Compensation and Retirement Disclosure [Abstract] Employee Benefit Plans Pension and Other Postretirement Benefits Disclosure [Text Block] Statement of Cash Flows [Abstract] Operating Activities Net Cash Provided by (Used in) Operating Activities [Abstract] Net earnings Net Income (Loss) Attributable to Parent Adjustments to reconcile net earnings to net cash provided by (used in) operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Net earnings from discontinued operations Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Depreciation and amortization Depreciation, Depletion and Amortization Stock-based compensation Share-based Compensation Deferred income taxes Deferred Income Tax Expense (Benefit) Excess tax benefits from stock-based compensation Excess Tax Benefit (Tax Deficiency) from Share-based Compensation, Operating Activities Gain on disposal of assets Gain (Loss) on Sale of Property Plant Equipment Other, net Other Noncash Income (Expense) Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Receivables Increase (Decrease) in Receivables Inventories Increase (Decrease) in Inventories Accounts payable and accrued expenses Increase (Decrease) in Accounts Payable and Accrued Liabilities Billings in excess of costs and earnings on uncompleted contracts Increase (Decrease) in Billing in Excess of Cost of Earnings Refundable and accrued income taxes Increase (Decrease) in Income Taxes Payable, Net of Income Taxes Receivable Other, net Increase (Decrease) in Other Operating Assets and Liabilities, Net Net cash provided by (used in) continuing operating activities Net Cash Provided by (Used in) Operating Activities, Continuing Operations Investing Activities Net Cash Provided by (Used in) Investing Activities [Abstract] Capital expenditures Payments to Acquire Property, Plant, and Equipment Proceeds from sales of property, plant and equipment Proceeds from Sale of Property, Plant, and Equipment Acquisition of intangibles Payments to Acquire Intangible Assets Purchases of restricted investments Payments to Acquire Restricted Investments Sales/maturities of restricted investments Proceeds from Sale of Restricted Investments Purchases of marketable securities Payments to Acquire Available-for-sale Securities, Debt Sales/maturities of marketable securities Proceeds from Sale of Available-for-sale Securities, Debt Investments in corporate-owned life insurance policies Payments to Acquire Life Insurance Policies Net cash (used in) provided by investing activities Net Cash Provided by (Used in) Investing Activities Financing Activities Net Cash Provided by (Used in) Financing Activities [Abstract] Proceeds from issuance of debt Proceeds from Issuance of Long-term Debt Payments on debt Repayments of Long-term Debt Payments on debt issue costs Payments of Debt Issuance Costs Shares withheld for taxes, net of stock issued to employees Shares Withheld For Taxes Net Of Stock Issued To Employees The cash outflow paid by the company to cover an employee's income tax withholding obligation as part of a net-share settlement of a share-based award, net of the total cash inflow associated with the amount received from holders to acquire the entity's shares under incentive and share awards, including stock option exercises. Excess tax benefits from stock-based compensation Excess Tax Benefit (Tax Deficiency) from Share-based Compensation, Financing Activities Repurchase and retirement of common stock Payments for Repurchase of Common Stock Dividends paid Payments of Ordinary Dividends, Common Stock Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities Cash Flows of Discontinued Operations Net Cash Provided by (Used in) Discontinued Operations [Abstract] Net cash used in operating activities Cash Provided by (Used in) Operating Activities, Discontinued Operations Net cash used in discontinued operations Net Cash Provided by (Used in) Discontinued Operations (Decrease) increase in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Effect of exchange rates on cash Effect of Exchange Rate on Cash and Cash Equivalents Cash and cash equivalents at beginning of year Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents at end of period Noncash Activity Noncash Investing and Financing Items [Abstract] Capital expenditures in accounts payable Capital Expenditures Incurred but Not yet Paid Dividends in accounts payable Dividends Payable Marketable Securities [Abstract] Statement [Table] Statement [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Prism Assurance Ltd [Member] Subsidiaries [Member] Statement [Line Items] Statement [Line Items] Marketable Securities (Textual) [Abstract] Marketable Securities (Textual) [Abstract] Marketable securities. Investments, Total Marketable Securities Short-term marketable securities available for sale Available-for-sale Securities, Debt Securities, Current Available-for-sale Securities, Debt Securities, Noncurrent Available-for-sale Securities, Debt Securities, Noncurrent Available-for-sale Securities, Gross Realized Gains Available-for-sale Securities, Gross Realized Gains Commitments and Contingencies Disclosure [Abstract] Future minimum rental payments under noncancelable operating leases Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] Total minimum payments, Remainder of Fiscal 2013 Operating Leases, Future Minimum Payments Due, Next Twelve Months Total minimum payments, Fiscal 2014 Operating Leases, Future Minimum Payments, Due in Two Years Total minimum payments, Fiscal 2015 Operating Leases, Future Minimum Payments, Due in Three Years Total minimum payments, Fiscal 2016 Operating Leases, Future Minimum Payments, Due in Four Years Total minimum payments, Fiscal 2017 Operating Leases, Future Minimum Payments, Due in Five Years Total minimum payments, Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Total Operating Leases, Future Minimum Payments Due Inventory Disclosure [Abstract] Inventories Inventory Disclosure [Text Block] Discontinued Operations and Disposal Groups [Abstract] Discontinued Operations Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Future minimum rental payments under noncancelable operating leases Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Guarantees and warranties Schedule of Product Warranty Liability [Table Text Block] Document and Entity Information [Abstract] Abstract for 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 Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Accounting Changes and Error Corrections [Abstract] New Accounting Standards New Accounting Pronouncements and Changes in Accounting Principles [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Basis of Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Goodwill and Intangible Assets Disclosure [Abstract] Schedule of goodwill attributable to each business segment Schedule of Goodwill [Table Text Block] Schedule of finite lived intangible assets Schedule of Finite-Lived Intangible Assets [Table Text Block] Schedule of estimated future amortization expense for identifiable intangible assets Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Schedule Of Goodwill [Table] Schedule of Goodwill [Table] Statement Business Segments [Axis] Business Segments [Axis] Segment [Domain] Segment [Domain] Architectural [Member] Architectural [Member] Architectural. Large-Scale Optical [Member] Large Scale Optical [Member] Large scale optical. Goodwill [Line Items] Goodwill [Line Items] Schedule of goodwill attributable to each business segment Goodwill [Roll Forward] Goodwill, Beginning Goodwill Foreign currency translation Goodwill, Translation Adjustments Goodwill, Ending Fair Value Disclosures [Abstract] Fair Value Measurements Fair Value Disclosures [Text Block] Components of inventories Inventory, Net, Items Net of Reserve Alternative [Abstract] Raw materials Inventory, Raw Materials, Net of Reserves Work-in-process Inventory, Work in Process, Net of Reserves Finished goods Inventory, Finished Goods, Net of Reserves Costs and earnings in excess of billings on uncompleted contracts Costs in Excess of Billings on Uncompleted Contracts or Programs Expected to be Collected within One Year Total inventories Inventory, Net Amortized cost, gross unrealized gains and losses, and estimated fair values of investments available for sale Schedule of Available-for-sale Securities Reconciliation [Table Text Block] Schedule of length of time that available-for-sale securities were in continuous unrealized loss positions Schedule of Unrealized Loss on Investments [Table Text Block] Schedule of amortized cost and estimated fair values of investments by contractual maturity Investments Classified by Contractual Maturity Date [Table Text Block] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Share based payment stock options valuation assumptions Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Award transactions on stock options Schedule of Share-based Compensation, Stock Options and Stock Appreciation Rights Award Activity [Table Text Block] Nonvested share award transactions Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block] Statement of Financial Position [Abstract] Assets Assets [Abstract] Current assets Assets, Current [Abstract] Cash and cash equivalents Restricted short-term investments Restricted Cash and Cash Equivalents, Current Receivables, net of allowance for doubtful accounts Accounts Receivable, Net, Current Inventories Refundable income taxes Income Taxes Receivable, Current Deferred tax assets Deferred Tax Assets, Net of Valuation Allowance, Current Other current assets Prepaid Expense and Other Assets, Current Total current assets Assets, Current Property, plant and equipment, net Property, Plant and Equipment, Net Marketable securities available for sale Restricted investments Restricted Cash and Cash Equivalents, Noncurrent Goodwill Intangible assets Intangible Assets, Net (Excluding Goodwill) Other assets Other Assets, Noncurrent Total assets Assets Liabilities and Shareholders' Equity Liabilities and Equity [Abstract] Current liabilities Liabilities, Current [Abstract] Accounts payable Accounts Payable, Current Accrued payroll and related benefits Employee-related Liabilities, Current Accrued self-insurance reserves Self Insurance Reserve, Current Other accrued expenses Other Liabilities, Current Current liabilities of discontinued operations Liabilities of Disposal Group, Including Discontinued Operation, Current Billings in excess of costs and earnings on uncompleted contracts Billings in Excess of Cost Current portion long-term debt Long-term Debt, Current Maturities Accrued income taxes Accrued Income Taxes, Current Total current liabilities Liabilities, Current Long-term debt Long-term Debt, Excluding Current Maturities Unrecognized tax benefits Liability for Uncertain Tax Positions, Noncurrent Long-term self-insurance reserves Self Insurance Reserve, Noncurrent Deferred tax liabilities Deferred Tax Liabilities, Net, Noncurrent Other long-term liabilities Other Liabilities, Noncurrent Liabilities of discontinued operations Liabilities of Disposal Group, Including Discontinued Operation, Noncurrent Commitments and contingent liabilities (Note 13) Commitments and Contingencies Shareholders' equity Stockholders' Equity Attributable to Parent [Abstract] Common stock of $0.33-1/3 par value; authorized 50,000,000 shares; issued and outstanding 28,437,410 and 28,062,049, respectively Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital Retained earnings Retained Earnings (Accumulated Deficit) Common stock held in trust Common Stock Issued, Employee Stock Trust Deferred compensation obligations Deferred Compensation Equity Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total shareholders’ equity Stockholders' Equity Attributable to Parent Total liabilities and shareholders' equity Liabilities and Equity Goodwill and Other Identifiable Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Stock option grant valuation assumptions Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract] Dividend yield Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Expected volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Risk-free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Expected Lives Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Income Tax Disclosure [Abstract] Income Taxes Income Tax Disclosure [Text Block] Segment Reporting [Abstract] Segment Information Segment Reporting Disclosure [Text Block] Components of net periodic benefit cost Schedule of Net Benefit Costs [Table Text Block] Components of inventories Schedule of Inventory, Current [Table Text Block] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Intersegment eliminations [Member] Intersegment Elimination [Member] Corporate and other [Member] Corporate and Other [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Number of Reportable Segments Number of Reportable Segments Sales and operating income data Segment Reporting Information, Profit (Loss) [Abstract] Net sales Revenue, Net Operating income (loss) Operating Income (Loss) Summary balance sheets of discontinued businesses Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures [Table Text Block] Sales and operating income data Schedule of Segment Reporting Information, by Segment [Table Text Block] Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Table] Major Types Of Debt And Equity Securities [Axis] Major Types of Debt and Equity Securities [Axis] Major Types Of Debt And Equity Securities [Domain] Major Types of Debt and Equity Securities [Domain] Municipal bonds [Member] Municipal Bonds [Member] Schedule of Available-for-sale Securities [Line Items] Schedule of Available-for-sale Securities [Line Items] Amortized cost, gross unrealized gains and losses, and estimated fair values of investments available for sale Available-for-sale Securities [Abstract] Amortized Cost Available-for-sale Debt Securities, Amortized Cost Basis Gross Unrealized Gains Available-for-sale Securities, Gross Unrealized Gains Gross Unrealized Losses Available-for-sale Securities, Gross Unrealized Losses Estimated Market Value, Total Available-for-sale Securities, Debt Securities Earnings Per Share [Abstract] Earnings Per Share Earnings Per Share [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] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] 2009 Stock Incentive Plan [Member] Two Thousand and Nine Stock Incentive Plan [Member] Two thousand and nine stock incentive plan. 2009 Non-Employee Director Stock Incentive Plan [Member] Two Thousand and Nine Non Employee Director Stock Incentive Plan [Member] Two thousand and nine non employee director stock incentive plan. 2002 Omnibus Stock Incentive Plan [Member] Two Thousand and Two Omnibus Stock Incentive Plan [Member] Two thousand and two omnibus stock incentive plan. 1997 Omnibus Stock Incentive Plan [Member] One Thousand Nine Hundred and Ninety Seven Omnibus Stock Incentive Plan [Member] One thousand nine hundred and ninety seven omnibus stock incentive plan. Award Type [Axis] Award Type [Axis] Award Type [Domain] Award Type [Domain] Stock Options [Member] Stock Options [Member] Stock Appreciation Rights (SARs) [Member] Stock Appreciation Rights (SARs) [Member] Employee Stock Option [Member] Employee Stock Option [Member] Restricted Stock [Member] Restricted Stock [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-Based Compensation Arrangement By Share Based Payment Award Number Of Shares Authorized Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Share-based Compensation Arrangement by Share-based Payment Award, Term Stock option and SARs term Stock option and SARs term Share-based Compensation Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Weighted average fair value per option Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Total unrecognized compensation related to stock options awards Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Stock Options Cash proceeds from exercise of stock options Employee Service Share-based Compensation, Cash Received from Exercise of Stock Options Aggregate intrinsic value of securities Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value Performance Shares cancelled Performance Shares cancelled Performance Shares cancelled/forfeited due to not meeting target level metrics. Number of performance share units granted Performance Shares Previously Granted Performance Shares Previously Granted under performance period. Number of performance share units granted and outstanding Number of Shares Granted and Outstanding Under Incentive Plan Number of shares granted and outstanding under incentive plan. Total unrecognized compensation cost related to nonvested share Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Share-based Awards Other than Options Weighted average period, Nonvested Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition Total fair value of shares vested Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Total Fair Value Performance period for cash based plan Performance period for cash based plan Performance period for cash based plan Payment period for cash based plan Payment period for cash based plan Payment period for cash based plan Long-term Purchase Commitment [Table] Long-term Purchase Commitment [Table] Category of Item Purchased [Axis] Category of Item Purchased [Axis] Long-term Purchase Commitment, Category of Item Purchased [Domain] Long-term Purchase Commitment, Category of Item Purchased [Domain] Long-term Purchase Commitment [Line Items] Long-term Purchase Commitment [Line Items] Company's backlog bonded by performance bonds Companies Backlog Related to Sales Companies backlog related to sales. Face value of performance bonds Debt Instrument, Face Amount Total value of letter of credit Letters of Credit Outstanding, Amount Line of Credit Facility, Maximum Borrowing Capacity Line of Credit Facility, Maximum Borrowing Capacity Letter of credits issued under credit facility Letters of credit outstanding under credit facility Letters of credit outstanding under credit facility Purchase obligations Purchase Obligation Other Commitment Other Commitment Debt Disclosure [Abstract] Debt Debt Disclosure [Text Block] Schedule of amortized cost and estimated fair values of investments by contractual maturity Amortized Cost and Estimated Fair Values of Investments [Abstract] Amortized cost and estimated fair values of investments. Amortized Cost, Due within one year Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis Amortized Cost, Due after one year through five years Available-for-sale Securities, Debt Maturities, Year Two Through Five, Amortized Cost Basis Amortized Cost, Due after five years through 10 years Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Amortized Cost Basis Amortized Cost, Due after 10 years through 15 years Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized Cost Basis Amortized Cost, Due beyond 15 years Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized Cost Basis Amortized Cost, Total Available-for-sale Securities, Debt Maturities, Amortized Cost Basis Estimated Market Value, Due within one year Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value Estimated Market Value, Due after one year through five years Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value Estimated Market Value, Due after five years through 10 years Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value Estimated Market Value, Due after 10 years through 15 years Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value Estimated Market Value, Due beyond 15 years Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value Schedule of estimated future amortization expense for identifiable intangible assets Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract] Estimated amortization expense, Remainder of Fiscal 2013 Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year Estimated amortization expense, Fiscal 2014 Finite-Lived Intangible Assets, Amortization Expense, Year Two Estimated amortization expense, Fiscal 2015 Finite-Lived Intangible Assets, Amortization Expense, Year Three Estimated amortization expense, Fiscal 2016 Finite-Lived Intangible Assets, Amortization Expense, Year Four Estimated amortization expense, Fiscal 2017 Finite-Lived Intangible Assets, Amortization Expense, Year Five Restricted Cash and Cash Equivalents, Noncurrent Mutual fund investments Mutual Fund Investments Fair Value Disclosure Mutual fund investments fair value disclosure. Financial assets and liabilities measured at fair value Fair Value Measurements, Recurring and Nonrecurring [Table Text Block] Guarantees and warranties Movement in Extended Product Warranty Accrual [Roll Forward] Balance at beginning of period Extended Product Warranty Accrual Additional accruals Extended Product Warranty Accrual, Warranties Issued Claims paid Extended Product Warranty Accrual, Payments Balance at end of period Award transactions on stock options Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Outstanding, Beginning Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Outstanding shares awards exercised Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Outstanding shares awards canceled Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Outstanding, Ending Outstanding shares vested or expected to vest Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number Outstanding shares exercisable Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Weighted average exercise price, Beginning Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Weighted average exercise price, Awards exercised Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Weighted average exercise price, Awards canceled Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Weighted average exercise price, Ending Weighted average exercise price, Vested or expected to vest Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price Weighted average exercise price, Exercisable Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Weighted average remaining contractual life, Outstanding Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Weighted average remaining contractual life, Vested of expected to vest Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term Weighted average remaining contractual life, Exercisable Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Aggregate intrinsic value, Outstanding Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Aggregate intrinsic value, Vested or expected to vest Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value Aggregate intrinsic value, Exercisable Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value Statement of Other Comprehensive Income [Abstract] Net earnings Other comprehensive earnings: Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Unrealized (loss) gain on marketable securities, net of $0, $0, $5 and $(4) tax expense (benefit), respectively Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax Foreign currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax, Portion Attributable to Parent Other comprehensive loss Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Total comprehensive earnings (loss) Comprehensive Income (Loss), Net of Tax, Attributable to Parent Tax expense (benefit) on marketable securities Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax Goodwill and Other Identifiable Intangible Assets (Textual) [Abstract] Goodwill and Other Identifiable Intangible Assets (Textual) [Abstract] Goodwill and other identifiable intangible assets. Amortization expense on identifiable intangible assets Amortization of Intangible Assets Deferred compensation liability Deferred Compensation Liability, Current and Noncurrent Investments in corporate-owned life insurance policies Life Insurance, Corporate or Bank Owned, Amount Mutual Fund Investments Mutual Fund Investments Mutual fund investments. Commitments and Contingent Liabilities Commitments and Contingencies Disclosure [Text Block] Nonvested share award transactions Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Number of shares, Granted Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Number of shares, Vested Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Number of shares, Canceled Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Nonvested Number, Ending Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Weighted average grant date fair value, Granted Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Weighted average grant date fair value, Vested Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Weighted average grant date fair value, Canceled Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Weighted average grant date fair value, Ending Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Stock-Based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value, Measurements, Fair Value Hierarchy [Domain] Quoted Prices in Active Markets (Level 1) [Member] Fair Value, Inputs, Level 1 [Member] Other Observable Inputs (Level 2) [Member] Fair Value, Inputs, Level 2 [Member] Unobservable Inputs (Level 3) [Member] Fair Value, Inputs, Level 3 [Member] Eligible Item or Group for Fair Value Option [Axis] Eligible Item or Group for Fair Value Option [Axis] Fair Value, Option, Eligible Item or Group [Domain] Fair Value, Option, Eligible Item or Group [Domain] Money market funds [Member] Money Market Funds [Member] Mutual funds [Member] Equity Funds [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] Financial assets and liabilities measured at fair value Fair Value, Assets Measured on Recurring and Nonrecurring Basis, Alternative [Abstract] Cash equivalents Cash and Cash Equivalents [Abstract] Total cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Short-term marketable securities available for sale [Abstract] Short-term marketable securities available for sale [Abstract] Short-term marketable securities available for sale [Abstract] Available for Sale Securities, current, fair value disclosure Available for Sale Securities, current, fair value disclosure Available for Sale Securities, current, fair value disclosure Marketable securities available for sale Total marketable securities available for sale Available-for-sale Securities, Fair Value Disclosure Restricted investments Restricted Investments Note [Abstract] Total restricted investments Restricted Investments, at Fair Value Mutual fund investments Investments, All Other Investments [Abstract] Total mutual fund investments Trading Securities, Fair Value Disclosure Total assets at fair value Assets, Fair Value Disclosure Line of Credit Facility [Table] Line of Credit Facility [Table] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Letter of Credit [Member] Letter of Credit [Member] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Recovery Zone Facility Bonds [Member] Recovery Zone Facility Bonds [Member] Recovery zone facility bonds. Industrial Development Bonds [Member] Industrial Development Bonds [Member] Industrial development bonds. Maximum [Member] Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Debt (Textual) [Abstract] Debt (Textual) [Abstract] Debt. Line of Credit Facility Maximum Capacity under Previous Facility Line of Credit Facility Maximum Capacity under Previous Facility Line of Credit Facility Maximum Capacity under Previous Facility Line of Credit Facility, Expiration Date Line of Credit Facility, Expiration Date Line of Credit Facility, Amount Outstanding Line of Credit Facility, Amount Outstanding Adjusted Debt to Ebitda Ratio under Previous Facility Adjusted Debt to Ebitda Ratio under Previous Facility Adjusted Debt to Ebitda Ratio under Previous Facility Minimum net worth required Minimum Net Worth Required for Compliance Net Worth Minimum Net Capital Required for Entity Adjusted debt-to-EBITDA ratio Adjusted Debt to Ebitda Ratio Adjusted debt to ebitda ratio. Decrease in non-credit facility debt Decrease In Non Credit Facility Debt Decrease in non credit facility debt Excess of non credit facility debt on unrestricted cash balances, cash equivalents and short-term marketable securities available for sale Excess of Non Credit Facility Debt on Unrestricted Cash Balances Cash Equivalents and Short Term Marketable Securities Available for Sale Excess of non credit facility debt on unrestricted cash balances, cash equivalents and short-term marketable securities available for sale Debt Instrument Issued Debt Instrument Issued Debt instrument issued Cash disbursements from restricted investments Cash disbursements from restricted investments Cash disbursements from restricted investments Debt Long-term Debt Interest payments Interest Paid Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Liability for Uncertain Tax Positions, Noncurrent UnrecognizedTaxBenefitsReductionsResultingFromSettlementsWithTaxingAuthoritiesAndLapseOfApplicableStatuteOfLimitations UnrecognizedTaxBenefitsReductionsResultingFromSettlementsWithTaxingAuthoritiesAndLapseOfApplicableStatuteOfLimitations UnrecognizedTaxBenefitsReductionsResultingFromSettlementsWithTaxingAuthoritiesAndLapseOfApplicableStatuteOfLimitations Schedule of length of time that available-for-sale securities were in continuous unrealized loss positions Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract] Less Than 12 Months, Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value Less Than 12 Months, Unrealized Losses Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses Greater Than or Equal to 12 Months, Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value Greater Than or Equal to 12 Months, Unrealized Losses Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses Total Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value Total Unrealized Losses Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses Components of net periodic benefit cost Defined Benefit Plan, Net Periodic Benefit Cost [Abstract] Interest cost Defined Benefit Plan, Interest Cost Expected return on assets Defined Benefit Plan, Expected Return on Plan Assets Amortization of unrecognized net loss Defined Benefit Plan, Amortization of Gains (Losses) Net periodic benefit cost Defined Benefit Plan, Net Periodic Benefit Cost Pre-tax income from discontinued operations Discontinued Operation, Amount of Other Income (Loss) from Disposition of Discontinued Operations, before Income Tax Resolving period of warranty issues Discontinued Operations And Warranty Expected Period In Recognition Discontinued operations and warranty expected period in recognition. Schedule Of Finite Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Finite Lived Intangible Assets By Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite Lived Intangible Assets Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Debt issue costs [Member] Debt Issue Costs [Member] Debt issue costs Noncompete Agreements [Member] Noncompete Agreements [Member] Customer Relationships [Member] Customer Relationships [Member] Purchased intellectual property [Member] Purchased Intellectual Property [Member] Purchased intellectual property. Finite Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Schedule of finite lived identifiable intangible assets Finite-Lived Intangible Assets, Net [Abstract] Gross Carrying Amount Finite-Lived Intangible Assets, Gross Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Foreign Currency Translation Finite Lived Identifiable Intangible Assets Translation Adjustments Finite lived identifiable intangible assets translation adjustments. Net Finite-Lived Intangible Assets, Net Income Statement [Abstract] Cost of sales Cost of Goods Sold Gross profit Gross Profit Selling, general and administrative expenses Selling, General and Administrative Expense Operating income Interest income Investment Income, Interest Interest expense Interest Expense Other income (expense), net Other Nonoperating Income (Expense) Earnings from continuing operations before income taxes Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest Income tax expense (benefit) Income Tax Expense (Benefit) Earnings from continuing operations Income (Loss) from Continuing Operations Attributable to Parent Earnings from discontinued operations, net of income taxes Net earnings Earnings per share - basic Earnings Per Share, Basic [Abstract] Earnings from continuing operations Income (Loss) from Continuing Operations, Per Basic Share Earnings from discontinued operations Income (Loss) from Discontinued Operations, Net of Tax, Per Basic Share Net earnings Earnings Per Share, Basic Earnings per share - diluted Earnings Per Share, Diluted [Abstract] Earnings from continuing operations Income (Loss) from Continuing Operations, Per Diluted Share Earnings from discontinued operations Income (Loss) from Discontinued Operations, Net of Tax, Per Diluted Share Net earnings Earnings Per Share, Diluted Weighted average basic shares outstanding Weighted Average Number of Shares Outstanding, Basic Weighted average diluted shares outstanding Weighted Average Number of Shares Outstanding, Diluted Cash dividends declared per common share Common Stock, Dividends, Per Share, Declared Marketable Securities Marketable Securities [Table Text Block] Reconciliation of basic and diluted earnings per share Earnings Per Share, Basic and Diluted [Abstract] Basic earnings per share - weighted common shares outstanding Incremental Common Shares Attributable to Share-based Payment Arrangements Incremental Common Shares Attributable to Share-based Payment Arrangements Weighted Average Number of Shares Outstanding, Diluted Earnings per share - basic Earnings per share - diluted Stock options excluded from the calculation of earnings per share because the exercise price was greater than the average market price of the common shares Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Summary balance sheets of discontinued businesses Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract] Accounts payable and accrued liabilities Long-term liabilities Reconciliation of basic and diluted earnings per share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Common stock, par value Common Stock, Par or Stated Value Per Share Common stock, shares authorized Common Stock, Shares Authorized Common stock, shares issued Common Stock, Shares, Issued Common stock, shares outstanding Common Stock, Shares, Outstanding