The contractual life of stock options under the Company's plans. ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodContractualTerm Granted Amount of deferred tax benefit attributable to unrecognized share-based compensation. Deferred tax benefit related to unrecognized compensation costs Name of the equity-based compensation arrangement plan. 2007 Plan [Member] Name of the equity-based compensation arrangement plan. 2000 Plan [Member] The entire disclosure for employee stock ownership plan. EmployeeStockOwnershipPlanTextBlock Employee Stock Ownership Plan Information by name of employee stock ownership plan. Employee Stock Ownership Plan [Member] Employee Stock Ownership Plan [Member] Minimum number of hours worked per year for nonunion employees to participate in ESOP. Number of hours worked per year Total of all stockholders' equity (deficit) items, before ESOP and Treasury stock. TotalStockholdersEquityBeforyEsopAndTreasuryStock Total stockholders equity before ESOP Document And Entity Information [Abstract] Basis of Presentation [Abstract] Net Income per Share [Abstract] Amendment Flag Recently Issued Accounting Standards [Abstract] Employee Stock Ownership Plan [Abstract] Weighted Average Assumptions Number of Shares Subject to Options Weight Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value Average Grant Date Fair Value Weighted Average Number of Shares Subject to Option Current Fiscal Year End Date Accrual of Dividends Accrual of dividends Represents the amount of dividends accrued in noncash investing or financing activities. Unearned ESOP Shares Cost Less: Unearned ESOP shares Cost of unearned shares that qualify as permanent equity that are held by an employee stock ownership plan (ESOP). Document Period End Date Award Type [Axis] Is Entity a Well-known Seasoned Issuer Is Entity a Voluntary Filer Is Entity's Reporting Status Current Entity Filer Category Entity Registrant Name Entity Central Index Key Entity Common Stock, Shares Outstanding Entity Common stock, per share value Document Fiscal Year Focus Document Fiscal Period Focus Document Type Accounts payable Trade accounts receivable, net Trade accounts receivable, net of allowance of $3,000 Accrued expenses: Salaries and wages Payroll and other taxes withheld Income taxes payable ESOP payable Vacation Accumulated other comprehensive loss Capital in excess of par value Adjustments to reconcile net income to net cash provided by operating activities: Stock based compensation expense Allowance for Doubtful Accounts Receivable Trade accounts receivable, allowance Allowance for Doubtful Accounts Receivable, Current Trade accounts receivable, allowance Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Anti-dilutive securities ASSETS: Assets Total assets Assets, Current Total current assets Available-for-sale Securities [Table Text Block] Schedule of cost, gross unrealized gains, gross unrealized losses and fair value of available-for-sale securities by major security type Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax Gross Unrealized Gains Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax Gross Unrealized Losses Available-for-sale Securities, Current Investment securities Fair Value Fair Value Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value One to Five Years Available-for-sale Securities, Debt Maturities, Single Maturity Date [Abstract] Contractual maturities of available-for-sale securities Amortized Cost Available-for-sale Securities, Amortized Cost Basis Amortized Cost Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value Less than One Year Basis of Presentation Cash and cash equivalents Cash and cash equivalents, beginning of period Cash and cash equivalents, end of period Cash and Cash Equivalents, Period Increase (Decrease) Increase in cash and cash equivalents Certificates of Deposit [Member] Certificates of deposit [Member] Commitments and contingencies (see Note 5) Commitments and Contingencies. Commitments and Contingencies Commitments and Contingencies [Abstract] Common stock, par value $.33-1/3 per share. Authorized 10,000,000 shares; Issued 3,029,874 shares as of December 31, 2015 and June 30, 2015. Outstanding 0 as of December 31, 2015 and 2,362,687 as of June 30, 2015 (includes 0 and 79,167 Unearned ESOP shares, respectively) Common stock, par value $.33-1/3 per share. Authorized 10,000,000 shares; Issued 3,029,874 shares on December 31, 2015 and June 30, 2015. Outstanding 2,352,184 and 2,362,687 on December 31, 2015 and June 30, 2015, respectively (includes 70,417 and 79,167 Unearned ESOP shares, respectively) Common stock, shares issued Common Stock, Dividends, Per Share, Cash Paid Cash divided paid (in dollars per share) Common stock, shares authorized Dividends per share: Common stock, par value Common stock, shares outstanding Common Stock, Shares Held in Employee Trust, Shares Unearned ESOP, shares Comprehensive Income (Loss), Net of Tax, Attributable to Parent Total comprehensive income Cost of sales Deferred income tax expense Deferred income taxes Deferred Tax Assets, Net of Valuation Allowance, Current Deferred tax liability Deferred Tax Liabilities, Net, Noncurrent Depreciation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Stock Based Compensation Stock Based Compensation [Abstract] Dividends Payable, Current Dividend payable Net Income per Share Basic Diluted Net income per share: Stock Option Plans [Member] Period in which compensation cost will be recognized Employee Stock Ownership Plan (ESOP) Disclosures [Line Items] ESOP compensation expense Deferred tax benefit related to stock based compensation Unrecognized compensation costs Employee Stock Ownership Plan (ESOP) Name [Axis] Unearned ESOP, shares Fair value of unreleased shares Plan description Employee Stock Ownership Plan ESOP Plan [Domain] Total shares held by the ESOP Total shares held by the ESOP Allocated shares Committed-to-be-released shares Unreleased shares Excess tax benefits from share-based compensation Excess Tax Benefit from Share-based Compensation, Operating Activities Excess tax benefits from share-based compensation Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property Loss on disposal of assets Accrued amount within the range that appears to be possible outcome Gain Contingency, Unrecorded Amount Gross Profit Gross profit Statement of Comprehensive Income [Abstract] Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest Income before income taxes Provision for income taxes Income taxes paid Income tax receivable Income taxes receivable Decrease (increase) in trade receivable, net Increase (Decrease) in Accounts Receivable Increase in income taxes payable Decrease in accrued salaries and wages Increase in accounts payable (Decrease) increase in accounts payable Decrease in other accrued expenses Changes in assets and liabilities: Decrease in ESOP payable Increase (Decrease) in Inventories Increase in inventories, net (Increase) decrease in income taxes receivable Increase (Decrease) in Income Taxes Receivable Decrease in vacation accrual Decrease in prepaid expenses and other current assets Increase (Decrease) in Prepaid Expense and Other Assets Increase (decrease) in payroll and other taxes withheld Inventories: Costs relating to contracts in process, net of advance payments of $0 at December 31, 2015 and $19,626 at June 30, 2015 Costs relating to contracts in process, net of advance payments of $2,174 at December 31, 2015 and $19,626 at June 30, 2015 Inventory, Net Total inventories Work-in-process Raw materials Interest income Fair Value of Financial Instruments and Investments Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Investments Classified by Contractual Maturity Date [Table Text Block] Schedule of contractual maturities of available-for-sale securities Fair Value of Financial Instruments and Investments [Abstract] Liabilities, Current Total current liabilities Liabilities, Noncurrent Total liabilities Liabilities Total liabilities LIABILITIES AND STOCKHOLDERS' EQUITY: Liabilities and Equity Total liabilities and stockholders' equity Major Types of Debt and Equity Securities [Domain] Major Types of Debt and Equity Securities [Axis] Investment securities Municipal Bonds [Member] Municipal bonds [Member] Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] Cash Flows from Financing Activities: Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Cash Flows from Operating Activities: Net Cash Provided by (Used in) Investing Activities, Continuing Operations Net cash (used in) provided by investing activities Net Cash Provided by (Used in) Operating Activities, Continuing Operations Net cash provided by operating activities Net income Net income Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Cash Flows from Investing Activities: Net Cash Provided by (Used in) Financing Activities, Continuing Operations Net cash used in financing activities New Accounting Pronouncements and Changes in Accounting Principles [Text Block] Recently Issued Accounting Standards Supplemental Schedule of Non-cash Financing Activities: Noncash Investing and Financing Items [Abstract] Nonoperating Income (Expense) Total other income Loan receivable Operating income Operating Income (Loss) Other income Unrealized gain (loss) on investment securities Unrealized loss on investment securities Unrealized (loss) gain on investment securities Other Other Nonoperating Income Other Other comprehensive income, net of tax: Payments for Repurchase of Common Stock Purchase of treasury stock Payments of Ordinary Dividends, Common Stock Dividends on common stock Payments to Acquire Available-for-sale Securities Purchase of investment securities Additions to property, plant and equipment Payments to Acquire Property, Plant, and Equipment Plan Name [Axis] Plan Name [Domain] Prepaid expenses and other current assets Proceeds from loan receivable Proceeds from exercise of stock options Proceeds from sale/maturity of investment securities Sale of treasury stock Advance payments of costs related to contracts in process Property, plant and equipment, net Retained earnings Exercisable, end of period Expected option life (in years) Balance, beginning Outstanding, ending Non-vested, beginning balance Non-vested, ending balance Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares Vested Balance, beginning Outstanding, ending 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, Vested, Number of Shares Vested Vested Vested or expected to vest, end of period Forfeited or expired Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested Options Forfeited, Weighted Average Grant Date Fair Value Forfeited or expired Forfeited or expired Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested Options Forfeited, Number of Shares Net sales Schedule of changes in non-vested stock options Schedule of stock option activity Schedule of weighted average assumptions for option awards Schedule of Available-for-sale Securities [Table] Investment in Fair Value [Line Items] Schedule of Available-for-sale Securities [Line Items] Schedule of Employee Stock Ownership Plan (ESOP) Disclosures [Table] Schedule of ESOP shares Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Selling, general and administrative expenses Weighted average fair value per share of options granted Exercised Exercised Exercised Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Stock-based compensation Granted Options granted Stock-Based Compensation [Line Items] Granted Dividend yield Exercisable, end of period Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Forfeited or expired Forfeited or expired Forfeited or expired Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price Expected stock price volatility Authorized shares under plan Risk-free interest rate Forfeited or expired Forfeited or expired Aggregate intrinsic value of options exercised Exercisable, end of period 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, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value Vested or expected to vest, end of period Exercisable, end of period Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted Average Exercise Price Outstanding end of period Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Share Based Compensation Arrangements By Share Based Payment Award Award Type And Plan Name [Domain] Share Based Compensation Arrangements By Share Based Payment Award Award Type And Plan Name [Domain] Balance, beginning Outstanding, ending Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Balance, beginning Outstanding, ending 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, Number Vested or expected to vest, end of period Granted 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, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price Vested or expected to vest, end of period Statements of Cash Flows [Abstract] Balance Sheets [Abstract] Stock Redeemed or Called During Period, Value Stock repurchased Exercised Exercised Stock repurchased (in shares) Stock Repurchased During Period, Shares Stockholders' Equity Attributable to Parent Total stockholders' equity Supplemental Schedule of Cash Flow Information: Treasury stock, shares Treasury shares, cost of 0 and 661,764 shares on September 30, 2014 and June 30, 2014, respectively Treasury shares, cost of 677,690 and 667,187 shares on December 31, 2015 and June 30, 2015, respectively Treasury Stock, Value Weighted average number of shares outstanding: Basic Weighted Average Number of Shares Outstanding, Basic Diluted Weighted Average Number of Shares Outstanding, Diluted