Income Taxes - Components of Deferred Tax Assets and Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Schedule of Components of Deferred Tax Provision [Line Items]
Book expenses capitalized for tax	6,336	$ 7,204
Post-retirement benefits	23,335	18,027
Inventory reserves	3,147	5,550
Vacation allowances	932	1,036
Net operating losses and tax credit carryforwards	7,479	6,711
Post employment benefits	2,382	757
Foreign tax credit carryforwards	11,231	2,227
Stock options	10,157msa_DeferredTaxAssetsStockOptions	10,185msa_DeferredTaxAssetsStockOptions
Liability insurance	3,918msa_DeferredTaxAssetsLiabilityInsurance	3,686msa_DeferredTaxAssetsLiabilityInsurance
Basis of capital assets	1,009	891
Warranties	3,210	3,049
Reserve for doubtful accounts	1,948	1,569
Accrued payroll	4,319	2,475
Other	5,801us-gaap_DeferredTaxAssetsOther	6,838us-gaap_DeferredTaxAssetsOther
Total deferred tax assets	85,204us-gaap_DeferredTaxAssetsGross	70,205us-gaap_DeferredTaxAssetsGross
Valuation allowances	(3,763)	(4,938)
Net deferred tax assets	81,441us-gaap_DeferredTaxAssetsNet	65,267us-gaap_DeferredTaxAssetsNet
Property, plant and equipment	(9,269)	(8,935)
Pension	(22,195)msa_DeferredTaxLiabilitiesPension	(40,833)msa_DeferredTaxLiabilitiesPension
Intangibles	(30,180)	(25,212)
Other	(2,045)us-gaap_DeferredTaxLiabilitiesOther	(2,455)us-gaap_DeferredTaxLiabilitiesOther
Total deferred tax liabilities	(63,689)us-gaap_DeferredTaxLiabilities	(77,435)us-gaap_DeferredTaxLiabilities
Net deferred taxes	17,752us-gaap_DeferredTaxAssetsLiabilitiesNet	$ (12,168)us-gaap_DeferredTaxAssetsLiabilitiesNet
Foreign
Schedule of Components of Deferred Tax Provision [Line Items]
Foreign tax credit carryforwards, expiration date	2019

Deferred tax assets basis of capital assets.

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Deferred tax assets liability insurance.

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Deferred tax assets stock options

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Deferred Tax Liabilities, Pension

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Tax Credit Carryforward, Expiration Year

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Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards, net of deferred tax liability attributable to taxable temporary differences.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from compensated absences (includes, but not limited to, sick and personal days).

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The tax effect as of the balance sheet date of the amount of the estimated future tax deductions arising from employee benefit costs not otherwise specified in the taxonomy, which can only be deducted for tax purposes when actual costs are incurred, and which can only be realized if sufficient tax-basis income is generated in future periods to enable the deduction to be taken.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from employee compensation.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from postretirement benefits.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from the allowance for doubtful accounts.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from other reserves not separately disclosed.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from warranty reserves.

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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

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Amount of deferred tax liability attributable to taxable temporary differences net of deferred tax asset attributable to deductible temporary differences and carryforwards after valuation allowances.

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Amount of deferred tax liability attributable to taxable temporary differences from intangible assets including goodwill.

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Amount of deferred tax liability attributable to taxable temporary differences not separately disclosed.

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Amount of deferred tax liability attributable to taxable temporary differences from property, plant, and equipment.

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