Employee Stock Ownership Plan [Member] Employee Stock Ownership Plan (ESOP) Name [Axis] Foreign U.K. Customers [Member] Concentration Risk Type [Axis] Treasury Stock [Member] Equity Components [Axis] Unearned ESOP Shares [Member] Land [Member] Property, Plant and Equipment, Type [Axis] Buildings and improvements [Member] Machinery and equipment [Member] Furniture and fixtures [Member] Certificates of deposit [Member] Major Types of Debt and Equity Securities [Axis] Municipal bonds [Member] Capital in Excess of Par Value [Member] Common Stock [Member] Accumulated Other Comprehensive Income (Loss) [Member] Retained Earnings [Member] 2007 Plan [Member] Plan Name [Axis] Stock Options [Member] Award Type [Axis] 2000 Plan [Member] Sales Revenue [Member] Concentration Risk Benchmark [Axis] Domestic U.S. Customers [Member] Accounts receivable [Member] Lower Range [Member] Range [Axis] Upper Range [Member] LIBOR [Member] Variable Rate [Axis] Subsequent event [Member] Subsequent Event Type [Axis] Adjustments for New Accounting Principle, Early Adoption [Member] Adjustments for New Accounting Pronouncements [Axis] Other Current Assets [Member] Balance Sheet Location [Axis] Other Noncurrent Liabilities [Member] Other Noncurrent Assets [Member] Document And Entity Information Entity Registrant Name Entity Central Index Key Document Type Document Period End Date Amendment Flag Current Fiscal Year End Date Is Entity a Well-known Seasoned Issuer Is Entity a Voluntary Filer Is Entitys Reporting Status Current Entity Filer Category Entity Public Float Entity Common stock, closing sale price Entity Common Stock, Shares Outstanding Document Fiscal Period Focus Document Fiscal Year Focus Statement of Financial Position [Abstract] ASSETS Cash and cash equivalents Investment securities Trade accounts receivable, net of allowance of $3,000 Income tax receivable Inventories: Raw materials Work-in-process Costs related to contracts in process, net of advance payments of $18,313 and $19,626 as of June 30, 2016 and 2015, respectively Total inventories Deferred tax assets Prepaid expenses and other current assets Total current assets Property, plant and equipment, net Loan receivable Total assets LIABILITIES AND STOCKHOLDERS' EQUITY Accounts payable Accrued expenses: Salaries and wages Vacation Dividends payable Other Payroll and other taxes withheld Income taxes payable Total current liabilities Deferred tax liabilities Total liabilities Commitments and Contingencies (See Note 14) Common stock, par value $.33-1/3 per share Authorized 10,000,000 shares; Issued 3,029,874 shares as of June 30, 2016 and 2015. Outstanding 2,364,684 and 2,362,687 as of June 30, 2016 and 2015, respectively (includes 61,667 and 79,167 Unearned ESOP Shares, respectively) Capital in excess of par value Accumulated other comprehensive loss Retained earnings Total stockholders equity before ESOP and treasury stock Less: Unearned ESOP shares Cost of 665,190 and 667,187 shares of common stock in treasury as of June 30, 2016 and 2015, respectively Total stockholders' equity Total liabilities and stockholders' equity Allowance for doubtful accounts Advance payments Common stock, par value Common stock, shares authorized Common stock, shares issued Common stock, shares outstanding Unearned ESOP, shares Treasury stock, shares Income Statement [Abstract] Net sales Cost of sales Gross profit Selling, general and administrative expenses Operating Income Other income Interest income Other Total other income Income before provision for income taxes Provision for income taxes Net income Other comprehensive income, net of tax: Unrealized gain/(loss) on investment securities Total comprehensive income Net income per share: Basic Diluted Weighted average number of shares outstanding: Basic Diluted Statement [Table] Statement [Line Items] Balance, beginning Balance, beginning, shares Net income Other comprehensive income (loss), net of tax Total comprehensive income Stock options exercised Stock options exercised, shares Stock option expense Dividends paid on common stock Tax effect of stock options exercised Tax effect of dividends on unallocated ESOP shares Purchase of treasury stock Purchase of treasury stock, shares Reduction of unearned ESOP shares Balance, ending Balance, ending, common shares Statement of Stockholders' Equity [Abstract] Other comprehensive income, tax portion Dividends paid per share Statement of Cash Flows [Abstract] Cash Flows from Operating Activities: Adjustments to reconcile net income to net cash provided by operating activities: Excess tax benefits from share-based compensation Tax effect of dividends on unallocated ESOP shares Stock-based compensation Depreciation ESOP compensation expense Loss on disposal of assets Deferred income tax expense (benefit) Changes in assets and liabilities: Decrease (increase) in trade receivables, net (Increase) decrease in income tax receivable Decrease (increase) in inventories, net Increase in prepaid expenses and other current assets (Decrease) increase in accounts payable Increase (decrease) in accrued salaries and wages Increase (decrease) in vacation accrual Decrease in other accrued expenses Increase (decrease) in payroll and other taxes withheld Increase in income taxes payable Net cash provided by operating activities Cash Flows from Investing Activities: Additions to property, plant and equipment Purchase of investment securities Proceeds from sale/maturity of investment securities Net cash (used in) provided by investing activities Cash Flows from Financing Activities: Dividends on common stock Purchase of treasury stock Proceeds from exercise of stock options Excess tax benefits from share-based compensation Net cash used in financing activities Increase (decrease) in cash and short term Investments Cash and cash equivalents, beginning of the year Cash and cash equivalents, end of the year Supplemental Schedule of Cash Flow Information: Income taxes paid Supplemental Schedule of Non-cash Financing Activities: Accrual of dividends Organization, Consolidation and Presentation of Financial Statements [Abstract] Nature of operations Accounting Policies [Abstract] Summary of Significant Accounting Policies Investments, Debt and Equity Securities [Abstract] Investment Securities Contractors [Abstract] Contracts in Process Property, Plant and Equipment [Abstract] Property, Plant and Equipment Compensation and Retirement Disclosure [Abstract] Pension Expense Income Tax Disclosure [Abstract] Provision for Income Taxes Significant Customers [Abstract] Significant Customers Stock Rights Plan [Abstract] Stock Rights Plan Employee Stock Ownership Plan [Abstract] Employee Stock Ownership Plan Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Stock-based Compensation Risks and Uncertainties [Abstract] Concentration of Credit Risk Related Party Transactions [Abstract] Related Parties Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Equity [Abstract] Stockholders' Equity Debt Disclosure [Abstract] Line of Credit Quarterly Financial Information Disclosure [Abstract] Quarterly Financial Information (Unaudited) Inventory Valuation, Cost Estimation and Revenue Recognition Depreciation Income Taxes Cash and Cash Equivalents Investment Securities Fair Value of Financial Instruments Accounts receivable and allowance for doubtful accounts Per Share Amounts Comprehensive Income Use of Estimates Investment Tax Credits Reclassifications Recently Issued Accounting Standards Impairment of Long-Lived Assets Concentrations of Risk Schedule of Estimated useful lives of depreciable assets Schedule of cost, gross unrealized gains, gross unrealized losses and fair value of available-for-sale securities Schedule of contractual maturities of available-for-sale securities Schedule of contracts in process Summary of the original cost of property, plant and equipment Schedule of components of the provision for income taxes Schedule of effective income tax rates Schedule of deferred tax assets and liabilities Schedule of ESOP shares Schedule of weighted average assumptions for option awards Schedule of stock option activity Schedule of changes in non-vested stock options Schedule of reserved common shares for future issuance Schedule of reconciliation of the numerators and denominators of basic and diluted per share computations Schedule of quarterly financial information Estimated useful lives of depreciated assets Effect of early adoption of new accounting standard, amount Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Years to maturity of Available-for-sale securities: Less than One Year One to Five Years Total Progress payments Costs relating to contracts that may not be completed within the next year Gross contract value Costs related to contracts in process, net of progress payments of $18,313 and $19,626 in fiscal 2016 and 2015 Property, plant and equipment, gross Accumulated depreciation Property, plant and equipment, net Defined benefit contributions and expenses Increase in contribution, hourly rate Employer matching contibutions of 401(k) plan (percentage) Employer matching contributions to 401(k) plan Components of the provision for income taxes Current tax expense - federal Current tax (benefit) - state Deferred tax expense (benefit) Provision for income taxes Income tax rate reconciliation U.S. federal statutory income tax rate Increase (reduction) in rate resulting from: State franchise tax, net of federal income tax benefit ESOP cost versus Fair Market Value Dividend on allocated ESOP shares Qualified production activities Stock-based compensation Other Effective tax rate Tax effects of temporary differences Deferred tax assets: Accrued expenses ESOP Stock-based compensation Inventory - effect on uniform capitalization Unrealized (gain)/loss on investment securities Other Total deferred tax assets Deferred tax liability: Property, plant and equipment - principally due to differences in depreciation methods Total deferred tax liability Net deferred tax asset Concentration Risk percentage Number of customers Expiration date of the plan Number of rights distributed as a dividend, per share of common stock Date purchased rights distributed Number of shares that can be purchased by exercising each stock right Exercise price (per share) Beneficial ownership percentage that causes rights to be exercisable Percentage sale of assets or earning power to another person where rights become exercisable Number of hours worked per year to quality for the plan Shares repurchased Value of shares repurchased ESOP share allocation Allocated shares Unreleased shares Total shares held by the ESOP Fair value of unreleased shares Stock based compensation expense Deferred tax benefit related to stock based compensation Unrecognized compensation costs Period in which compensation cost will be recognized Deferred tax benefit related to unrecognized compensation costs Authorized shares under plan Vesting period Contractual life Options granted Options outstanding Aggregate intrinsic value of options exercised Weighted average assumptions to calculation option fair value Dividend yield Expected stock price volatility Risk-free interest rate Expected option life (in years) Weighted average fair value per share of options granted during the period Number of Shares Subject to Option Balance, beginning Granted Exercised Forfeited or expired Outstanding, ending Vested or expected to vest, end of period Exercisable, end of period Weight Average Exercise Price Balance, beginning Granted Exercised Forfeited or expired Outstanding, ending Vested or expected to vest, end of period Exercisable, end of period Weighted Average Remaining Contractual Term Outstanding Granted Vested or expected to vest, end of period Exercisable, end of period Aggregate Intrinsic Value Outstanding end of period Vested or expected to vest, end of period Exercisable, end of period Weighted Average Number of Shares Subject to Option Non-vested, beginning balance Vested Forfeited or expired Non-vested, ending balance Average Grant Date Fair Value Balance, beginning Granted Vested Forfeited or expired Outstanding, ending Contingent liability on outstanding letters of credit Dividends Payable [Table] Dividends Payable [Line Items] Cash dividends on common stock (in dollars per share) Anti-dilutive options excluded from calculation of EPS Dividend payable, amount per share Dividend payable, date to be paid Dividend payable, date of record Shares reserved for future issuance Stock options available for issuance Number of common shares reserved Calculation of EPS Numerator: Net Income Denominator: Basic EPS: Unearned ESOP shares Weighted average common shares issued during the period Weighted average common shares purchased during the period Weighted average ESOP shares earned during the period Denominator for basic earnings per common shares - Weighted average common shares Diluted EPS: Weighted average dilutive effect of stock options Denominator for diluted earnings per common shares - Weighted average common shares Maximum amount of Line of Credit Spread on variable interest rate Gross profit Represents the amount of dividends accrued in noncash investing or financing activities. Represents the amount of increase (decrease) in additional paid in capital (APIC) resulting from a tax effect of dividends on unallocated ESOP shares. The threshold percentage of ownership of the Company's stock that triggers the exercise of stock rights. The number of customers specifically identified in disclosure of concentration risk. Amount of deferred tax benefit attributable to unrecognized share-based compensation. Amount of contributions which the employer contributes in a matching contribution to a defined contribution plan. The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate attributable to differences in ESOP fair value. Minimum number of hours worked per year for nonunion employees to participate in ESOP. Information by name of employee stock ownership plan. The entire disclosure for employee stock ownership plan. The closing price per share of security quoted in same currency as Trading currency. Expiration date of the stock rights plan in CCYY-MM-DD format. Reflects the percentage that a specified dollar value on the balance sheet or income statement in the period from one or more specified geographic areas is to a corresponding consolidated, segment, or product line amount. Risk is the materially adverse effects of economic decline or antagonistic political actions resulting in loss of assets, sales volume, labor supply, or source of materials and supplies in a US state or a specified country, continent, or region such as EMEA (Europe, Middle East, Africa). Value of contracts before progress payments and reserves of inventories associated with long-term contracts or programs. The hourly increase in pension contributions, per year, based upon the negotiated union contract. Disclosure of accounting policy for the basis and manner that goods are added and removed from inventory in the course of production (work in process) and the accounting policy for revenue recognition. Disclosure of accounting policy for recognizing investment tax credits. The number of common stock purchase rights distributed as a dividend per share of common stock outstanding as of the date of record. The percentage of the Company's assets, or earning power, that are sold to another person that triggers the exercise of stock rights. Schedule of contracts in process. Tabular disclosure of estimated useful lives of depreciable assets. The schedule of common shares reserved for future issuance as stock option awards. The contractual life of stock options under the Company's plans. The disclosure for revenues in the period from one or more significant customers. The entire disclosure for stock right plans. Represents the amount of tax effect of dividends on unallocated ESOP shares during the reporting period. Total of all stockholders' equity (deficit) items, before ESOP and Treasury stock. Name of the equity-based compensation arrangement plan. Name of the equity-based compensation arrangement plan. Information pertaining to unearned employee stock ownership plan shares. The material effect on the financial statements due to the early adoption of a new accounting pronouncement. Cost of unearned shares that qualify as permanent equity that are held by an employee stock ownership plan (ESOP). Inventory, Net Assets, Current Assets Liabilities, Current Liabilities, Noncurrent TotalStockholdersEquityBeforyEsopAndTreasuryStock UnearnedEsopSharesCost Treasury Stock, Value Stockholders' Equity Attributable to Parent Liabilities and Equity Operating Income (Loss) Other Nonoperating Income Nonoperating Income (Expense) Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Dividends, Common Stock, Cash Excess Tax Benefit from Share-based Compensation, Operating Activities Tax Effect of Dividends on Unallocated Employee Stock Ownership Plan Operating Activities Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property Increase (Decrease) in Accounts Receivable Increase (Decrease) in Income Taxes Receivable Increase (Decrease) in Inventories Increase (Decrease) in Prepaid Expense and Other Assets Net Cash Provided by (Used in) Operating Activities, Continuing Operations Payments to Acquire Property, Plant, and Equipment Payments to Acquire Available-for-sale Securities Net Cash Provided by (Used in) Investing Activities, Continuing Operations Payments of Ordinary Dividends, Common Stock Payments for Repurchase of Common Stock Net Cash Provided by (Used in) Financing Activities, Continuing Operations Cash and Cash Equivalents, Period Increase (Decrease) Depreciation, Depletion, and Amortization [Policy Text Block] Investment, Policy [Policy Text Block] Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Effective Income Tax Rate Reconciliation, Deduction, Employee Stock Ownership Plan Dividend, Percent Effective Income Tax Rate Reconciliation, Deduction, Qualified Production Activity, Percent Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Compensation Cost, Percent Effective Income Tax Rate Reconciliation, Other Adjustments, Percent Effective Income Tax Rate Reconciliation, Percent Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost Deferred Tax Assets, Other Deferred Tax Assets, Gross Deferred Tax Liabilities, Gross Deferred Tax Assets, Net Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodContractualTerm Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Aggregate Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested Options Forfeited, Number of Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested Options Forfeited, Weighted Average Grant Date Fair Value Weighted Average Number of Shares, Employee Stock Ownership Plan Shares Not Committed to be Released Weighted Average Number of Shares, Common Stock Subject to Repurchase or Cancellation