Statement of Financial Position [Abstract] ASSETS: ASSETS: [Abstract] Current assets: Current assets: [Abstract] Cash and cash equivalents Marketable securities Accounts receivable, net of allowance for doubtful accounts of $234 in 2014 and $288 in 2013 Costs and estimated earnings in excess of billings, net Inventories, net Deferred income taxes Prepaid income taxes Prepaid expenses and other Total current assets Property, plant and equipment, at cost, net of accumulated depreciation and amortization Deferred income taxes Goodwill and other intangible assets Cash Surrender Value Of Life Insurance And Cash Held In Trust Cash surrender value of life insurance and cash held in trust Other assets Total assets LIABILITIES AND STOCKHOLDERS' EQUITY: LIABILITIES AND STOCKHOLDERS' EQUITY: [Abstract] Current liabilities: Current liabilities: [Abstract] Short-term credit obligations Accounts payable - trade Accrued liabilities Total current liabilities Credit obligations- noncurrent Deferred compensation Deferred rent and other liabilities Total liabilities Commitments and contingencies Stockholders' equity: Stockholders' equity: [Abstract] Preferred stock, $1.00 par value authorized 600 shares, no shares issued Common stock, $1.00 par value; authorized 20,000 shares, 9,164 shares issued and 8,571 outstanding in 2014; 8,463 outstanding in 2013 Additional paid-in capital Retained earnings Common stock reacquired and held in treasury - at cost (593 shares in 2014 and 701 shares in 2013) Accumulated other comprehensive income Total stockholders' equity Total liabilities and stockholders' equity Allowance for doubtful accounts (in Dollars) Preferred stock, par value (in Dollars per share) Preferred stock, shares authorized Preferred stock, shares issued Common stock, par value (in Dollars per share) Common stock, shares authorized Common stock shares issued Common stock, shares outstanding Treasury stock, shares Income Statement [Abstract] Revenues Cost of revenues Gross margin Selling and administrative expenses Research and development expenses Operating profit Other income (expense): Other income (expense): [Abstract] Investment income Interest expense Other income (expense), net Income before provision for income taxes Provision for income taxes Net income Net income per common share: Net income per common share: [Abstract] Basic (in Dollars per share) Diluted (in Dollars per share) Average shares outstanding: Average shares outstanding: [Abstract] Basic (in Shares) Diluted (in Shares) Statements of Comprehensive Income Statements of Comprehensive Income [Abstract] Net Income Other comprehensive income (loss): Other comprehensive income (loss): [Abstract] Foreign currency translation adjustment Amount before reclassification adjustments, of unrealized holding gain (loss) on available-for-sale securities. Change in market value of marketable securities Deferred tax effect of change in marketable securities Total other comprehensive income (loss) Comprehensive income Statement of Cash Flows [Abstract] Cash flows from operating activities: Cash flows from operating activities: [Abstract] Net income Adjustments to reconcile net income to net cash provided in operating activities: Adjustments to reconcile net income to net cash provided in operating activities: [Abstract] Deferred income tax benefit Depreciation and amortization Deferred lease obligation Amount of expense related to write-down of accounts receivable, inventories and warranty reserve. Provision for losses on accounts receivable, inventories and warranty reserve Gains on marketable securities (Gain) loss on sale of fixed and other assets, net Employee benefit plans expense Stock-based compensation expense Tax benefit from exercise of stock-based compensation Changes in operating assets and liabilities: Changes in operating assets and liabilities: [Abstract] Accounts receivable Inventories Prepaid expenses and other Other assets Accounts payable - trade Accrued liabilities Income taxes refundable/payable Other liabilities Net cash provided by operating activities Cash flows from investing activities: Cash flows from investing activities: [Abstract] Purchase of marketable securities Proceeds from sale or redemption of marketable securities Proceeds from sale of fixed assets (a) Capital expenditures Net cash used in investing activities Cash flows from financing activities: Cash flows from financing activities: [Abstract] Proceeds from credit line borrowing Payment of short-term credit and lease obligations Proceeds from exercise of stock options Dividends paid Tax benefit from exercise of stock-based compensation Net cash provided by (used in) financing activities Net increase (decrease) in cash and cash equivalents before effect of exchange rate changes Effect of exchange rate changes on cash and cash equivalents Net increase (decrease) in cash and cash equivalents Cash and cash equivalents at beginning of year Cash and cash equivalents at end of year Supplemental disclosures of cash flow information: Supplemental disclosures of cash flow information: [Abstract] Cash paid during the year for: Cash paid during the year for: [Abstract] Interest Income taxes Statement of Stockholders' Equity [Abstract] Equity Component [Domain] Balance Balance Balance (in Shares) Balance (in Shares) Contribution of stock to 401(k) plan Contribution of stock to 401(k) plan (in Shares) Stock-based compensation expense Stock-based compensation expense (in Shares) Tax benefit from stock option exercise Exercise of stock options and stock appreciation rights - net of Exercise of stock options and stock appreciation rights - net of (in Shares) Cash dividend $0.20 per share Change in unrealized gains and losses on marketable securities, net of taxes Cash dividend, per share Supplemental Cash Flow Elements [Abstract] Cash Flow, Supplemental Disclosures [Text Block] Accounting Policies [Abstract] Significant Accounting Policies [Text Block] Earnings Per Share [Abstract] Earnings Per Share [Text Block] Contractors [Abstract] Long-term Contracts or Programs Disclosure [Text Block] Inventory Disclosure [Abstract] Inventory Disclosure [Text Block] Property, Plant and Equipment [Abstract] Property, Plant and Equipment Disclosure [Text Block] Investments, Debt and Equity Securities [Abstract] Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Debt Disclosure [Abstract] Debt Disclosure [Text Block] Payables and Accruals [Abstract] Accounts Payable and Accrued Liabilities Disclosure [Text Block] Product Warranties Disclosures [Abstract] Product Warranty Disclosure [Text Block] Investment Holdings [Abstract] Investment Holdings [Abstract] Investment Holdings [Text Block] Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Disclosure [Text Block] Disclosure Text Block Supplement [Abstract] Compensation and Employee Benefit Plans [Text Block] Income Tax Disclosure [Abstract] Income Tax Disclosure [Text Block] Segment Reporting [Abstract] Segment Reporting Disclosure [Text Block] Equity [Abstract] Other Comprehensive Income, Noncontrolling Interest [Text Block] Consolidation, Policy [Policy Text Block] Cash and Cash Equivalents, Policy [Policy Text Block] Marketable Securities, Policy [Policy Text Block] Receivables, Trade and Other Accounts Receivable, Allowance for Doubtful Accounts, Policy [Policy Text Block] Inventory, Policy [Policy Text Block] Property, Plant and Equipment, Policy [Policy Text Block] Depreciation, Depletion, and Amortization [Policy Text Block] Intangible Assets, Finite-Lived, Policy [Policy Text Block] Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block] Revenue Recognition, Policy [Policy Text Block] Comprehensive Income, Policy [Policy Text Block] Research and Development Expense, Policy [Policy Text Block] Income Tax, Policy [Policy Text Block] Earnings Per Share, Policy [Policy Text Block] Fair Value of Financial Instruments, Policy [Policy Text Block] Foreign Currency Transactions and Translations Policy [Policy Text Block] Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block] Concentration Risk, Credit Risk, Policy [Policy Text Block] New Accounting Pronouncements, Policy [Policy Text Block] Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Cost and Estimated Earnings on Uncompleted Contracts