value Hierarchy [Domain] Quoted Prices in Active Markets for Identical Assets (Level 1) Fair Value, Inputs, Level 1 [Member] Significant Other Observable Inputs (Level 2) Fair Value, Inputs, Level 2 [Member] Significant Unobservable Inputs (Level 3) Fair Value, Inputs, Level 3 [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Assets: Assets, Fair Value Disclosure [Abstract] Cash and cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Short-term investments Short-term Investments, Fair Value Disclosure Short-term Investments, Fair Value Disclosure Restricted cash Restricted Cash, Fair Value Disclosure Restricted Cash, Fair Value Disclosure Deferred compensation Deferred Compensation Plan Assets Fair Value Disclosure Deferred compensation plan assets fair value disclosure. Liabilities: Liabilities, Fair Value Disclosure [Abstract] Deferred compensation Deferred Compensation Liability, Current and Noncurrent Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Balance at beginning of period Increases related to tax positions taken during the current period Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Increases related to tax positions taken during a prior period Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions Decreases related to expiration of statute of limitations Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations Decreases related to settlement with taxing authorities Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities Balance at end of period Earnings Per Share [Abstract] Computation of Basic and Diluted Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Current: Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal Current Federal Tax Expense (Benefit) State Current State and Local Tax Expense (Benefit) Foreign Current Foreign Tax Expense (Benefit) Current income tax provision Current Income Tax Expense (Benefit) Deferred: Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal Deferred Federal Income Tax Expense (Benefit) State Deferred State and Local Income Tax Expense (Benefit) Foreign Deferred Foreign Income Tax Expense (Benefit) Deferred income tax provision Deferred Income Tax Provision Deferred income tax provision. Total income tax provision (benefit) Income Tax Expense (Benefit) Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Property, Plant and Equipment, Type Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type Property, Plant and Equipment, Type [Domain] Land Land [Member] Buildings and improvements Building and Building Improvements [Member] Machinery and equipment Machinery and Equipment [Member] Furniture and fixtures Furniture and Fixtures [Member] Construction in process Construction in Progress [Member] Range Range [Axis] Range Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Property, plant and equipment gross Property, Plant and Equipment, Gross Less: Accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Total property, plant and equipment, net Property, Plant and Equipment, Net Asset lives Property, Plant and Equipment, Useful Life Quarterly Financial Information Disclosure [Abstract] Revenues Contracts Revenue Gross profit Gross Profit Net income (loss) Net Income (Loss) Attributable to Parent Earnings (loss) per share: Basic (in dollars per share) Earnings Per Share, Basic Diluted (in dollars per share) Earnings Per Share, Diluted Schedule of Revenues from External Customers and Long-Lived Assets [Table] Schedule of Revenues from External Customers and Long-Lived Assets [Table] Geographical Geographical [Axis] Geographical Geographical [Domain] United States UNITED STATES Canada CANADA Middle East and Africa Segment Geographical Group Of Countries Group One [Member] Segment geographical group of countries group One. Europe Europe [Member] Mexico, Central and South America Segment Geographical Groups Of Countries Group Four [Member] Segment geographical groups of countries group four. Far East Segment Geographical Groups Of Countries Group Three [Member] Segment geographical groups of countries group three. Revenues from External Customers and Long-Lived Assets [Line Items] Revenues from External Customers and Long-Lived Assets [Line Items] Total revenues Revenues Current deferred income taxes: Deferred Tax Assets, Net of Valuation Allowance, Current Classification [Abstract] Gross assets Deferred Tax Assets, Gross, Current Gross liabilities and valuation allowance Deferred Tax Liabilities, Gross, Current Net current deferred income tax asset Deferred Income Tax Assets Liabilities Net Current Deferred income tax assets liabilities net current. Noncurrent deferred income taxes: Deferred Tax Assets, Net of Valuation Allowance, Noncurrent Classification [Abstract] Gross assets Deferred Tax Assets, Gross, Noncurrent Gross liabilities and valuation allowance Deferred Tax Liabilities, Gross, Noncurrent Net noncurrent deferred income tax asset (liability) Deferred Income Tax Assets Liabilities Net Noncurrent Deferred income tax assets liabilities net noncurrent. Net deferred income tax asset Deferred Tax Assets, Net Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Schedule of Restricted Stock Units Activity Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block] Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Raw materials, parts and subassemblies Inventory, Raw Materials and Supplies, Gross Work-in-progress Inventory, Work in Process, Gross Provision for excess and obsolete inventory Inventory Valuation Reserves Total inventories Inventory, Net Statutory rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent State income taxes, net of federal benefit Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent Research and development credit Effective Income Tax Rate Reconciliation, Tax Credit, Research, Percent Foreign rate differential Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Percent Domestic production activities deduction Effective Income Tax Rate Reconciliation, Deduction, Qualified Production Activity, Percent Foreign valuation allowance Effective Income Tax Rate Reconciliation Change In Foreign Valuation Allowance Effective income tax rate reconciliation change in foreign valuation allowance. NOL carryback impact on deductions Effective Income Tax Rate Reconciliation NOL Carryback Impact On Deductions, Percent Effective Income Tax Rate Reconciliation NOL Carryback Impact On Deductions, Percent Other Effective Income Tax Rate Reconciliation,Other Reconciling Items, Percent Effective rate Net Income (Loss) Attributable to Parent [Abstract] Consolidated Statement of Comprehensive Income (Loss) [Abstract] Statement of Comprehensive Income [Abstract] Net income (loss) Foreign currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Postretirement benefit adjustment, net of tax Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax Comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Attributable to Parent Assets under capital leases Assets Held under Capital Leases [Member] Depreciation Depreciation Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward] Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward] Balance at beginning of period Product Warranty Accrual, Current Increase to warranty expense Standard and Extended Product Warranty Accrual, Increase for Warranties Issued Deduction for warranty charges Standard and Extended Product Warranty Accrual, Decrease for Payments Change due to foreign currency translation Standard and Extended Product Warranty Accrual, Foreign Currency Translation Gain (Loss) Balance at end of period Business and Organization Nature of Operations [Text Block] Equity [Abstract] Share Repurchase Program Stock Repurchase Program [Text Block] Stock repurchase program. Accounting Policies [Abstract] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Supplemental Disclosures of Cash Flow Information Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Revenue from External Customers by Products and Services [Table] Revenue from External Customers by Products and Services [Table] Revenue from External Customer [Line Items] Revenue from External Customer [Line Items] Retention amounts included in accounts receivable Contract Receivable Retainage Long-term contract beginning Long-term Contract, Period Long-term Contract, Period Warranty for parts and services date of shipment Warranty, Parts And Services, Date Of Shipment, Period Warranty, Parts And Services, Date Of Shipment, Period Warranty parts and services date of energization Warranty, Parts And Services, Date Of Energization, Period Warranty, Parts And Services, Date Of Energization, Period Research and development expenses Research and Development Expense U.S. Income (Loss) from Continuing Operations before Income Taxes, Domestic Other than U.S. Income (Loss) from Continuing Operations before Income Taxes, Foreign Income (loss) before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Document And Entity Information [Abstract] Document and entity information. Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Document Type Document Type Document Period End Date Document Period End Date Amendment Flag Amendment Flag Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Voluntary Filers Entity Current Reporting Status Entity Current Reporting Status Trading Symbol Trading Symbol Entity Public Float Entity Public Float Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Statement of Financial Position [Abstract] Allowance for doubtful accounts Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Preferred stock, shares authorized Preferred Stock, Shares Authorized Preferred stock, shares issued Preferred Stock, Shares Issued Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized Common Stock, Shares Authorized Common stock, shares issued Common Stock, Shares, Issued Treasury stock, shares Treasury Stock, Shares Restructuring and Related Activities [Abstract] Schedule of Restructuring and Related Costs [Table] Schedule of Restructuring and Related Costs [Table] Restructuring Type [Axis] Restructuring Type [Axis] Type of Restructuring [Domain] Type of Restructuring [Domain] Employee Severance Employee Severance [Member] Restructuring Cost and Reserve [Line Items] Restructuring Cost and Reserve [Line Items] Restructuring and separation costs incurred Restructuring Charges Restructuring and separation costs paid Payments for Restructuring Restructuring and separation costs payable over the next fiscal year Restructuring and Related Cost, Expected Cost Remaining Separation costs Severance Costs Restructuring costs related to exited of Canadian facility lease and write-off of associated leasehold improvements Business Exit Costs Number of previously occupied leased facilities Number Of Leased Facilities Number Of Leased Facilities Debt Disclosure [Abstract] Year Ending September 30, Long-term Debt, Fiscal Year Maturity [Abstract] 2018 Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months 2019 Long-term Debt, Maturities, Repayments of Principal in Year Two 2020 Long-term Debt, Maturities, Repayments of Principal in Year Three 2021 Long-term Debt, Maturities, Repayments of Principal in Year Four 2022 Long-term Debt, Maturities, Repayments of Principal in Year Five Industrial development revenue bonds Long-term Debt Quarterly Information Quarterly Financial Information [Text Block] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Award Type Award Type [Axis] Equity Award Equity Award [Domain] Restricted Stock Units (RSUs) Restricted Stock Units (RSUs) [Member] Restricted Stock Restricted Stock [Member] Plan Name Plan Name [Axis] Plan Name Plan Name [Domain] 2014 Equity Incentive Plan Two Thousand Fourteen Equity Incentive Plan [Member] Two thousand fourteen equity incentive plan. 2014 Non-Employee Director Equity Incentive Plan Non Employee Director Equity Incentive Plan [Member] 2014 Non-Employee Director Equity Incentive Plan Member Class of Stock Class of Stock [Axis] Class of Stock Class of Stock [Domain] Time Based Restricted Stock Unit Time Based Restricted Stock Unit [Member] Time based restricted stock unit. Performance Based Restricted Stock Unit Performance Based Restricted Stock Unit [Member] Performance based restricted stock unit. Vesting Vesting [Axis] Vesting Vesting [Domain] Vesting of First Anniversary Share-based Compensation Award, Tranche One [Member] Vesting of Second Anniversary Share-based Compensation Award, Tranche Two [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Actual amount of RSUs earned based on cumulative earnings Share Based Compensation Arrangement By Share Based Payment Award Percent Of Actual Amount Of Units Earned Share based compensation arrangement by share based payment award percent of actual amount of units earned. Target RSUs granted range Share Based Compensation Arrangement By Share Based Payment Award Target R S U Granted Range Share based compensation arrangement by share based payment award target RSU granted range. Unvested restricted stock outstanding (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Common stock, capital shares reserved for future issuance Common Stock, Capital Shares Reserved for Future Issuance Number of shares available for grant Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Maximum number of shares granted to any individual Share-based Compensation Arrangement by Share-based Payment Award, Maximum Number of Shares Per Employee Number of shares issued to any individual Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant Other Than Options And SARs Share based compensation arrangement by share based payment award number of shares available for grant other than options and SARs. Restricted stock issuable to eligible Board of Directors members annually (in shares) Share Based Compensation Arrangement By Share Based Payment Award Annual Shares Issuable Share-based compensation arrangement by share-based payment award annual shares issuable. Vesting percentage Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Shares issued under the plan Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period Shares issued, price per share (in dollars per share) Shares Issued, Price Per Share Compensation expense Allocated Share-based Compensation Expense Amounts not yet recognized related to non-vested stock totaled Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options Weighted average remaining contractual life Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition United Kingdom UNITED KINGDOM Property, plant and equipment, net Number of Restricted Stock Units Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Outstanding Beginning Balance (in shares) Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Outstanding Ending Balance (in shares) Weighted Average Fair Value Per Share Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Outstanding Beginning Balance (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Granted (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Vested (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Forfeited (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Outstanding Ending Balance (in dollars per share) Detail of Selected Balance Sheet Accounts Supplemental Balance Sheet Disclosures [Text Block] Fair Value Measurements Fair Value Disclosures [Text Block] Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Equity Components Equity Components [Axis] Equity Component Equity Component [Domain] Common Stock Common Stock [Member] Additional Paid-in Capital Additional Paid-in Capital [Member] Retained Earnings Retained Earnings [Member] Treasury Stock Treasury Stock [Member] Accumulated Other Comprehensive Income/(Loss) AOCI Attributable to Parent [Member] Statement [Line Items] Statement [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Balance Stockholders' Equity Attributable to Parent Balance, shares Common Stock, Shares, Outstanding Stock-based compensation Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Stock-based compensation, shares Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Excess tax benefit from share-based compensation Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net Shares withheld in lieu of employee tax withholding Adjustments Related to Tax Withholding for Share-based Compensation Issuance of restricted stock Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Issuance of restricted stock, shares Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Purchase of treasury shares Treasury Stock, Value, Acquired, Cost Method Purchase of treasury shares, shares Treasury Stock, Shares, Acquired Dividends paid Dividends, Common Stock, Cash Balance Balance, shares Supplemental Cash Flow Information [Abstract] Interest paid, net of interest income Interest Paid, Net Of Interest Income Interest Paid, Net Of Interest Income Income taxes paid, net of refunds Income Taxes Paid, Net Non-cash capital expenditures Capital Expenditures Incurred but Not yet Paid Valuation Allowance [Table] Valuation Allowance [Table] Valuation Allowances and Reserves Type Valuation Allowances and Reserves Type [Axis] Valuation Allowances and Reserves Valuation Allowances and Reserves [Domain] Valuation Allowance of Deferred Tax Assets Valuation Allowance of Deferred Tax Assets [Member] Valuation Allowance [Line Items] Valuation Allowance [Line Items] Movement in Valuation Allowances and Reserves [Roll Forward] Movement in Valuation Allowances and Reserves [Roll Forward] Beginning balance Valuation Allowances and Reserves, Balance Charged to cost and expenses Valuation Allowances And Reserves Charged Or Credited To Cost And Expense Valuation allowances and reserves charged or credited to cost and expense. Charged to other accounts Valuation Allowances And Reserves Charged Or Credited To Other Accounts Valuation allowances and reserves charged or credited to other accounts. Ending balance Principles of Consolidation Consolidation, Policy [Policy Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Cash and Cash Equivalents Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] Fair Value of Financial Instruments Fair Value Measurement, Policy [Policy Text Block] Accounts Receivable Trade and Other Accounts Receivable, Policy [Policy Text Block] Costs and Estimated Earnings in Excess of Billings on Uncompleted Contracts Costs And Estimated Earnings In Excess Of Billings On Uncompleted Contracts Policy [Policy Text Block] Costs and estimated earnings in excess of billings on uncompleted contracts. Inventories Inventory, Policy [Policy Text Block] Property, Plant and Equipment Property, Plant and Equipment, Policy [Policy Text Block] Income Taxes Income Tax, Policy [Policy Text Block] Revenue Recognition Revenue Recognition Accounting Policy, Gross and Net Revenue Disclosure [Policy Text Block] Warranty Costs Standard Product Warranty, Policy [Policy Text Block] Research and Development Expense Research and Development Expense, Policy [Policy Text Block] Foreign Currency Translation Foreign Currency Transactions and Translations Policy [Policy Text Block] Stock-Based Compensation Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block] New Accounting Standards New Accounting Pronouncements, Policy [Policy Text Block] Activity in Allowance for Doubtful Accounts Allowance for Credit Losses on Financing Receivables [Table Text Block] Components of Inventories Schedule of Inventory, Current [Table Text Block] Components of Cost and Estimated Earnings and Related Amounts Billed on Uncompleted Contracts Costs in Excess of Billings and Billings in Excess of Costs [Table Text Block] Schedule of Property, Plant and Equipment Property, Plant and Equipment [Table Text Block] Activity in Warranty Accrual Schedule of Product Warranty Liability [Table Text Block] 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 Subsequent Event [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Cash dividends declared (in dollars per share) Common Stock, Dividends, Per Share, Declared Schedule of Quarterly Financial Information Quarterly Financial Information [Table Text Block] Commitments and Contingencies Disclosure [Abstract] Schedule of Future Minimum Annual Rental Commitments Under Leases Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Schedule of Lease Expense and Sublease Income Schedule of Lease Expense and Sublease Income [Table Text Block] Schedule of Lease Expense and Sublease Income [Table Text Block] Postretirement benefit adjustment, tax Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Tax ASSETS Assets [Abstract] Current Assets: Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Short-term investments Short-term Investments Restricted cash Restricted Cash and Cash Equivalents, Current Accounts receivable, less allowance for doubtful accounts of $179 and $811 Accounts Receivable, Net, Current Costs and estimated earnings in excess of billings on uncompleted contracts Costs in Excess of Billings, Current Inventories Income taxes receivable Income Taxes Receivable, Current Deferred income taxes Deferred Tax Assets, Net of Valuation Allowance, Current Prepaid expenses Prepaid Expense, Current Other current assets Other Assets, Current Total Current Assets Assets, Current Restricted cash Restricted Cash and Cash Equivalents, Noncurrent Goodwill and intangible assets, net Intangible Assets, Net (Including Goodwill) Other assets Other Assets, Noncurrent Deferred income taxes Deferred Tax Assets, Net of Valuation Allowance, Noncurrent Total Assets Assets LIABILITIES AND STOCKHOLDERS' EQUITY Liabilities and Equity [Abstract] Current Liabilities: Liabilities, Current [Abstract] Current maturities of long-term debt Long-term Debt, Current Maturities Income taxes payable Accrued Income Taxes, Current Accounts payable Accounts Payable, Current Accrued salaries, bonuses and commissions Employee-related Liabilities, Current Billings in excess of costs and estimated earnings on uncompleted contracts Billings in Excess of Cost, Current Accrued product warranty Other accrued expenses Other Accrued Liabilities, Current Deferred credit ─ short term (Note E) Deferred Revenue and Credits, Current Total Current Liabilities Liabilities, Current Long-term debt, net of current maturities Long-term Debt, Excluding Current Maturities Deferred compensation (Note I) Deferred Compensation Liability, Classified, Noncurrent Deferred income taxes Deferred Tax Liabilities, Net, Noncurrent Other long-term liabilities Other Liabilities, Noncurrent Deferred credit ─ long term (Note E) Deferred Revenue and Credits, Noncurrent Total Liabilities Liabilities Commitments and Contingencies (Note G) Commitments and Contingencies Stockholders' Equity: Stockholders' Equity Attributable to Parent [Abstract] Preferred stock, par value $.01; 5,000,000 shares authorized; none issued Preferred Stock, Value, Issued Common stock, par value $.01; 30,000,000 shares authorized; 12,234,656 and 12,199,511 shares issued, respectively Common Stock, Value, Outstanding Additional paid-in capital Additional Paid in Capital, Common Stock Retained earnings Retained Earnings (Accumulated Deficit) Treasury stock, 806,018 shares at cost Treasury Stock, Value Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total Stockholders' Equity Total Liabilities and Stockholders' Equity Liabilities and Equity Components of Long-Term Debt Schedule of Long-term Debt Instruments [Table Text Block] Schedule of Maturities of Long-Term Debt Schedule of Maturities of Long-term Debt [Table Text Block] Statement of Cash Flows [Abstract] Operating Activities: Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Adjustments to reconcile net income (loss) to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Amortization Amortization Stock-based compensation Share-based Compensation Excess tax benefit from stock-based compensation Excess Tax Benefit from Share-based Compensation, Operating Activities Bad debt expense/(recovery) Deferred income tax expense Deferred Income Tax Expense (Benefit) Gain on amended supply agreement Gain (Loss) on Disposition of Intangible Assets Cash received from amended supply agreement Cash Received From Amended Supply Agreement Cash received from amended supply agreement. Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Accounts receivable Increase (Decrease) in Accounts Receivable Costs and billings in excess of estimates on uncompleted contracts Increase (Decrease) in Unbilled Receivables Inventories Increase (Decrease) in Inventories Income taxes Increase (Decrease) in Income Taxes Payable Prepaid expenses and other current assets Increase (Decrease) in Prepaid Expense and Other Assets Accounts payable Increase (Decrease) in Accounts Payable Accrued liabilities Increase (Decrease) in Accrued Liabilities Other, net Increase (Decrease) in Other Operating Assets and Liabilities, Net Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities, Continuing Operations Investing Activities: Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Purchases of property, plant and equipment Payments to Acquire Property, Plant, and Equipment Proceeds from sale of property, plant and equipment Proceeds from Sale of Property, Plant, and Equipment Purchases of short-term investments Payments to Acquire Short-term Investments Maturities of short-term investments Proceeds from Maturities, Prepayments and Calls of Short-term Investments Changes in restricted cash Increase in Restricted Cash Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations Financing Activities: Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] Payments on industrial development revenue bonds Repayments of Long-term Debt Excess tax benefit from stock-based compensation Excess Tax Benefit from Share-based Compensation, Financing Activities Shares withheld in lieu of employee tax withholding Payments Related to Tax Withholding for Share-based Compensation Purchase of treasury shares Payments for Repurchase of Common Stock Dividends paid Payments of Ordinary Dividends, Common Stock Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities, Continuing Operations Net increase (decrease) in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect Effect of exchange rate changes on cash and cash equivalents Effect of Exchange Rate on Cash and Cash Equivalents Cash and cash equivalents, beginning of period Cash and cash equivalents, end of period Restructuring and Separation Expenses Restructuring and Related Activities Disclosure [Text Block] Operating Leases Payments Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] 2018 Operating Leases, Future Minimum Payments Due, Next Twelve Months 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 lease commitments Operating Leases, Future Minimum Payments Due Operating Sublease Income Operating Leases, Sublease Future Minimum Payments Due, Rolling Maturity [Abstract] [Abstract] Operating Leases, Sublease Future Minimum Payments Due, Rolling Maturity [Abstract] [Abstract] 2018 Operating Leases, Rent Expense, Sublease Rentals, Future Minimum Payments, Due Next Twelve Months Operating Leases, Rent Expense, Sublease Rentals, Future Minimum Payments, Due Next Twelve Months 2019 Operating Leases, Rent Expense, Sublease Rentals, Future Minimum Payments, Due In Two Years Operating Leases, Rent Expense, Sublease Rentals, Future Minimum Payments, Due In Two Years 2020 Operating Leases, Rent Expense, Sublease Rentals, Future Minimum Payments, Due In Three Years Operating Leases, Rent Expense, Sublease Rentals, Future Minimum Payments, Due In Three Years 2021 Operating Leases, Rent Expense, Sublease Rentals, Future Minimum Payments, Due In Four Years Operating Leases, Rent Expense, Sublease Rentals, Future Minimum Payments, Due In Four Years 2022 Operating Leases, Rent Expense, Sublease Rentals, Future Minimum Payments, Due In Five Years Operating Leases, Rent Expense, Sublease Rentals, Future Minimum Payments, Due In Five Years Thereafter Operating Leases, Rent Expense, Sublease Rentals, Future Minimum Payments, Due Thereafter Operating Leases, Rent Expense, Sublease Rentals, Future Minimum Payments, Due Thereafter Total lease commitments Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals Costs incurred on uncompleted contracts Costs Incurred On Uncompleted Contracts Costs incurred on uncompleted contracts. Estimated earnings Estimated Earnings Estimated earnings. Total Receivables, Long-term Contracts or Programs Less: Billings to date Billed Contracts Receivable Net underbilled position Unbilled Contracts Receivable Included in the accompanying balance sheets under the following captions: Contracts Receivable [Abstract] Costs and estimated earnings in excess of billings on uncompleted contracts – underbilled Billings in excess of costs and estimated earnings on uncompleted contracts – overbilled Line of Credit Facility [Table] Line of Credit Facility [Table] Guarantor Obligations, Nature Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature Guarantor Obligations, Nature [Domain] Financial Standby Letter of Credit Financial Standby Letter of Credit [Member] Debt Instrument Debt Instrument [Axis] Debt Instrument, Name Debt Instrument, Name [Domain] The Third Amendment The Third Amendment [Member] The Third Amendment [Member] Credit Facility Credit Facility [Axis] Credit Facility Credit Facility [Domain] U.S. Revolver Domestic Line of Credit [Member] Industrial Development Revenue Bonds Industrial Development Revenue Bonds [Member] Industrial development revenue bonds. Variable Rate Variable Rate [Axis] Variable Rate Variable Rate [Domain] Federal Funds Rate Federal Funds Effective Swap Rate [Member] Eurocurrency Rate Eurodollar [Member] Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Revolving credit facility Line of Credit Facility, Maximum Borrowing Capacity Fee percentage Line of Credit Facility, Collateral Fee Percentage Line of Credit Facility, Collateral Fee Percentage Commitment fee percentage Line of Credit Facility, Commitment Fee Percentage Cash collateral percent of outstanding debt (at least) Line Of Credit Facility, Covenant Terms, Cash Collateral, Percent Of Debt Outstanding Line Of Credit Facility, Covenant Terms, Cash Collateral, Percent Of Debt Outstanding Consolidated current ratio (no less than) Line Of Credit Facility, Covenant Terms, Consolidated Current Ratio Line Of Credit Facility, Covenant Terms, Consolidated Current Ratio Cash collateral pledged balance Line Of Credit Facility, Collateral Amount Line Of Credit Facility, Collateral Amount Basis spread on variable rate Debt Instrument, Basis Spread on Variable Rate Guarantee liability Guarantor Obligations, Current Carrying Value Revolving credit facility borrowings, outstanding amount Long-term Line of Credit Amount of credit facility remaining borrowing capacity Line of Credit Facility, Remaining Borrowing Capacity Percentage of voting capital stock pledged as collateral Percentage Of Domestic Capital Stock Pledged As Collateral For Credit Facility Percentage of domestic capital stock pledged as collateral for credit facility. Non-domestic subsidiaries of voting capital stock Percentage Of Non Domestic Capital Stock Pledged As Collateral For Credit Facility Percentage of non domestic capital stock pledged as collateral for credit facility. Borrowings Debt Instrument, Face Amount Reimbursement agreement requires annual redemptions Debt Instrument, Annual Principal Payment Interest rate Debt Instrument, Interest Rate, Effective Percentage Class of Treasury Stock [Table] Class of Treasury Stock [Table] 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 repurchase program expiration date Stock Repurchase Program Expiration Date Stock purchased under repurchase program (in shares) Stock purchased under repurchase program, value Stock purchased under repurchased program, average purchase price per share (in dollars per share) Stock Repurchased During Period Average Price Per Share Stock repurchased during period average price per share. Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Earnings Per Share Earnings Per Share [Text Block] Long-Term Debt Long-term Debt [Text Block] Compensation and Retirement Disclosure [Abstract] Schedule of Deferred Compensation Arrangement with Individual, Postretirement Benefits [Table] Schedule of Deferred Compensation Arrangement with Individual, Postretirement Benefits [Table] Investment Issuer [Axis] Investment Issuer [Axis] Investment Issuer [Domain] Investment Issuer [Domain] Company owned life insurance policies Company Owned Life Insurance Policies [Member] Company Owned Life Insurance Policies [Member] Other Postretirement Benefits, Individual Contracts, Type of Deferred Compensation Other Postretirement Benefits, Individual Contracts, Type of Deferred Compensation [Axis] Other Postretirement Benefits, Individual Contracts, Type of Deferred Compensation Other Postretirement Benefits, Individual Contracts, Type of Deferred Compensation [Domain] Deferred compensation plan Deferred Compensation Arrangement with Individual, by Type of Compensation, Pension and Other Postretirement Benefits [Member] Retiree medical plan Postretirement Health Coverage [Member] Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items] Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items] Defined contribution plan recognized expenses Defined Contribution Plan, Cost Recognized Percentage of employee based salary permitted for deferral under the plan Deferred Compensation Arrangement With Individual Maximum Employee Subscription Rate Deferred compensation arrangement with individual maximum employee subscription rate. Percentage of employee annual bonus permitted for deferral under the plan Deferred Compensation Arrangement With Individual Maximum Contractual Amount Bonus Deferred compensation arrangement with individual maximum contractual amount bonus. Deferred compensation expense adjustment Deferred Compensation Arrangement With Individual Compensation Adjustment Income Expense Deferred compensation arrangement with individual compensation adjustment income (expense). Deferred compensation plan assets Deferred Compensation Plan Assets Deferred compensation liabilities Deferred compensation, retirement age Deferred Compensation Arrangement With Individual, Age Of Individual Deferred Compensation Arrangement With Individual, Age Of Individual Deferred compensation requisite service period Deferred Compensation Arrangement with Individual, Requisite Service Period Deferred compensation recorded liability Deferred Compensation Arrangement with Individual, Recorded Liability Cash surrender value of life insurance Cash Surrender Value of Life Insurance Age older but less than Defined Benefit Plan, Employee Coverage, Age Of Individual Defined Benefit Plan, Employee Coverage, Age Of Individual Unfunded liability Defined Benefit Plan, Funded Status of Plan Net periodic postretirement benefit cost (less than) Defined Benefit Plan, Net Periodic Benefit Cost September 30, Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract] 2018 Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months 2019 Finite-Lived Intangible Assets, Amortization Expense, Year Two 2020 Finite-Lived Intangible Assets, Amortization Expense, Year Three 2021 Finite-Lived Intangible Assets, Amortization Expense, Year Four 2022 Finite-Lived Intangible Assets, Amortization Expense, Year Five Employee Benefit Plans Pension and Other Postretirement Benefits Disclosure [Text Block] Deferred Tax Assets: Deferred Tax Assets, Net, Classification [Abstract] Net operating income/loss Deferred Tax Assets, Operating Loss Carryforwards Uniform capitalization and inventory Deferred Tax Assets Uniform Capitalization And Inventory Deferred tax assets uniform capitalization and inventory. Deferred compensation Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Pensions Stock-based compensation Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost Reserve for accrued employee benefits Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Benefits Warranty accrual Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Warranty Reserves Goodwill Deferred Tax Assets, Goodwill and Intangible Assets Postretirement benefits liability Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Postretirement Benefits Allowance for doubtful accounts Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Allowance for Doubtful Accounts Accrued legal Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Legal Settlements Credit carryforwards Deferred Tax Assets, Tax Credit Carryforwards Other Deferred Tax Assets, Other Deferred tax assets Deferred Tax Assets, Gross Deferred Tax Liabilities: Deferred Tax Liabilities, Net, Classification [Abstract] Depreciation and amortization Deferred Tax Liabilities Depreciation And Amortization Deferred tax liabilities depreciation and amortization. Deferred tax liabilities Deferred Tax Liabilities, Gross Less: valuation allowance Subsequent Events Subsequent Events [Text Block] Schedule of Intangible Assets Subject to Amortization Schedule of Finite-Lived Intangible Assets [Table Text Block] Schedule of Estimated Amortization Expense Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Fair Value of Assets and Liabilities Measured on Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Less: current portion Long-term Debt and Capital Lease Obligations, Current Total long-term debt Long-term Debt and Capital Lease Obligations Stock-Based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Finite-Lived Intangible Assets by Major Class Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name Finite-Lived Intangible Assets, Major Class Name [Domain] Purchased Technology Purchased Technology [Member] Purchased technology. Supply Agreement Supply Agreement [Member] Supply agreement. Income Statement Location Income Statement Location [Axis] Income Statement Location Income Statement Location [Domain] Other Income Other Income [Member] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Goodwill Goodwill Purchased technology Finite-Lived Intangible Assets, Net Impairment of goodwill Goodwill, Impairment Loss Amortization of intangible assets Amortization of Intangible Assets Useful life of intangible asset Finite-Lived Intangible Asset, Useful Life Additional amount paid on execution of agreement Additional Amount Paid On Execution Of Agreement Additional amount paid on execution of agreement. Acquired finite-lived intangible assets, period Acquired Finite-lived Intangible Assets, Weighted Average Useful Life Deferred credit Deferred Revenue and Credits Deferred credit amortization period Finite-Lived Intangible Assets, Remaining Amortization Period Gains in other income Other Nonoperating Income (Expense) Schedule of Revenues from External Customers by Geographical Areas Revenue from External Customers by Geographic Areas [Table Text Block] Schedule of Long-Lived Assets by Geographical Areas Long-lived Assets by Geographic Areas [Table Text Block] Schedule of Components of Income Tax Provision (Benefit) Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Schedule of Income (Loss) Before Income Taxes Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block] Schedule of Effective Income Tax Rate Reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Schedule of Deferred Tax Assets and Liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Schedule of Valuation Allowance Summary of Valuation Allowance [Table Text Block] Reconciliation of Unrecognized Tax Benefits Summary of Income Tax Contingencies [Table Text Block] Denominator: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Weighted average basic shares (in shares) Weighted Average Number of Shares Outstanding, Basic Dilutive effect of restricted stock units (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Weighted average diluted shares with assumed conversions Weighted Average Number of Shares Outstanding, Diluted Net earnings (loss) per share: Earnings Per Share, Basic and Diluted [Abstract] Basic earnings (loss) per share (in dollars per share) Diluted earnings (loss) per share (in dollars per share) Rental expense Operating Leases, Rent Expense, Net Sublease income from third parties Operating Leases, Rent Expense, Sublease Rentals Income Statement [Abstract] Cost of goods sold Contract Revenue Cost Gross profit Selling, general and administrative expenses Selling, General and Administrative Expense Restructuring and separation expenses Operating income (loss) Operating Income (Loss) Other income (See Note E) Interest expense Interest Expense Interest income Investment Income, Interest Income tax provision (benefit) Net income (loss) Weighted average shares: Basic (in shares) Diluted (in shares) Dividends per share (in dollars per share) Gross Carrying Value Finite-Lived Intangible Assets, Gross Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Net Carrying Value Schedule of Guarantor Obligations [Table] Schedule of Guarantor Obligations [Table] Surety Bond Surety Bond [Member] Facility Agreement Facility Agreement [Member] Facility agreement. Legal Entity Legal Entity [Axis] Entity Entity [Domain] Powell (UK) Limited Powell U K Limited [Member] Powell (UK) limited. Guarantor Obligations [Line Items] Guarantor Obligations [Line Items] Additional bonding capacity Commitments And Contingencies Additional Bonding Capacity Commitments and contingencies additional bonding capacity. Liquidated damages Loss Contingency, Loss in Period Probable liquidated damages Loss Contingency Probable Loss In Period Loss contingency probable loss in period. Loss contingency, estimate of actual or projected loss Loss Contingency, Estimate of Possible Loss