Segment Information - Schedule of Reportable Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Revenues	$ 351,014	$ 331,096	$ 1,026,726	$ 996,320
Operating income	59,614	40,003	146,252	131,235
Restructuring charges	1,850	2,615	11,203	10,223
Currency exchange gains (losses), net	(913)	(252)	17,338	2,571
Product liability expense	1,730	14,627	8,155	25,469
Strategic transaction costs	952	56	2,937	208
Adjusted operating income (loss)	63,233	57,049	185,885	169,706
Depreciation and amortization	9,547	9,378	28,339	28,585
Adjusted EBITDA	72,780	66,427	214,224	198,291
Americas
Segment Reporting Information [Line Items]
Revenues	234,624	209,343	679,699	633,812
Restructuring charges				2,000
Corporate
Segment Reporting Information [Line Items]
Restructuring charges			500	4,700
Reportable Segments \| Americas
Segment Reporting Information [Line Items]
Revenues	234,624	209,343	679,699	633,812
Adjusted operating income (loss)	$ 58,971	$ 51,532	$ 171,463	$ 151,456
Adjusted operating margin, percentage	25.10%	24.60%	25.20%	23.90%
Adjusted EBITDA	$ 65,342	$ 57,573	$ 190,084	$ 169,691
Adjusted EBITDA, percentage	27.80%	27.50%	28.00%	26.80%
Reportable Segments \| International
Segment Reporting Information [Line Items]
Revenues	$ 116,390	$ 121,753	$ 347,027	$ 362,508
Adjusted operating income (loss)	$ 13,776	$ 13,329	$ 39,888	$ 41,960
Adjusted operating margin, percentage	11.80%	10.90%	11.50%	11.60%
Adjusted EBITDA	$ 16,854	$ 16,559	$ 49,313	$ 52,001
Adjusted EBITDA, percentage	14.50%	13.60%	14.20%	14.30%
Reportable Segments \| Corporate
Segment Reporting Information [Line Items]
Revenues	$ 0	$ 0	$ 0	$ 0
Adjusted operating income (loss)	(9,514)	(7,812)	(25,466)	(23,710)
Adjusted EBITDA	(9,416)	(7,705)	(25,173)	(23,401)
Reconciling Items
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Adjusted operating income (loss)	0	0	0	0
Adjusted EBITDA	0	0	0
Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenues	(177,911)	(116,729)	(642,731)	(354,265)
Intersegment Eliminations \| Americas
Segment Reporting Information [Line Items]
Revenues	104,151	33,877	412,188	104,520
Intersegment Eliminations \| International
Segment Reporting Information [Line Items]
Revenues	73,760	82,852	230,543	249,745
Intersegment Eliminations \| Corporate
Segment Reporting Information [Line Items]
Revenues	$ 0	$ 0	$ 0	$ 0

Adjusted EBITDA

No definition available.

Name:	msa_AdjustedEBITDA
Namespace Prefix:	msa_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Adjusted EBITDA, Percentage

+ References

No definition available.

+ Details

Name:	msa_AdjustedEBITDAPercentage
Namespace Prefix:	msa_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Adjusted Operating Margin Percent

+ References

No definition available.

+ Details

Name:	msa_AdjustedOperatingMarginPercent
Namespace Prefix:	msa_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Operating Income (Loss), Adjusted

+ References

No definition available.

+ Details

Name:	msa_OperatingIncomeLossAdjusted
Namespace Prefix:	msa_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Product Liability Expense

+ References

No definition available.

+ Details

Name:	msa_ProductLiabilityExpense
Namespace Prefix:	msa_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Strategic Transaction and Corporate Development Costs

+ References

No definition available.

+ Details

Name:	msa_StrategicTransactionCosts
Namespace Prefix:	msa_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

+ Details

Name:	us-gaap_DepreciationDepletionAndAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount before tax of foreign currency transaction realized and unrealized gain (loss) recognized in the income statement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6450222&loc=d3e30840-110895

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 20
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109240200&loc=d3e30700-110894

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=109240200&loc=d3e30690-110894

+ Details

Name:	us-gaap_ForeignCurrencyTransactionGainLossBeforeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The net result for the period of deducting operating expenses from operating revenues.

+ References

No definition available.

+ Details

Name:	us-gaap_OperatingIncomeLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 5.P.3)
-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140864-122747

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 5.P.4(b))
-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747

+ Details

Name:	us-gaap_RestructuringCharges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045

+ Details

Name:	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_SegmentReportingInformationLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=srt_AmericasMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=us-gaap_CorporateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidationItemsAxis=us-gaap_OperatingSegmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=msa_InternationalSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidationItemsAxis=us-gaap_MaterialReconcilingItemsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidationItemsAxis=us-gaap_IntersegmentEliminationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: