Assets Held for Sale and Discontinued Operations [Abstract] Assets Held for Sale and Discontinued Operations [Abstract] Net sales Disposal Group, Including Discontinued Operation, Revenue Other income (loss), net Disposal Group, Including Discontinued Operation, Other Income Cost of products sold Disposal Group, Including Discontinued Operation, Costs of Goods Sold Selling, general and administrative Disposal Group, Including Discontinued Operation, General and Administrative Expense Interest expense Disposal Group, Including Discontinued Operation, Interest Expense Currency exchange losses, net Disposal Group, Including Discontinued Operation, Foreign Currency Translation Gains (Losses) Income from discontinued operations before income taxes Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax Provision for income taxes Discontinued Operation, Tax Effect of Income (Loss) from Discontinued Operation During Phase-out Period Income from discontinued operations, net of tax Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Statement of Cash Flows [Abstract] Statement [Table] Statement [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Statement [Line Items] Statement [Line Items] Operating Activities Net Cash Provided by (Used in) Operating Activities [Abstract] Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Depreciation and amortization Depreciation, Depletion and Amortization Pensions Pension Expense, Including Discontinued Operations Pension Expense, Including Discontinued Operations Net gain from investing activities-disposal of assets Gain (Loss) on Disposition of Other Assets Stock-based compensation Share-based Compensation Deferred income tax (benefit) provision Deferred Income Tax Expense (Benefit), Including Discontinued Operations Deferred Income Tax Expense (Benefit), Including Discontinued Operations Other noncurrent assets and liabilities Increase (Decrease) in Other Operating Assets and Liabilities, Net Currency exchange losses, net Foreign Currency Transaction Gain (Loss), Including Discontinued Operations, before Tax Foreign Currency Transaction Gain (Loss), Including Discontinued Operations, before Tax Excess tax benefit related to stock plans Excess Tax Benefit from Share-based Compensation, Operating Activities Other, net Other Noncash Income (Expense) Operating cash flow before changes in certain working capital items Net Cash Provided By Used In Operating Activities Before Changes In Operating Capital Net cash provided by (used in) operating activities before changes in operating capital (Increase) in trade receivables Increase (Decrease) in Accounts Receivable (Increase) decrease in inventories Increase (Decrease) in Inventories Increase in accounts payable and accrued liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Decrease in income taxes receivable, prepaid expenses and other current assets Increase (Decrease) in Other Operating Assets Decrease (increase) in certain working capital items Increase (Decrease) in Operating Capital Cash Flow From Operating Activities Net Cash Provided by (Used in) Operating Activities Investing Activities Net Cash Provided by (Used in) Investing Activities [Abstract] Capital expenditures Payments to Acquire Property, Plant, and Equipment Property disposals and other investing Payments for (Proceeds from) Other Investing Activities Cash Flow From Investing Activities Net Cash Provided by (Used in) Investing Activities Financing Activities Net Cash Provided by (Used in) Financing Activities [Abstract] (Payments on) proceeds from short-term debt, net Proceeds from (Repayments of) Short-term Debt Proceeds from long-term debt Proceeds from Issuance of Long-term Debt Payments on long-term debt Repayments of Long-term Debt Restricted cash Increase (Decrease) in Restricted Cash Cash dividends paid Payments of Dividends Distributions to noncontrolling interests Payments of Ordinary Dividends, Noncontrolling Interest Company stock purchases Payments for Repurchase of Equity Exercise of stock options Proceeds from Stock Options Exercised Excess tax benefit related to stock plans Excess Tax Benefit from Share-based Compensation, Financing Activities Cash Flow From Financing Activities Net Cash Provided by (Used in) Financing Activities Effect of exchange rate changes on cash and cash equivalents Effect of Exchange Rate on Cash and Cash Equivalents Increase (decrease) in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Beginning cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Ending cash and cash equivalents Commitments and Contingencies Disclosure [Abstract] Contingencies Commitments and Contingencies Disclosure [Text Block] Restructuring and Related Activities [Abstract] Schedule of Restructuring and Related Costs [Table] Schedule of Restructuring and Related Costs [Table] Segments [Axis] Segments [Axis] Segments [Domain] North America North America [Member] Europe Europe [Member] International International [Member] International. Restructuring Cost and Reserve [Line Items] Restructuring Cost and Reserve [Line Items] Restructuring and other charges, net of tax Restructuring And Other Charges Net Of Tax Restructuring and other charges, net of tax. Severance costs Severance Costs Restructuring Reserve [Roll Forward] Restructuring Reserve [Roll Forward] Restructuring Reserve, beginning balance Restructuring Reserve Cash payments Payments for Restructuring Restructuring charges Restructuring Charges Restructuring Reserve, ending balance Restructuring and Other Charges Restructuring and Related Activities Disclosure [Text Block] Property, Plant and Equipment [Abstract] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Land Land [Member] Building Building [Member] Machinery and Equipment Machinery and Equipment [Member] Construction in Progress Construction in Progress [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 Net property Property, Plant and Equipment, Net Property, Plant and Equipment Property, Plant and Equipment [Table Text Block] Equity [Abstract] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Parent [Member] Parent [Member] Noncontrolling Interest [Member] Noncontrolling Interest [Member] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Balance at beginning of period Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax Amortization of prior service cost Other Comprehensive (Income) Loss, Amortization Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Prior Service Cost (Credit), before Tax Recognized net actuarial losses Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), before Tax Tax benefit Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Tax Reclassification from AOCI, current period, net of tax Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Net of Tax Balance at end of period Beginning balance Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax Foreign currency translation adjustments, parent Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent Foreign currency translation adjustments, noncontrolling interest Other Comprehensive (Income) Loss, Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Noncontrolling Interest Ending balance Accumulated Other Comprehensive Income (Loss), Net of Tax Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] Restricted Stock Restricted Stock [Member] Range Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Stock options expiration period Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period Stock options exercisable period after grant date Stock Options Exercisable Years Stock options exercisable, years. Vest period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Percentage of target award based on achieving specified performance targets Percentage Of Target Award Based On Achieving Targeted Return On Net Assets Based On Which Final Number Of Shares To Be Issued For Performance Stock Units Percentage of target award based on achieving a targeted return on net assets based on which final number of shares to be issued for performance stock units. Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Financial Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Region Reporting Information, by Region Region Reporting Information By Region [Axis] Disclosure of profit or loss, total assets for each reportable region, and a description of the types of products and services for each reportable region. Reporting Region [Domain] Reporting Region [Domain] A regional component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements. Reconciling Items Reconciling Items [Member] Reconciling Items. Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Sales to external customers Revenue, Net Intercompany sales Intercompany Sales Intercompany sales. Net income: Income Amounts Attributable to Parent, Disclosures [Abstract] Continuing operations Income (Loss) from Continuing Operations Attributable to Parent Discontinued operations Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Earnings Per Share [Abstract] Earnings per Share Earnings Per Share [Text Block] Reclassifications Out of Accumulated Other Comprehensive Loss Disclosure of Reclassification Amount [Text Block] Cash and cash equivalents Disposal Group, Including Discontinued Operation, Cash and Cash Equivalents Trade receivables, less allowance for doubtful accounts Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net Inventories Disposal Group, Including Discontinued Operation, Inventory Net property Disposal Group, Including Discontinued Operation, Property, Plant, and Equipment, Net Other assets Disposal Group, Including Discontinued Operation, Other Assets Total assets Assets of Disposal Group, Including Discontinued Operation Accounts payable Disposal Group, Including Discontinued Operation, Accounts Payable Accrued and other liabilities Disposal Group, Including Discontinued Operation, Accrued Liabilities Total liabilities Liabilities of Disposal Group, Including Discontinued Operation Net assets Disposal Group, Including Discontinued Operation, Assets and Liabilities of Disposal Group, Net Disposal Group, Including Discontinued Operation, Assets and Liabilities of Disposal Group, Net Loss Contingency, Quantities [Roll Forward] Loss Contingency, Quantities [Roll Forward] Loss Contingency, Quantities [Roll Forward] Open claims, beginning of period Loss Contingency, Pending Claims, Number New claims Loss Contingency, New Claims Filed, Number Settled and dismissed claims Loss Contingency, Claims Settled and Dismissed, Number Open claims, end of period Inventory Disclosure [Abstract] Schedule of Inventories Schedule of Inventory, Current [Table Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Basis of Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Balance Sheet Location and Fair Value of Assets and Liabilities Associated with Derivative Financial Instruments Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Income Statement Location and Impact of Derivative Financial Instruments Derivative Instruments, Gain (Loss) [Table Text Block] Schedule Of Share Based Compensation Arrangements By Share Based Payment Award Plan Name Schedule Of Share Based Compensation Arrangements By Share Based Payment Award Plan Name [Axis] Schedule Of Share Based Compensation Arrangements By Share Based Payment Award Plan Name [Axis] Schedule Of Share Based Compensation Arrangements By Share Based Payment Award Plan Name [Domain] Schedule Of Share Based Compensation Arrangements By Share Based Payment Award Plan Name [Domain] Schedule Of Share Based Compensation Arrangements By Share Based Payment Award Plan Name [Domain] Performance Stock Unit Activity Performance Stock Unit [Member] Performance Stock Unit [Member] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Unvested Shares, Beginning Balance Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Granted, Shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Performance adjustments, Shares Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Performance Adjustment In Period Share-based compensation arrangement by share-based payment award equity instruments other than options performance adjustment in period. Vested, Shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Unvested Shares, Ending Balance Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Unvested Weighted Average Grant Date Fair value, Beginning Balance Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Granted, Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Performance adjustments, Weighted Average Grant Date Fair Value Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Performance Adjustment In Period Weighted Average Grant Date Fair Value Share-based compensation arrangement by share-based payment award equity instruments other than options performance adjustment in period, weighted average grant date fair value. Vested, Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Unvested Weighted Average Grant Date Fair value, Ending Balance Income Statement [Abstract] Net sales Other income (loss), net Other Income Revenues, Total Revenues Costs and expenses Costs and Expenses [Abstract] Cost of products sold Cost of Goods Sold Selling, general and administrative Selling, General and Administrative Expense Research and development Research and Development Expense Interest expense Interest Expense Currency exchange losses, net Foreign Currency Transaction Gain (Loss), before Tax Costs and Expenses, Total Costs and Expenses Income from continuing operations before income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest Provision for income taxes Income Tax Expense (Benefit) Income from continuing operations Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest Income from discontinued operations Net income Net loss (income) attributable to noncontrolling interests Net Income (Loss) Attributable to Noncontrolling Interest Net income attributable to MSA Safety Incorporated Net Income (Loss) Attributable to Parent Amounts attributable to MSA Safety Incorporated common shareholders: Net Income (Loss) Attributable to Parent [Abstract] Income from continuing operations Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Earnings per share attributable to MSA Safety Incorporated common shareholders: Basic Earnings Per Share, Basic [Abstract] Income from continuing operations, basic (dollars per share) Income (Loss) from Continuing Operations, Per Basic Share Income from discontinued operations, basic (dollars per share) Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share Net Income,basic (dollars per share) Earnings Per Share, Basic Diluted Earnings Per Share, Diluted [Abstract] Income from continuing operations, diluted (dollars per share) Income (Loss) from Continuing Operations, Per Diluted Share Income from discontinued operations, diluted (dollars per share) Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share Net Income, diluted (dollars per share) Earnings Per Share, Diluted Stock compensation expense Income tax benefit Employee Service Share-based Compensation, Tax Benefit from Compensation Expense Stock compensation expense, net of income tax benefit Allocated Share-based Compensation Expense, Net of Tax Derivative Instruments, Gain (Loss) [Table] Derivative Instruments, Gain (Loss) [Table] Hedging Relationship Hedging Relationship [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Derivatives Not Designated As Hedging Instruments Not Designated as Hedging Instrument [Member] Defined Benefit Plan, Asset Categories Defined Benefit Plan, Asset Categories [Axis] Plan Asset Categories [Domain] Plan Asset Categories [Domain] Foreign exchange contract Foreign Exchange Contract [Member] Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Currency exchange losses, net Derivative, Gain (Loss) on Derivative, Net Finished products Inventory, Finished Goods, Net of Reserves Work in process Inventory, Work in Process, Net of Reserves Raw materials and supplies Inventory, Raw Materials, Net of Reserves Total inventories Inventory, Net Statement of Stockholders' Equity [Abstract] Retained Earnings Retained Earnings [Member] Accumulated Other Comprehensive (Loss) Accumulated Other Comprehensive Income (Loss) [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning balance Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Net income Foreign currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Pension and post-retirement plan adjustments, net of tax of $805 and $1,278 Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax (Income) loss attributable to noncontrolling interests Other Comprehensive Income Loss Attributable To Non Controlling Interests Other Comprehensive Income Loss Attributable To Non Controlling Interests Common dividends Stock Issued During Period, Value, Stock Dividend Preferred dividends Dividends, Preferred Stock, Stock Ending balance Statement of Comprehensive Income [Abstract] Foreign currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax Pension and post-retirement plan adjustments, net of tax of $805 and $1,278 Total other comprehensive income net of tax Other Comprehensive Income (Loss), Net of Tax Comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Comprehensive loss attributable to noncontrolling interests Comprehensive (Income) Loss, Net of Tax, Attributable to Noncontrolling Interest Comprehensive income attributable to MSA Safety Incorporated Comprehensive Income (Loss), Net of Tax, Attributable to Parent Stock Plans Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Restricted Stock Activity Restricted Stock Activity [Member] Restricted Stock Activity [Member] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Forfeited, Shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Forfeited, Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Property, Plant and Equipment Property, Plant and Equipment Disclosure [Text Block] Disclosure Capital Stock Additional Information [Abstract] Disclosure - Capital Stock - Additional Information [Abstract] Schedule of Capital Units [Table] Schedule of Capital Units [Table] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Board of Directors Board of Directors [Member] Board of Directors [Member] 4 1/2% Cumulative Preferred Nonvoting Stock Cumulative Preferred Stock [Member] Second Cumulative Preferred Voting Stock Second Cumulative Preferred Voting Stock [Member] Second Cumulative Preferred Voting Stock [Member] Capital Unit [Line Items] Capital Unit [Line Items] Preferred stock, shares authorized Preferred Stock, Shares Authorized Preferred stock, par value Preferred Stock, Par or Stated Value Per Share Percentage of cumulative preferred stock Percentage Of Cumulative Preferred Stock Percentage of cumulative preferred stock. Preferred stock, callable price per share Preferred Stock, Redemption Price Per Share Preferred stock, shares issued Preferred Stock, Shares Issued Treasury share, number of shares held Treasury Stock Preferred Shares Treasury stock preferred shares. Purchase of treasury shares Purchase Of Treasury Stock Purchase Of Treasury Stock Common Stock, Shares Authorized Common Stock, Shares Authorized Common stock, par value Common Stock, No Par Value Common stock, shares, outstanding Common Stock, Shares, Outstanding Common stock, shares, issued Common Stock Held In Trust Shares Total number of common stock shares held in trust. Common stock, value, issued Common Stock, Value, Issued Treasury stock, shares Treasury Stock, Shares Schedule of Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Goodwill and Intangible Assets Disclosure [Abstract] Finite-Lived Intangible Assets, Net [Abstract] Finite-Lived Intangible Assets, Net [Abstract] Net balance at January 1 Finite-Lived Intangible Assets, Net Amortization expense Amortization of Intangible Assets Currency translation Finite-Lived Intangible Assets, Translation Adjustments Net balance at March 31 Schedule of Reportable Segment Information Schedule of Segment Reporting Information, by Segment [Table Text Block] Compensation and Retirement Disclosure [Abstract] Pensions and Other Postretirement Benefits Pension and Other Postretirement Benefits Disclosure [Text Block] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Foreign exchange contracts: Prepaid expenses and other current assets Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value Movement in Loss Contingency Receivable, Increase (Decrease) [Roll Forward] Movement in Loss Contingency Receivable, Increase (Decrease) [Roll Forward] Balance beginning of period Insurance Settlements Receivable Additions Loss Contingency, Receivable, Additions Collections and settlements Loss Contingency, Receivable, Receipts Balance end of period Fair Value Disclosures [Abstract] Carrying amount of fixed rate long-term debt Long-term Debt, Gross Fair value of long-term debt Long-term Debt, Fair Value Debt Disclosure [Abstract] Long-Term Debt Debt Disclosure [Text Block] Schedule of Stock Compensation Expense Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan [Table Text Block] Schedule of Valuation Assumptions Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Summary of Stock Option Activity Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block] Summary of Restricted Stock Activity Schedule of Share-based Compensation, Restricted Stock Units Award Activity [Table Text Block] Summary of Performance Stock Unit Activity Schedule of Nonvested Performance-based Units Activity [Table Text Block] Outstanding Beginning balance,Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Granted, Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures Exercised, Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Forfeited, Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Outstanding Ending balance,Shares Exercisable Ending balance,Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Outstanding Beginning balance, Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Granted, Weighted Average Exercise Price Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Exercised, Weighted Average Exercise Price Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Forfeited, Weighted Average Exercise Price Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Outstanding Ending balance,Weighted Average Exercise Price Exercisable Ending balance, Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Fair value per option Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Risk-free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Expected 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 Expected life (years) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Inventories Inventory Disclosure [Text Block] Pension and post-retirement plan adjustments, tax Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Tax Loss Contingencies [Table] Loss Contingencies [Table] Loss Contingency Nature Loss Contingency Nature [Axis] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Single Incident Single Incident [Member] Single Incident [Member] Uninsured Cumulative Trauma Uninsured Cumulative Trauma [Member] Uninsured cumulative trauma. Cumulative Trauma Cumulative Trauma [Member] Cumulative Trauma [Member] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Reserves for product liability claims Loss Contingency Product Liability Claim Reserve Loss contingency product liability claim reserve. Number of lawsuits Number of insurance carriers Minimum Number Of Insurance Carriers Minimum number of insurance carriers. Insurance receivables Insurance receivables, current Insurance Settlements Receivable, Current Insurance receivables, noncurrent Insurance Settlements Receivable, Noncurrent Product liability expense Product Liability Accrual, Period Expense Summary of Cumulative Trauma Product Liability Claims Activity Product Liability Contingencies [Table Text Block] Summary of Insurance Receivable Balances and Activity Related to Cumulative Trauma Product Liability Losses Summary Of Insurance Receivable Balances And Activity Related To Product Liability Losses Table [Text Block] Summary of insurance receivable balances and activity related to product liability losses. Statement of Financial Position [Abstract] Preferred Stock, 4 1/2% Cumulative Preferred Stock [Member] Trade receivables, allowance for doubtful accounts Allowance for Doubtful Accounts Receivable, Current Assets Assets [Abstract] Current assets Assets, Current [Abstract] Cash and cash equivalents Trade receivables, less allowance for doubtful accounts of $7,162 and $7,306 Accounts Receivable, Net, Current Inventories Deferred tax assets Deferred Tax Assets, Net of Valuation Allowance, Current Prepaid income taxes Income Taxes Receivable, Current Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Total current assets Assets, Current Property, plant and equipment Prepaid pension cost Defined Benefit Plan, Assets for Plan Benefits, Noncurrent Deferred tax assets Deferred Tax Assets, Net of Valuation Allowance, Noncurrent Goodwill Goodwill Intangible assets Other noncurrent assets Other Assets, Noncurrent Total assets Assets Liabilities Liabilities [Abstract] Current liabilities Liabilities, Current [Abstract] Notes payable and current portion of long-term debt Debt, Current Accounts payable Accounts Payable, Current Employees’ compensation Employee-related Liabilities, Current Insurance and product liability Self Insurance Reserve, Current Taxes on income Accrued Income Taxes, Current Other current liabilities Other Liabilities, Current Total current liabilities Liabilities, Current Long-term debt Long-term Debt, Excluding Current Maturities Pensions and other employee benefits Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent Deferred tax liabilities Deferred Tax Liabilities, Net, Noncurrent Other noncurrent liabilities Other Liabilities, Noncurrent Total liabilities Liabilities Commitments and contingencies Commitments and Contingencies Shareholders' Equity Stockholders' Equity Attributable to Parent [Abstract] Mine Safety Appliances Company shareholders' equity: Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Preferred stock, 4 1/2% cumulative, $50 par value Preferred Stock, Value, Outstanding Common stock, no par value Common Stock, Value, Outstanding Stock compensation trust Common Stock Held in Trust Treasury shares, at cost Treasury Stock, Value Accumulated other comprehensive loss Retained earnings Retained Earnings (Accumulated Deficit) Total MSA Safety Incorporated shareholders' equity Stockholders' Equity Attributable to Parent Noncontrolling interests Stockholders' Equity Attributable to Noncontrolling Interest Total shareholders’ equity Total liabilities and shareholders’ equity Liabilities and Equity Goodwill [Roll Forward] Goodwill [Roll Forward] Balance at January 1 Currency translation Goodwill, Translation Adjustments Balance at March 31 Number of geographic operating segments Number of Operating Segments Number of reportable segments Number of Reportable Segments Capital Stock Stockholders' Equity Note Disclosure [Text Block] Assets Held for Sale Assets Held For Sale [Text Block] Assets held for sale. Income Tax Disclosure [Abstract] Effective income tax rate Effective Income Tax Rate Reconciliation, Percent U.S. federal income tax rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Unrecognized tax benefits Unrecognized Tax Benefits Recognized tax benefits Recognized Tax Benefits Recognized tax benefits. Accrued interest and penalties related to uncertain tax positions Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued Changes in Goodwill Schedule of Goodwill [Table Text Block] Changes in Intangible Assets, Net of Accumulated Amortization Schedule of Finite-Lived Intangible Assets [Table Text Block] Reclassification of Pension and Post-Retirement Benefit Plan Out of Accumulated Other Comprehensive Loss Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Goodwill and Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Recently Adopted and Recently Issued Accounting Standards Recently Adopted And Recently Issued Accounting Standards [Text Block] Recently Adopted And Recently Issued Accounting Standards. Restructuring and Related Costs Restructuring and Related Costs [Table Text Block] Class of Stock Disclosures [Abstract] Net income attributable to continuing operations Preferred stock dividends Dividends, Preferred Stock, Stock, Continuing Operations Dividends, Preferred Stock, Stock, Continuing Operations Income from continuing operations available to common equity Net Income (Loss) Available to Common Stockholders, Basic, Continuing Operations Net Income (Loss) Available to Common Stockholders, Basic, Continuing Operations Dividends and undistributed earnings allocated to participating securities Undistributed Earnings Allocated to Participating Securities, Continuing Operations Undistributed Earnings Allocated to Participating Securities, Continuing Operations Income from continuing operations available to common shareholders Net Income (Loss) Available to Common Stockholders, Diluted, Continuing Operations Net Income (Loss) Available to Common Stockholders, Diluted, Continuing Operations Net income attributable to discontinued operations Preferred stock dividends Dividends, Preferred Stock, Stock, Discontinued Operations Dividends, Preferred Stock, Stock, Discontinued Operations Income from discontinued operations available to common equity Net Income (Loss) Available to Common Stockholders, Basic, Discontinued Operations Net Income (Loss) Available to Common Stockholders, Basic, Discontinued Operations Dividends and undistributed earnings allocated to participating securities Undistributed Earnings Allocated to Participating Securities, Discontinued Operations Undistributed Earnings Allocated to Participating Securities, Discontinued Operations Income from discontinued operations available to common shareholders Net Income (Loss) Available to Common Stockholders, Diluted, Discontinued Operations Net Income (Loss) Available to Common Stockholders, Diluted, Discontinued Operations Basic weighted-average shares outstanding Weighted Average Number of Shares Outstanding, Basic Stock options and other stock compensation Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Diluted weighted-average shares outstanding Weighted Average Number of Shares Outstanding, Diluted Antidilutive stock options Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Earnings per share attributable to continuing operations: Earnings Per Share, Continuing Operations [Abstract] Earnings Per Share, Continuing Operations [Abstract] Earnings per share attributable to discontinued operations: Earnings Per Share, Discontinued Operations [Abstract] Earnings Per Share, Discontinued Operations [Abstract] Components of Net Periodic Benefit Cost Schedule of Net Benefit Costs [Table Text Block] Derivative [Table] Derivative [Table] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Derivative [Line Items] Derivative [Line Items] Notional amount of open forward contracts Derivative, Notional Amount Unrealized gain (loss) on contract Unrealized Gain (Loss) on Derivatives Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Defined Benefit Plans and Other Postretirement Benefit Plans Defined Benefit Plans and Other Postretirement Benefit Plans [Axis] Defined Benefit Plan and Other Postretirement Benefit Plan [Domain] Defined Benefit Plan and Other Postretirement Benefit Plan [Domain] Pension Benefits Pension Plan, Defined Benefit [Member] Other Benefits Other Postretirement Benefit Plan, Defined Benefit [Member] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Service cost Defined Benefit Plan, Service Cost Interest cost Defined Benefit Plan, Interest Cost Expected return on plan assets Defined Benefit Plan, Expected Return on Plan Assets Amortization of prior service cost Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Recognized net actuarial losses Defined Benefit Plan, Actuarial Gain (Loss) Settlement / Curtailment loss Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments Net periodic benefit cost Defined Benefit Plan, Net Periodic Benefit Cost Document And Entity Information [Abstract] Document And Entity Information [Abstract] Entities [Table] Entities [Table] Document Information [Line Items] Document Information [Line Items] Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Trading Symbol Trading Symbol Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key 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 Schedule of Acquired Finite-Lived Intangible Asset by Major Class [Table] Schedule of Acquired Finite-Lived Intangible Asset by Major Class [Table] Business Segments Segments [Domain] Acquired Finite-Lived Intangible Assets [Line Items] Acquired Finite-Lived Intangible Assets [Line Items] Schedule of Assets Held for Sale Disclosure of Long Lived Assets Held-for-sale [Table Text Block] Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures [Table Text Block] Loss from continuing operations Income (Loss) from Continuing Operations Attributable to Noncontrolling Interest (Income) from discontinued operations Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Noncontrolling Interest Net loss (income) Pension plans contributions Defined Benefit Plan, Contributions by Employer Total pension plans contributions for the period Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year Segment Information Segment Reporting Disclosure [Text Block] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Senior Notes Senior Notes [Member] Restricted Cash and Cash Equivalents [Axis] Restricted Cash and Cash Equivalents [Axis] Cash and Cash Equivalents [Domain] Cash and Cash Equivalents [Domain] Unspecified Arrangement Unspecified Arrangement [Member] Unspecified Arrangement [Member] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Revolving Credit Facility Revolving Credit Facility [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Industrial Development Debt Payable Through 2022, 0.30% Industrial Development Debt Payable Through Two Thousand Twenty Two To Zero Point Three Zero Percentage [Member] Industrial Development Debt Payable Through Two Thousand Twenty Two To Zero Point Three Zero Percentage [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Unsecured senior revolving credit facility Line of Credit Facility, Maximum Borrowing Capacity Increase in the senior credit facility Increase In Senior Credit Facility Increase In The Senior Credit Facility Line of credit facility, remaining borrowing capacity Line of Credit Facility, Remaining Borrowing Capacity Debt instrument, potential face amount Debt Instrument, Potential Face Amount Debt Instrument, Potential Face Amount Letters of credit and bank guarantees outstanding, amount Letters of Credit and Bank Guarantees Outstanding, Amount Letters of Credit and Bank Guarantees Outstanding, Amount Line of credit facility, amount outstanding Line of Credit Facility, Amount Outstanding Restricted cash and cash equivalents Restricted Cash and Cash Equivalents Voluntary retirement payments guaranteed Voluntary Retirement Payments Guaranteed Voluntary Retirement Payments Guaranteed Extinguishment of debt, amount Extinguishment of Debt, Amount Income Taxes Income Tax Disclosure [Text Block] Inventory Inventories, Property Held-for-sale, Current Property, net of depreciation Assets Held-for-sale, Property, Plant and Equipment Total assets Assets Held-for-sale, at Carrying Value Fair Value Measurements Fair Value, Measurement Inputs, Disclosure [Text Block]