MSA Safety (MSA) 10-K 19 Feb 21 2020 FY Annual report Financial data

Cover

Cover - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2020	Feb. 12, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	1-15579
Entity Registrant Name	MSA SAFETY INC
Entity Incorporation, State or Country Code	PA
Entity Tax Identification Number	46-4914539
Entity Address, Address Line One	1000 Cranberry Woods Drive
Entity Address, City or Town	Cranberry Township,
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	16066-5207
City Area Code	724
Local Phone Number	776-8600
Title of 12(b) Security	Common Stock, no par value
Trading Symbol	MSA
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 4.1
Entity Common Stock, Shares Outstanding (in shares)		39,089,206
Documents Incorporated by Reference	Portions of the Proxy Statement for the May 19, 2021 Annual Meeting of Shareholders are incorporated by reference into Part III.
Entity Central Index Key	0000066570
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false

Other Income (Loss), Net

Other Income (Loss), Net	12 Months Ended
	Dec. 31, 2020
Other Income and Expenses [Abstract]
Other Income (Loss), Net	Other Income, Net (In thousands) 2020 2019 2018 Interest income $ 3,498 $ 4,411 $ 4,588 Components of net periodic benefit cost other than service cost (Note 14) 1,680 7,997 4,641 (Loss) Gain on asset dispositions, net (236) (371) 646 Other, net 742 (943) (644) Total other income, net $ 5,684 $ 11,094 $ 9,231

Quarterly Financial Information

Quarterly Financial Information (Unaudited)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information (Unaudited)	Quarterly Financial Information (Unaudited) 2020 Quarters (In thousands, except earnings per share) 1st 2nd 3rd 4th Year Net sales $ 341,145 $ 314,438 $ 304,392 $ 388,248 $ 1,348,223 Gross profit 157,359 141,585 132,232 159,272 590,448 Net income attributable to MSA Safety Incorporated 43,674 36,055 28,034 12,338 120,101 Earnings per share (1) Basic $ 1.12 $ 0.93 $ 0.72 $ 0.32 $ 3.09 Diluted 1.11 0.92 0.71 0.31 3.05 2019 Quarters (In thousands, except earnings per share) 1st 2nd 3rd 4th Year Net sales $ 326,038 $ 349,675 $ 351,014 $ 375,254 $ 1,401,981 Gross profit 149,982 161,084 158,701 166,845 636,612 Net income attributable to MSA Safety Incorporated 23,232 39,806 42,239 31,163 136,440 Earnings per share (1) Basic $ 0.60 $ 1.03 $ 1.09 $ 0.80 $ 3.52 Diluted 0.59 1.01 1.08 0.79 3.48

Other Income (Loss), Net (Table

Other Income (Loss), Net (Tables)	12 Months Ended
	Dec. 31, 2020
Other Income and Expenses [Abstract]
Schedule of Other Income (Loss), Net	(In thousands) 2020 2019 2018 Interest income $ 3,498 $ 4,411 $ 4,588 Components of net periodic benefit cost other than service cost (Note 14) 1,680 7,997 4,641 (Loss) Gain on asset dispositions, net (236) (371) 646 Other, net 742 (943) (644) Total other income, net $ 5,684 $ 11,094 $ 9,231

Quarterly Financial Informati_2

Quarterly Financial Information (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Schedule Of Quarterly Financial Information	2020 Quarters (In thousands, except earnings per share) 1st 2nd 3rd 4th Year Net sales $ 341,145 $ 314,438 $ 304,392 $ 388,248 $ 1,348,223 Gross profit 157,359 141,585 132,232 159,272 590,448 Net income attributable to MSA Safety Incorporated 43,674 36,055 28,034 12,338 120,101 Earnings per share (1) Basic $ 1.12 $ 0.93 $ 0.72 $ 0.32 $ 3.09 Diluted 1.11 0.92 0.71 0.31 3.05 2019 Quarters (In thousands, except earnings per share) 1st 2nd 3rd 4th Year Net sales $ 326,038 $ 349,675 $ 351,014 $ 375,254 $ 1,401,981 Gross profit 149,982 161,084 158,701 166,845 636,612 Net income attributable to MSA Safety Incorporated 23,232 39,806 42,239 31,163 136,440 Earnings per share (1) Basic $ 0.60 $ 1.03 $ 1.09 $ 0.80 $ 3.52 Diluted 0.59 1.01 1.08 0.79 3.48

Consolidated Statement of Incom

Consolidated Statement of Income - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Revenues	$ 1,348,223,000	$ 1,401,981,000	$ 1,358,104,000
Cost of Goods and Services Sold	757,775,000	765,369,000	746,241,000
Gross profit	590,448,000	636,612,000	611,863,000
Selling, general and administrative
Selling, general and administrative	290,334,000	330,502,000	324,784,000
Research and development	58,268,000	57,848,000	52,696,000
Restructuring charges (Note 2)	27,381,000	13,846,000	13,247,000
Currency exchange losses, net (Note 5)	8,578,000	19,814,000	2,330,000
Product liability (Note 19) and other operating expense	39,036,000	28,372,000	45,327,000
Operating income	166,851,000	186,230,000	173,479,000
Interest expense	9,432,000	13,589,000	18,881,000
Loss on extinguishment of debt (Note 11)	0	0	1,494,000
Other income, net (Note 15)	(5,684,000)	(11,094,000)	(9,231,000)
Total other expense, net	3,748,000	2,495,000	11,144,000
Income before income taxes	163,103,000	183,735,000	162,335,000
Provision for income taxes (Note 9)	41,941,000	46,086,000	37,220,000
Net income	121,162,000	137,649,000	125,115,000
Net income attributable to noncontrolling interests	(1,061,000)	(1,209,000)	(965,000)
Net income attributable to MSA Safety Incorporated	$ 120,101,000	$ 136,440,000	$ 124,150,000
Basic
Income from continuing operations	$ 3.09	$ 3.52	$ 3.23
Diluted
Income from continuing operations	$ 3.05	$ 3.48	$ 3.18
Dividends per common share (dollars per share)	$ 1.71	$ 1.64	$ 1.49

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 121,162	$ 137,649	$ 125,115
Foreign currency translation adjustments (Note 5)	22,260	(1,657)	(30,103)
Pension and post-retirement plan actuarial gains (losses), net of tax (Note 5)	9,296	(5,559)	(17,569)
Unrealized (losses) gains on available-for-sale securities (Note 5)	(7)	578	(572)
Reclassifications from accumulated other comprehensive (loss) into net income (Note 5)	216	15,261	774
Total other comprehensive income (loss), net of tax	31,765	8,623	(47,470)
Comprehensive income	152,927	146,272	77,645
Comprehensive income attributable to noncontrolling interests	(1,220)	(1,136)	(660)
Comprehensive income attributable to MSA Safety Incorporated	$ 151,707	$ 145,136	$ 76,985

Consolidated Balance Sheet

Consolidated Balance Sheet - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current Assets
Cash and cash equivalents	$ 160,672	$ 152,195
Trade receivables, less allowance for credit loss of $5,344 and $4,860	252,283	255,082
Inventories (Note 3)	197,819	185,027
Investments, short-term (Note 18)	74,982	49,892
Prepaid income taxes	26,185	13,072
Notes receivable, insurance companies (Note 19)	3,796	3,676
Prepaid expenses and other current assets	38,541	34,419
Total current assets	754,278	693,363
Property, plant and equipment, net (Note 4)	189,620	167,038
Operating lease assets, net (Note 16)	53,451	51,675
Prepaid pension cost (Note 14)	97,545	75,066
Deferred tax assets (Note 9)	35,665	32,596
Goodwill (Note 12)	443,272	436,679
Intangible assets, net (Note 12)	161,051	171,326
Notes receivable, insurance companies, noncurrent (Note 19)	48,540	52,336
Insurance receivable (Note 19) and other noncurrent assets	89,062	59,614
Total assets	1,872,484	1,739,693
Current Liabilities
Notes payable and current portion of long-term debt (Note 11)	20,000	20,000
Accounts payable	86,854	89,120
Employees’ compensation	40,277	41,882
Insurance and product liability (Note 19)	43,706	25,870
Income taxes payable (Note 9)	3,580	6,739
Accrued restructuring (Note 2) and other current liabilities	116,128	93,898
Total current liabilities	310,545	277,509
Long-term debt, net (Note 11)	287,157	328,394
Pensions and other employee benefits (Note 14)	208,068	186,697
Noncurrent operating lease liabilities (Note 16)	44,639	42,632
Deferred tax liabilities (Note 9)	10,916	9,787
Product liability (Note 19) and other noncurrent liabilities	201,268	162,101
Total liabilities	1,062,593	1,007,120
Commitments and contingencies (Note 19)
Mine Safety Appliances Company shareholders' equity:
Preferred stock, 4.5% cumulative, $50 par value (Note 6)	3,569	3,569
Common stock, no par value (180,000,000 shares authorized; 62,081,391 shares issued; 39,067,902 and 38,841,194 shares outstanding at December 31, 2020 and 2019, respectively)	242,693	229,127
Treasury shares, at cost (Note 6)	(327,756)	(305,159)
Accumulated other comprehensive loss (Note 5)	(182,397)	(214,003)
Retained earnings	1,065,789	1,012,266
Total MSA Safety Incorporated shareholders’ equity	801,898	725,800
Noncontrolling interests	7,993	6,773
Total shareholders’ equity	809,891	732,573
Total liabilities and shareholders’ equity	$ 1,872,484	$ 1,739,693

Consolidated Balance Sheet (Par

Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Allowance for credit loss	$ 5,344	$ 4,860
Cumulative preferred nonvoting stock (as a percent)	4.50%	4.50%
Preferred stock, par value (dollars per share)	$ 50,000	$ 50,000
Common stock, no par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized (in shares)	180,000,000	180,000,000
Common stock, shares issued (in shares)	62,081,391	62,081,391
Common stock, shares outstanding (in shares)	39,067,902	38,841,194

Consolidated Statement of Cash

Consolidated Statement of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Activities
Net income	$ 121,162	$ 137,649	$ 125,115
Depreciation and amortization	39,674	38,020	37,852
Stock-based compensation (Note 10)	6,920	13,760	12,239
Pension expense (Note 14) and other charges	10,082	3,382	5,901
Deferred income tax (benefit) provision (Note 9)	(3,322)	1,272	(4,065)
Losses on asset dispositions, net	236	371	484
Pension contributions (Note 14)	(5,596)	(5,537)	(4,718)
Currency exchange losses, net (Note 5)	8,578	19,814	2,330
Product liability expense (Note 19)	39,036	26,619	45,327
Collections on insurance receivable and notes receivable, insurance companies (Note 19)	10,853	21,035	101,552
Product liability payments (Note 19)	(23,727)	(54,504)	(61,500)
Loss on extinguishment of debt (Note 11)	0	0	1,494
Trade receivables	7,677	(8,855)	(10,075)
Inventories (Note 3)	(8,601)	(23,246)	(11,122)
Prepaid expenses and other current assets	(8,861)	(822)	10,866
Accounts payable and accrued liabilities	13,541	5,801	17,985
Other noncurrent assets and liabilities	(1,097)	(9,797)	(5,778)
Cash Flow From Operating Activities	206,555	164,962	263,887
Investing Activities
Capital expenditures	(48,905)	(36,604)	(33,960)
Purchase of short-term investments (Note 18)	(199,318)	(169,245)	(73,022)
Proceeds from maturities of short-term investments (Note 18)	175,000	174,670	18,000
Acquisition, net of cash acquired (Note 13)	0	(33,196)	0
Property disposals and other investing	454	218	4,587
Cash Flow Used In Investing Activities	(72,769)	(64,157)	(84,395)
Financing Activities
(Payments on) proceeds from short-term debt, net (Note 11)	0	(65)	51
Payments on long-term debt (Note 11)	(1,031,000)	(880,500)	(570,167)
Proceeds from long-term debt (Note 11)	987,000	864,000	462,500
Debt issuance costs	0	0	(1,216)
Cash dividends paid	(66,578)	(63,523)	(57,248)
Company stock purchases (Note 6)	(29,144)	(12,648)	(4,824)
Exercise of stock options (Note 6)	12,446	7,471	8,573
Employee stock purchase plan (Note 6)	747	641	556
Other, net	0	0	(1,494)
Cash Flow Used In Financing Activities	(126,529)	(84,624)	(163,269)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	1,234	(4,242)	(13,508)
Increase in cash, cash equivalents and restricted cash	8,491	11,939	2,715
Beginning cash, cash equivalents and restricted cash	152,543	140,604	137,889
Ending cash, cash equivalents and restricted cash	161,034	152,543	140,604
Supplemental cash flow information:
Total cash, cash equivalents and restricted cash	161,034	140,604	137,889
Interest paid in cash	9,856	14,490	20,408
Income tax paid in cash	$ 61,072	$ 48,673	$ 40,587

Consolidated Statement of Chang

Consolidated Statement of Changes in Retained Earnings and Accumulated Other Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	$ 732,573
Net income	121,162	$ 137,649	$ 125,115
Pension and post-retirement plan adjustments, net of tax	9,296	(5,559)	(17,569)
(Income) loss attributable to noncontrolling interests	(1,220)	(1,136)	(660)
Balance at end of period	809,891	732,573
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	1,012,266	935,577	868,675
Net income	121,162	137,649	125,115
(Income) loss attributable to noncontrolling interests	(1,061)	(1,209)	(965)
Common dividends	(66,537)	(63,481)	(57,206)
Preferred dividends	(41)	(42)	(42)
Balance at end of period	1,065,789	1,012,266	935,577
Retained Earnings | Cumulative effect, period of adoption, adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period		3,772
Balance at end of period			3,772
Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	(214,003)	(218,927)	(171,762)
Foreign currency translation adjustments	22,260	(1,657)	(30,103)
Pension and post-retirement plan adjustments, net of tax	9,296	(5,559)	(17,569)
Unrecognized net gains on available-for-sale securities (Note 18)	(7)	578	(572)
Reclassification of currency translation from accumulated other comprehensive (loss) into net income (Note 5)	216	15,261
(Income) loss attributable to noncontrolling interests	(159)	73	305
Balance at end of period	(182,397)	(214,003)	(218,927)
Accumulated Other Comprehensive Loss | Cumulative effect, period of adoption, adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period		(3,772)
Balance at end of period			(3,772)
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	6,773	5,637	4,977
(Income) loss attributable to noncontrolling interests	1,220	1,136	660
Balance at end of period	$ 7,993	$ 6,773	$ 5,637

Consolidated Statement of Cha_2

Consolidated Statement of Changes in Retained Earnings and Accumulated Other Comprehensive Loss (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Stockholders' Equity [Abstract]
Tax reclassification adjustment	$ 2,245	$ (3,072)	$ (6,325)
Preferred stock dividend (in USD per share)	$ 0.5625	$ 0.5625	$ 0.5625

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Basis of Presentation— The consolidated financial statements of MSA Safety Incorporated ("MSA" or "the Company") are prepared in conformity with accounting principles generally accepted in the United States of America (U.S. GAAP) and require management to make certain judgments, estimates, and assumptions. These may affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the consolidated financial statements. They also may affect the reported amounts of revenues and expenses during the period. Actual results could differ from those estimates upon subsequent resolution of identified matters. Principles of Consolidation— The consolidated financial statements include the accounts of the Company and all subsidiaries. Intercompany accounts and transactions are eliminated. Noncontrolling Interests— Noncontrolling interests reflect noncontrolling shareholders’ investments in certain consolidated subsidiaries and their proportionate share of the income and accumulated other comprehensive income (loss) of those subsidiaries. Currency Translation— The functional currency of all significant non-U.S. subsidiaries is the local country currency. Assets and liabilities of these operations are translated at year-end exchange rates. Income statement accounts are translated using the average exchange rates for the reporting period. Translation adjustments for these companies are reported as a component of shareholders’ equity and are not included in income. Foreign currency transaction gains and losses are included in net income for the reporting period. Cash Equivalents— Cash equivalents include temporary deposits with financial institutions and highly liquid investments with original maturities of 90 days or less. Other highly liquid investments consist of money market funds and balances were $0.6 million and $17.9 million at December 31, 2020 and 2019, respectively. These funds are valued at net asset value (“NAV”). The money market funds are required to price and transact at a NAV per share that fluctuates based upon the pricing of the underlying portfolio of securities and this requirement may impact the value of those fund shares. Restricted Cash— Restricted cash, which is designated for use other than current operations, is included in prepaid expenses and other current assets in the Consolidated Balance Sheets. Restricted cash balances were $0.4 million and $0.3 million at December 31, 2020 and 2019, respectively. These balances were used to support letter of credit balances. Inventories— Inventories are stated at the lower of cost or net realizable value. The majority of U.S. inventories are valued on the last-in, first-out (LIFO) cost method which is used since this method provides better matching of costs and revenues. Other inventories are valued at standard costs which approximate actual costs. It is the Company's general policy to write-down any inventory identified as obsolete. Additionally, it will write-down any inventory balance in excess of the last twenty-four months of consumption. Investment securities — The Company’s investment securities, primarily fixed income, are classified as available-for-sale. The securities are recorded at fair market value and reported in “Investments, short-term” in the accompanying Consolidated Balance Sheets with changes in fair market value recorded in other comprehensive income, net of tax. The purchases and sales of these investments are classified as investing activities in the Consolidated Statements of Cash Flows. Property and Depreciation— Property is recorded at cost. Depreciation is computed primarily using the straight-line method over the estimated useful lives of the assets, generally as follows: buildings 20 to 40 years and machinery and equipment 3 to 10 years. Expenditures for significant renewals and improvements are capitalized. Ordinary repairs and maintenance are expensed as incurred. Gains or losses on property dispositions are included in other income, net and the cost and related depreciation are removed from the accounts. Depreciation expense for the years ended December 31, 2020, 2019 and 2018 was $27.7 million, $26.5 million and $26.9 million, respectively. Properties, plants, and equipment are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets or asset groups may not be recoverable. Software Development Costs— Software development costs consist primarily of costs incurred in software development and related personnel compensation to create, enhance and deploy the Company’s broad range of wireless technology and cloud-based computing safety services. Software development costs, other than software development costs qualifying for capitalization, are expensed as incurred. Costs of computer software developed or obtained for internal use that are incurred in the preliminary project and post implementation stages are expensed as incurred. Certain costs incurred during the application and development stage, which primarily include compensation and related expenses, are capitalized. Additionally, costs of upgrades and enhancements are capitalized when it is probable that the upgrades and enhancements will result in added functionality. Capitalized costs are amortized through Cost of products sold using the straight-line method over the estimated useful life, which is normally three years, beginning in the period in which the software is ready for its intended use or when the upgrade or enhancement is deployed. During 2020, 2019, and 2018 there was approximately $8.2 million, $5.0 million and $1.6 million, respectively, of software development costs capitalized. Goodwill and Other Intangible Assets— Intangible assets with a finite useful life are amortized on a straight-line basis over their useful lives. Indefinite lived intangible assets are assessed for possible impairment annually on October 1st or whenever circumstances change such that the recorded value of the asset may not be recoverable. We performed a quantitative assessment of the indefinite lived trade name intangible asset as outlined in Accounting Standards Codification ("ASC") 350 by comparing the estimated fair value of the trade name intangible asset to its carrying value. We estimate the fair value using the relief from royalty income approach. A number of assumptions and estimates are involved in the application of the relief from royalty model, including sales volumes and prices, royalty rates and tax rates. Forecasts are based on sales generated by the underlying trade name assets and are generally based on approved business unit operating plans for the early years and historical relationships in later years. Based on these assessments, no impairments were identified during the years ended December 31, 2020, 2019 or 2018. Goodwill is not amortized, but is subject to impairment assessments. On October 1st of each year, or more frequently if indicators of impairment exist or if a decision is made to sell a business, we evaluate goodwill for impairment. Judgment is involved in determining if an indicator of impairment has occurred. Such indicators may include a decline in expected cash flows, a significant adverse change in the business climate, unanticipated competition, slower growth rates, or negative developments in equity and credit markets, among others. All goodwill is assigned to and evaluated for impairment at the reporting unit level, which is defined as an operating segment or one level below an operating segment. The evaluation of impairment involves using either a qualitative or quantitative approach as outlined in ASC Topic 350. In 2020, we performed a two-step quantitative test at October 1, 2020. Step 1 of the quantitative testing involves comparing the estimated fair value of each reporting unit to its carrying value. We estimate reporting unit fair value using a weighted average of fair values determined by discounted cash flow (DCF) and market approach methodologies, as we believe both are important indicators of fair value. A number of assumptions and estimates are involved in the application of the DCF model, including sales volumes and prices, costs to produce, tax rates, capital spending, discount rates, and working capital changes. Cash flow forecasts are generally based on approved reporting unit operating plans for the early years and historical relationships in later years. The market approach methodology measures value through an analysis of peer companies. The analysis entails measuring the multiples of EBITDA at which peer companies are trading. There has been no impairment of our goodwill during the years ended December 31, 2020, 2019 or 2018. Revenue Recognition— We account for revenue in accordance with ASC Topic 606, Revenue from Contracts with Customers , which we adopted on January 1, 2018, using the modified retrospective method. Revenue from the sale of products is recognized when there is persuasive evidence of an arrangement and control passes to the customer, which generally occurs either when product is shipped to the customer or, in the case of most U.S. distributor customers, when product is delivered to the distributor's delivery site. We establish our shipping terms according to local practice and market characteristics. We do not ship product unless we have an order or other documentation authorizing shipment to our customers. Our payment terms vary by the type and location of our customer and the products offered. The term between invoicing and when payment is due is not significant. Revenue is measured as the amount of consideration we expect to receive in exchange for transferring goods or providing services. Amounts billed and due from our customers are classified as receivables on the Consolidated Balance Sheets. We make appropriate provisions for credit losses which have historically been insignificant in relation to our net sales. Certain contracts with customers, primarily distributor customers, have an element of variable consideration that is estimated when revenue is recognized under the contract to the extent that it is material to the individual contract. Variable consideration includes volume incentive rebates, performance guarantees, price concessions and returns. Rebates are based on achieving a certain level of purchases and other performance criteria that are documented in established distributor programs. These rebates are estimated based on projected sales to the customer and accrued as a reduction of net sales as they are earned by the customer. The rebate accrual is reviewed monthly and adjustments are made as the estimate of projected sales changes. Product returns, including an adjustment for restocking fees if it is material, are estimated based on historical return experience and revenue is adjusted. Sales, value add and other taxes collected with revenue-producing activities and remitted to governmental authorities are excluded from revenue. Depending on the terms of the arrangement, we may defer revenue for which we have a future obligation, including training and extended warranty and technical services, until such time that the obligation has been satisfied. We use an observable price, or a cost plus margin approach when one is not available, to determine the stand-alone selling price for separate performance obligations. We have elected to recognize the cost for shipping and handling as an expense when control of the product has passed to the customer. These costs are included within the Cost of products sold line on the Consolidated Statements of Income. Amounts billed to customers for shipping and handling are included in net sales. Product Warranties— Estimated expenses related to product warranties and additional service actions are charged to Cost of products sold in the period in which the related revenue is recognized or when significant product quality issues are identified. Research and Development— Research and development costs are expensed as incurred. Income Taxes— Deferred income taxes are recognized for temporary differences between financial and tax reporting. Deferred tax assets and liabilities are measured using enacted tax rates in effect for the year in which those temporary differences are expected to be recovered or settled. If it is more likely than not that some portion or all of a deferred tax asset will not be realized, a valuation allowance is recognized. We record tax benefits related to uncertain tax positions taken or expected to be taken on a tax return when such benefits meet a more likely than not threshold. We recognize interest related to unrecognized tax benefits in interest expense and penalties in operating expenses. Deferred taxes are booked for available cash in excess of working capital for non-U.S. subsidiaries as these earnings are not considered to be permanently reinvested. Stock-Based Compensation— We recognize expense for employee and non-employee director stock-based compensation based on the grant date fair value of the awards. Except for retirement-eligible participants, for whom there is no requisite service period, this expense is recognized ratably over the requisite service periods following the date of grant. For retirement-eligible participants, this expense is recognized over an accelerated period of at least one year. Derivative Instruments— We may use derivative instruments to minimize the effects of changes in currency exchange rates. We do not enter into derivative transactions for speculative purposes and do not hold derivative instruments for trading purposes. Changes in the fair value of derivative instruments designated as fair value hedges are recorded in the balance sheet as adjustments to the underlying hedged asset or liability. Changes in the fair value of derivative instruments that do not qualify for hedge accounting treatment are recognized in the Consolidated Statements of Income and Consolidated Statements of Cash Flows as Currency exchange losses, net in the current period. Commitments and Contingencies— For asserted claims and assessments, liabilities are recorded when a loss is deemed to be probable and the amount of the loss is reasonably estimable. Management assesses the probability of an unfavorable outcome with respect to asserted claims or assessments based on many factors such as the nature of the matter, available defenses and case strategy, progress of the matter, views and opinions of legal counsel and other advisors, applicability and success of appeals processes, and the outcome of similar historical matters, among others. Once an unfavorable outcome is assessed to be probable, management evaluates estimates of the potential loss, and the most reasonable loss estimate is recorded (or, if the estimate of the loss is a range, and no amount within the range is considered to be a better estimate than any other amount, the minimum amount in the range is recorded). If a loss is deemed to be reasonably possible but less than probable and/or such loss cannot be reasonably estimated, then the matter is disclosed and no liability is recorded. With respect to unasserted claims or assessments, management first determines whether it is probable that a claim or assessment may be asserted and then, if so, the degree of probability of an unfavorable outcome. If an unfavorable outcome is probable, management assesses whether the amount of potential loss can be reasonably estimated and, if so, accrues the most reasonable estimate of the loss (or, if the estimate of the loss is a range, and not amount within the range is considered to be a better estimate than any other amount, the minimum amount in the range is recorded). If an unfavorable outcome is reasonably possible but less than probable, or the amount of loss cannot be reasonably estimated, then the matter is disclosed and no liability is recorded. Legal matters are reviewed on a continuous basis to determine if there has been a change in management’s judgment regarding the likelihood and/or estimate of a potential loss. Please refer to Note 19 for further details on product liability related matters. Concentration of credit and business risks - We are exposed to credit risk in the event of nonpayment by customers, principally in the oil, gas and petrochemical, fire service, construction, utilities, and mining industries. Changes in these industries or other developments may significantly affect our financial performance and management's estimates. We mitigate our exposure to credit risk by performing ongoing credit evaluations and, when deemed necessary, requiring letters of credit, credit insurance, prepayments, guarantees or other collateral. No individual customer represented more than 10% of our sales or receivables. Recently Adopted and Recently Issued Accounting Standards— In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses. This ASU introduces an approach based on expected losses to estimate credit losses on certain types of financial instruments, including loans, held-to-maturity debt securities, loan commitments, financial guarantees and net investments in leases, as well as reinsurance and trade receivables. This ASU was adopted on January 1, 2020, which did not have an impact on the consolidated financial statements. In January 2018, the FASB issued ASU 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income ("AOCI"), which gives entities the option to reclassify to retained earnings the tax effects resulting from the new tax reform legislation commonly known as the Tax Cuts and Jobs Act of 2017 (the "Act") related to items in AOCI that the FASB refers to as having been stranded in AOCI. The new guidance may be applied retrospectively to each period in which the effect of the Act is recognized in the period of adoption. ASU2018-02 requires new disclosures regarding the Company’s accounting policy for releasing the tax effects in accumulated other comprehensive loss and allows the Company to reclassify the effect of remeasuring deferred tax liabilities and assets related to items within accumulated other comprehensive loss using the then newly enacted 21% federal corporate income tax rate. The Company adopted ASU 2018-02 on January 1, 2019, and this adoption resulted in a reclassification that increased retained earnings by $3.8 million, with an offsetting increase to accumulated other comprehensive loss for the same amount. In August 2018, the FASB issued ASU 2018-13, Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement , which improves fair value disclosure requirements by removing disclosures that are not cost beneficial, clarifying disclosures’ specific requirements and adding relevant disclosure requirements. This ASU was effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019, and was adopted in 2020. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. The Company's adoption of ASU 2018-13 did not have an impact on the consolidated financial statements, but did change our disclosures. In August 2018, the FASB issued ASU 2018-14, Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans , which improves defined benefit disclosure requirements by removing disclosures that are not cost beneficial, clarifying disclosures’ specific requirements and adding relevant disclosure requirements. This ASU is effective for fiscal years ending after December 15, 2020, and early adoption is permitted. The amendments in this ASU are required to be applied on a retrospective basis to all periods presented. The Company adopted ASU 2018-14 on December 31, 2020, which did not have an impact on the consolidated financial statements, but did change our disclosures.

Restructuring and Other Charges

Restructuring and Other Charges	12 Months Ended
	Dec. 31, 2020
Restructuring and Related Activities [Abstract]
Restructuring and Other Charges	Restructuring Charges During the years ended December 31, 2020, 2019 and 2018, we recorded restructuring charges of $27.4 million, $13.8 million and $13.2 million, respectively. These charges were primarily related to our ongoing initiatives to drive profitable growth and right size our operations. Americas segment restructuring charges of $4.7 million during the year ended December 31, 2020, were primarily related to costs associated with our global Fixed Gas & Flame Detection manufacturing footprint optimization as well as programs to adjust our operations in response to current business conditions. International segment restructuring charges of $21.9 million during the year ended December 31, 2020, were primarily related to severance costs for staff reductions and footprint optimization associated with our ongoing initiatives to drive profitable growth. Corporate segment restructuring charges of $0.8 million during the year ended December 31, 2020, were primarily related to programs to adjust our operations in response to current business conditions. A total of 121 positions were eliminated in 2020. There were 42 positions eliminated in the Americas segment, 76 in the International segment and 3 in the Corporate segment. Americas segment restructuring charges of $0.5 million during the year ended December 31, 2019, were related to severance costs for staff reductions in our Latin America Region. International segment restructuring charges of $12.7 million during the year ended December 31, 2019, were primarily related to severance costs for staff reductions associated with our ongoing initiatives to drive profitable growth and a non-cash settlement charge for the termination of our pension plan in the United Kingdom. Corporate segment restructuring charges of $0.6 million during the year ended December 31, 2019, related primarily to the legal and operational realignment of our U.S. and Canadian operations. A total of 99 positions were eliminated in 2019. There were 12 positions eliminated in the Americas segment and 87 in the International segment. Americas segment restructuring charges of $2.3 million during the year ended December 31, 2018, were related to severance costs for staff reductions in our Northern North America and Latin America Regions. International segment restructuring charges of $5.6 million during the year ended December 31, 2018, were primarily related to severance costs for staff reductions associated with our ongoing initiatives to drive profitable growth in Europe. Corporate segment restructuring charges of $5.3 million during the year ended December 31, 2018, related primarily to the legal and operational realignment of our U.S. and Canadian operations. A total of 45 positions were eliminated in 2018. There were 8 positions were eliminated in the Americas segment, 34 in the International segment and 3 in the Corporate segment. Activity and reserve balances for restructuring charges by segment were as follows: (in millions) Americas International Corporate Total Reserve balances at January 1, 2018 $ 0.5 $ 3.6 $ — $ 4.1 Restructuring charges 2.3 5.6 5.3 13.2 Currency translation and other adjustments (0.3) (0.3) — (0.6) Cash payments (2.0) (4.9) (5.3) (12.2) Reserve balances at December 31, 2018 $ 0.5 $ 4.0 $ — $ 4.5 Restructuring charges 0.5 12.7 0.6 13.8 Currency translation and other adjustments (0.1) (0.6) — (0.7) Cash payments / utilization (0.6) (10.2) (0.6) (11.4) Reserve balances at December 31, 2019 $ 0.3 $ 5.9 $ — $ 6.2 Restructuring charges 4.7 21.9 0.8 27.4 Currency translation and other adjustments (0.1) 0.1 — — Cash payments / utilization (2.1) (8.6) (0.4) (11.1) Reserve balances at December 31, 2020 $ 2.8 $ 19.3 $ 0.4 $ 22.5

Inventories

Inventories	12 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Inventories	Inventories The following table sets forth the components of inventory: December 31, (In thousands) 2020 2019 Finished products $ 81,048 $ 71,918 Work in process 2,618 4,083 Raw materials and supplies 161,300 151,129 Inventories at current cost 244,966 227,130 Less: LIFO valuation (47,147) (42,103) Total inventories $ 197,819 $ 185,027 Inventories stated on the LIFO basis represent 48% and 43% of total inventories at December 31, 2020 and 2019, respectively. We did not have any LIFO liquidations during the years ended December 31, 2020 and 2019.

Property, Plant, and Equipment

Property, Plant, and Equipment	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property, Plant, and Equipment	Property, Plant, and Equipment The following table sets forth the components of property, plant and equipment: December 31, (In thousands) 2020 2019 Land $ 4,275 $ 4,194 Buildings 128,887 125,223 Machinery and equipment 422,333 397,287 Construction in progress 38,753 24,759 Total 594,249 551,463 Less accumulated depreciation (404,629) (384,425) Property, plant and equipment, net $ 189,620 $ 167,038

Reclassifications Out of Accumu

Reclassifications Out of Accumulated Other Comprehensive Loss	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Reclassifications Out of Accumulated Other Comprehensive Loss	Reclassifications Out of Accumulated Other Comprehensive Loss MSA Safety Incorporated Noncontrolling Interests (In thousands) 2020 2019 2018 2020 2019 2018 Pension and other post-retirement benefits (a) Balance at beginning of period $ (124,848) $ (115,517) $ (97,948) $ — $ — $ — Unrecognized net actuarial losses (6,322) (19,479) (37,977) — — — Tax benefit 1,997 5,847 9,936 — — — Total other comprehensive loss before reclassifications, net of tax (4,325) (13,632) (28,041) — — — Amounts reclassified from accumulated other comprehensive loss into net income: Amortization of prior service credit (Note 14) (216) (180) (424) — — — Recognized net actuarial losses (Note 14) 18,079 11,028 14,507 — — — Tax benefit (4,242) (2,775) (3,611) — — — Total amount reclassified from accumulated other comprehensive loss, net of tax, into net income 13,621 8,073 10,472 — — — Reclassification to retained earnings due to the adoption of ASU 2018-02 (Note 1) — (3,772) — — — — Total other comprehensive income (loss) $ 9,296 $ (9,331) $ (17,569) $ — $ — $ — Balance at end of period $ (115,552) $ (124,848) $ (115,517) $ — $ — $ — Available-for-sale securities Balance at beginning of period $ 6 $ (572) $ — $ — $ — $ — Unrealized (loss) gain on available-for-sale securities (Note 18) (7) 578 (572) — — — Balance at end of period $ (1) $ 6 $ (572) $ — $ — $ — Foreign currency translation Balance at beginning of period $ (89,161) $ (102,838) $ (73,814) $ 423 $ 496 $ 801 Reclassification from accumulated other comprehensive loss into net income 216 (c) 15,261 (b) 774 (c) — — — Foreign currency translation adjustments 22,101 (1,584) (29,798) 159 (73) (305) Balance at end of period $ (66,844) $ (89,161) $ (102,838) $ 582 $ 423 $ 496 (a) Reclassifications out of accumulated other comprehensive loss and into net income are included in the computation of net periodic pension and other post-retirement benefit costs (refer to Note 14—Pensions and Other Post-retirement Benefits). (b) Reclassifications out of accumulated other comprehensive loss and into net income relate primarily to the approval of our plan to close our South Africa affiliates and are included in Currency exchange losses, net, within the Consolidated Statements of Income.

Capital Stock

Capital Stock	12 Months Ended
	Dec. 31, 2020
Disclosure Capital Stock Additional Information [Abstract]
Capital Stock	Capital Stock Preferred Stock - The Company has authorized 100,000 shares of $50 par value 4.5% cumulative preferred nonvoting stock which is callable at $52.50. There are 71,340 shares issued at both December 31, 2020 and 2019 and 52,998 and 52,878 shares held in treasury at December 31, 2020 and 2019, respectively. The Treasury shares at cost line of the Consolidated Balance Sheet includes $1.8 million related to preferred stock. There were 120 shares of preferred stock purchased and subsequently held in treasury during the year ended December 31, 2020, and no treasury purchases of preferred stock during the year ended December 31, 2019. The Company has also authorized 1,000,000 shares of $10 par value second cumulative preferred voting stock. No shares have been issued as of December 31, 2020 or 2019. Common Stock - The Company has authorized 180,000,000 shares of no par value common stock. There were 62,081,391 shares issued as of both December 31, 2020 and December 31, 2019. There were 39,067,902 and 38,841,194 shares outstanding at December 31, 2020 and 2019, respectively. Treasury Shares - The Company's stock repurchase program authorizes up to $100.0 million to repurchase MSA common stock in the open market and in private transactions. The share repurchase program has no expiration date. The maximum number of shares that may be purchased is calculated based on the dollars remaining under the program and the respective month-end closing share price. There were 175,000 shares repurchased during 2020 and 33,465 shares repurchased during 2019. No shares were repurchased during 2018. We do not have any other share repurchase programs. There were 23,013,489 and 23,240,197 Treasury Shares at December 31, 2020 and 2019, respectively. The Company issues Treasury Shares for all stock based benefit plans. Shares are issued from Treasury at the average Treasury Share cost on the date of the transaction. There were 471,681 and 436,549 Treasury Shares issued for these purposes during the years ended December 31, 2020 and 2019, respectively. Common stock activity is summarized as follows: Shares Dollars (Dollars in thousands) Issued Treasury Common Treasury Balances January 1, 2018 62,081,391 (23,858,463) $ 194,953 $ (296,081) Restricted stock awards — 92,401 (1,079) 1,079 Restricted stock expense — — 6,504 — Restricted stock forfeitures — — (283) Stock options exercised — 215,724 5,738 2,835 Stock option expense — 272 — Stock option forfeitures — — (55) — Performance stock issued — 41,660 (523) 523 Performance stock expense — — 6,186 — Performance stock forfeitures — (385) — Employee stock purchase plan — 7,725 478 78 Treasury shares purchased for stock compensation programs — (53,915) — (4,824) Balances December 31, 2018 62,081,391 (23,554,868) $ 211,806 $ (296,390) Restricted stock awards — 96,893 (1,253) 1,253 Restricted stock expense — — 7,397 — Restricted stock forfeitures — — (483) — Stock options exercised — 193,681 5,107 2,364 Stock option expense — — 492 — Stock option forfeitures — — (5) — Performance stock issued — 139,478 (1,778) 1,778 Performance stock expense — — 6,574 — Performance stock forfeitures — — (215) — Stock consideration in acquisition — — 921 — Employee stock purchase plan — 5,895 564 77 Treasury shares purchased for stock compensation programs — (87,811) — (9,301) Share repurchase program — (33,465) — (3,347) Balances December 31, 2019 62,081,391 (23,240,197) $ 229,127 $ (303,566) Restricted stock awards — 55,691 (773) 773 Restricted stock expense — — 7,065 — Restricted stock forfeitures — — (807) — Stock options exercised — 274,672 8,590 3,856 Stock option expense — — 153 — Stock option forfeitures — — (40) — Performance stock issued — 134,824 (1,826) 1,826 Performance stock expense — — 1,305 — Performance stock forfeitures — — (755) — Employee stock purchase plan — 6,494 654 93 Treasury shares purchased for stock compensation programs — (69,973) — (9,025) Share repurchase program — (175,000) — (20,113) Balances December 31, 2020 62,081,391 (23,013,489) $ 242,693 $ (326,156)

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Segment Information	Segment Information On January 1, 2020, we restructured our business from six geographical operating segments into four geographical operating segments that are based on management responsibilities: Northern North America, Latin America, Europe, Middle East & Africa ("EMEA"), and Asia Pacific ("APAC") to better serve customer needs. The operating segments have been aggregated (based on economic similarities, the nature of their products, end-user markets and methods of distribution) into three reportable segments: Americas, International, and Corporate. The operating segment change did not impact reportable segments as all changes were within the International reportable segment. The Americas segment is comprised of our operations in North America and Latin America geographies. The International segment is comprised of our operations in all geographies outside of the Americas. Certain global expenses are allocated to each segment in a manner consistent with where the benefits from the expenses are derived. The Company's sales are allocated to each segment based primarily on the country destination of the end-customer. Adjusted operating income (loss), adjusted operating margin, adjusted earnings before interest, taxes, depreciation and amortization (EBITDA) and adjusted EBITDA margin are the measures used by the chief operating decision maker to evaluate segment performance and allocate resources. Adjusted operating income (loss) is defined as operating income excluding restructuring charges, currency exchange gains (losses), product liability expense, strategic transaction costs and COVID-19 related costs, consisting of a one-time bonus for essential manufacturing employees and adjusted operating margin is defined as adjusted operating income (loss) divided by segment sales to external customers. Adjusted EBITDA is defined as adjusted operating income (loss) plus depreciation and amortization and adjusted EBITDA margin is defined as adjusted EBITDA divided by segment sales to external customers. Adjusted operating income (loss), adjusted operating margin, adjusted EBITDA and adjusted EBITDA margin are not recognized terms under U.S. GAAP, and therefore, do not purport to be alternatives to operating income or operating margin as a measure of operating performance. Further, the Company's measure of adjusted operating income (loss), adjusted operating margin, adjusted EBITDA and adjusted EBITDA margin may not be comparable to similarly titled measures of other companies. Adjusted operating income (loss) and adjusted EBITDA on a consolidated basis is presented in the following table to reconcile the segment operating performance measure to operating income as presented on the Consolidated Statements of Income. The accounting principles applied at the operating segment level in determining operating income (loss) are generally the same as those applied at the consolidated financial statement level. Sales and transfers between operating segments are accounted for at market-based transaction prices and are eliminated in consolidation. Reportable segment information is presented in the following table: (In thousands) Americas International Corporate Reconciling Items (1) Consolidated 2020 Net sales to external customers $ 874,305 $ 473,918 $ — $ — $ 1,348,223 Operating income 166,851 Restructuring charges (Note 2) 27,381 Currency exchange losses, net (Note 5) 8,578 Product liability expense (Note 19) 39,036 Strategic transaction costs (Note 13) 717 COVID-19 related costs 757 Adjusted operating income (loss) 200,536 70,864 (28,080) — 243,320 Adjusted operating margin % 22.9 % 15.0 % Depreciation and amortization 26,762 12,521 391 — 39,674 Adjusted EBITDA 227,298 83,385 (27,689) — 282,994 Adjusted EBITDA % 26.0 % 17.6 % Noncash items: Pension expense 910 8,113 — — 9,023 Total Assets 1,228,739 615,114 29,761 (1,130) 1,872,484 Capital expenditures 43,181 5,724 — — 48,905 2019 Net sales to external customers $ 915,118 $ 486,863 $ — $ — $ 1,401,981 Operating income 186,230 Restructuring charges (Note 2) 13,846 Currency exchange losses, net (Note 5) 19,814 Product liability expense (Note 19) 26,619 Strategic transaction costs (Note 13) 4,400 Adjusted operating income (loss) 226,596 59,910 (35,597) — 250,909 Adjusted operating margin % 24.8 % 12.3 % Depreciation and amortization 24,691 12,938 391 — 38,020 Adjusted EBITDA 251,287 72,848 (35,206) — 288,929 Adjusted EBITDA % 27.5 % 15.0 % Noncash items: Pension (income) expense (6,111) 7,044 — — 933 Total Assets 1,131,911 584,195 22,367 1,220 1,739,693 Capital expenditures 26,823 9,781 — — 36,604 2018 Net sales to external customers $ 854,287 $ 503,817 $ — $ — $ 1,358,104 Operating income 173,479 Restructuring charges (Note 2) 13,247 Currency exchange losses, net (Note 5) 2,330 Product liability expense (Note 19) 45,327 Strategic transaction costs (Note 13) 421 Adjusted operating income (loss) 206,839 59,866 (31,901) — 234,804 Adjusted operating margin % 24.2 % 11.9 % Depreciation and amortization 24,143 13,303 406 — 37,852 Adjusted EBITDA 230,982 73,169 (31,495) — 272,656 Adjusted EBITDA % 27.0 % 14.5 % Noncash items: Pension (income) expense (1,201) 7,102 — — 5,901 Total Assets 1,077,938 522,042 10,842 (2,810) 1,608,012 Capital expenditures 25,001 8,959 — — 33,960 (1) Reconciling items consist primarily of intercompany eliminations and items not directly attributable to operating segments. Geographic information on Net sales to external customers, based on country of origin: (In thousands) 2020 2019 2018 United States $ 750,315 $ 785,155 $ 734,033 Other 597,908 616,826 624,071 Total $ 1,348,223 $ 1,401,981 $ 1,358,104 Geographic information on tangible long-lived assets, net based on country of origin: (In thousands) 2020 2019 2018 United States $ 134,234 $ 113,528 $ 92,511 Other 108,837 105,185 65,429 Total $ 243,071 $ 218,713 $ 157,940 Total Net sales by product group was as follows: 2020 Consolidated Americas International (In thousands) Dollars Percent Dollars Percent Dollars Percent Breathing Apparatus $ 329,179 24% $ 220,650 25% $ 108,529 23% Fixed Gas & Flame Detection 287,414 21% 158,924 18% 128,490 27% Firefighter Helmets & Protective Apparel 162,207 12% 133,653 15% 28,554 6% Portable Gas Detection 142,581 11% 90,545 10% 52,036 11% Industrial Head Protection 125,921 9% 92,075 11% 33,846 7% Fall Protection 103,075 8% 58,060 7% 45,015 10% Other (a) 197,846 15% 120,398 14% 77,448 16% Total $ 1,348,223 100% $ 874,305 100% $ 473,918 100% 2019 Consolidated Americas International (In thousands) Dollars Percent Dollars Percent Dollars Percent Breathing Apparatus $ 317,678 23% $ 212,463 23% $ 105,215 22% Fixed Gas & Flame Detection 292,988 21% 159,892 17% 133,096 27% Firefighter Helmets & Protective Apparel 178,012 13% 142,043 16% 35,969 7% Portable Gas Detection 169,479 12% 113,914 12% 55,565 11% Industrial Head Protection 145,403 10% 112,673 12% 32,730 7% Fall Protection 125,869 9% 78,054 9% 47,815 10% Other (a) 172,552 12% 96,079 11% 76,473 16% Total $ 1,401,981 100% $ 915,118 100% $ 486,863 100% 2018 Consolidated Americas International (In thousands) Dollars Percent Dollars Percent Dollars Percent Breathing Apparatus $ 324,672 24% $ 205,100 24% $ 119,572 24% Fixed Gas & Flame Detection 262,432 19% 135,922 16% 126,510 25% Firefighter Helmets & Protective Apparel 169,679 13% 136,794 16% 32,885 6% Portable Gas Detection 163,716 12% 109,401 13% 54,315 11% Industrial Head Protection 146,388 11% 114,465 13% 31,923 6% Fall Protection 109,472 8% 61,289 7% 48,183 10% Other (a) 181,745 13% 91,316 11% 90,429 18% Total $ 1,358,104 100% $ 854,287 100% $ 503,817 100%

Earnings per Share

Earnings per Share	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Earnings per Share	Earnings per Share Basic earnings per share is computed by dividing net income, after the deduction of preferred stock dividends and undistributed earnings allocated to participating securities, by the weighted average number of common shares outstanding during the period. Diluted earnings per share assumes the issuance of common stock for all potentially dilutive share equivalents outstanding not classified as participating securities. Participating securities are defined as unvested stock-based payment awards that contain nonforfeitable rights to dividends. Amounts attributable to MSA Safety Incorporated common shareholders: (In thousands, except per share amounts) 2020 2019 2018 Net income $ 120,101 $ 136,440 $ 124,150 Preferred stock dividends (41) (42) (42) Net income available to common equity 120,060 136,398 124,108 Dividends and undistributed earnings allocated to participating securities (84) (183) (117) Net income available to common shareholders $ 119,976 $ 136,215 $ 123,991 Basic weighted-average shares outstanding 38,885 38,653 38,362 Stock options and other stock compensation 401 536 599 Diluted weighted-average shares outstanding 39,286 39,189 38,961 Earnings per share: Basic $ 3.09 $ 3.52 $ 3.23 Diluted $ 3.05 $ 3.48 $ 3.18

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes (In thousands) 2020 2019 2018 Components of income before income taxes U.S. income $ 104,682 $ 126,552 $ 85,234 Non-U.S. income 58,421 57,183 77,101 Income before income taxes $ 163,103 $ 183,735 $ 162,335 Provision for income taxes Current Federal $ 23,587 $ 13,770 $ 13,574 State 4,896 5,436 4,265 Non-U.S. 16,780 25,608 23,446 Total current provision $ 45,263 $ 44,814 $ 41,285 Deferred Federal $ (1,493) $ 5,744 $ 291 State (727) 1,346 (1,604) Non-U.S. (1,102) (5,818) (2,752) Total deferred provision (benefit) (3,322) 1,272 (4,065) Provision for income taxes $ 41,941 $ 46,086 $ 37,220 The Company elected to treat Global Intangible Low Taxed Income, which was effective in 2018 for the Company, as a period cost. The Tax Cuts and Jobs Act of 2017 ("the Act"), which was signed into law on December 22, 2017, has resulted in significant changes to the U.S. corporate income tax system including reducing the U.S. corporate rate to 21% starting in 2018. The Act also creates a territorial tax system with a one-time mandatory tax on previously deferred foreign earnings of U.S. subsidiaries. On December 22, 2017, SAB 118 was issued to address the application of US GAAP in situations when a registrant does not have the necessary information available, prepared or analyzed in reasonable detail to complete the accounting for certain income tax effects of the Act. In accordance with SAB 118, the Company calculated its best estimate of the impact of the Act and recorded income tax expense of $19.8 million during the fourth quarter of 2017, the period in which the legislation was enacted. Of this amount, $18.0 million related to the one-time transition tax and the remaining $1.8 million was related to the revaluation of U.S. deferred tax assets and liabilities. The Company previously considered the earnings in non-U.S. subsidiaries to be indefinitely reinvested and, accordingly, recorded no deferred income taxes. As as result of the Act, among other things, the Company determined it will repatriate earnings for all non-U.S. subsidiaries with cash in excess of working capital needs. The Company has estimated the associated tax to be $1.9 million, offset partially by $0.7 million of foreign tax credits. As of December 31, 2018, the Company had completed its accounting for all of the enactment-date income tax effects of the Act. Accordingly, we reduced our estimate for the one-time transition tax by $2.0 million and increased our estimate for the revaluation of U.S. deferred tax assets and liabilities by $2.5 million and a $2.0 million increase associated with prepaid taxes for updated regulations related to the Act. During 2018, the Company recorded $1.8 million of foreign income tax reserves related to the legal and operational realignment of our U.S., Canadian and European operations. During 2020, an additional reserve of $1.1 million was recorded related to the operating realignment of our European operations. Reconciliation of the U.S. federal income tax rates to our effective tax rate: 2020 2019 2018 U.S. federal income tax rate 21.0 % 21.0 % 21.0 % Nondeductible compensation 3.4 % 1.9 % 1.0 % Taxes on non-U.S. income 2.6 % (0.5) % 0.4 % State income taxes—U.S. 2.0 % 2.9 % 1.3 % Valuation allowances 0.8 % 0.4 % 0.5 % Taxes on non-U.S. income - U.S., Canadian & European reorganization 0.7 % 0.3 % 1.1 % Foreign exchange on entity closures — % 1.8 % — % U.S. tax reform — % — % 1.6 % Manufacturing deduction credit — % — % (1.0) % Employee share-based payments (3.9) % (2.6) % (1.6) % Research and development credit (1.2) % (0.6) % (0.9) % Other 0.3 % 0.5 % (0.5) % Effective income tax rate 25.7 % 25.1 % 22.9 % Components of deferred tax assets and liabilities: December 31, (In thousands) 2020 2019 Deferred tax assets Product liability $ 33,689 $ 29,405 Capitalized research and development 22,915 17,886 Employee benefits 10,539 12,009 Net operating losses and tax credit carryforwards 6,310 6,026 Accrued expenses and other reserves 5,195 4,384 Share-based compensation 3,588 5,396 Other 5,287 3,828 Total deferred tax assets 87,523 78,934 Valuation allowances (7,188) (5,937) Net deferred tax assets 80,335 72,997 Deferred tax liabilities Goodwill and intangibles (39,040) (35,999) Property, plant and equipment (14,649) (11,714) Other (1,897) (2,475) Total deferred tax liabilities (55,586) (50,188) Net deferred taxes $ 24,749 $ 22,809 At December 31, 2020, we had net operating loss carryforwards of approximately $31.0 million, all of which are in non-U.S. tax jurisdictions. All net operating loss carryforwards without a valuation allowance may be carried forward for a period of at least six years. A reconciliation of the change in the tax liability for unrecognized tax benefits for the years ended December 31, 2020 and 2019 is as follows: (In thousands) 2020 2019 Beginning balance $ 5,119 $ 16,155 Adjustments for tax positions related to the current year 425 — Adjustments for tax positions related to prior years 2,950 (7,740) Statute expiration (402) (3,296) Ending balance $ 8,092 $ 5,119 The total amount of unrecognized tax benefits, if recognized, would reduce our future effective tax rate. We have recognized tax benefits associated with these liabilities in the amount of $2.7 million and $2.2 million at December 31, 2020 and 2019, respectively. We recognize interest related to unrecognized tax benefits in interest expense and penalties in operating expenses. Our liability for accrued interest and penalties related to uncertain tax positions was $1.0 million and $0.5 million at December 31, 2020 and 2019, respectively. We are subject to regular review and audit by both foreign and domestic tax authorities. While we believe our tax positions will be sustained, the final outcome of tax audits and related litigation may differ materially from the tax amounts recorded in our consolidated financial statements. We file a U.S. federal income tax return along with various state and foreign income tax returns. Examinations of our U.S. federal returns have been completed through 2013, with the 2014, 2015 and 2016 tax years closed by statute. Various state and foreign income tax returns may be subject to tax audits for periods after 2014.

Stock Plans

Stock Plans	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock Plans	Stock Plans The 2016 Management Equity Incentive Plan provides for various forms of stock-based compensation for eligible key employees through May 2026. Management stock-based compensation includes stock options, restricted stock, restricted stock units and performance stock units. Additionally, 2019 amounts granted include outstanding Sierra Monitor Corporation awards converted into MSA awards after the acquisition. See Note 13—Acquisitions for more information. The 2017 Non-Employee Directors’ Equity Incentive Plan provides for grants of stock options and restricted stock to non-employee directors through May 2027. Stock options are granted at market prices and expire after ten years. Stock options are exercisable beginning three years after the grant date. Restricted stock and restricted stock units are granted without payment to the Company and generally vest three years after the grant date. Restricted stock and restricted stock units are valued at the market value of the stock on the grant date. Performance stock units with a market condition are valued at an estimated fair value using a Monte Carlo simulation model. The final number of shares to be issued for performance stock units may range from zero to 200% of the target award based on achieving the specified performance targets over the performance period and further range based upon the achieved market metric over the performance period. In general, unvested stock options, restricted stock and performance stock units are forfeited if the participant’s employment with the Company terminates for any reason other than retirement, death or disability. We issue Treasury shares for stock option exercises and grants of restricted stock and performance stock. Please refer to Note 6 for further information regarding stock compensation share issuance. As of December 31, 2020, there were 802,439 and 94,020 shares, respectively, reserved for future grants under the management and non-employee directors’ equity incentive plans. Stock-based compensation expense was as follows: (In thousands) 2020 2019 2018 Restricted stock units $ 6,258 $ 6,914 $ 6,221 Stock options 113 487 217 Performance stock units 549 6,359 5,801 Total stock-compensation expense before income taxes 6,920 13,760 12,239 Income tax benefit 1,668 3,357 2,974 Total stock-compensation expense, net of income tax benefit $ 5,252 $ 10,403 $ 9,265 We did not capitalize any stock-based compensation expense, and all expense is recorded in selling, general and administrative expense in 2020, 2019, and 2018. The Company utilized the Black-Scholes valuation model for estimating the fair value of stock option expense with the following weighted average assumptions. There were no stock options granted in 2020 or 2018. 2019 Fair value per option $ 59.07 Risk-free interest rate 2.3 % Expected dividend yield 1.7 % Expected volatility 31 % Expected life (years) 6.4 The risk-free interest rate is based on the U.S. Treasury yield curve. Expected dividend yield is based on the most recent annualized dividend divided by the one year average closing share price. Expected volatility is based on the historical volatility using daily stock prices. Expected life is based on historical stock option exercise data. A summary of option activity follows: Shares Weighted Exercisable at Outstanding January 1, 2018 955,446 $ 42.75 Exercised (215,724) 39.25 Forfeited (4,721) 44.50 Outstanding December 31, 2018 735,001 43.79 638,673 Granted 23,285 43.54 Exercised (198,535) 38.16 Forfeited (95) 49.19 Outstanding December 31, 2019 559,656 45.78 552,682 Exercised (274,704) 45.31 Forfeited (954) 42.00 Outstanding December 31, 2020 283,998 $ 46.23 281,593 For various exercise price ranges, characteristics of outstanding and exercisable stock options at December 31, 2020 were as follows: Stock Options Outstanding Range of Exercise Prices Shares Weighted-Average Exercise Price Remaining Life $33.01 – $45.00 158,836 43.88 3.06 $45.01 – $57.93 125,162 49.22 2.93 $33.01 – $57.93 283,998 $ 46.23 3.00 Stock Options Exercisable Range of Exercise Prices Shares Weighted-Average Exercise Price Remaining Life $33.01 – $45.00 158,208 43.90 3.05 $45.01 – $57.93 123,385 49.22 2.87 $33.01 – $57.93 281,593 $ 46.23 2.97 Cash received from the exercise of stock options was $12.4 million, $7.5 million and $8.6 million for the years ended December 31, 2020, 2019 and 2018, respectively. The tax benefit we realized from these exercises was $6.4 million, $4.8 million and $2.5 million for the years ended December 31, 2020, 2019 and 2018, respectively. Stock options become exercisable when they are vested. The aggregate intrinsic value of stock options exercisable at December 31, 2020 was $29.0 million. The aggregate intrinsic value of all stock options outstanding at December 31, 2020 was $29.3 million. A summary of restricted stock unit activity follows: Shares Weighted Average Unvested January 1, 2017 227,161 $ 57.50 Granted 75,430 87.36 Vested (92,401) 58.10 Forfeited (4,741) 59.61 Unvested at December 31, 2018 205,449 68.97 Granted 70,160 104.53 Vested (97,253) 56.47 Forfeited (5,655) 85.48 Unvested at December 31, 2019 172,701 90.38 Granted 51,468 124.61 Vested (70,399) 81.58 Forfeited (7,579) 106.54 Unvested at December 31, 2020 146,191 $ 105.83 A summary of performance stock unit activity follows: Shares Weighted Average Unvested at January 1, 2017 242,186 $ 55.06 Granted 62,775 84.79 Vested (41,660) 40.23 Performance adjustments (35,756) 45.21 Forfeited (8,659) 44.53 Unvested at December 31, 2018 218,886 68.43 Granted 83,819 101.03 Vested (139,478) 44.75 Performance adjustments 76,960 44.24 Forfeited (2,152) 99.82 Unvested at December 31, 2019 238,035 85.39 Granted 67,479 127.48 Vested (132,036) 73.00 Performance adjustments 33,499 72.36 Forfeited (6,765) 111.60 Unvested at December 31, 2020 200,212 $ 104.69 The 2020 performance adjustments relate to to awards that exceeded the performance targets when vested during 2020, including the final number of shares issued, which were 135.7% of the target award based on actual results during the three year performance period. During the years ended December 31, 2020, 2019 and 2018, the total intrinsic value of stock options exercised (the difference between the market price on the date of exercise and the option price paid to exercise the option) was $24.6 million, $14.6 million and $12.2 million, respectively. The fair values of restricted stock vested during the years ended December 31, 2020, 2019 and 2018 were $5.7 million, $5.5 million and $5.4 million, respectively. The fair value of performance stock units vested during the years ended December 31, 2020, 2019 and 2018 was $9.6 million, $6.2 million and $1.7 million, respectively. On December 31, 2020, there was $8.3 million of unrecognized stock-based compensation expense. The weighted average period over which this expense is expected to be recognized was approximately 1.7 years.

Short and Long-Term Debt

Short and Long-Term Debt	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Short and Long-Term Debt	Long-Term Debt Long-Term Debt December 31, (In thousands) 2020 2019 2010 Senior Notes payable through 2021, 4.00%, net of debt issuance costs $ 20,000 $ 40,000 2016 Senior Notes payable through 2031, 3.40%, net of debt issuance costs 74,926 72,708 Senior revolving credit facility maturing in 2023, net of debt issuance costs 212,231 235,686 Total 307,157 348,394 Short-term debt 20,000 20,000 Long-term debt $ 287,157 $ 328,394 On September 7, 2018, the Company entered into a Third Amended and Restated Credit Agreement associated with our senior revolving credit facility which extended the term of the revolving credit facility through September 2023 and increased the capacity to $600.0 million. Under this 2018 Amended and Restated Credit Agreement, the Company may elect either a Base rate of interest (“BASE”) or an interest rate based on the London Interbank Offered Rate (“LIBOR”). The BASE is a daily fluctuating per annum rate equal to the highest of (i) 0.0%, (ii) the Prime Rate, (ii) the Federal Funds Open Rate plus one half of one percent (0.5%), (iii) the Overnight Bank Funding Rate, plus one half of one percent (0.5%), or (iv) the Daily LIBOR Rate plus one percent (1.00%). The Company pays a credit spread of 0 to 175 basis points based on the Company’s net EBITDA leverage ratio and the elected rate (BASE or LIBOR). The facility contemplates the discontinuance of LIBOR and includes an option to replace LIBOR with a comparable rate, or if a comparable rate cannot be found, the base rate would be utilized. The Company has a weighted average revolver interest rate of 1.15% as of December 31, 2020. At December 31, 2020, $385.5 million of the existing $600.0 million senior revolving credit facility was unused, including letters of credit. On January 22, 2016, the Company entered into a Second Amended and Restated Multi-Currency Note Purchase and Private Shelf Agreement (the "Notes"), pursuant to which MSA issued notes in an aggregate original principal amount of £54.9 million (approximately $75.1 million at December 31, 2020). The Notes are repayable in annual installments of £6.1 million (approximately $8.3 million at December 31, 2020), commencing January 22, 2023, with a final payment of any remaining amount outstanding on January 22, 2031. The interest rate on these Notes is fixed at 3.4%. On September 7, 2018, the Company entered into a first amendment of such amended and restated agreement associated with these Notes. Under the Second Amended and Restated Multi-Currency Note Purchase and Private Shelf Agreement, as amended ("Amended Note Purchase Agreement"), the Company may request from time to time during a three-year period ending September 7, 2021, the issuance of up to $150 million of additional senior notes. On January 4, 2019, the Company entered into an amended and restated agreement associated with the New York Life master note facility dated June 2, 2014. Under this Amended and Restated Master Note Facility ("Amended Note Facility"), the Company may request from time to time during a three-year period ending January 4, 2022, the issuance of up to $150 million of additional senior promissory notes. As of the Form 10-K filing date, there are no promissory notes outstanding. Both the Amended Note Purchase Agreement and Amended Note Facility require MSA to comply with specified financial covenants, including a requirement to maintain a minimum fixed charges coverage ratio of not less than 1.50 to 1.00 and a consolidated net leverage ratio not to exceed 3.50 to 1.00, except during an acquisition period in which case the consolidated net leverage ratio shall not exceed 4.00 to 1.00; in each case calculated on the basis of the trailing four fiscal quarters. In addition, the Amended Note Purchase Agreement and Amended Note Facility both contain negative covenants limiting the ability of MSA and its subsidiaries to incur additional indebtedness or issue guarantees, create or incur liens, make loans and investments, make acquisitions, transfer or sell assets, enter into transactions with affiliated parties, make changes in its organizational documents that are materially adverse to lenders or modify the nature of MSA's or its subsidiaries' business. However, the covenants contained in the Amended Note Facility do not apply until promissory notes are issued. The revolving credit facilities require the Company to comply with specified financial covenants. In addition, the revolving credit facilities contain negative covenants limiting the ability of the Company and its subsidiaries to enter into specified transactions. The Company was in compliance with all covenants at December 31, 2020.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Intangible Assets Changes in goodwill during the years ended December 31, 2020 and 2019, were as follows: (In thousands) 2020 2019 Net balance at January 1 $ 436,679 $ 413,640 Additions (Note 13) — 19,917 Currency translation 6,593 3,122 Net balance at December 31 $ 443,272 $ 436,679 At December 31, 2020, goodwill of $293.2 million and $150.1 million related to the Americas and International reporting segments, respectively. Changes in intangible assets, net of accumulated amortization, during the years ended December 31, 2020 and 2019, were as follows: (In thousands) 2020 2019 Net balance at January 1 $ 171,326 $ 169,515 Additions and measurement period adjustments (Note 13) 121 11,100 Amortization expense (11,570) (11,119) Currency translation 1,174 1,830 Net balance at December 31 $ 161,051 $ 171,326 (In millions) December 31, 2020 December 31, 2019 Intangible Assets: Weighted Average Useful Life (years) Gross Carrying Amount Accumulated Amortization and Reserves Net Carrying Amount Gross Carrying Amount Accumulated Amortization and Reserves Net Carrying Amount Customer relationships 14 $ 59.7 $ (20.4) $ 39.3 $ 58.3 $ (15.3) $ 43.0 Distribution agreements 20 66.4 (20.7) 45.7 66.0 (17.3) 48.7 Technology related assets 8 30.2 (21.3) 8.9 30.0 (18.3) 11.7 Patents, trademarks and copyrights 12 19.4 (12.5) 6.9 19.0 (11.3) 7.7 License agreements 5 5.4 (5.3) 0.1 5.3 (5.3) — Other 2 3.0 (2.8) 0.2 3.0 (2.8) 0.2 Total 14 $ 184.1 $ (83.0) $ 101.1 $ 181.6 $ (70.3) $ 111.3 At December 31, 2020, the above intangible assets balance includes a trade name related to the Globe acquisition with an indefinite life totaling $60.0 million.

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Acquisitions	Acquisitions Acquisition of Sierra Monitor Corporation On May 20, 2019, we acquired 100% of the common stock in Sierra Monitor Corporation ("SMC") in an all-cash transaction valued at $33.2 million, net of cash acquired. Additionally, we converted outstanding stock options and restricted stock units into MSA stock options and restricted stock units which resulted in additional goodwill of approximately $0.9 million based on the fair value of the awards identified as transaction consideration. Based in Milpitas, California, in the heart of Silicon Valley, SMC is a leading provider of fixed gas and flame detection instruments and Industrial Internet of Things solutions that connect and help protect high-value infrastructure assets. The acquisition enables MSA to accelerate its strategy to enhance worker safety and accountability through the use of cloud technology and wireless connectivity. This acquisition enhances a key focus of the Company's recently established Safety io subsidiary, launched in 2018 primarily to leverage the capabilities of its portable gas detection portfolio as it relates to cloud connectivity. The transaction was funded through borrowings on our unsecured senior revolving credit facility. SMC operating results are included in our consolidated financial statements from the acquisition date as part of the Americas reportable segment. The acquisition qualifies as a business combination and was accounted for using the acquisition method of accounting. We finalized the purchase price allocation as of December 31, 2019. The following table summarizes the fair values of the SMC assets acquired and liabilities assumed at the date of acquisition: (In millions) May 20, 2019 Current assets (including cash of $2.1 million) $ 10.5 Property, plant and equipment and other noncurrent assets 1.3 Customer relationships 9.6 Acquired technology 1.4 Goodwill 19.9 Total assets acquired 42.7 Total liabilities assumed 6.5 Net assets acquired $ 36.2 Assets acquired and liabilities assumed in connection with the acquisition have been recorded at their fair values. Fair values were determined by management, based, in part on an independent valuation performed by a third-party valuation specialist. The valuation methods used to determine the fair value of intangible assets included the relief from royalty method for technology related intangible assets; the excess earnings approach for customer relationships using customer inputs and contributory charges; and the cost method for assembled workforce which is included in goodwill. A number of significant assumptions and estimates were involved in the application of these valuation methods, including sales volumes and prices, royalty rates, costs to produce, tax rates, capital spending, discount rates, and working capital changes. Cash flow forecasts were generally based on SMC pre-acquisition forecasts coupled with estimated MSA sales synergies. Identifiable intangible assets with finite lives are subject to amortization over their estimated useful lives. The customer relationships acquired in the SMC transaction will be amortized over a period of 10 years and the technology will be amortized over 5 years. Estimated future amortization expense related to the identifiable intangible assets is approximately $1.0 million in each of the next five years. The step up to fair value of acquired inventory as part of the purchase price allocation totaled $1.6 million which was fully recognized as amortization expense during the year ended December 31, 2019. Goodwill is calculated as the excess of the purchase price over the fair value of net assets acquired and represents the future economic benefits arising from other assets acquired that could not be individually identified and separately recognized. Among the factors that contributed to a purchase price in excess of the fair value of the net tangible and intangible assets acquired were the acquisition of an assembled workforce, the expected synergies and other benefits that we believe will result from combining the operations of SMC with our operations. Goodwill of $19.9 million related to the SMC acquisition has been recorded in the Americas reportable segment and is non-deductible for tax purposes. Our results for the year ended December 31, 2020, include SMC sales and net income of $21.2 million and $2.8 million, respectively. Excluding purchase accounting amortization for intangible assets of $1.2 million, adjusted earnings for SMC for the year ended December 31, 2020 was $3.8 million. Our operating results for the year ended December 31, 2019 include SMC sales and net loss of $13.5 million and $3.3 million, respectively. Excluding purchase accounting amortization for intangible assets and inventory step up of $2.6 million, transaction costs of $2.2 million, and stock compensation cost related to converted options and excess performance on PSUs related to the acquisition of $1.5 million, adjusted earnings for SMC for the year ended December 31, 2019 was $1.5 million. The following unaudited pro forma information presents our combined results as if the SMC acquisition had occurred at the beginning of 2018. The unaudited pro forma financial information was prepared to give effect to events that are (1) directly attributable to the acquisition; (2) factually supportable; and (3) expected to have a continuing impact on the combined company’s results. There were no material transactions between MSA and SMC during the periods presented that are required to be eliminated. Intercompany transactions between SMC companies during the periods presented have been eliminated in the unaudited pro forma combined financial information. The unaudited pro forma financial information does not reflect any cost savings, operating synergies or revenue enhancements that the combined companies may achieve as a result of the acquisitions or the costs to integrate the operations or the costs necessary to achieve cost savings, operating synergies or revenue enhancements. Pro forma financial information (Unaudited) (In millions, except per share amounts) 2019 2018 Net sales $ 1,410 $ 1,380 Net Income 131 124 Basic earnings per share 3.40 3.24 Diluted earnings per share 3.35 3.19 The unaudited pro forma combined financial information is presented for information purposes only and is not intended to represent or be indicative of the combined results of operations or financial position that we would have reported had the acquisitions been completed as of the date and for the periods presented, and should not be taken as representative of our consolidated results of operations or financial condition following the acquisitions. In addition, the unaudited pro forma combined financial information is not intended to project the future financial position or results of operations of the combined company. The unaudited pro forma financial information was prepared using the acquisition method of accounting for both acquisitions under existing U.S. GAAP. MSA has been treated as the acquirer.

Pensions and Other Post-retirem

Pensions and Other Post-retirement Benefits	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
Pensions and Other Post-retirement Benefits	Pensions and Other Post-retirement Benefits We maintain various defined benefit and defined contribution plans covering the majority of our employees. Our principal U.S. plan is funded in compliance with the Employee Retirement Income Security Act (ERISA). It is our general policy to fund current costs for the international plans, except in Germany and Mexico, where it is common practice and permissible under tax laws to maintain an unfunded liability. We provide health care benefits and limited life insurance for certain retired employees who are covered by our principal U.S. defined benefit pension plan until they become Medicare-eligible. Information pertaining to defined benefit pension plans and other post-retirement benefits plans is provided in the following tables: Pension Benefits Other Benefits (In thousands) 2020 2019 2020 2019 Change in Benefit Obligations Benefit obligations at January 1 $ 603,551 $ 525,520 $ 28,151 $ 28,477 Service cost 12,094 10,342 396 354 Interest cost 14,905 18,803 716 996 Participant contributions 396 470 370 380 Plan amendments (430) — — — Actuarial losses (a) 54,606 81,132 5,284 1,319 Benefits paid (24,496) (24,452) (2,692) (3,375) Curtailments (1,559) — — — Settlements (506) (7,265) — — Currency translation 12,296 (999) — — Benefit obligations at December 31 $ 670,857 $ 603,551 $ 32,225 $ 28,151 Change in Plan Assets Fair value of plan assets at January 1 $ 515,858 $ 443,112 $ — $ — Actual return on plan assets 87,769 98,210 — — Employer contributions 5,596 5,537 2,322 2,995 Participant contributions 396 470 370 380 Settlements (506) (7,265) — — Benefits paid (24,496) (24,452) (2,692) (3,375) Administrative expenses paid (172) (297) — — Currency translation 2,377 543 — — Fair value of plan assets at December 31 $ 586,822 $ 515,858 $ — $ — Funded Status Funded status at December 31 $ (84,035) $ (87,693) $ (32,225) $ (28,151) Unrecognized transition losses 4 4 — — Unrecognized prior service credit 1,717 1,572 (1,125) (1,519) Unrecognized net actuarial losses 169,028 183,733 16,686 12,547 Net amount recognized $ 86,714 $ 97,616 $ (16,664) $ (17,123) Amounts Recognized in the Balance Sheets Noncurrent assets $ 97,545 $ 75,066 $ — $ — Current liabilities (6,600) (5,944) (2,849) (2,406) Noncurrent liabilities (174,980) (156,815) (29,376) (25,745) Net amount recognized $ (84,035) $ (87,693) $ (32,225) $ (28,151) Amounts Recognized in Accumulated Other Comprehensive Loss Net actuarial losses $ 169,028 $ 183,733 $ 16,686 $ 12,547 Prior service cost (credit) 1,717 1,572 (1,125) (1,519) Unrecognized net initial obligation 4 4 — — Total (before tax effects) $ 170,749 $ 185,309 $ 15,561 $ 11,028 Accumulated Benefit Obligations for all Defined Benefit Plans $ 619,167 $ 558,183 $ — $ — (a) Actuarial losses for both periods relate primarily to the decrease in discount rates used in measuring plan obligations as of December 31, 2020 and 2019, respectively. Pension Benefits Other Benefits (In thousands) 2020 2019 2018 2020 2019 2018 Components of Net Periodic Benefit Cost Service cost $ 12,094 $ 10,342 $ 11,125 $ 396 $ 354 $ 369 Interest cost 14,905 18,803 17,214 716 996 793 Expected return on plan assets (34,029) (38,644) (36,352) — — — Amortization of transition amounts — 2 1 — — — Amortization of prior service cost (credit) 178 223 (21) (394) (405) (405) Recognized net actuarial losses 15,799 10,159 13,755 1,145 869 752 Settlement/curtailment loss 1,135 (b) 2,497 (c) 179 — — — Net periodic benefit cost (a) $ 10,082 $ 3,382 $ 5,901 $ 1,863 $ 1,814 $ 1,509 (a) Components of net periodic benefit cost other than service cost are included in the line item "Other income, net" and service costs are included in the line items "Cost of products sold" and "Selling, general and administrative" in the Consolidated Statements of Income. (b) Relates primarily to the conversion of our Netherlands pension plan into a defined contribution plan and is included in "Restructuring charges" on the Consolidated Statements of Income. (c) Relates to the termination of our pension plan in the U.K. and is included in "Restructuring charges" on the Consolidated Statements of Income. The Company utilizes a spot rate approach, which discounts the individual plan specific expected cash flows underlying the service and interest cost using the applicable spot rates derived from a yield curve used in the determination of the benefit obligation to the relevant projected cash flows. For plans where the discount rate is not derived from plan specific expected cash flows, the Company uses a single weighted-average discount rate derived from the yield curve used to measure the projected benefit obligation at the beginning of the period for measuring both the projected benefit obligations and the service and interest cost components of net periodic benefit cost for pension and other post-retirement benefits. Information for pension plans with an accumulated benefit obligation in excess of plan assets: Pension Benefits Other Benefits (In thousands) 2020 2019 2020 2019 Aggregate accumulated benefit obligations (ABO) $ 209,351 $ 185,747 $ 32,225 $ 28,151 Aggregate fair value of plan assets 40,294 35,882 — — Information for pension plans with a projected benefit obligation in excess of plan assets: Pension Benefits (In thousands) 2020 2019 Aggregate projected benefit obligations (PBO) 223,343 198,633 Aggregate fair value of plan assets 41,764 35,882 Pension Benefits Other Benefits 2020 2019 2020 2019 Assumptions used to determine benefit obligations Average discount rate 2.28 % 2.86 % 2.21 % 3.05 % Rate of compensation increase 2.93 % 2.93 % 3.00 % — % Assumptions used to determine net periodic benefit cost Average discount rate - Service cost 3.08 % 3.10 % 2.42 % 3.15 % Average discount rate - Interest cost 2.52 % 2.52 % 1.48 % 2.61 % Expected return on plan assets 7.10 % 7.09 % — — Rate of compensation increase 2.93 % 2.93 % 3.00 % — % Discount rates for all U.S. and foreign plans were determined using the aforementioned spot rate methodology for 2020 and 2019. Aside from sovereign bonds used in Mexico, the remaining plans' discount rates were determined using various corporate bonds and by matching our projected benefit obligation payment stream to current yields on high quality bonds. The expected return on assets for the 2020 net periodic pension cost was determined by multiplying the expected returns of each asset class (based on capital market expectations) by the expected percentage of the total portfolio invested in that asset class. A total return was determined by summing the expected returns over all asset classes. Pension Plan Assets at 2020 2019 Equity securities 49 % 46 % Fixed income securities 25 30 Pooled investment funds 21 19 Insurance contracts 4 4 Cash and cash equivalents 1 1 Total 100 % 100 % The overall objective of our pension investment strategy is to earn a rate of return over time to satisfy the benefit obligations of the pension plans and to maintain sufficient liquidity to pay benefits and meet other cash requirements of our pension funds. Investment policies for our primary U.S. pension plan are determined by the plan’s Investment Committee and set forth in the plan’s investment policy. Asset managers are granted discretion for determining sector mix, selecting securities and timing transactions, subject to the guidelines of the investment policy. An aggressive, flexible management of the portfolio is permitted and encouraged, with shifts of emphasis among equities, fixed income securities and cash equivalents at the discretion of each manager. No target asset allocations are set forth in the investment policy. For our non-U.S. pension plans, our investment objective is generally met through the use of pooled investment funds and insurance contracts. The fair values of the Company's pension plan assets are determined using net asset value (NAV) as a practical expedient, or by information categorized in the fair value hierarchy level based on the inputs used to determine fair value, as further discussed in Note 18—Fair Value Measurements. The fair values at December 31, 2020, were as follows: Fair Value (In thousands) Total NAV Quoted Prices Significant Significant Equity securities $ 283,516 $ 66,847 $ 216,669 $ — $ — Fixed income securities 148,173 — 76,502 71,671 — Pooled investment funds 123,119 123,119 — — — Insurance contracts 24,396 — — — 24,396 Cash and cash equivalents 7,618 6,681 937 — — Total $ 586,822 $ 196,647 $ 294,108 $ 71,671 $ 24,396 The fair values of the Company's pension plan assets at December 31, 2019, were as follows: Fair Value (In thousands) Total NAV Quoted Prices Significant Significant Equity securities $ 235,491 $ 56,449 $ 179,042 $ — $ — Fixed income securities 154,640 — 73,874 80,766 — Pooled investment funds 97,373 97,373 — — — Insurance contracts 21,502 — — — 21,502 Cash and cash equivalents 6,852 5,792 1,060 — — Total $ 515,858 $ 159,614 $ 253,976 $ 80,766 $ 21,502 Equity securities consist primarily of publicly traded U.S. and non-U.S. common stocks. Equities are valued at closing prices reported on the listing stock exchange. Fixed income securities consist primarily of U.S. government and agency bonds and U.S. corporate bonds. Fixed income securities are valued at closing prices reported in active markets or based on yields currently available on comparable securities of issuers with similar credit ratings. When quoted prices are not available for identical or similar bonds, the bond is valued under a discounted cash flow approach that maximizes observable inputs, such as current yields of similar instruments, and may include adjustments, for certain risks that may not be observable, such as credit and liquidity risks. A financial instrument's categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. Pooled investment funds consist of mutual and collective investment funds that invest primarily in publicly traded equity and fixed income securities. Pooled investment funds are valued using the net asset value (NAV) provided by the administrator of the fund. The NAV is based on the value of the underlying assets owned by the fund, minus its liabilities, divided by the number of shares outstanding. The underlying securities are generally valued at closing prices reported in active markets, quoted prices of similar securities, or discounted cash flows approach that maximizes observable inputs such as current value measurement at the reporting date. These investments are not classified in the fair value hierarchy in accordance with guidance in ASU 2015-07. Insurance contracts are valued in accordance with the terms of the applicable collective pension contract. The fair value of the plan assets equals the discounted value of the expected cash flows of the accrued pensions which are guaranteed by the counterparty insurer. Cash equivalents consist primarily of money market and similar temporary investment funds. Cash equivalents are valued at closing prices reported in active markets. The preceding methods may produce fair value measurements that are not indicative of net realizable value or reflective of future fair values. Although we believe the valuation methods are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different fair value measurement at the reporting date. The following table presents a reconciliation of Level 3 assets: (In thousands) Insurance Balance January 1, 2019 $ 17,033 Net realized and unrealized losses 5,602 Net purchases, issuances and settlements (1,133) Balance December 31, 2019 21,502 Net realized and unrealized gains 2,564 Net purchases, issuances and settlements 330 Balance December 31, 2020 $ 24,396 The following table presents amounts related to Level 3 assets recognized in accumulated other comprehensive loss: (In thousands) Insurance Net actuarial losses 972 Prior service cost 1,406 Total (before tax effects) $ 2,378 We expect to make net contributions of $7.7 million to our pension plans in 2021, which are primarily associated with statutorily required plans in the International segment. For the 2020 beginning of the year measurement purposes (net periodic benefit expense), a 6.5% increase in the costs of covered health care benefits was assumed, decreasing by 0.5% for each successive year to 4.5% in 2024 and thereafter. For the 2020 end of the year measurement purposes (benefit obligation), a 5.9% increase in the costs of covered health care benefits was assumed, decreasing by approximately 0.2% for each successive year to 4.5% in 2029 and thereafter. Expense for defined contribution pension plans was $10.6 million in 2020, $8.3 million in 2019 and $9.0 million in 2018.

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	Leases Effective January 1, 2019, we implemented ASU 2016-02, Leases , which amended authoritative guidance on leases and is codified in ASC Topic 842. The amended guidance requires lessees to recognize most leases on their balance sheets as right-of-use assets along with corresponding lease liabilities. The new standard requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase by the lessee. This classification determines whether lease expense is recognized based on an effective interest method or on a straight-line basis over the term of the lease. The FASB's authoritative guidance provides companies with the option to apply this ASU to new and existing leases within the scope of the guidance as of the beginning of the period of adoption. We elected this transition method of applying the new standard and have recognized right-of-use assets and lease liabilities as of January 1, 2019. Prior period amounts were not adjusted and will continue to be reported under the accounting standards in effect for those periods. The adoption of this standard had a material impact on our Consolidated Balance Sheet as of December 31, 2020 due to the capitalization of right-of-use assets and lease liabilities associated with our current operating leases in which we are the lessee. Adoption of the new standard resulted in the recording of additional right-of-use assets and lease liabilities of approximately $54 million, respectively, as of January 1, 2019. Upon adoption of the new standard on January 1, 2019, we elected the package of practical expedients provided under the guidance. The practical expedient package applies to leases that commenced prior to adoption of the new standard and permits companies not to reassess whether existing or expired contracts are or contain a lease, the lease classification and any initial direct costs for existing leases. We have elected to not separate the lease and non-lease components within our lease contracts. Therefore, all fixed costs associated with the lease are included in the right-of-use asset and the lease liability. These costs often relate to the payments for a proportionate share of real estate taxes, insurance, common area maintenance and other operating costs in addition to base rent. We did not elect the hindsight practical expedient. At the inception of our contracts we determine if the contract is or contains a lease. A contract is or contains a lease if it conveys the right to control the use of an identified asset for a period of time in exchange for consideration. Right-of-use assets and operating lease liabilities are recognized based on the present value of lease payments over the lease term at commencement. We use our incremental borrowing rate ("IBR") at the recognition date in determining the present value of future payments for leases that do not have a readily determinable implicit rate. Our IBR reflects a fully secured rate based on our credit rating, taking into consideration the repayment timing of the lease and any impacts due to the economic environment in which the lease operates. Lease right-of-use assets and liabilities are recognized based on the present value of the fixed future lease payments over the lease term. Lease expense for all operating leases is classified in Cost of products sold or Selling, general and administrative expense in the Consolidated Statements of Income. For finance leases, the amortization of the right-of-use asset is included in depreciation and amortization, and the interest is included in interest expense. As a lessee, we have various operating lease agreements primarily related to real estate, vehicles and office and plant equipment. Our lease payments are largely fixed. Variable lease payments that depend on an index or a rate are included in the lease payments and are measured using the prevailing index or rate at the measurement date, with differences between the calculated lease payment and the actual lease payment being expensed in the period of the change. Other variable lease payments, including utilities, consumption and common area maintenance as well as repairs, maintenance and mileage overages on vehicles, are expensed during the period incurred. Variable lease costs were immaterial for the twelve months ended December 31, 2020. A majority of our real estate leases include options to extend the lease and options to early terminate the lease. Leases with an early termination option generally involve a termination payment. If we are reasonably certain to exercise an option to extend a lease, the extension period is included as part of the right-of-use asset and the lease liability. Some of our leases contain residual value guarantees. These are guarantees made to the lessor that the value of an underlying asset returned to the lessor at the end of a lease will be at least a specified amount. Our leases do not contain restrictions or covenants that restrict us from incurring other financial obligations. We do not have any significant leases not yet commenced. For our leases, we have elected to not apply the recognition requirements to leases of less than twelve months. These leases are expensed on a straight-line basis and are not included within the Company's operating lease asset or liability. Lease costs associated with leases of less than twelve months were immaterial for the three and twelve months ended December 31, 2020. We did not have any lease transactions with related parties. Other Information Twelve Months Ended December 31, (In thousands, except percentage amounts) 2020 2019 Lease cost: Operating lease cost recognized as rent expense $ 12,997 $ 13,364 Total lease cost 12,997 13,364 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows related to operating leases $ 13,476 $ 13,346 Non-cash other information: Right-of-use assets obtained in exchange for new operating lease liabilities $ 10,737 $ 6,637 December 31, 2020 December 31, 2019 Weighted-average remaining lease term (in years): Operating leases 11 11 Weighted-average discount rate: Operating leases 3.89 % 4.28 % Rent expense was approximately $13.0 million in 2020, $13.4 million in 2019 and $12.5 million in 2018. At December 31, 2020, future lease payments under operating leases were as follows: (In thousands) Operating Leases 2021 $ 11,445 2022 7,856 2023 6,266 2024 4,539 2025 4,692 After 2025 31,687 Total future minimum operating lease payments $ 66,485 Less: Imputed interest 12,258 Present value of operating lease liabilities 54,227 Less: Current portion operating lease liabilities (a) 9,588 Noncurrent operating lease liabilities $ 44,639 (a) Included in "Warranty reserve and other current liabilities" on the Consolidated Balance Sheet.

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments As part of our currency exchange rate risk management strategy, we enter into certain derivative foreign currency forward contracts that do not meet the U.S. GAAP criteria for hedge accounting but have the impact of partially offsetting certain foreign currency exposures. We account for these forward contracts at fair value and report the related gains or losses in currency exchange losses, net, in the Consolidated Statements of Income. At December 31, 2020, the notional amount of open forward contracts was $96.0 million and there was no unrealized gain/loss on these contracts. All open forward contracts will mature during the first quarter of 2021. The following table presents the Consolidated Balance Sheets location and fair value of assets and liabilities associated with derivative financial instruments: December 31, (In thousands) 2020 2019 Derivatives not designated as hedging instruments: Foreign exchange contracts: other current liabilities $ 157 $ 125 Foreign exchange contracts: other current assets 160 687 The following table presents the Consolidated Statements of Income location and impact of derivative financial instruments: (In thousands) Income Statement Location (Gain) Loss Recognized in Income Year ended 2020 2019 Derivatives not designated as hedging instruments: Foreign exchange contracts Currency exchange losses, net $ (7,457) $ 3,015

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The fair value hierarchy consists of three broad levels, which gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). The three levels of the fair value hierarchy are: Level 1—Observable inputs that reflect unadjusted quoted prices for identical assets or liabilities in active markets. Level 2—Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. Level 3—Unobservable inputs for the asset or liability. The valuation methodologies we used to measure financial assets and liabilities were limited to the pension plan assets described in Note 14—Pensions and Other Post-retirement Benefits and the derivative financial instruments described in Note 17—Derivative Financial Instruments. See Note 14 for the fair value hierarchy classification of pension plan assets. We estimate the fair value of the derivative financial instruments, consisting of foreign currency forward contracts, based upon valuation models with inputs that generally can be verified by observable market conditions and do not involve significant management judgment. Accordingly, the fair values of the derivative financial instruments are classified within Level 2 of the fair value hierarchy. With the exception of our investments in marketable securities and fixed rate long-term debt both as disclosed below, we believe that the reported carrying amounts of our remaining financial assets and liabilities approximate their fair values.

Contingencies

Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies Product liability We face an inherent business risk of exposure to product liability claims arising from the alleged failure of our products to prevent the types of personal injury or death against which they are designed to protect. Product liability claims are categorized as either single incident or cumulative trauma. Single incident product liability claims. Single incident product liability claims involve incidents of short duration that are typically known when they occur and involve observable injuries, which provide an objective basis for quantifying damages. The Company estimates its liability for single incident product liability claims based on expected settlement costs for asserted single incident product liability claims, and an estimate of costs for single incident product liability claims incurred but not reported ("IBNR"). The estimate for IBNR claims is based on experience, sales volumes, and other relevant information. The reserve for single incident product liability claims, which includes asserted single incident product liability claims and IBNR single incident product liability claims, was $1.4 million at December 31, 2020 and $3.1 million at December 31, 2019. Single incident product liability expense was a benefit of $1.7 million for the year ended December 31, 2020 compared to a benefit of $0.5 million and expense of $2.0 million for the years ended December 31, 2019 and 2018, respectively. Single incident product liability exposures are evaluated on an annual basis, or more frequently if changing circumstances warrant. Adjustments are made to the reserve as appropriate. Cumulative trauma product liability claims. Cumulative trauma product liability claims involve exposures to harmful substances (e.g., silica, asbestos and coal dust) that occurred years ago and may have developed over long periods of time into diseases such as silicosis, asbestosis, mesothelioma, or coal worker’s pneumoconiosis. One of the Company's affiliates, Mine Safety Appliances Company, LLC ("MSA LLC"), was named as a defendant in 1,622 lawsuits comprised of 2,878 claims as of December 31, 2020. These lawsuits mainly involve respiratory protection products allegedly manufactured and sold by MSA LLC or its predecessors. The products at issue were manufactured many years ago and are not currently offered by MSA LLC. A summary of cumulative trauma product liability lawsuits and asserted cumulative trauma product liability claims activity is as follows: 2020 2019 2018 Open lawsuits, beginning of period 1,605 1,481 1,420 New lawsuits 402 346 369 Settled and dismissed lawsuits (385) (222) (308) Open lawsuits, end of period 1,622 1,605 1,481 2020 2019 2018 Asserted claims, beginning of period 2,456 2,355 2,242 New claims 917 486 479 Settled, inactive and dismissed claims (495) (385) (366) Asserted claims, end of period 2,878 2,456 2,355 The increase in the number of claims in 2020 is largely attributable to an increase in claims alleging injuries from exposure to coal mine dust. More than half of the total open lawsuits at December 31, 2020 have had a de minimis level of activity over the last 5 years. It is possible that these cases could become active again at any time due to changes in circumstances. Total cumulative trauma product liability reserve was $221.5 million, including $7.8 million for claims settled but not yet paid and related defense costs, as of December 31, 2020 and $167.5 million, including $3.0 million for claims settled but not yet paid and related defense costs, as of December 31, 2019. This reserve includes estimated amounts for asserted claims and IBNR claims. Those estimated amounts reflect asbestos, silica, and coal dust claims expected to be resolved through the year 2069 and are not discounted to present value. The Company revised its estimates of MSA LLC's potential liability for cumulative trauma product liability claims for the year ended December 31, 2020 as a result of its annual review process described below. The reserve does not include amounts which will be spent to defend the claims covered by the reserve. Defense costs are recognized in the Consolidated Statements of Income as incurred. At December 31, 2020, $35.3 million of the total reserve for cumulative trauma product liability claims is recorded in the Insurance and product liability line within other current liabilities in the Consolidated Balance Sheets and the remainder, $186.2 million, is recorded in the Product liability and other noncurrent liabilities line. At December 31, 2019, $17.4 million of the total reserve for cumulative trauma product liability claims was recorded in the Insurance and product liability line within other current liabilities in the Consolidated Balance Sheet and the remainder, $150.1 million, was recorded in the Product liability and other noncurrent liabilities line. Total cumulative trauma liability losses were $77.8 million, $36.1 million, and $63.8 million for the years ended December 31, 2020, 2019 and 2018, respectively. Uninsured cumulative trauma product liability losses which were included in Product liability and other operating expense on the Consolidated Statements of Income during the years ended December 31, 2020, 2019 and 2018, were $39.0 million, $27.1 million and $43.8 million, respectively, and represent the total cumulative trauma liability losses net of any estimated insurance receivables as discussed below. To develop a reasonable estimate of MSA LLC’s potential exposure to cumulative trauma product liability claims, Management performs an annual review of MSA LLC’s cumulative trauma product liability claims, in consultation with an outside valuation consultant and outside legal counsel. The review process takes into account developments in MSA LLC’s claims experience over the past year, developments in the tort system generally, and any other relevant information. Quarterly, management and outside legal counsel review whether significant new developments have occurred which could materially impact recorded amounts. Certain significant assumptions underlying the material components of the reserve for cumulative trauma product liability claims have been made based on MSA LLC's experience related to the following: • The types and severity, of illnesses alleged by claimants to give rise to their claims; • The venues in which claims are asserted; • The number of claims that may be asserted in the future against MSA LLC and the counsel asserting those claims; and • The percentage of claims resolved through settlement and the values of settlements paid to claimants. Additional assumptions include the following: • MSA LLC will continue to evaluate and handle cumulative trauma product liability claims in accordance with its existing defense strategy; • The number and effect of co-defendant bankruptcies will not materially change in the future; • No material changes in medical science occur with respect to cumulative trauma product liability claims; and • No material changes in law occur with respect to cumulative trauma product liability claims including no material state or federal tort reform actions. Cumulative trauma product liability litigation is inherently unpredictable and MSA LLC's expense with respect to cumulative trauma product liability claims could vary significantly in future periods. With respect to asserted claims, this is because it is unclear at the time of filing whether a claim will be actively litigated. Even when a case is actively litigated, it is often difficult to determine if the lawsuit will be dismissed without payment or settled, because of sufficiency of product identification, statute of limitations challenges, or other defenses. As a result, it is typically unclear until late into a lawsuit whether any particular claim will result in a loss and, if so, to what extent. Actual loss amounts for settled claims are highly variable and turn on a case-by-case analysis of the relevant facts. With respect to asserted or IBNR claims, MSA LLC’s expense in future periods may vary from the reserve currently established for several reasons. In particular, MSA LLC’s actual claims experience may differ in one or more respects from the significant assumptions listed above that were used by in establishing the reserve. Factors that make MSA LLC's asserted and IBNR claims difficult to reasonably estimate include uncertainty as to the number of claims that may be asserted in the future (and over what time periods), the wide variability in the alleged severity of claims asserted, and the number of claims that ultimately will be resolved with payment. This difficulty is increased when claims are asserted by plaintiff's counsel with which MSA LLC does not have substantial prior experience (as claims experience can vary significantly among different counsel), the absence of discovery into many pending claims, the historically low volume of claims asserted and resolved, and numerous other factors. Numerous uncertainties also exist with respect to factors not specific to MSA LLC, including potential legislative or judicial changes at the federal level or in key states concerning claims adjudication, future bankruptcy proceedings involving key co-defendants, payments from trusts established to compensate claimants, and/or changes in medical science relating to the diagnosis and treatment of claims. Because cumulative trauma product liability litigation is subject to the significant modeling assumptions and inherent uncertainties described above, and unfavorable developments or rulings could occur, there can be no certainty that MSA LLC may not ultimately incur charges in excess of presently recorded liabilities. The reserve for cumulative trauma product liability claims may be adjusted from time to time based on changes to the factors and assumptions described above. If future estimates of cumulative trauma product liability claims are materially different than the accrued liability, we will record an appropriate adjustment to the Consolidated Statement of Income. These adjustments could materially impact our consolidated financial statements in future periods. Insurance Receivable and Notes Receivable, Insurance Companies Many years ago, MSA LLC purchased insurance policies from various insurance carriers that, subject to common contract exclusions, provided coverage for cumulative trauma product liability losses (the "Occurrence-Based Policies"). While we continue to pursue reimbursement under certain remaining Occurrence-Based Policies, the vast majority of these policies have been exhausted, settled or converted into either (1) negotiated settlement agreements, with scheduled payment streams (recorded as notes receivables) or (2) negotiated Coverage-in-Place Agreements (recorded as insurance receivables). As a result, MSA LLC is largely self-insured for cumulative trauma product liability claims, and additional amounts recorded as insurance receivables or notes receivables will be limited. When adjustments are made to amounts recorded in the cumulative trauma product liability reserve, we calculate amounts due to be reimbursed pursuant to the terms of the negotiated Coverage-In-Place Agreements, including cumulative trauma product liability losses and related defense costs, and we record the amounts probable of reimbursement as insurance receivables. These amounts are not subject to current coverage litigation. Insurance receivables at December 31, 2020, totaled $97.0 million, of which $12.0 million is reported in Prepaid expenses and other current assets in the Consolidated Balance Sheet and $85.0 million is reported in Insurance receivable and other noncurrent assets. Insurance receivables at December 31, 2019, totaled $63.8 million, of which $7.6 million was reported in Prepaid expenses and other current assets in the Consolidated Balance Sheet and $56.2 million was reported in Insurance receivable and other noncurrent assets. The vast majority of the $97.0 million insurance receivables balance at December 31, 2020, is attributable to reimbursement believed to be due under the terms of signed Coverage-In-Place Agreements and a portion of this amount represents the estimated recovery of IBNR amounts not yet incurred. A summary of insurance receivables balance and activity related to cumulative trauma product liability losses is as follows: (In millions) 2020 2019 Balance beginning of period $ 63.8 $ 71.7 Additions 39.0 9.1 Collections and other adjustments (5.8) (17.0) Balance end of period $ 97.0 $ 63.8 We record formal notes receivables due from scheduled payment streams according to negotiated settlement agreements with insurers. These amounts are not subject to current coverage litigation. Notes receivable from insurance companies at December 31, 2020, totaled $52.3 million, of which $3.8 million is reported in Notes receivable, insurance companies, current on the Consolidated Balance Sheet and $48.5 million is reported in Notes receivable, insurance companies, noncurrent. Notes receivable from insurance companies at December 31, 2019, totaled $56.0 million, of which $3.7 million was reported in Notes receivable, insurance companies, current on the Consolidated Balance Sheet and $52.3 million was reported in Notes receivable, insurance companies, noncurrent. A summary of notes receivables from insurance companies balance is as follows: December 31, (In millions) 2020 2019 Balance beginning of period $ 56.0 $ 59.6 Additions 1.4 1.5 Collections (5.1) (5.1) Balance end of period $ 52.3 $ 56.0 The vast majority of the insurance receivables balances at December 31, 2020, is attributable to reimbursement under the terms of signed agreements with insurers and are not currently subject to litigation. The collectibility of MSA LLC's insurance receivables and notes receivables is regularly evaluated and we believe that the amounts recorded are probable of collection. The determination that the recorded insurance receivables are probable of collection is based on the terms of the settlement agreements reached with the insurers, our history of collection, and the advice of MSA LLC's outside legal counsel and consultants. Various factors could affect the timing and amount of recovery of the insurance and notes receivables, including assumptions regarding various aspects of the composition and characteristics of future claims (which are relevant to calculating reimbursement under the terms of certain Coverage-In-Place Agreements) and the extent to which the issuing insurers may become insolvent in the future. Product Warranty The Company provides warranties on certain product sales. Product warranty reserves are established in the same period that revenue from the sale of the related products is recognized, or in the period that a specific issue arises as to the functionality of the Company's product. The determination of such reserves requires the Company to make estimates of product return rates and expected costs to repair or to replace the products under warranty. The amounts of the reserves are based on established terms and the Company's best estimate of the amounts necessary to settle future and existing claims on products sold as of the balance sheet date. If actual return rates and/or repair and replacement costs differ significantly from estimates, adjustments to recognize additional cost of sales may be required in future periods. The following table reconciles the changes in the Company's accrued warranty reserve: December 31, (In thousands) 2020 2019 2018 Beginning warranty reserve $ 12,715 $ 14,214 $ 14,753 Warranty payments (10,861) (12,664) (9,955) Warranty claims 10,233 12,033 10,585 Provision for product warranties and other adjustments (659) (868) (1,169) Ending warranty reserve $ 11,428 $ 12,715 $ 14,214 Warranty expense for the years ended December 31, 2020, 2019 and 2018 was $9.6 million, $11.2 million and $9.4 million, respectively and is included in Costs of products sold on the Consolidated Statements of Income.

Subsequent Event

Subsequent Event	12 Months Ended
	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Event	Subsequent Event On January 25, 2021, we acquired 100% of the common stock of B T Q Limited, including Bristol Uniforms and Bell Apparel ("Bristol") in an all-cash transaction valued at $62.4 million, net of cash acquired. There is no contingent consideration. Bristol, which is headquartered in the U.K., is a leading innovator and provider of protective apparel to the fire, rescue services and utility sectors. The acquisition strengthens MSA's position as a global leader in fire service PPE products while providing an avenue to expand its business in the U.K. and key European markets. Our results for the year ended December 31, 2020 include transaction and integration costs of $0.5 million related to the acquisition. These costs are reported in selling, general and administrative expenses. Bristol operating results will be included in our financial statements from the acquisition date. The acquisition qualifies as a business combination and will be accounted for using the acquisition method of accounting. At the date of issuance of these financial statements, the initial purchase accounting was not complete. We are also unable to provide pro forma revenues and earnings of the combined entity due to the limited time since the acquisition. This information will be included in our Quarterly Report on Form 10-Q for the quarter ended March 31, 2021.

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2020
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts	2020 2019 2018 (In thousands) Allowance for doubtful accounts: Balance at beginning of year $ 4,860 $ 5,369 $ 5,540 Additions— Charged to costs and expenses 1,172 2,015 375 Deductions— Deductions from reserves, net (1)(2) 688 2,524 546 Balance at end of year $ 5,344 $ 4,860 $ 5,369 Income tax valuation allowance: Balance at beginning of year $ 5,936 $ 5,039 $ 4,559 Additions— Charged to costs and expenses (3) 2,854 1,138 859 Deductions— Deductions from reserves (3) 1,602 241 379 Balance at end of year $ 7,188 $ 5,936 $ 5,039 (1) Bad debts written off, net of recoveries. (2) Activity for 2020, 2019 and 2018 includes currency translation losses of $(107), $(1,058) and $(291), respectively. (3) Activity for 2020, 2019 and 2018 includes currency translation (losses) gains of $(41), $104 and $(367), respectively.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation— The consolidated financial statements of MSA Safety Incorporated ("MSA" or "the Company") are prepared in conformity with accounting principles generally accepted in the United States of America (U.S. GAAP) and require management to make certain judgments, estimates, and assumptions. These may affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the consolidated financial statements. They also may affect the reported amounts of revenues and expenses during the period. Actual results could differ from those estimates upon subsequent resolution of identified matters.
Principles of Consolidation	Principles of Consolidation— The consolidated financial statements include the accounts of the Company and all subsidiaries. Intercompany accounts and transactions are eliminated.
Noncontrolling Interests	Noncontrolling Interests— Noncontrolling interests reflect noncontrolling shareholders’ investments in certain consolidated subsidiaries and their proportionate share of the income and accumulated other comprehensive income (loss) of those subsidiaries.
Currency Translation	Currency Translation— The functional currency of all significant non-U.S. subsidiaries is the local country currency. Assets and liabilities of these operations are translated at year-end exchange rates. Income statement accounts are translated using the average exchange rates for the reporting period. Translation adjustments for these companies are reported as a component of shareholders’ equity and are not included in income. Foreign currency transaction gains and losses are included in net income for the reporting period.
Cash Equivalents	Cash Equivalents—Cash equivalents include temporary deposits with financial institutions and highly liquid investments with original maturities of 90 days or less. Other highly liquid investments consist of money market funds and balances were $0.6 million and $17.9 million at December 31, 2020 and 2019, respectively. These funds are valued at net asset value (“NAV”). The money market funds are required to price and transact at a NAV per share that fluctuates based upon the pricing of the underlying portfolio of securities and this requirement may impact the value of those fund shares.
Restricted Cash	Restricted Cash— Restricted cash, which is designated for use other than current operations, is included in prepaid expenses and other current assets in the Consolidated Balance Sheets. Restricted cash balances were $0.4 million and $0.3 million at December 31, 2020 and 2019, respectively. These balances were used to support letter of credit balances.
Inventories	Inventories— Inventories are stated at the lower of cost or net realizable value. The majority of U.S. inventories are valued on the last-in, first-out (LIFO) cost method which is used since this method provides better matching of costs and revenues. Other inventories are valued at standard costs which approximate actual costs. It is the Company's general policy to write-down any inventory identified as obsolete. Additionally, it will write-down any inventory balance in excess of the last twenty-four months of consumption.
Investment Securities	Investment securities — The Company’s investment securities, primarily fixed income, are classified as available-for-sale. The securities are recorded at fair market value and reported in “Investments, short-term” in the accompanying Consolidated Balance Sheets with changes in fair market value recorded in other comprehensive income, net of tax. The purchases and sales of these investments are classified as investing activities in the Consolidated Statements of Cash Flows.
Property and Depreciation	Property and Depreciation—Property is recorded at cost. Depreciation is computed primarily using the straight-line method over the estimated useful lives of the assets, generally as follows: buildings 20 to 40 years and machinery and equipment 3 to 10 years. Expenditures for significant renewals and improvements are capitalized. Ordinary repairs and maintenance are expensed as incurred. Gains or losses on property dispositions are included in other income, net and the cost and related depreciation are removed from the accounts. Depreciation expense for the years ended December 31, 2020, 2019 and 2018 was $27.7 million, $26.5 million and $26.9 million, respectively. Properties, plants, and equipment are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets or asset groups may not be recoverable.
Internal Use Software	Software Development Costs—Software development costs consist primarily of costs incurred in software development and related personnel compensation to create, enhance and deploy the Company’s broad range of wireless technology and cloud-based computing safety services. Software development costs, other than software development costs qualifying for capitalization, are expensed as incurred. Costs of computer software developed or obtained for internal use that are incurred in the preliminary project and post implementation stages are expensed as incurred. Certain costs incurred during the application and development stage, which primarily include compensation and related expenses, are capitalized. Additionally, costs of upgrades and enhancements are capitalized when it is probable that the upgrades and enhancements will result in added functionality. Capitalized costs are amortized through Cost of products sold using the straight-line method over the estimated useful life, which is normally three years, beginning in the period in which the software is ready for its intended use or when the upgrade or enhancement is deployed. During 2020, 2019, and 2018 there was approximately $8.2 million, $5.0 million and $1.6 million, respectively, of software development costs capitalized.
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets— Intangible assets with a finite useful life are amortized on a straight-line basis over their useful lives. Indefinite lived intangible assets are assessed for possible impairment annually on October 1st or whenever circumstances change such that the recorded value of the asset may not be recoverable. We performed a quantitative assessment of the indefinite lived trade name intangible asset as outlined in Accounting Standards Codification ("ASC") 350 by comparing the estimated fair value of the trade name intangible asset to its carrying value. We estimate the fair value using the relief from royalty income approach. A number of assumptions and estimates are involved in the application of the relief from royalty model, including sales volumes and prices, royalty rates and tax rates. Forecasts are based on sales generated by the underlying trade name assets and are generally based on approved business unit operating plans for the early years and historical relationships in later years. Based on these assessments, no impairments were identified during the years ended December 31, 2020, 2019 or 2018. Goodwill is not amortized, but is subject to impairment assessments. On October 1st of each year, or more frequently if indicators of impairment exist or if a decision is made to sell a business, we evaluate goodwill for impairment. Judgment is involved in determining if an indicator of impairment has occurred. Such indicators may include a decline in expected cash flows, a significant adverse change in the business climate, unanticipated competition, slower growth rates, or negative developments in equity and credit markets, among others. All goodwill is assigned to and evaluated for impairment at the reporting unit level, which is defined as an operating segment or one level below an operating segment. The evaluation of impairment involves using either a qualitative or quantitative approach as outlined in ASC Topic 350. In 2020, we performed a two-step quantitative test at October 1, 2020. Step 1 of the quantitative testing involves comparing the estimated fair value of each reporting unit to its carrying value. We estimate reporting unit fair value using a weighted average of fair values determined by discounted cash flow (DCF) and market approach methodologies, as we believe both are important indicators of fair value. A number of assumptions and estimates are involved in the application of the DCF model, including sales volumes and prices, costs to produce, tax rates, capital spending, discount rates, and working capital changes. Cash flow forecasts are generally based on approved reporting unit operating plans for the early years and historical relationships in later years. The market approach methodology measures value through an analysis of peer companies. The analysis entails measuring the multiples of EBITDA at which peer companies are trading. There has been no impairment of our goodwill during the years ended December 31, 2020, 2019 or 2018.
Revenue Recognition	Revenue Recognition— We account for revenue in accordance with ASC Topic 606, Revenue from Contracts with Customers , which we adopted on January 1, 2018, using the modified retrospective method. Revenue from the sale of products is recognized when there is persuasive evidence of an arrangement and control passes to the customer, which generally occurs either when product is shipped to the customer or, in the case of most U.S. distributor customers, when product is delivered to the distributor's delivery site. We establish our shipping terms according to local practice and market characteristics. We do not ship product unless we have an order or other documentation authorizing shipment to our customers. Our payment terms vary by the type and location of our customer and the products offered. The term between invoicing and when payment is due is not significant.
Product Warranties	Product Warranties— Estimated expenses related to product warranties and additional service actions are charged to Cost of products sold in the period in which the related revenue is recognized or when significant product quality issues are identified.
Research and Development	Research and Development— Research and development costs are expensed as incurred.
Income Taxes	Income Taxes— Deferred income taxes are recognized for temporary differences between financial and tax reporting. Deferred tax assets and liabilities are measured using enacted tax rates in effect for the year in which those temporary differences are expected to be recovered or settled. If it is more likely than not that some portion or all of a deferred tax asset will not be realized, a valuation allowance is recognized. We record tax benefits related to uncertain tax positions taken or expected to be taken on a tax return when such benefits meet a more likely than not threshold. We recognize interest related to unrecognized tax benefits in interest expense and penalties in operating expenses. Deferred taxes are booked for available cash in excess of working capital for non-U.S. subsidiaries as these earnings are not considered to be permanently reinvested.
Stock-Based Compensation	Stock-Based Compensation— We recognize expense for employee and non-employee director stock-based compensation based on the grant date fair value of the awards. Except for retirement-eligible participants, for whom there is no requisite service period, this expense is recognized ratably over the requisite service periods following the date of grant. For retirement-eligible participants, this expense is recognized over an accelerated period of at least one year.
Derivative Instruments	Derivative Instruments— We may use derivative instruments to minimize the effects of changes in currency exchange rates. We do not enter into derivative transactions for speculative purposes and do not hold derivative instruments for trading purposes. Changes in the fair value of derivative instruments designated as fair value hedges are recorded in the balance sheet as adjustments to the underlying hedged asset or liability. Changes in the fair value of derivative instruments that do not qualify for hedge accounting treatment are recognized in the Consolidated Statements of Income and Consolidated Statements of Cash Flows as Currency exchange losses, net in the current period.
Commitments and Contingencies	Commitments and Contingencies— For asserted claims and assessments, liabilities are recorded when a loss is deemed to be probable and the amount of the loss is reasonably estimable. Management assesses the probability of an unfavorable outcome with respect to asserted claims or assessments based on many factors such as the nature of the matter, available defenses and case strategy, progress of the matter, views and opinions of legal counsel and other advisors, applicability and success of appeals processes, and the outcome of similar historical matters, among others. Once an unfavorable outcome is assessed to be probable, management evaluates estimates of the potential loss, and the most reasonable loss estimate is recorded (or, if the estimate of the loss is a range, and no amount within the range is considered to be a better estimate than any other amount, the minimum amount in the range is recorded). If a loss is deemed to be reasonably possible but less than probable and/or such loss cannot be reasonably estimated, then the matter is disclosed and no liability is recorded.
Concentration of Credit and Business Risks	Concentration of credit and business risks - We are exposed to credit risk in the event of nonpayment by customers, principally in the oil, gas and petrochemical, fire service, construction, utilities, and mining industries. Changes in these industries or other developments may significantly affect our financial performance and management's estimates. We mitigate our exposure to credit risk by performing ongoing credit evaluations and, when deemed necessary, requiring letters of credit, credit insurance, prepayments, guarantees or other collateral. No individual customer represented more than 10% of our sales or receivables.
Recently Adopted and Recently Issued Accounting Standards	Recently Adopted and Recently Issued Accounting Standards— In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses. This ASU introduces an approach based on expected losses to estimate credit losses on certain types of financial instruments, including loans, held-to-maturity debt securities, loan commitments, financial guarantees and net investments in leases, as well as reinsurance and trade receivables. This ASU was adopted on January 1, 2020, which did not have an impact on the consolidated financial statements. In January 2018, the FASB issued ASU 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income ("AOCI"), which gives entities the option to reclassify to retained earnings the tax effects resulting from the new tax reform legislation commonly known as the Tax Cuts and Jobs Act of 2017 (the "Act") related to items in AOCI that the FASB refers to as having been stranded in AOCI. The new guidance may be applied retrospectively to each period in which the effect of the Act is recognized in the period of adoption. ASU2018-02 requires new disclosures regarding the Company’s accounting policy for releasing the tax effects in accumulated other comprehensive loss and allows the Company to reclassify the effect of remeasuring deferred tax liabilities and assets related to items within accumulated other comprehensive loss using the then newly enacted 21% federal corporate income tax rate. The Company adopted ASU 2018-02 on January 1, 2019, and this adoption resulted in a reclassification that increased retained earnings by $3.8 million, with an offsetting increase to accumulated other comprehensive loss for the same amount. In August 2018, the FASB issued ASU 2018-13, Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement , which improves fair value disclosure requirements by removing disclosures that are not cost beneficial, clarifying disclosures’ specific requirements and adding relevant disclosure requirements. This ASU was effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019, and was adopted in 2020. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. The Company's adoption of ASU 2018-13 did not have an impact on the consolidated financial statements, but did change our disclosures. In August 2018, the FASB issued ASU 2018-14, Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans , which improves defined benefit disclosure requirements by removing disclosures that are not cost beneficial, clarifying disclosures’ specific requirements and adding relevant disclosure requirements. This ASU is effective for fiscal years ending after December 15, 2020, and early adoption is permitted. The amendments in this ASU are required to be applied on a retrospective basis to all periods presented. The Company adopted ASU 2018-14 on December 31, 2020, which did not have an impact on the consolidated financial statements, but did change our disclosures.

Restructuring and Other Charg_2

Restructuring and Other Charges (Tables)	12 Months Ended
	Dec. 31, 2020
Restructuring and Related Activities [Abstract]
Restructuring and Related Costs	Activity and reserve balances for restructuring charges by segment were as follows: (in millions) Americas International Corporate Total Reserve balances at January 1, 2018 $ 0.5 $ 3.6 $ — $ 4.1 Restructuring charges 2.3 5.6 5.3 13.2 Currency translation and other adjustments (0.3) (0.3) — (0.6) Cash payments (2.0) (4.9) (5.3) (12.2) Reserve balances at December 31, 2018 $ 0.5 $ 4.0 $ — $ 4.5 Restructuring charges 0.5 12.7 0.6 13.8 Currency translation and other adjustments (0.1) (0.6) — (0.7) Cash payments / utilization (0.6) (10.2) (0.6) (11.4) Reserve balances at December 31, 2019 $ 0.3 $ 5.9 $ — $ 6.2 Restructuring charges 4.7 21.9 0.8 27.4 Currency translation and other adjustments (0.1) 0.1 — — Cash payments / utilization (2.1) (8.6) (0.4) (11.1) Reserve balances at December 31, 2020 $ 2.8 $ 19.3 $ 0.4 $ 22.5

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Schedule of Inventories	The following table sets forth the components of inventory: December 31, (In thousands) 2020 2019 Finished products $ 81,048 $ 71,918 Work in process 2,618 4,083 Raw materials and supplies 161,300 151,129 Inventories at current cost 244,966 227,130 Less: LIFO valuation (47,147) (42,103) Total inventories $ 197,819 $ 185,027

Property, Plant, and Equipment

Property, Plant, and Equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	The following table sets forth the components of property, plant and equipment: December 31, (In thousands) 2020 2019 Land $ 4,275 $ 4,194 Buildings 128,887 125,223 Machinery and equipment 422,333 397,287 Construction in progress 38,753 24,759 Total 594,249 551,463 Less accumulated depreciation (404,629) (384,425) Property, plant and equipment, net $ 189,620 $ 167,038

Reclassifications Out of Accu_2

Reclassifications Out of Accumulated Other Comprehensive Loss (Tables)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Reclassifications Out of Accumulated Other Comprehensive Loss	MSA Safety Incorporated Noncontrolling Interests (In thousands) 2020 2019 2018 2020 2019 2018 Pension and other post-retirement benefits (a) Balance at beginning of period $ (124,848) $ (115,517) $ (97,948) $ — $ — $ — Unrecognized net actuarial losses (6,322) (19,479) (37,977) — — — Tax benefit 1,997 5,847 9,936 — — — Total other comprehensive loss before reclassifications, net of tax (4,325) (13,632) (28,041) — — — Amounts reclassified from accumulated other comprehensive loss into net income: Amortization of prior service credit (Note 14) (216) (180) (424) — — — Recognized net actuarial losses (Note 14) 18,079 11,028 14,507 — — — Tax benefit (4,242) (2,775) (3,611) — — — Total amount reclassified from accumulated other comprehensive loss, net of tax, into net income 13,621 8,073 10,472 — — — Reclassification to retained earnings due to the adoption of ASU 2018-02 (Note 1) — (3,772) — — — — Total other comprehensive income (loss) $ 9,296 $ (9,331) $ (17,569) $ — $ — $ — Balance at end of period $ (115,552) $ (124,848) $ (115,517) $ — $ — $ — Available-for-sale securities Balance at beginning of period $ 6 $ (572) $ — $ — $ — $ — Unrealized (loss) gain on available-for-sale securities (Note 18) (7) 578 (572) — — — Balance at end of period $ (1) $ 6 $ (572) $ — $ — $ — Foreign currency translation Balance at beginning of period $ (89,161) $ (102,838) $ (73,814) $ 423 $ 496 $ 801 Reclassification from accumulated other comprehensive loss into net income 216 (c) 15,261 (b) 774 (c) — — — Foreign currency translation adjustments 22,101 (1,584) (29,798) 159 (73) (305) Balance at end of period $ (66,844) $ (89,161) $ (102,838) $ 582 $ 423 $ 496

Capital Stock (Tables)

Capital Stock (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure Capital Stock Additional Information [Abstract]
Schedule Of Common Stock Activity	Common stock activity is summarized as follows: Shares Dollars (Dollars in thousands) Issued Treasury Common Treasury Balances January 1, 2018 62,081,391 (23,858,463) $ 194,953 $ (296,081) Restricted stock awards — 92,401 (1,079) 1,079 Restricted stock expense — — 6,504 — Restricted stock forfeitures — — (283) Stock options exercised — 215,724 5,738 2,835 Stock option expense — 272 — Stock option forfeitures — — (55) — Performance stock issued — 41,660 (523) 523 Performance stock expense — — 6,186 — Performance stock forfeitures — (385) — Employee stock purchase plan — 7,725 478 78 Treasury shares purchased for stock compensation programs — (53,915) — (4,824) Balances December 31, 2018 62,081,391 (23,554,868) $ 211,806 $ (296,390) Restricted stock awards — 96,893 (1,253) 1,253 Restricted stock expense — — 7,397 — Restricted stock forfeitures — — (483) — Stock options exercised — 193,681 5,107 2,364 Stock option expense — — 492 — Stock option forfeitures — — (5) — Performance stock issued — 139,478 (1,778) 1,778 Performance stock expense — — 6,574 — Performance stock forfeitures — — (215) — Stock consideration in acquisition — — 921 — Employee stock purchase plan — 5,895 564 77 Treasury shares purchased for stock compensation programs — (87,811) — (9,301) Share repurchase program — (33,465) — (3,347) Balances December 31, 2019 62,081,391 (23,240,197) $ 229,127 $ (303,566) Restricted stock awards — 55,691 (773) 773 Restricted stock expense — — 7,065 — Restricted stock forfeitures — — (807) — Stock options exercised — 274,672 8,590 3,856 Stock option expense — — 153 — Stock option forfeitures — — (40) — Performance stock issued — 134,824 (1,826) 1,826 Performance stock expense — — 1,305 — Performance stock forfeitures — — (755) — Employee stock purchase plan — 6,494 654 93 Treasury shares purchased for stock compensation programs — (69,973) — (9,025) Share repurchase program — (175,000) — (20,113) Balances December 31, 2020 62,081,391 (23,013,489) $ 242,693 $ (326,156)

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Schedule Of Reportable Segment Information	Reportable segment information is presented in the following table: (In thousands) Americas International Corporate Reconciling Items (1) Consolidated 2020 Net sales to external customers $ 874,305 $ 473,918 $ — $ — $ 1,348,223 Operating income 166,851 Restructuring charges (Note 2) 27,381 Currency exchange losses, net (Note 5) 8,578 Product liability expense (Note 19) 39,036 Strategic transaction costs (Note 13) 717 COVID-19 related costs 757 Adjusted operating income (loss) 200,536 70,864 (28,080) — 243,320 Adjusted operating margin % 22.9 % 15.0 % Depreciation and amortization 26,762 12,521 391 — 39,674 Adjusted EBITDA 227,298 83,385 (27,689) — 282,994 Adjusted EBITDA % 26.0 % 17.6 % Noncash items: Pension expense 910 8,113 — — 9,023 Total Assets 1,228,739 615,114 29,761 (1,130) 1,872,484 Capital expenditures 43,181 5,724 — — 48,905 2019 Net sales to external customers $ 915,118 $ 486,863 $ — $ — $ 1,401,981 Operating income 186,230 Restructuring charges (Note 2) 13,846 Currency exchange losses, net (Note 5) 19,814 Product liability expense (Note 19) 26,619 Strategic transaction costs (Note 13) 4,400 Adjusted operating income (loss) 226,596 59,910 (35,597) — 250,909 Adjusted operating margin % 24.8 % 12.3 % Depreciation and amortization 24,691 12,938 391 — 38,020 Adjusted EBITDA 251,287 72,848 (35,206) — 288,929 Adjusted EBITDA % 27.5 % 15.0 % Noncash items: Pension (income) expense (6,111) 7,044 — — 933 Total Assets 1,131,911 584,195 22,367 1,220 1,739,693 Capital expenditures 26,823 9,781 — — 36,604 2018 Net sales to external customers $ 854,287 $ 503,817 $ — $ — $ 1,358,104 Operating income 173,479 Restructuring charges (Note 2) 13,247 Currency exchange losses, net (Note 5) 2,330 Product liability expense (Note 19) 45,327 Strategic transaction costs (Note 13) 421 Adjusted operating income (loss) 206,839 59,866 (31,901) — 234,804 Adjusted operating margin % 24.2 % 11.9 % Depreciation and amortization 24,143 13,303 406 — 37,852 Adjusted EBITDA 230,982 73,169 (31,495) — 272,656 Adjusted EBITDA % 27.0 % 14.5 % Noncash items: Pension (income) expense (1,201) 7,102 — — 5,901 Total Assets 1,077,938 522,042 10,842 (2,810) 1,608,012 Capital expenditures 25,001 8,959 — — 33,960 (1) Reconciling items consist primarily of intercompany eliminations and items not directly attributable to operating segments.
Schedule Of Geographic Information On Sales To External Customers, Based On Country Of Origin	Geographic information on Net sales to external customers, based on country of origin: (In thousands) 2020 2019 2018 United States $ 750,315 $ 785,155 $ 734,033 Other 597,908 616,826 624,071 Total $ 1,348,223 $ 1,401,981 $ 1,358,104
Schedule Of Geographic Information On Net Property, Based On Country Of Origin	Geographic information on tangible long-lived assets, net based on country of origin: (In thousands) 2020 2019 2018 United States $ 134,234 $ 113,528 $ 92,511 Other 108,837 105,185 65,429 Total $ 243,071 $ 218,713 $ 157,940
Revenue from External Customers by Products and Services	Total Net sales by product group was as follows: 2020 Consolidated Americas International (In thousands) Dollars Percent Dollars Percent Dollars Percent Breathing Apparatus $ 329,179 24% $ 220,650 25% $ 108,529 23% Fixed Gas & Flame Detection 287,414 21% 158,924 18% 128,490 27% Firefighter Helmets & Protective Apparel 162,207 12% 133,653 15% 28,554 6% Portable Gas Detection 142,581 11% 90,545 10% 52,036 11% Industrial Head Protection 125,921 9% 92,075 11% 33,846 7% Fall Protection 103,075 8% 58,060 7% 45,015 10% Other (a) 197,846 15% 120,398 14% 77,448 16% Total $ 1,348,223 100% $ 874,305 100% $ 473,918 100% 2019 Consolidated Americas International (In thousands) Dollars Percent Dollars Percent Dollars Percent Breathing Apparatus $ 317,678 23% $ 212,463 23% $ 105,215 22% Fixed Gas & Flame Detection 292,988 21% 159,892 17% 133,096 27% Firefighter Helmets & Protective Apparel 178,012 13% 142,043 16% 35,969 7% Portable Gas Detection 169,479 12% 113,914 12% 55,565 11% Industrial Head Protection 145,403 10% 112,673 12% 32,730 7% Fall Protection 125,869 9% 78,054 9% 47,815 10% Other (a) 172,552 12% 96,079 11% 76,473 16% Total $ 1,401,981 100% $ 915,118 100% $ 486,863 100% 2018 Consolidated Americas International (In thousands) Dollars Percent Dollars Percent Dollars Percent Breathing Apparatus $ 324,672 24% $ 205,100 24% $ 119,572 24% Fixed Gas & Flame Detection 262,432 19% 135,922 16% 126,510 25% Firefighter Helmets & Protective Apparel 169,679 13% 136,794 16% 32,885 6% Portable Gas Detection 163,716 12% 109,401 13% 54,315 11% Industrial Head Protection 146,388 11% 114,465 13% 31,923 6% Fall Protection 109,472 8% 61,289 7% 48,183 10% Other (a) 181,745 13% 91,316 11% 90,429 18% Total $ 1,358,104 100% $ 854,287 100% $ 503,817 100%

Earnings per Share (Tables)

Earnings per Share (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Schedule Of Earnings Per Share	Amounts attributable to MSA Safety Incorporated common shareholders: (In thousands, except per share amounts) 2020 2019 2018 Net income $ 120,101 $ 136,440 $ 124,150 Preferred stock dividends (41) (42) (42) Net income available to common equity 120,060 136,398 124,108 Dividends and undistributed earnings allocated to participating securities (84) (183) (117) Net income available to common shareholders $ 119,976 $ 136,215 $ 123,991 Basic weighted-average shares outstanding 38,885 38,653 38,362 Stock options and other stock compensation 401 536 599 Diluted weighted-average shares outstanding 39,286 39,189 38,961 Earnings per share: Basic $ 3.09 $ 3.52 $ 3.23 Diluted $ 3.05 $ 3.48 $ 3.18

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Components Of Income Before Income Taxes	(In thousands) 2020 2019 2018 Components of income before income taxes U.S. income $ 104,682 $ 126,552 $ 85,234 Non-U.S. income 58,421 57,183 77,101 Income before income taxes $ 163,103 $ 183,735 $ 162,335 Provision for income taxes Current Federal $ 23,587 $ 13,770 $ 13,574 State 4,896 5,436 4,265 Non-U.S. 16,780 25,608 23,446 Total current provision $ 45,263 $ 44,814 $ 41,285 Deferred Federal $ (1,493) $ 5,744 $ 291 State (727) 1,346 (1,604) Non-U.S. (1,102) (5,818) (2,752) Total deferred provision (benefit) (3,322) 1,272 (4,065) Provision for income taxes $ 41,941 $ 46,086 $ 37,220
Reconciliation Of U.S. Federal Income Tax Rates To Effective Tax Rate	Reconciliation of the U.S. federal income tax rates to our effective tax rate: 2020 2019 2018 U.S. federal income tax rate 21.0 % 21.0 % 21.0 % Nondeductible compensation 3.4 % 1.9 % 1.0 % Taxes on non-U.S. income 2.6 % (0.5) % 0.4 % State income taxes—U.S. 2.0 % 2.9 % 1.3 % Valuation allowances 0.8 % 0.4 % 0.5 % Taxes on non-U.S. income - U.S., Canadian & European reorganization 0.7 % 0.3 % 1.1 % Foreign exchange on entity closures — % 1.8 % — % U.S. tax reform — % — % 1.6 % Manufacturing deduction credit — % — % (1.0) % Employee share-based payments (3.9) % (2.6) % (1.6) % Research and development credit (1.2) % (0.6) % (0.9) % Other 0.3 % 0.5 % (0.5) % Effective income tax rate 25.7 % 25.1 % 22.9 %
Components of Deferred Tax Assets and Liabilities	Components of deferred tax assets and liabilities: December 31, (In thousands) 2020 2019 Deferred tax assets Product liability $ 33,689 $ 29,405 Capitalized research and development 22,915 17,886 Employee benefits 10,539 12,009 Net operating losses and tax credit carryforwards 6,310 6,026 Accrued expenses and other reserves 5,195 4,384 Share-based compensation 3,588 5,396 Other 5,287 3,828 Total deferred tax assets 87,523 78,934 Valuation allowances (7,188) (5,937) Net deferred tax assets 80,335 72,997 Deferred tax liabilities Goodwill and intangibles (39,040) (35,999) Property, plant and equipment (14,649) (11,714) Other (1,897) (2,475) Total deferred tax liabilities (55,586) (50,188) Net deferred taxes $ 24,749 $ 22,809
Schedule Of Reconciliation Of Change In Tax Liability For Unrecognized Tax Benefits	A reconciliation of the change in the tax liability for unrecognized tax benefits for the years ended December 31, 2020 and 2019 is as follows: (In thousands) 2020 2019 Beginning balance $ 5,119 $ 16,155 Adjustments for tax positions related to the current year 425 — Adjustments for tax positions related to prior years 2,950 (7,740) Statute expiration (402) (3,296) Ending balance $ 8,092 $ 5,119

Stock Plans (Tables)

Stock Plans (Tables)	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Schedule Of Stock-Based Compensation Expense	Stock-based compensation expense was as follows: (In thousands) 2020 2019 2018 Restricted stock units $ 6,258 $ 6,914 $ 6,221 Stock options 113 487 217 Performance stock units 549 6,359 5,801 Total stock-compensation expense before income taxes 6,920 13,760 12,239 Income tax benefit 1,668 3,357 2,974 Total stock-compensation expense, net of income tax benefit $ 5,252 $ 10,403 $ 9,265
Schedule Of Fair Value Weighted Average Assumptions For Options Granted	the following weighted average assumptions. There were no stock options granted in 2020 or 2018. 2019 Fair value per option $ 59.07 Risk-free interest rate 2.3 % Expected dividend yield 1.7 % Expected volatility 31 % Expected life (years) 6.4
Summary Of Option Activity	A summary of option activity follows: Shares Weighted Exercisable at Outstanding January 1, 2018 955,446 $ 42.75 Exercised (215,724) 39.25 Forfeited (4,721) 44.50 Outstanding December 31, 2018 735,001 43.79 638,673 Granted 23,285 43.54 Exercised (198,535) 38.16 Forfeited (95) 49.19 Outstanding December 31, 2019 559,656 45.78 552,682 Exercised (274,704) 45.31 Forfeited (954) 42.00 Outstanding December 31, 2020 283,998 $ 46.23 281,593
Characteristics of Outstanding and Exercisable Stock Options	For various exercise price ranges, characteristics of outstanding and exercisable stock options at December 31, 2020 were as follows: Stock Options Outstanding Range of Exercise Prices Shares Weighted-Average Exercise Price Remaining Life $33.01 – $45.00 158,836 43.88 3.06 $45.01 – $57.93 125,162 49.22 2.93 $33.01 – $57.93 283,998 $ 46.23 3.00 Stock Options Exercisable Range of Exercise Prices Shares Weighted-Average Exercise Price Remaining Life $33.01 – $45.00 158,208 43.90 3.05 $45.01 – $57.93 123,385 49.22 2.87 $33.01 – $57.93 281,593 $ 46.23 2.97
Summary of Restricted Stock and Unit Activity	A summary of restricted stock unit activity follows: Shares Weighted Average Unvested January 1, 2017 227,161 $ 57.50 Granted 75,430 87.36 Vested (92,401) 58.10 Forfeited (4,741) 59.61 Unvested at December 31, 2018 205,449 68.97 Granted 70,160 104.53 Vested (97,253) 56.47 Forfeited (5,655) 85.48 Unvested at December 31, 2019 172,701 90.38 Granted 51,468 124.61 Vested (70,399) 81.58 Forfeited (7,579) 106.54 Unvested at December 31, 2020 146,191 $ 105.83
Summary of Performance Stock Unit Activity	A summary of performance stock unit activity follows: Shares Weighted Average Unvested at January 1, 2017 242,186 $ 55.06 Granted 62,775 84.79 Vested (41,660) 40.23 Performance adjustments (35,756) 45.21 Forfeited (8,659) 44.53 Unvested at December 31, 2018 218,886 68.43 Granted 83,819 101.03 Vested (139,478) 44.75 Performance adjustments 76,960 44.24 Forfeited (2,152) 99.82 Unvested at December 31, 2019 238,035 85.39 Granted 67,479 127.48 Vested (132,036) 73.00 Performance adjustments 33,499 72.36 Forfeited (6,765) 111.60 Unvested at December 31, 2020 200,212 $ 104.69

Short and Long-Term Debt (Table

Short and Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Schedule Of Outstanding Debt	December 31, (In thousands) 2020 2019 2010 Senior Notes payable through 2021, 4.00%, net of debt issuance costs $ 20,000 $ 40,000 2016 Senior Notes payable through 2031, 3.40%, net of debt issuance costs 74,926 72,708 Senior revolving credit facility maturing in 2023, net of debt issuance costs 212,231 235,686 Total 307,157 348,394 Short-term debt 20,000 20,000 Long-term debt $ 287,157 $ 328,394

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Changes In Goodwill	Changes in goodwill during the years ended December 31, 2020 and 2019, were as follows: (In thousands) 2020 2019 Net balance at January 1 $ 436,679 $ 413,640 Additions (Note 13) — 19,917 Currency translation 6,593 3,122 Net balance at December 31 $ 443,272 $ 436,679
Changes In Intangible Assets, Net Of Accumulated Amortization	Changes in intangible assets, net of accumulated amortization, during the years ended December 31, 2020 and 2019, were as follows: (In thousands) 2020 2019 Net balance at January 1 $ 171,326 $ 169,515 Additions and measurement period adjustments (Note 13) 121 11,100 Amortization expense (11,570) (11,119) Currency translation 1,174 1,830 Net balance at December 31 $ 161,051 $ 171,326 (In millions) December 31, 2020 December 31, 2019 Intangible Assets: Weighted Average Useful Life (years) Gross Carrying Amount Accumulated Amortization and Reserves Net Carrying Amount Gross Carrying Amount Accumulated Amortization and Reserves Net Carrying Amount Customer relationships 14 $ 59.7 $ (20.4) $ 39.3 $ 58.3 $ (15.3) $ 43.0 Distribution agreements 20 66.4 (20.7) 45.7 66.0 (17.3) 48.7 Technology related assets 8 30.2 (21.3) 8.9 30.0 (18.3) 11.7 Patents, trademarks and copyrights 12 19.4 (12.5) 6.9 19.0 (11.3) 7.7 License agreements 5 5.4 (5.3) 0.1 5.3 (5.3) — Other 2 3.0 (2.8) 0.2 3.0 (2.8) 0.2 Total 14 $ 184.1 $ (83.0) $ 101.1 $ 181.6 $ (70.3) $ 111.3

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2020
Business Acquisition [Line Items]
Pro Forma Financial Information (Unaudited)	(In millions, except per share amounts) 2019 2018 Net sales $ 1,410 $ 1,380 Net Income 131 124 Basic earnings per share 3.40 3.24 Diluted earnings per share 3.35 3.19
Sierra Monitor Corporation
Business Acquisition [Line Items]
Schedule of Preliminary Fair Values of the Assets Acquired and Liabilities Assumed	The following table summarizes the fair values of the SMC assets acquired and liabilities assumed at the date of acquisition: (In millions) May 20, 2019 Current assets (including cash of $2.1 million) $ 10.5 Property, plant and equipment and other noncurrent assets 1.3 Customer relationships 9.6 Acquired technology 1.4 Goodwill 19.9 Total assets acquired 42.7 Total liabilities assumed 6.5 Net assets acquired $ 36.2

Pensions and Other Post-retir_2

Pensions and Other Post-retirement Benefits (Tables)	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
Schedule Of Defined Benefit Pension Plans And Other Postretirement Benefits Plan	Information pertaining to defined benefit pension plans and other post-retirement benefits plans is provided in the following tables: Pension Benefits Other Benefits (In thousands) 2020 2019 2020 2019 Change in Benefit Obligations Benefit obligations at January 1 $ 603,551 $ 525,520 $ 28,151 $ 28,477 Service cost 12,094 10,342 396 354 Interest cost 14,905 18,803 716 996 Participant contributions 396 470 370 380 Plan amendments (430) — — — Actuarial losses (a) 54,606 81,132 5,284 1,319 Benefits paid (24,496) (24,452) (2,692) (3,375) Curtailments (1,559) — — — Settlements (506) (7,265) — — Currency translation 12,296 (999) — — Benefit obligations at December 31 $ 670,857 $ 603,551 $ 32,225 $ 28,151 Change in Plan Assets Fair value of plan assets at January 1 $ 515,858 $ 443,112 $ — $ — Actual return on plan assets 87,769 98,210 — — Employer contributions 5,596 5,537 2,322 2,995 Participant contributions 396 470 370 380 Settlements (506) (7,265) — — Benefits paid (24,496) (24,452) (2,692) (3,375) Administrative expenses paid (172) (297) — — Currency translation 2,377 543 — — Fair value of plan assets at December 31 $ 586,822 $ 515,858 $ — $ — Funded Status Funded status at December 31 $ (84,035) $ (87,693) $ (32,225) $ (28,151) Unrecognized transition losses 4 4 — — Unrecognized prior service credit 1,717 1,572 (1,125) (1,519) Unrecognized net actuarial losses 169,028 183,733 16,686 12,547 Net amount recognized $ 86,714 $ 97,616 $ (16,664) $ (17,123) Amounts Recognized in the Balance Sheets Noncurrent assets $ 97,545 $ 75,066 $ — $ — Current liabilities (6,600) (5,944) (2,849) (2,406) Noncurrent liabilities (174,980) (156,815) (29,376) (25,745) Net amount recognized $ (84,035) $ (87,693) $ (32,225) $ (28,151) Amounts Recognized in Accumulated Other Comprehensive Loss Net actuarial losses $ 169,028 $ 183,733 $ 16,686 $ 12,547 Prior service cost (credit) 1,717 1,572 (1,125) (1,519) Unrecognized net initial obligation 4 4 — — Total (before tax effects) $ 170,749 $ 185,309 $ 15,561 $ 11,028 Accumulated Benefit Obligations for all Defined Benefit Plans $ 619,167 $ 558,183 $ — $ —
Components Of Net Periodic Benefit (Credit) Cost	Pension Benefits Other Benefits (In thousands) 2020 2019 2018 2020 2019 2018 Components of Net Periodic Benefit Cost Service cost $ 12,094 $ 10,342 $ 11,125 $ 396 $ 354 $ 369 Interest cost 14,905 18,803 17,214 716 996 793 Expected return on plan assets (34,029) (38,644) (36,352) — — — Amortization of transition amounts — 2 1 — — — Amortization of prior service cost (credit) 178 223 (21) (394) (405) (405) Recognized net actuarial losses 15,799 10,159 13,755 1,145 869 752 Settlement/curtailment loss 1,135 (b) 2,497 (c) 179 — — — Net periodic benefit cost (a) $ 10,082 $ 3,382 $ 5,901 $ 1,863 $ 1,814 $ 1,509
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Table Text Block]	Information for pension plans with an accumulated benefit obligation in excess of plan assets: Pension Benefits Other Benefits (In thousands) 2020 2019 2020 2019 Aggregate accumulated benefit obligations (ABO) $ 209,351 $ 185,747 $ 32,225 $ 28,151 Aggregate fair value of plan assets 40,294 35,882 — —
Defined Benefit Plan, Plan with Projected Benefit Obligation in Excess of Plan Assets	Information for pension plans with a projected benefit obligation in excess of plan assets: Pension Benefits (In thousands) 2020 2019 Aggregate projected benefit obligations (PBO) 223,343 198,633 Aggregate fair value of plan assets 41,764 35,882
Schedule Of Assumptions Used To Determine Benefit Obligations And Net Periodic Benefit Cost	Pension Benefits Other Benefits 2020 2019 2020 2019 Assumptions used to determine benefit obligations Average discount rate 2.28 % 2.86 % 2.21 % 3.05 % Rate of compensation increase 2.93 % 2.93 % 3.00 % — % Assumptions used to determine net periodic benefit cost Average discount rate - Service cost 3.08 % 3.10 % 2.42 % 3.15 % Average discount rate - Interest cost 2.52 % 2.52 % 1.48 % 2.61 % Expected return on plan assets 7.10 % 7.09 % — — Rate of compensation increase 2.93 % 2.93 % 3.00 % — %
Schedule Of Expected Return On Assets For Net Periodic Pension Cost	Pension Plan Assets at 2020 2019 Equity securities 49 % 46 % Fixed income securities 25 30 Pooled investment funds 21 19 Insurance contracts 4 4 Cash and cash equivalents 1 1 Total 100 % 100 %
Summary Of Pension Plan Assets Measured At Fair Value On A Recurring Basis By Fair Value Hierarchy	The fair values at December 31, 2020, were as follows: Fair Value (In thousands) Total NAV Quoted Prices Significant Significant Equity securities $ 283,516 $ 66,847 $ 216,669 $ — $ — Fixed income securities 148,173 — 76,502 71,671 — Pooled investment funds 123,119 123,119 — — — Insurance contracts 24,396 — — — 24,396 Cash and cash equivalents 7,618 6,681 937 — — Total $ 586,822 $ 196,647 $ 294,108 $ 71,671 $ 24,396 The fair values of the Company's pension plan assets at December 31, 2019, were as follows: Fair Value (In thousands) Total NAV Quoted Prices Significant Significant Equity securities $ 235,491 $ 56,449 $ 179,042 $ — $ — Fixed income securities 154,640 — 73,874 80,766 — Pooled investment funds 97,373 97,373 — — — Insurance contracts 21,502 — — — 21,502 Cash and cash equivalents 6,852 5,792 1,060 — — Total $ 515,858 $ 159,614 $ 253,976 $ 80,766 $ 21,502
Schedule Of Reconciliation Of Level 3 Assets	The following table presents a reconciliation of Level 3 assets: (In thousands) Insurance Balance January 1, 2019 $ 17,033 Net realized and unrealized losses 5,602 Net purchases, issuances and settlements (1,133) Balance December 31, 2019 21,502 Net realized and unrealized gains 2,564 Net purchases, issuances and settlements 330 Balance December 31, 2020 $ 24,396
Level 3 Assets Recognized in Accumulated Other Comprehensive Loss	The following table presents amounts related to Level 3 assets recognized in accumulated other comprehensive loss: (In thousands) Insurance Net actuarial losses 972 Prior service cost 1,406 Total (before tax effects) $ 2,378

Leases Lease Cost (Tables)

Leases Lease Cost (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Lease Cost	Other Information Twelve Months Ended December 31, (In thousands, except percentage amounts) 2020 2019 Lease cost: Operating lease cost recognized as rent expense $ 12,997 $ 13,364 Total lease cost 12,997 13,364 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows related to operating leases $ 13,476 $ 13,346 Non-cash other information: Right-of-use assets obtained in exchange for new operating lease liabilities $ 10,737 $ 6,637 December 31, 2020 December 31, 2019 Weighted-average remaining lease term (in years): Operating leases 11 11 Weighted-average discount rate: Operating leases 3.89 % 4.28 %
Future Lease Payments	At December 31, 2020, future lease payments under operating leases were as follows: (In thousands) Operating Leases 2021 $ 11,445 2022 7,856 2023 6,266 2024 4,539 2025 4,692 After 2025 31,687 Total future minimum operating lease payments $ 66,485 Less: Imputed interest 12,258 Present value of operating lease liabilities 54,227 Less: Current portion operating lease liabilities (a) 9,588 Noncurrent operating lease liabilities $ 44,639 (a) Included in "Warranty reserve and other current liabilities" on the Consolidated Balance Sheet.

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Balance Sheet Location And Fair Value Of Assets And Liabilities Associated With Derivative Financial Instruments	The following table presents the Consolidated Balance Sheets location and fair value of assets and liabilities associated with derivative financial instruments: December 31, (In thousands) 2020 2019 Derivatives not designated as hedging instruments: Foreign exchange contracts: other current liabilities $ 157 $ 125 Foreign exchange contracts: other current assets 160 687
Income Statement Location and Impact of Derivative Financial Instruments	The following table presents the Consolidated Statements of Income location and impact of derivative financial instruments: (In thousands) Income Statement Location (Gain) Loss Recognized in Income Year ended 2020 2019 Derivatives not designated as hedging instruments: Foreign exchange contracts Currency exchange losses, net $ (7,457) $ 3,015

Contingencies (Tables)

Contingencies (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Summary of Cumulative Trauma Product Liability Claims Activity	A summary of cumulative trauma product liability lawsuits and asserted cumulative trauma product liability claims activity is as follows: 2020 2019 2018 Open lawsuits, beginning of period 1,605 1,481 1,420 New lawsuits 402 346 369 Settled and dismissed lawsuits (385) (222) (308) Open lawsuits, end of period 1,622 1,605 1,481 2020 2019 2018 Asserted claims, beginning of period 2,456 2,355 2,242 New claims 917 486 479 Settled, inactive and dismissed claims (495) (385) (366) Asserted claims, end of period 2,878 2,456 2,355
Summary Of Insurance Receivable Balances And Activity Related To Product Liability Losses	A summary of insurance receivables balance and activity related to cumulative trauma product liability losses is as follows: (In millions) 2020 2019 Balance beginning of period $ 63.8 $ 71.7 Additions 39.0 9.1 Collections and other adjustments (5.8) (17.0) Balance end of period $ 97.0 $ 63.8
Summary of Notes Receivable from Insurance Companies Activity During the Year	A summary of notes receivables from insurance companies balance is as follows: December 31, (In millions) 2020 2019 Balance beginning of period $ 56.0 $ 59.6 Additions 1.4 1.5 Collections (5.1) (5.1) Balance end of period $ 52.3 $ 56.0
Schedule of Product Warranty Liability	The following table reconciles the changes in the Company's accrued warranty reserve: December 31, (In thousands) 2020 2019 2018 Beginning warranty reserve $ 12,715 $ 14,214 $ 14,753 Warranty payments (10,861) (12,664) (9,955) Warranty claims 10,233 12,033 10,585 Provision for product warranties and other adjustments (659) (868) (1,169) Ending warranty reserve $ 11,428 $ 12,715 $ 14,214

Significant Accounting Polici_3

Significant Accounting Policies - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2019	Dec. 31, 2017
Significant Accounting Policies [Line Items]
Money Market Funds, at Carrying Value	$ 600,000	$ 17,900,000
Restricted cash balances	$ 362,000	348,000	$ 509,000
Period for inventory write-down	24 months
Unamortized software development costs	$ 8,200,000	5,000,000	1,600,000
Depreciation	27,700,000	26,500,000	26,900,000
Goodwill, impairment loss	0	0	0
Operating lease liability	54,227,000
Operating lease, right-of-use asset	53,451,000	51,675,000
Income tax benefit	1,668,000	3,357,000	2,974,000
Change in retained earnings	$ 809,891,000	732,573,000
Buildings | Minimum
Significant Accounting Policies [Line Items]
Useful lives	20 years
Buildings | Maximum
Significant Accounting Policies [Line Items]
Useful lives	40 years
Machinery and equipment | Minimum
Significant Accounting Policies [Line Items]
Useful lives	3 years
Machinery and equipment | Maximum
Significant Accounting Policies [Line Items]
Useful lives	10 years
Software development
Significant Accounting Policies [Line Items]
Useful lives	3 years
Accounting Standards Update 2016-02
Significant Accounting Policies [Line Items]
Operating lease, right-of-use asset				$ 54,000,000
Retained Earnings
Significant Accounting Policies [Line Items]
Change in retained earnings	$ 1,065,789,000	$ 1,012,266,000	935,577,000		$ 868,675,000
Retained Earnings | Cumulative effect, period of adoption, adjustment
Significant Accounting Policies [Line Items]
Change in retained earnings			$ 3,772,000

Restructuring and Other Charg_3

Restructuring and Other Charges - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)position	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)position
Restructuring Cost and Reserve [Line Items]
Restructuring charges (Note 2)	$ 27,381	$ 13,846	$ 13,247
Restructuring charges	27,400	13,800	13,200
Restructuring Reserve, Accrual Adjustment	0	(700)	(600)
Americas
Restructuring Cost and Reserve [Line Items]
Restructuring charges	4,700	500	2,300
Restructuring Reserve, Accrual Adjustment	(100)	(100)	(300)
International
Restructuring Cost and Reserve [Line Items]
Restructuring charges	21,900	12,700	5,600
Restructuring Reserve, Accrual Adjustment	100	(600)	(300)
Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring charges (Note 2)		600	5,300
Restructuring charges	800	600	5,300
Restructuring Reserve, Accrual Adjustment	$ 0	$ 0	$ 0
Staff Reductions
Restructuring Cost and Reserve [Line Items]
Reduction in headcount	121	99	45
Staff Reductions | Americas
Restructuring Cost and Reserve [Line Items]
Restructuring charges (Note 2)	$ 4,700	$ 500	$ 2,300
Reduction in headcount	42	12	8
Staff Reductions | International
Restructuring Cost and Reserve [Line Items]
Restructuring charges (Note 2)	$ 21,900	$ 12,700	$ 5,600
Reduction in headcount	76	87	34
Staff Reductions | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring charges (Note 2)	$ 800
Reduction in headcount | position	3		3

Restructuring and Other Charg_4

Restructuring and Other Charges - Roll Forward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	$ 6.2	$ 4.5	$ 4.1
Restructuring charges	27.4	13.8	13.2
Currency translation and other adjustments	0	(0.7)	(0.6)
Cash payments	(11.1)	(11.4)	(12.2)
Restructuring reserve, ending balance	22.5	6.2	4.5
Americas
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	0.3	0.5	0.5
Restructuring charges	4.7	0.5	2.3
Currency translation and other adjustments	(0.1)	(0.1)	(0.3)
Cash payments	(2.1)	(0.6)	(2)
Restructuring reserve, ending balance	2.8	0.3	0.5
International
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	5.9	4	3.6
Restructuring charges	21.9	12.7	5.6
Currency translation and other adjustments	0.1	(0.6)	(0.3)
Cash payments	(8.6)	(10.2)	(4.9)
Restructuring reserve, ending balance	19.3	5.9	4
Corporate
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	0	0	0
Restructuring charges	0.8	0.6	5.3
Currency translation and other adjustments	0	0	0
Cash payments	(0.4)	(0.6)	(5.3)
Restructuring reserve, ending balance	$ 0.4	$ 0	$ 0

Inventories - Schedule of Inven

Inventories - Schedule of Inventories (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Finished products	$ 81,048	$ 71,918
Work in process	2,618	4,083
Raw materials and supplies	161,300	151,129
Inventories at current cost	244,966	227,130
Less: LIFO valuation	(47,147)	(42,103)
Total inventories	$ 197,819	$ 185,027

Inventories - Additional Inform

Inventories - Additional Information (Detail)	Dec. 31, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Percentage of LIFO Inventory	48.00%	43.00%

Property, Plant, and Equipmen_2

Property, Plant, and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Unamortized computer software costs	$ 12,600	$ 6,200
Property, Plant and Equipment [Line Items]
Total	594,249	551,463
Less accumulated depreciation	(404,629)	(384,425)
Property, plant and equipment, net	189,620	167,038
Land
Property, Plant and Equipment [Line Items]
Total	4,275	4,194
Buildings
Property, Plant and Equipment [Line Items]
Total	128,887	125,223
Machinery and equipment
Property, Plant and Equipment [Line Items]
Total	422,333	397,287
Construction in progress
Property, Plant and Equipment [Line Items]
Total	$ 38,753	$ 24,759

Reclassifications Out of Accu_3

Reclassifications Out of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	$ 732,573
Total amount reclassified from accumulated other comprehensive loss, net of tax, into net income	216	$ 15,261	$ 774
Reclassification to retained earnings due to the adoption of ASU 2018-02 (Note 1)	31,765	8,623	(47,470)
Balance at end of period	809,891	732,573
MSA Safety Incorporated - Pension and other post-retirement benefits
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	(124,848)	(115,517)	(97,948)
Tax benefit	1,997	5,847	9,936
Total other comprehensive loss before reclassifications, net of tax	(4,325)	(13,632)	(28,041)
Tax benefit	(4,242)	(2,775)	(3,611)
Total amount reclassified from accumulated other comprehensive loss, net of tax, into net income	13,621	8,073	10,472
Total other comprehensive income (loss)	0	(3,772)	0
Reclassification to retained earnings due to the adoption of ASU 2018-02 (Note 1)	9,296	(9,331)	(17,569)
Balance at end of period	(115,552)	(124,848)	(115,517)
MSA Safety Incorporated - Net actuarial (losses) gains
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Unrecognized net actuarial losses/prior service credit (cost)	(6,322)	(19,479)	(37,977)
Amounts reclassified from accumulated other comprehensive loss	18,079	11,028	14,507
MSA Safety Incorporated - Prior service (cost) credit
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Amounts reclassified from accumulated other comprehensive loss	(216)	(180)	(424)
MSA Safety Incorporated - Net investment gain (loss)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	6	(572)	0
Reclassification to retained earnings due to the adoption of ASU 2018-02 (Note 1)	(7)	578	(572)
Balance at end of period	(1)	6	(572)
MSA Safety Incorporated - Foreign currency translation
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	(89,161)	(102,838)	(73,814)
Total amount reclassified from accumulated other comprehensive loss, net of tax, into net income	(216)	(15,261)	(774)
Reclassification to retained earnings due to the adoption of ASU 2018-02 (Note 1)	22,101	(1,584)	(29,798)
Balance at end of period	(66,844)	(89,161)	(102,838)
Noncontrolling Interests - Pension and other post-retirement benefits
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	0	0	0
Tax benefit	0	0	0
Total other comprehensive loss before reclassifications, net of tax	0	0	0
Tax benefit	0	0	0
Total amount reclassified from accumulated other comprehensive loss, net of tax, into net income	0	0	0
Total other comprehensive income (loss)	0	0	0
Reclassification to retained earnings due to the adoption of ASU 2018-02 (Note 1)	0	0	0
Balance at end of period	0	0	0
Noncontrolling Interests - Net actuarial (losses) gains
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Unrecognized net actuarial losses/prior service credit (cost)	0	0	0
Amounts reclassified from accumulated other comprehensive loss	0	0	0
Noncontrolling Interests - Prior service credit (cost)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Amounts reclassified from accumulated other comprehensive loss	0	0	0
Noncontrolling Interests - Net investment gain (loss)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	0	0	0
Reclassification to retained earnings due to the adoption of ASU 2018-02 (Note 1)	0	0	0
Balance at end of period	0	0	0
Noncontrolling Interests - Foreign currency translation
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	423	496	801
Total amount reclassified from accumulated other comprehensive loss, net of tax, into net income	0	0	0
Reclassification to retained earnings due to the adoption of ASU 2018-02 (Note 1)	159	(73)	(305)
Balance at end of period	$ 582	$ 423	$ 496

Capital Stock - Additional Info

Capital Stock - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Capital Unit [Line Items]
Preferred stock, par value (dollars per share)	$ 50,000	$ 50,000
Cumulative preferred nonvoting stock (as a percent)	4.50%	4.50%
Shares held in treasury (in shares)	23,013,489	23,240,197
Preferred stock included in Treasury shares at cost line of the Consolidated Balance Sheet	$ 327,756	$ 305,159
Common stock, shares authorized (in shares)	180,000,000	180,000,000
Common stock, no par value (in dollars per share)	$ 0	$ 0
Common stock, shares issued (in shares)	62,081,391	62,081,391
Common stock, shares outstanding (in shares)	39,067,902	38,841,194
Stock Issued During Period, Shares, Treasury Stock Reissued	471,681	436,549
4 1/2% Cumulative Preferred Nonvoting Stock
Capital Unit [Line Items]
Preferred stock, shares authorized	100,000
Preferred stock, par value (dollars per share)	$ 50
Cumulative preferred nonvoting stock (as a percent)	4.50%
Preferred stock, callable price per share (dollars per share)	$ 52.50
Preferred stock, shares issued	71,340	71,340
Shares held in treasury (in shares)	52,998	52,878
Preferred stock included in Treasury shares at cost line of the Consolidated Balance Sheet	$ 1,800
Treasury purchases (in shares)	120	0
Second Cumulative Preferred Voting Stock
Capital Unit [Line Items]
Preferred stock, shares authorized	1,000,000
Preferred stock, par value (dollars per share)	$ 10
Preferred stock, shares issued	0	0
Common Stock
Capital Unit [Line Items]
Common stock, shares outstanding (in shares)	62,081,391	62,081,391	62,081,391	62,081,391
Treasury
Capital Unit [Line Items]
Common stock, shares outstanding (in shares)	23,013,489	23,240,197	23,554,868	23,858,463
Share Repurchase Program, May 2015 | Common Stock
Capital Unit [Line Items]
Stock repurchased program, authorized amount (up to)	$ 100,000
Share Repurchase Program, May 2015 | Treasury
Capital Unit [Line Items]
Treasury purchases (in shares)	175,000	33,465	0

Capital Stock - Summary of Comm

Capital Stock - Summary of Common Stock Activity (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balances (in shares)	(38,841,194)
Stock options exercised (in shares)	274,704	198,535	215,724
Stock options forfeitures, Shares		(95)	(4,721)
Ending Balances (in shares)	(39,067,902)	(38,841,194)
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balances (in shares)	(62,081,391)	(62,081,391)	(62,081,391)
Ending Balances (in shares)	(62,081,391)	(62,081,391)	(62,081,391)
Beginning Balances	$ (229,127)	$ (211,806)	$ (194,953)
Ending Balances	$ (242,693)	$ (229,127)	$ (211,806)
Treasury
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balances (in shares)	(23,240,197)	(23,554,868)	(23,858,463)
Ending Balances (in shares)	(23,013,489)	(23,240,197)	(23,554,868)
Beginning Balances	$ (303,566)	$ (296,390)	$ (296,081)
Ending Balances	$ (326,156)	$ (303,566)	$ (296,390)
Restricted Stock | Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock awards (in shares)	0	0	0
Restricted stock expense (in shares)	0	0	0
Restricted stock forfeitures (in shares)	0	0	0
Restricted stock awards	$ (773)	$ (1,253)	$ (1,079)
Share-based compensation expense	7,065	7,397	6,504
Stock compensation awards forfeited, Value	$ (807)	$ (483)	$ (283)
Restricted Stock | Treasury
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock awards (in shares)	55,691	96,893	92,401
Restricted stock expense (in shares)	0	0	0
Restricted stock forfeitures (in shares)	0	0	0
Restricted stock awards	$ (773)	$ (1,253)	$ (1,079)
Share-based compensation expense	0	0	0
Stock compensation awards forfeited, Value	$ 0	$ 0
Stock Options | Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock expense (in shares)	0	0
Stock options exercised (in shares)	0	0	0
Stock options forfeitures, Shares	0	0	0
Share-based compensation expense	$ 153	$ 492	$ 272
Stock compensation awards forfeited, Value	(40)	(5)	(55)
Stock options exercised	$ 8,590	$ 5,107	$ 5,738
Stock Options | Treasury
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock expense (in shares)	0	0	0
Stock options exercised (in shares)	274,672	193,681	215,724
Stock options forfeitures, Shares	0	0	0
Share-based compensation expense	$ 0	$ 0	$ 0
Stock compensation awards forfeited, Value	0	0	0
Stock options exercised	$ 3,856	$ 2,364	$ 2,835
Performance Stock | Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock expense (in shares)	0	0	0
Restricted stock forfeitures (in shares)	0	0
Performance stock issued (in shares)	0	0	0
Share-based compensation expense	$ 1,305	$ 6,574	$ 6,186
Stock compensation awards forfeited, Value	(755)	$ (215)	(385)
Stock Issued During Period, Shares, Acquisitions		0
Performance stock issued	$ (1,826)	$ (1,778)	$ (523)
Stock Issued During Period, Value, Acquisitions		$ 921
Performance Stock | Treasury
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock expense (in shares)	0	0	0
Restricted stock forfeitures (in shares)	0	0	0
Performance stock issued (in shares)	134,824	139,478	41,660
Share-based compensation expense	$ 0	$ 0	$ 0
Stock compensation awards forfeited, Value	0	$ 0	0
Stock Issued During Period, Shares, Acquisitions		0
Performance stock issued	$ (1,826)	$ (1,778)	$ (523)
Stock Issued During Period, Value, Acquisitions		$ 0
Employee Stock Purchase Plan | Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee stock purchase plan (in shares)	0	0	0
Employee stock purchase plan	$ 654	$ 564	$ 478
Employee Stock Purchase Plan | Treasury
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee stock purchase plan (in shares)	6,494	5,895	7,725
Employee stock purchase plan	$ 93	$ 77	$ 78
Stock Compensation Plan | Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury shares purchased (in shares)	0	0	0
Treasury shares purchased for stock compensation programs	$ 0	$ 0	$ 0
Stock Compensation Plan | Treasury
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury shares purchased (in shares)	(69,973)	(87,811)	(53,915)
Treasury shares purchased for stock compensation programs	$ (9,025)	$ (9,301)	$ (4,824)
Share Repurchase Program, May 2015 | Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury shares purchased (in shares)	0	0
Treasury shares purchased for stock compensation programs	$ 0	$ 0
Share Repurchase Program, May 2015 | Treasury
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury shares purchased (in shares)	(175,000)	(33,465)
Treasury shares purchased for stock compensation programs	$ (20,113)	$ (3,347)
Share Repurchase Program, May 2015 | Treasury
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury shares purchased (in shares)	(175,000)	(33,465)	0

Segment Information - Additiona

Segment Information - Additional Information (Detail) - Segment	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting [Abstract]
Number of geographic operating segments (in segments)	4	6
Number of reportable segments (in segments)	3

Segment Information - Schedule

Segment Information - Schedule Of Reportable Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Revenues	$ 388,248	$ 304,392	$ 314,438	$ 341,145	$ 375,254	$ 351,014	$ 349,675	$ 326,038	$ 1,348,223	$ 1,401,981	$ 1,358,104
Operating income									166,851	186,230	173,479
Restructuring charges (Note 2)									27,381	13,846	13,247
Currency exchange losses, net (Note 5)									8,578	19,814	2,330
Product Liability Expense									39,036	26,619	45,327
Strategic transaction costs (Note 13)									717	4,400	421
COVID-19 related costs									757
Adjusted operating income (loss)									243,320	250,909	234,804
Depreciation and amortization									39,674	38,020	37,852
Adjusted EBITDA									282,994	288,929	272,656
Pension expense									(9,023)	(933)	(5,901)
Total Assets	1,872,484				1,739,693				1,872,484	1,739,693	1,608,012
Capital expenditures									48,905	36,604	33,960
Americas
Segment Reporting Information [Line Items]
Revenues									874,305	915,118	854,287
Corporate
Segment Reporting Information [Line Items]
Revenues									0	0	0
Restructuring charges (Note 2)										600	5,300
Adjusted operating income (loss)									(28,080)	(35,597)	(31,901)
Depreciation and amortization									391	391	406
Adjusted EBITDA									(27,689)	(35,206)	(31,495)
Pension expense									0	0	0
Total Assets	29,761				22,367				29,761	22,367	10,842
Capital expenditures									0	0	0
Operating Segments | Americas
Segment Reporting Information [Line Items]
Revenues									874,305	915,118	854,287
Adjusted operating income (loss)									$ 200,536	$ 226,596	$ 206,839
Adjusted operating margin %									22.90%	24.80%	24.20%
Depreciation and amortization									$ 26,762	$ 24,691	$ 24,143
Adjusted EBITDA									$ 227,298	$ 251,287	$ 230,982
Adjusted EBITDA, Percentage									26.00%	27.50%	27.00%
Pension expense									$ 910	$ 6,111	$ (1,201)
Total Assets	1,228,739				1,131,911				1,228,739	1,131,911	1,077,938
Capital expenditures									43,181	26,823	25,001
Operating Segments | International
Segment Reporting Information [Line Items]
Revenues									473,918	486,863	503,817
Adjusted operating income (loss)									$ 70,864	$ 59,910	$ 59,866
Adjusted operating margin %									15.00%	12.30%	11.90%
Depreciation and amortization									$ 12,521	$ 12,938	$ 13,303
Adjusted EBITDA									$ 83,385	$ 72,848	$ 73,169
Adjusted EBITDA, Percentage									17.60%	15.00%	14.50%
Pension expense									$ (8,113)	$ (7,044)	$ (7,102)
Total Assets	615,114				584,195				615,114	584,195	522,042
Capital expenditures									5,724	9,781	8,959
Reconciling Items
Segment Reporting Information [Line Items]
Revenues									0	0	0
Adjusted operating income (loss)									0	0	0
Depreciation and amortization									0	0	0
Adjusted EBITDA									0	0	0
Pension expense									0	0	0
Total Assets	$ (1,130)				$ 1,220				(1,130)	1,220	(2,810)
Capital expenditures									$ 0	$ 0	$ 0

Segment Information - Geographi

Segment Information - Geographic Information on Sales to External Customers (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 388,248	$ 304,392	$ 314,438	$ 341,145	$ 375,254	$ 351,014	$ 349,675	$ 326,038	$ 1,348,223	$ 1,401,981	$ 1,358,104
United States
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									750,315	785,155	734,033
Other
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									$ 597,908	$ 616,826	$ 624,071

Segment Information - Geograp_2

Segment Information - Geographic Information on Property (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Long-Lived Assets by Geographical Areas [Line Items]
Net property	$ 189,620	$ 167,038
Property, plant, equipment, and operating leases, net	243,071	218,713	$ 157,940
United States
Long-Lived Assets by Geographical Areas [Line Items]
Net property	134,234	113,528	92,511
Other
Long-Lived Assets by Geographical Areas [Line Items]
Net property	$ 108,837	$ 105,185	$ 65,429

Segment Information - Revenue f

Segment Information - Revenue from External Customers by Products and Services (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue from External Customer [Line Items]
Revenues	$ 388,248	$ 304,392	$ 314,438	$ 341,145	$ 375,254	$ 351,014	$ 349,675	$ 326,038	$ 1,348,223	$ 1,401,981	$ 1,358,104
Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									100.00%	100.00%	100.00%
Breathing Apparatus
Revenue from External Customer [Line Items]
Revenues									$ 329,179	$ 317,678	$ 324,672
Breathing Apparatus | Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									24.00%	23.00%	24.00%
Fixed Gas and Flame Detection
Revenue from External Customer [Line Items]
Revenues									$ 287,414	$ 292,988	$ 262,432
Fixed Gas and Flame Detection | Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									21.00%	21.00%	19.00%
Fire Helmets & Protective Apparel
Revenue from External Customer [Line Items]
Revenues									$ 162,207	$ 178,012	$ 169,679
Fire Helmets & Protective Apparel | Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									12.00%	13.00%	13.00%
Portable Gas Detection
Revenue from External Customer [Line Items]
Revenues									$ 142,581	$ 169,479	$ 163,716
Portable Gas Detection | Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									11.00%	12.00%	12.00%
Head Protection
Revenue from External Customer [Line Items]
Revenues									$ 125,921	$ 145,403	$ 146,388
Head Protection | Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									9.00%	10.00%	11.00%
Fall Protection
Revenue from External Customer [Line Items]
Revenues									$ 103,075	$ 125,869	$ 109,472
Fall Protection | Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									8.00%	9.00%	8.00%
Other
Revenue from External Customer [Line Items]
Revenues									$ 197,846	$ 172,552	$ 181,745
Other | Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									15.00%	12.00%	13.00%
Americas
Revenue from External Customer [Line Items]
Revenues									$ 874,305	$ 915,118	$ 854,287
Americas | Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									100.00%	100.00%	100.00%
Americas | Breathing Apparatus
Revenue from External Customer [Line Items]
Revenues									$ 220,650	$ 212,463	$ 205,100
Americas | Breathing Apparatus | Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									25.00%	23.00%	24.00%
Americas | Fixed Gas and Flame Detection
Revenue from External Customer [Line Items]
Revenues									$ 158,924	$ 159,892	$ 135,922
Americas | Fixed Gas and Flame Detection | Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									18.00%	17.00%	16.00%
Americas | Fire Helmets & Protective Apparel
Revenue from External Customer [Line Items]
Revenues									$ 133,653	$ 142,043	$ 136,794
Americas | Fire Helmets & Protective Apparel | Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									15.00%	16.00%	16.00%
Americas | Portable Gas Detection
Revenue from External Customer [Line Items]
Revenues									$ 90,545	$ 113,914	$ 109,401
Americas | Portable Gas Detection | Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									10.00%	12.00%	13.00%
Americas | Head Protection
Revenue from External Customer [Line Items]
Revenues									$ 92,075	$ 112,673	$ 114,465
Americas | Head Protection | Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									11.00%	12.00%	13.00%
Americas | Fall Protection
Revenue from External Customer [Line Items]
Revenues									$ 58,060	$ 78,054	$ 61,289
Americas | Fall Protection | Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									7.00%	9.00%	7.00%
Americas | Other
Revenue from External Customer [Line Items]
Revenues									$ 120,398	$ 96,079	$ 91,316
Americas | Other | Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									14.00%	11.00%	11.00%
International
Revenue from External Customer [Line Items]
Revenues									$ 473,918	$ 486,863	$ 503,817
International | Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									100.00%	100.00%	100.00%
International | Breathing Apparatus
Revenue from External Customer [Line Items]
Revenues									$ 108,529	$ 105,215	$ 119,572
International | Breathing Apparatus | Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									23.00%	22.00%	24.00%
International | Fixed Gas and Flame Detection
Revenue from External Customer [Line Items]
Revenues									$ 128,490	$ 133,096	$ 126,510
International | Fixed Gas and Flame Detection | Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									27.00%	27.00%	25.00%
International | Fire Helmets & Protective Apparel
Revenue from External Customer [Line Items]
Revenues									$ 28,554	$ 35,969	$ 32,885
International | Fire Helmets & Protective Apparel | Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									6.00%	7.00%	6.00%
International | Portable Gas Detection
Revenue from External Customer [Line Items]
Revenues									$ 52,036	$ 55,565	$ 54,315
International | Portable Gas Detection | Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									11.00%	11.00%	11.00%
International | Head Protection
Revenue from External Customer [Line Items]
Revenues									$ 33,846	$ 32,730	$ 31,923
International | Head Protection | Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									7.00%	7.00%	6.00%
International | Fall Protection
Revenue from External Customer [Line Items]
Revenues									$ 45,015	$ 47,815	$ 48,183
International | Fall Protection | Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									10.00%	10.00%	10.00%
International | Other
Revenue from External Customer [Line Items]
Revenues									$ 77,448	$ 76,473	$ 90,429
International | Other | Sales
Revenue from External Customer [Line Items]
Concentration risk (percentage)									16.00%	16.00%	18.00%

Earnings per Share - Schedule O

Earnings per Share - Schedule Of Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share [Abstract]
Net income	$ 12,338	$ 28,034	$ 36,055	$ 43,674	$ 31,163	$ 42,239	$ 39,806	$ 23,232	$ 120,101	$ 136,440	$ 124,150
Preferred stock dividends									41	42	42
Net income available to common equity									120,060	136,398	124,108
Dividends and undistributed earnings allocated to participating securities									(84)	(183)	(117)
Net income available to common shareholders									$ 119,976	$ 136,215	$ 123,991
Basic weighted-average shares outstanding									38,885	38,653	38,362
Stock options and other stock compensation									401	536	599
Diluted weighted-average shares outstanding									39,286	39,189	38,961
Earnings per share:
Basic (dollars per share)	$ 0.32	$ 0.72	$ 0.93	$ 1.12	$ 0.80	$ 1.09	$ 1.03	$ 0.60	$ 3.09	$ 3.52	$ 3.23
Diluted (dollars per share)	$ 0.31	$ 0.71	$ 0.92	$ 1.11	$ 0.79	$ 1.08	$ 1.01	$ 0.59	$ 3.05	$ 3.48	$ 3.18

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
U.S. federal income tax rate		21.00%	21.00%	21.00%
Tax Cuts and Jobs Act of 2017, provisional income tax expense	$ 19.8
Tax Cuts and Jobs Act of 2017, provisional transition tax	18
Tax Cuts and Jobs Act of 2017, income tax expense related to remeasurement of deferred tax assets and liabilities	1.8
Tax Cuts and Jobs Act of 2017, differences of Non-U.S. subsidiaries offset by foreign tax credits		$ 1.9
Tax Cuts And Jobs Act Of 2017, Change In Tax Rate, Foreign Tax Credits Related to Differences of Non-U.S. Subsidiaries		0.7
Tax Cuts And Jobs Act Of 2017, Incomplete Accounting, Provisional Income Tax Expense (Benefit) Adjustment During the Period		2
Tax Cuts And Jobs Act Of 2017 Incomplete Accounting Revaluation of Deferred Taxes Adjustment During the Period		2.5
Tax Cuts And Jobs Act Of 2017, Revaluation of Prepaid Taxes, Adjustment During the Period		2
Net operating loss carryforwards		$ 31
Net operating loss carryforwards, expiration term (at least)		6 years
Recognized tax benefits	2.2	$ 2.7	$ 2.2
Liability for interest expense and penalties accrued	$ 0.5	1	$ 0.5
International
Segment Reporting Information [Line Items]
Charges associated with exit taxes		$ 1.1
Americas
Segment Reporting Information [Line Items]
Charges associated with exit taxes				$ 1.8

Income Taxes - Components of In

Income Taxes - Components of Income Before Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
U.S. income	$ 104,682	$ 126,552	$ 85,234
Non-U.S. income	58,421	57,183	77,101
Income before income taxes	163,103	183,735	162,335
Current
Federal	23,587	13,770	13,574
State	4,896	5,436	4,265
Non-U.S.	16,780	25,608	23,446
Total current provision	45,263	44,814	41,285
Deferred
Federal	(1,493)	5,744	291
State	(727)	1,346	(1,604)
Non-U.S.	(1,102)	(5,818)	(2,752)
Total deferred provision (benefit)	(3,322)	1,272	(4,065)
Provision for income taxes	$ 41,941	$ 46,086	$ 37,220

Income Taxes - Reconciliation B

Income Taxes - Reconciliation Between U.S. Federal Income Tax Rate and Effective Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
U.S. federal income tax rate	21.00%	21.00%	21.00%
State income taxes—U.S.	2.00%	2.90%	1.30%
Nondeductible compensation	3.40%	1.90%	1.00%
Foreign exchange on entity closures	0.00%	1.80%	0.00%
Valuation allowances	0.80%	0.40%	0.50%
Taxes on non-U.S. income - U.S., Canadian & European reorganization	0.70%	0.30%	1.10%
U.S. tax reform	0.00%	0.00%	1.60%
Manufacturing deduction credit	0.00%	0.00%	(1.00%)
Employee share-based payments	3.90%	2.60%	1.60%
Research and development credit	(1.20%)	(0.60%)	(0.90%)
Taxes on non-U.S. income	2.60%	(0.50%)	0.40%
Other	0.30%	0.50%	(0.50%)
Effective income tax rate	25.70%	25.10%	22.90%

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Product liability	$ 33,689	$ 29,405
Capitalized research and development	22,915	17,886
Employee benefits	10,539	12,009
Net operating losses and tax credit carryforwards	6,310	6,026
Share-based compensation	3,588	5,396
Accrued expenses and other reserves	5,195	4,384
Other	5,287	3,828
Total deferred tax assets	87,523	78,934
Valuation allowances	(7,188)	(5,937)
Net deferred tax assets	80,335	72,997
Goodwill and intangibles	(39,040)	(35,999)
Property, plant and equipment	(14,649)	(11,714)
Other	(1,897)	(2,475)
Total deferred tax liabilities	55,586	50,188
Net deferred tax assets	$ 24,749	$ 22,809

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Change in Tax Liability for Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 5,119	$ 16,155
Adjustments for tax positions related to the current year	425	0
Adjustments for tax positions related to prior years	2,950	(7,740)
Statute expiration	(402)	(3,296)
Ending balance	$ 8,092	$ 5,119

Stock Plans - Additional Inform

Stock Plans - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options exercisable period after grant date		3 years
Restricted stock and restricted stock unit vest period after grant date		3 years
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value		0		0
Average closing share price, period				1 year
Cash proceeds from exercise of options		$ 12,446	$ 7,471	$ 8,573
Aggregate intrinsic value of stock options exercisable		29,000
Aggregate intrinsic value of stock options outstanding		29,300
Total intrinsic value of stock options exercised		24,600	14,600	12,200
Unrecognized stock-based compensation expense		$ 8,300
Weighted average period over which unrecognized stock-based compensation expense is expected to be recognized, in years		1 year 8 months 12 days
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of target award based on achieving targeted performance conditions		0.00%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of target award based on achieving targeted performance conditions		200.00%
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		135.70%
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excess tax benefit (provision) related to stock plans		$ 6,400	4,800	2,500
Restricted Stock and Unit Activity
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of stock units vested		5,700	5,500	5,400
Performance Stock Unit Activity
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	3 years
Fair value of stock units vested		$ 9,600	$ 6,200	$ 1,700
Management
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future grants		802,439
Non Employee Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future grants		94,020
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options expiration period		10 years

Stock Plans - Schedule of Stock

Stock Plans - Schedule of Stock Compensation Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Payment Arrangement [Abstract]
Restricted stock units	$ 6,258	$ 6,914	$ 6,221
Stock options	113	487	217
Performance stock units	549	6,359	5,801
Total stock-compensation expense before income taxes	6,920	13,760	12,239
Income tax benefit	1,668	3,357	2,974
Total stock-compensation expense, net of income tax benefit	$ 5,252	$ 10,403	$ 9,265

Stock Plans - Weighted Average

Stock Plans - Weighted Average Assumptions and Fair Value of Stock Option Grants (Detail)	12 Months Ended
	Dec. 31, 2019$ / shares
Share-based Payment Arrangement [Abstract]
Fair value per option (dollars per share)	$ 59.07
Risk-free interest rate	2.30%
Expected dividend yield	1.70%
Expected volatility	31.00%
Expected life (years)	6 years 4 months 24 days

Stock Plans - Summary of Stock

Stock Plans - Summary of Stock Option Activity (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding Beginning balance, Shares	559,656	735,001	955,446
Exercised, Shares	(274,704)	(198,535)	(215,724)
Granted, Shares		23,285
Stock options forfeitures, Shares		(95)	(4,721)
Outstanding Ending balance, Shares	283,998	559,656	735,001
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding Beginning balance, Weighted Average Exercise Price (dollars per share)	$ 45.78	$ 43.79	$ 42.75
Exercised, Weighted Average Exercise Price (dollars per share)	45.31	38.16	39.25
Granted, Weighted Average Exercise Price (dollars per share)		43.54
Forfeited, Weighted Average Exercise Price (dollars per share)		49.19	44.50
Outstanding Ending balance, Weighted Average Exercise Price (dollars per share)	$ 46.23	$ 45.78	$ 43.79
Exercisable at end of period	281,593	552,682	638,673
Share-based Compensation Arrangement by Share-based Payment Award, Options, Expirations in Period	954
Share-based Compensation Arrangements by Share-based Payment Award, Options, Expirations in Period, Weighted Average Exercise Price	$ 42

Stock Plans - Schedule of Exerc

Stock Plans - Schedule of Exercise Price Ranges, Characteristics of Outstanding Stock Options (Detail)	12 Months Ended
	Dec. 31, 2020$ / sharesshares
$17.83 – $33.00
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Range of Exercise Prices, minimum (dollars per share)	$ 33.01
Range of Exercise Prices, maximum (dollars per share)	$ 45
$33.01 – $45.00
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Stock Options Outstanding, Shares | shares	158,836
Stock Options Outstanding, Weighted-Average Exercise Price (dollars per share)	$ 43.88
Stock Options Outstanding, Weighted-Average Remaining Life	3 years 21 days
Stock Options Exercisable, Shares | shares	158,208
Stock Options Exercisable, Weighted-Average Exercise Price (dollars per share)	$ 43.90
Stock Options Exercisable, Weighted-Average Remaining Life	3 years 18 days
$45.01 – $57.93
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Range of Exercise Prices, minimum (dollars per share)	$ 45.01
Range of Exercise Prices, maximum (dollars per share)	$ 57.93
Stock Options Outstanding, Shares | shares	125,162
Stock Options Outstanding, Weighted-Average Exercise Price (dollars per share)	$ 49.22
Stock Options Outstanding, Weighted-Average Remaining Life	2 years 11 months 4 days
Stock Options Exercisable, Shares | shares	123,385
Stock Options Exercisable, Weighted-Average Exercise Price (dollars per share)	$ 49.22
Stock Options Exercisable, Weighted-Average Remaining Life	2 years 10 months 13 days
$33.01 – $57.93
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Range of Exercise Prices, minimum (dollars per share)	$ 33.01
Range of Exercise Prices, maximum (dollars per share)	$ 57.93
Stock Options Outstanding, Shares | shares	283,998
Stock Options Outstanding, Weighted-Average Exercise Price (dollars per share)	$ 46.23
Stock Options Outstanding, Weighted-Average Remaining Life	3 years
Stock Options Exercisable, Shares | shares	281,593
Stock Options Exercisable, Weighted-Average Exercise Price (dollars per share)	$ 46.23
Stock Options Exercisable, Weighted-Average Remaining Life	2 years 11 months 19 days

Stock Plans - Summary of Restri

Stock Plans - Summary of Restricted Stock Activity (Detail) - Restricted Stock and Unit Activity - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested Shares, Beginning Balance	172,701	205,449	227,161
Granted, Shares	51,468	70,160	75,430
Vested, Shares	(70,399)	(97,253)	(92,401)
Forfeited, Shares	(7,579)	(5,655)	(4,741)
Unvested Shares, Ending Balance	146,191	172,701	205,449
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 (dollars per share)	$ 90.38	$ 68.97	$ 57.50
Granted, Weighted Average Grant Date Fair Value (dollars per share)	124.61	104.53	87.36
Vested, Weighted Average Grant Date Fair Value (dollars per share)	81.58	56.47	58.10
Forfeited, Weighted Average Grant Date Fair Value (dollars per share)	106.54	85.48	59.61
Unvested Weighted Average Grant Date Fair Value, Ending Balance (dollars per share)	$ 105.83	$ 90.38	$ 68.97

Stock Plans - Summary of Perfor

Stock Plans - Summary of Performance Stock Unit Activity (Detail) - Performance Stock Unit Activity - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Unvested Shares, Beginning Balance	238,035	218,886	242,186
Granted, Shares	67,479	83,819	62,775
Vested, Shares	(132,036)	(139,478)	(41,660)
Performance adjustments, Shares	33,499	76,960	(35,756)
Forfeited, Shares	(6,765)	(2,152)	(8,659)
Unvested Shares, Ending Balance	200,212	238,035	218,886
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 (dollars per share)	$ 85.39	$ 68.43	$ 55.06
Granted, Weighted Average Grant Date Fair Value (dollars per share)	127.48	101.03	84.79
Vested, Weighted Average Grant Date Fair Value (dollars per share)	73	44.75	40.23
Performance adjustments, Weighted Average Grant Date Fair value (dollars per share)	72.36	44.24	45.21
Forfeited, Weighted Average Grant Date Fair Value (dollars per share)	111.60	99.82	44.53
Unvested Weighted Average Grant Date Fair Value, Ending Balance (dollars per share)	$ 104.69	$ 85.39	$ 68.43

Short and Long-Term Debt - Shor

Short and Long-Term Debt - Short-Term Debt Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Line of Credit Facility [Line Items]
Restricted Cash and Cash Equivalents	$ 400	$ 300
Gain (Loss) on Extinguishment of Debt	0	$ 0	$ (1,494)
Revolving Credit Facility
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 600,000
Debt, Weighted Average Interest Rate	1.15%
Line of Credit Facility, Remaining Borrowing Capacity	$ 385,500
Federal Funds Effective Swap Rate | Revolving Credit Facility
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.50%
Daily Libor Rate | Revolving Credit Facility
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.00%
Minimum | BASE or LIBOR | Revolving Credit Facility
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.00%
Maximum | BASE or LIBOR | Revolving Credit Facility
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.75%
Senior Revolving Credit Facility Maturing in 2023 | Overnight Bank Funding Rate
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.50%
Multi-currency Notes Due in 2031
Line of Credit Facility [Line Items]
Debt Instrument, Covenant, Fixed Charges Coverage Ratio, Minimum	1.50
Debt Instrument, Covenant, Consolidated Leverage Ratio, Maximum	3.50
Debt Instrument, Covenant, Consolidated Leverage Ratio In Period Of Acquisition, Maximum	4
Notes Payable, Other Payables [Member] | Multi-currency Notes Due in 2031
Line of Credit Facility [Line Items]
Additional Senior Notes Available for Request	$ 150,000
Notes Payable, Other Payables [Member] | Master Note Facility Due in 2022
Line of Credit Facility [Line Items]
Additional Senior Notes Available for Request	$ 150,000

Short and Long-Term Debt - Sche

Short and Long-Term Debt - Schedule of Outstanding Debt (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Total	$ 307,157	$ 348,394
Short-term debt	20,000	20,000
Long-term debt	287,157	328,394
Senior Notes Payable Through 2021, 4.00%
Debt Instrument [Line Items]
Senior notes payable	$ 20,000	40,000
Senior notes, interest rate	4.00%
Senior Notes Payable Through 2031, 3.40%
Debt Instrument [Line Items]
Senior notes payable	$ 74,926	72,708
Senior notes, interest rate	3.40%
Revolving Credit Facility
Debt Instrument [Line Items]
Senior revolving credit facility maturing in 2023, net of debt issuance costs	$ 212,231	$ 235,686

Short and Long-Term Debt - Long

Short and Long-Term Debt - Long-Term Debt Additional Information (Detail)	Jan. 22, 2016GBP (£)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Debt Instrument [Line Items]
Maturity obligation, year one		$ 20,000,000
Maturity obligation, year two		0
Maturity obligation, year three		221,600,000
Maturity obligation, year four		8,300,000
Maturity obligation, year 5		8,300,000
Maturity obligation, thereafter		50,100,000
Bank guarantees and letters of credit, outstanding		9,000,000
Restricted Cash and Cash Equivalents		$ 400,000	$ 300,000
Revolving Credit Facility
Debt Instrument [Line Items]
Weighted average revolver interest rate		1.15%
Unused senior revolving credit facility		$ 385,500,000
Line of credit, maximum borrowing capacity		600,000,000
Bank guarantees and letters of credit, outstanding		1,300,000
Multi-currency Notes Due in 2031
Debt Instrument [Line Items]
Notes payable, principal amount	£ 54,900,000	75,100,000
Notes payable, annual repayment installments	£ 6,100,000	$ 8,300,000
Notes payable, interest rate		3.40%
Minimum fixed charges coverage ratio (not less than)		1.50
Consolidated leverage ratio (not to exceed)		3.50
Federal Funds Open Rate | Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate		0.50%
Daily Libor Rate | Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate		1.00%
Minimum | BASE or LIBOR | Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate		0.00%
Maximum | BASE or LIBOR | Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate		1.75%

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 443,272	$ 436,679	$ 413,640
Intangible Assets
Acquired Finite-Lived Intangible Assets [Line Items]
Future amortization expense, year one	12,000
Future amortization expense, year two	10,000
Future amortization expense, year three	9,000
Future amortization expense, year four	9,000
Future amortization expense, year five	9,000
Americas
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	293,200
International
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 150,100
Globe Holding Company LLC | Trade Names
Acquired Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets			$ 60,000

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Schedule of Changes in Goodwill (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Roll Forward]
Net balance at January 1	$ 436,679,000	$ 413,640,000
Additions (Note 13)	0	19,917,000
Goodwill, impairment loss	0	0	$ 0
Currency translation	6,593,000	3,122,000
Net balance at December 31	$ 443,272,000	$ 436,679,000	$ 413,640,000

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Schedule of Changes in Intangible Assets, Net of Accumulated Amortization (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finite-lived Intangible Assets [Roll Forward]
Net balance at January 1	$ 111,300
Additions	121	$ 11,100
Amortization expense	(11,570)	(11,119)
Currency translation	1,174	1,830
Net balance at December 31	101,100	111,300
Intangible assets, net (Note 12)	$ 161,051	$ 171,326	$ 169,515

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets - Net Carrying Amount (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life (years)	14 years
Gross Carrying Amount	$ 184.1	$ 181.6
Accumulated Amortization and Reserves	(83)	(70.3)
Net Carrying Amount	$ 101.1	111.3
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life (years)	14 years
Gross Carrying Amount	$ 59.7	58.3
Accumulated Amortization and Reserves	(20.4)	(15.3)
Net Carrying Amount	$ 39.3	43
Distribution agreements
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life (years)	20 years
Gross Carrying Amount	$ 66.4	66
Accumulated Amortization and Reserves	(20.7)	(17.3)
Net Carrying Amount	$ 45.7	48.7
Technology related assets
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life (years)	8 years
Gross Carrying Amount	$ 30.2	30
Accumulated Amortization and Reserves	(21.3)	(18.3)
Net Carrying Amount	$ 8.9	11.7
Patents, trademarks and copyrights
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life (years)	12 years
Gross Carrying Amount	$ 19.4	19
Accumulated Amortization and Reserves	(12.5)	(11.3)
Net Carrying Amount	$ 6.9	7.7
License agreements
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life (years)	5 years
Gross Carrying Amount	$ 5.4	5.3
Accumulated Amortization and Reserves	(5.3)	(5.3)
Net Carrying Amount	$ 0.1	0
Other
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life (years)	2 years
Gross Carrying Amount	$ 3	3
Accumulated Amortization and Reserves	(2.8)	(2.8)
Net Carrying Amount	$ 0.2	$ 0.2

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail) - USD ($) $ in Thousands	May 20, 2019	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired										$ 0	$ 33,196	$ 0
Estimated amortization period										14 years
Goodwill		$ 443,272				$ 436,679				$ 443,272	436,679	413,640
Strategic transaction costs (Note 13)										717	4,400	421
Revenues		388,248	$ 304,392	$ 314,438	$ 341,145	375,254	$ 351,014	$ 349,675	$ 326,038	1,348,223	1,401,981	1,358,104
Net income (loss)										120,101	136,440	124,150
Depreciation										27,700	26,500	26,900
Amortization primarily related to intangible assets										11,570	11,119
Americas
Business Acquisition [Line Items]
Goodwill		293,200								293,200
Revenues										874,305	915,118	$ 854,287
Sierra Monitor Corporation
Business Acquisition [Line Items]
Common stock acquired (as a percent)	100.00%
Payments to Acquire Businesses, Net of Cash Acquired	$ 33,200
Future amortization expense, year one		1,000								1,000
Future amortization expense, year two		1,000								1,000
Future amortization expense, year three		1,000								1,000
Finite-Lived Intangible Assets, Amortization Expense, Year Four		1,000								1,000
Future amortization expense, year five		$ 1,000								1,000
Step up to fair value of acquired inventory as part of purchase price allocation	1,600
Goodwill	19,900
Revenues										21,200
Net income (loss)										2,800
Purchase accounting amortization for intangible assets and inventory step up excluded from acquisitions										1,200	2,600
Business Acquisition, Transaction Costs						$ 2,200					2,200
Net income related to acquiree adjusted to remove transaction costs										$ 3,800	1,500
Sierra Monitor Corporation | Americas
Business Acquisition [Line Items]
Goodwill	$ 19,900
Globe Holding Company LLC
Business Acquisition [Line Items]
Revenues											13,500
Net income (loss)											(3,300)
Technology related assets
Business Acquisition [Line Items]
Estimated amortization period										8 years
Technology related assets | Sierra Monitor Corporation
Business Acquisition [Line Items]
Estimated amortization period	5 years
Customer-related intangibles | Sierra Monitor Corporation
Business Acquisition [Line Items]
Estimated amortization period	10 years
Stock Options And Restricted Stock Units | Sierra Monitor Corporation
Business Acquisition [Line Items]
Goodwill	$ 900
Performance Stock | Sierra Monitor Corporation
Business Acquisition [Line Items]
Share-based Payment Arrangement, Expense											$ 1,500

Acquisitions - Preliminary Fair

Acquisitions - Preliminary Fair Values of the Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	May 20, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill	$ 443,272	$ 436,679		$ 413,640
Sierra Monitor Corporation
Business Acquisition [Line Items]
Current assets			$ 10,500
Cash included in current assets			2,100
Property, plant and equipment			1,300
Goodwill			19,900
Total assets acquired			42,700
Total liabilities assumed			6,500
Net assets acquired			36,200
Acquired technology | Sierra Monitor Corporation
Business Acquisition [Line Items]
Finite-lived intangible assets			1,400
Customer relationships | Sierra Monitor Corporation
Business Acquisition [Line Items]
Finite-lived intangible assets			$ 9,600
Trade Names | Globe Holding Company LLC
Business Acquisition [Line Items]
Indefinite-lived intangible assets				$ 60,000

Acquisitions - Pro Forma Financ

Acquisitions - Pro Forma Financial Information (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Net sales	$ 1,410	$ 1,380
Net Income	$ 131	$ 124
Basic earnings per share from continuing operations (in dollars per share)	$ 3.40	$ 3.24
Diluted earnings per share from continuing operations (in dollars per share)	$ 3.35	$ 3.19

Pensions and Other Post-retir_3

Pensions and Other Post-retirement Benefits - Schedule of Defined Benefit Pension Plans and Other Postretirement Benefits Plan (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Funded Status
Noncurrent assets	$ 97,545	$ 75,066
Noncurrent liabilities	(208,068)	(186,697)
Pension Benefits
Change in Benefit Obligations
Benefit obligations at January 1	603,551	525,520
Service cost	12,094	10,342	$ 11,125
Interest cost	14,905	18,803	17,214
Participant contributions	396	470
Plan amendments	(430)	0
Actuarial losses(a)	54,606	81,132
Benefits paid	(24,496)	(24,452)
Curtailments	1,559	0
Settlements	(506)	(7,265)
Currency translation	12,296	(999)
Benefit obligations at December 31	670,857	603,551	525,520
Change in Plan Assets
Fair value of plan assets at January 1	515,858	443,112
Actual return on plan assets	87,769	98,210
Employer contributions	5,596	5,537
Participant contributions	396	470
Settlements	(506)	(7,265)
Benefits paid	24,496	24,452
Administrative expenses paid	(172)	(297)
Currency translation	2,377	543
Fair value of plan assets at December 31	586,822	515,858	443,112
Funded Status
Funded status at December 31	(84,035)	(87,693)
Unrecognized transition losses	4	4
Unrecognized prior service credit	1,717	1,572
Unrecognized net actuarial losses	169,028	183,733
Net amount recognized	86,714	97,616
Noncurrent assets	97,545	75,066
Current liabilities	(6,600)	(5,944)
Noncurrent liabilities	(174,980)	(156,815)
Net amount recognized	(84,035)	(87,693)
Amounts Recognized in Accumulated Other Comprehensive Loss
Net actuarial losses	169,028	183,733
Prior service cost (credit)	1,717	1,572
Unrecognized net initial obligation	4	4
Total (before tax effects)	170,749	185,309
Accumulated Benefit Obligations for all Defined Benefit Plans	619,167	558,183
Other Benefits
Change in Benefit Obligations
Benefit obligations at January 1	28,151	28,477
Service cost	396	354	369
Interest cost	716	996	793
Participant contributions	370	380
Plan amendments	0	0
Actuarial losses(a)	5,284	1,319
Benefits paid	(2,692)	(3,375)
Curtailments	0	0
Settlements	0	0
Currency translation	0	0
Benefit obligations at December 31	32,225	28,151	28,477
Change in Plan Assets
Fair value of plan assets at January 1	0	0
Actual return on plan assets	0	0
Employer contributions	2,322	2,995
Participant contributions	370	380
Settlements	0	0
Benefits paid	2,692	3,375
Administrative expenses paid	0	0
Currency translation	0	0
Fair value of plan assets at December 31	0	0	$ 0
Funded Status
Funded status at December 31	(32,225)	(28,151)
Unrecognized transition losses	0	0
Unrecognized prior service credit	(1,125)	(1,519)
Unrecognized net actuarial losses	16,686	12,547
Net amount recognized	(16,664)	(17,123)
Noncurrent assets	0	0
Current liabilities	(2,849)	(2,406)
Noncurrent liabilities	(29,376)	(25,745)
Net amount recognized	(32,225)	(28,151)
Amounts Recognized in Accumulated Other Comprehensive Loss
Net actuarial losses	16,686	12,547
Prior service cost (credit)	(1,125)	(1,519)
Unrecognized net initial obligation	0	0
Total (before tax effects)	15,561	11,028
Accumulated Benefit Obligations for all Defined Benefit Plans	$ 0	$ 0

Pensions and Other Post-retir_4

Pensions and Other Post-retirement Benefits - Components of Net Periodic Benefit Cost (Credit) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 12,094	$ 10,342	$ 11,125
Interest cost	14,905	18,803	17,214
Expected return on plan assets	(34,029)	(38,644)	(36,352)
Amortization of transition amounts	0	2	1
Amortization of prior service cost (credit)	178	223	(21)
Recognized net actuarial losses	15,799	10,159	13,755
Settlement/curtailment loss	1,135	2,497	179
Net periodic benefit cost(a)	10,082	3,382	5,901
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	396	354	369
Interest cost	716	996	793
Expected return on plan assets	0	0	0
Amortization of transition amounts	0	0	0
Amortization of prior service cost (credit)	(394)	(405)	(405)
Recognized net actuarial losses	1,145	869	752
Settlement/curtailment loss	0	0	0
Net periodic benefit cost(a)	$ 1,863	$ 1,814	$ 1,509

Pensions and Other Post-retir_5

Pensions and Other Post-retirement Benefits - Accumulated Benefit Obligation in Excess of Plan Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Aggregate accumulated benefit obligations (ABO)	$ 209,351	$ 185,747
Aggregate fair value of plan assets	40,294	35,882
Other Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Aggregate accumulated benefit obligations (ABO)	32,225	28,151
Aggregate fair value of plan assets	$ 0	$ 0

Pension and Other Post-retireme

Pension and Other Post-retirement Benefits - Pension Plans with PBO in Excess of Plan Assets (Details) - Pension Benefits - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Aggregate projected benefit obligations (PBO)	$ 223,343	$ 198,633
Aggregate fair value of plan assets	$ 41,764	$ 35,882

Pensions and Other Post-retir_6

Pensions and Other Post-retirement Benefits - Schedule of Assumptions Used to Determine Benefit Obligations and Net Periodic Benefit Cost (Detail)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Assumptions used to determine benefit obligations, average discount rate	2.28%	2.86%
Assumptions used to determine benefit obligations, rate of compensation increase	2.93%	2.93%
Assumptions used to determine net periodic benefit cost, average discount rate, service cost	3.08%	3.10%
Assumptions used to determine net periodic benefit cost, average discount rate, interest cost	2.52%	2.52%
Assumptions used to determine net periodic benefit cost, expected return on plan assets	7.10%	7.09%
Assumptions used to determine net periodic benefit cost, rate of compensation increases	2.93%	2.93%
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Assumptions used to determine benefit obligations, average discount rate	2.21%	3.05%
Assumptions used to determine benefit obligations, rate of compensation increase	3.00%	0.00%
Assumptions used to determine net periodic benefit cost, average discount rate, service cost	2.42%	3.15%
Assumptions used to determine net periodic benefit cost, average discount rate, interest cost	1.48%	2.61%
Assumptions used to determine net periodic benefit cost, expected return on plan assets	0.00%	0.00%
Assumptions used to determine net periodic benefit cost, rate of compensation increases	3.00%	0.00%

Pensions and Other Post-retir_7

Pensions and Other Post-retirement Benefits - Schedule of Expected Return on Assets for Net Periodic Pension Cost (Detail)	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Pension Plan Assets at December 31,	100.00%	100.00%
Equity securities
Defined Benefit Plan Disclosure [Line Items]
Pension Plan Assets at December 31,	49.00%	46.00%
Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Pension Plan Assets at December 31,	25.00%	30.00%
Pooled investment funds
Defined Benefit Plan Disclosure [Line Items]
Pension Plan Assets at December 31,	21.00%	19.00%
Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Pension Plan Assets at December 31,	4.00%	4.00%
Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Pension Plan Assets at December 31,	1.00%	1.00%

Pensions and Other Post-retir_8

Pensions and Other Post-retirement Benefits - Summary of Pension Plan Assets Measured at Fair Value on Recurring Basis by Fair Value Hierarchy (Detail) - Pension Plan - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	$ 586,822	$ 515,858	$ 443,112
Fair Value, Measurements, Recurring
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	586,822	515,858
Plan assets at NAV	196,647	159,614
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	294,108	253,976
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	71,671	80,766
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	24,396	21,502
Fair Value, Measurements, Recurring | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	283,516	235,491
Plan assets at NAV	66,847	56,449
Fair Value, Measurements, Recurring | Equity securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	216,669	179,042
Fair Value, Measurements, Recurring | Equity securities | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	0	0
Fair Value, Measurements, Recurring | Equity securities | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	0	0
Fair Value, Measurements, Recurring | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	148,173	154,640
Plan assets at NAV	0	0
Fair Value, Measurements, Recurring | Fixed income securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	76,502	73,874
Fair Value, Measurements, Recurring | Fixed income securities | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	71,671	80,766
Fair Value, Measurements, Recurring | Fixed income securities | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	0	0
Fair Value, Measurements, Recurring | Pooled investment funds
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	123,119	97,373
Plan assets at NAV	123,119	97,373
Fair Value, Measurements, Recurring | Pooled investment funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	0	0
Fair Value, Measurements, Recurring | Pooled investment funds | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	0	0
Fair Value, Measurements, Recurring | Pooled investment funds | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	0	0
Fair Value, Measurements, Recurring | Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	24,396	21,502
Plan assets at NAV	0	0
Fair Value, Measurements, Recurring | Insurance contracts | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	0	0
Fair Value, Measurements, Recurring | Insurance contracts | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	0	0
Fair Value, Measurements, Recurring | Insurance contracts | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	24,396	21,502
Fair Value, Measurements, Recurring | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	7,618	6,852
Plan assets at NAV	6,681	5,792
Fair Value, Measurements, Recurring | Cash and cash equivalents | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	937	1,060
Fair Value, Measurements, Recurring | Cash and cash equivalents | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	0	0
Fair Value, Measurements, Recurring | Cash and cash equivalents | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets measured at fair value	$ 0	$ 0

Pensions and Other Post-retir_9

Pensions and Other Post-retirement Benefits - Schedule of Reconciliation of Level Three Assets (Detail) - Significant Unobservable Inputs (Level 3) - Insurance contracts - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at January 1	$ 21,502	$ 17,033
Net realized and unrealized losses	2,564	5,602
Net purchases, issuances and settlements	330	(1,133)
Fair value of plan assets at December 31	$ 24,396	$ 21,502

Pension and Other Post-retire_2

Pension and Other Post-retirement Benefits - Level 3 Assets Recognized in AOCL (Details) - Insurance contracts $ in Thousands	Dec. 31, 2020USD ($)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net actuarial losses	$ 972
Prior service cost (credit)	1,406
Total (before tax effects)	$ 2,378

Pensions and Other Post-reti_10

Pensions and Other Post-retirement Benefits - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Estimated contributions by employer to pension plans	$ 7,700
Percentage increase in health care benefit cost		6.50%
Percentage decrease in health care benefits for successive year	0.20%	0.50%
Estimated future percentage of health care benefits	4.50%	4.50%
Increase in costs of covered health care benefits	5.90%
Defined contribution pension plan expense	$ 10,600	$ 8,300	$ 9,000
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	10,082	3,382	5,901
Service cost	12,094	10,342	11,125
Estimated benefit payments, year one	26,100
Estimated benefit payments, year two	27,000
Estimated benefit payments, year three	28,200
Estimated benefit payments, year four	28,800
Estimated benefit payments, year five	29,900
Estimated benefit payments, five years thereafter	155,900
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	1,863	1,814	1,509
Service cost	396	$ 354	$ 369
Estimated benefit payments, year one	2,800
Estimated benefit payments, year two	2,700
Estimated benefit payments, year three	2,300
Estimated benefit payments, year four	2,400
Estimated benefit payments, year five	2,200
Estimated benefit payments, five years thereafter	$ 10,300

Other Income (Loss), Net - Sche

Other Income (Loss), Net - Schedule of Other Income (Loss) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other Income and Expenses [Abstract]
Interest income	$ 3,498	$ 4,411	$ 4,588
Nonoperating pension income (expense)	1,680	7,997	4,641
(Loss) Gain on asset dispositions, net	(236)	(371)	646
Other, net	742	(943)	(644)
Total other income, net	$ 5,684	$ 11,094	$ 9,231

Leases - Additional Information

Leases - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2019
Lessee, Lease, Description [Line Items]
Operating lease, right-of-use asset	$ 53,451	$ 51,675
Operating lease liability	54,227
Rent expense	$ 13,000	$ 13,400	$ 12,500
Accounting Standards Update 2016-02
Lessee, Lease, Description [Line Items]
Operating lease, right-of-use asset				$ 54,000

Leases Lease Cost (Details)

Leases Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease cost	$ 12,997	$ 13,364
Operating cash flows related to operating leases	13,476	13,346
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 10,737	$ 6,637
Weighted-average remaining lease term	11 years	11 years
Weighted-average discount rate	3.89%	4.28%

Leases Future Lease Payments (D

Leases Future Lease Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
2020	$ 11,445
2021	7,856
2022	6,266
2023	4,539
2024	4,692
After 2025	31,687
Total future minimum operating lease payments	66,485
Less: Imputed interest	12,258
Present value of operating lease liabilities	$ 54,227
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesCurrent
Less: Current portion operating lease liabilities	$ 9,588
Noncurrent operating lease liabilities (Note 16)	$ 44,639	$ 42,632

Derivative Financial Instrume_3

Derivative Financial Instruments - Additional Information (Detail) $ in Millions	Dec. 31, 2020USD ($)
Foreign Exchange Forward
Derivative [Line Items]
Notional amount of open forward contracts	$ 96

Derivative Financial Instrume_4

Derivative Financial Instruments - Balance Sheet Location And Fair Value Of Assets And Liabilities Associated With Derivative Financial Instruments (Detail) - Foreign exchange contracts - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Other Current Liabilities
Derivatives, Fair Value [Line Items]
Derivatives not designated as hedging instruments	$ 157	$ 125
Other Current Assets
Derivatives, Fair Value [Line Items]
Derivatives not designated as hedging instruments	$ 160	$ 687

Derivative Financial Instrume_5

Derivative Financial Instruments - Income Statement Location And Impact Of Derivative Financial Instruments (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Foreign Exchange Contract | Derivatives not designated as hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Currency exchange losses, net	$ (7,457)	$ 3,015

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Carrying amount of short-term investments	$ 74.9	$ 49.7
Fair Value of Short Term investments	75	49.9
Carrying amount of long-term debt	95	113
Fair value of long-term debt	$ 113	$ 129

Contingencies - Additional Info

Contingencies - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)lawsuittrauma_claim	Dec. 31, 2019USD ($)lawsuittrauma_claim	Dec. 31, 2018USD ($)lawsuittrauma_claim	Dec. 31, 2017lawsuittrauma_claim
Loss Contingencies [Line Items]
Loss Contingency, Years of Activity	5 years
Reserves for product liability claims	$ 221,500	$ 167,500
Insurance receivables	97,000	63,800	$ 71,700
Notes receivable from insurance companies	52,300	56,000	59,600
Reported in Notes receivable	3,796	3,676
Notes receivable, insurance companies, noncurrent (Note 19)	48,540	52,336
Product Warranty Expense	9,600	11,200	9,400
Single Incident
Loss Contingencies [Line Items]
Reserves for product liability claims	1,400	3,100
Product liability losses	$ (1,700)	$ 500	$ 2,000
Lawsuits
Loss Contingencies [Line Items]
Number of lawsuits | lawsuit	1,622	1,605	1,481	1,420
Insurance Claims
Loss Contingencies [Line Items]
Number of lawsuits | trauma_claim	2,878	2,456	2,355	2,242
Cumulative Trauma, Reported Claims
Loss Contingencies [Line Items]
Product liability losses	$ 77,800	$ 36,100	$ 63,800
Claims Settled, But Not Yet Paid
Loss Contingencies [Line Items]
Reserves for product liability claims	7,800	3,000
Uninsured Cumulative Trauma
Loss Contingencies [Line Items]
Product liability losses	39,000	27,100	$ 43,800
Other Current Liabilities | Cumulative Trauma, Reported Claims
Loss Contingencies [Line Items]
Reserves for product liability claims	35,300	17,400
Other Noncurrent Liabilities | Cumulative Trauma, Reported Claims
Loss Contingencies [Line Items]
Reserves for product liability claims	186,200	150,100
Prepaid Expenses and Other Current Assets
Loss Contingencies [Line Items]
Insurance Receivables, current	12,000	7,600
Other Noncurrent Assets
Loss Contingencies [Line Items]
Insurance receivable, noncurrent	$ 85,000	$ 56,200

Contingencies - Summary of Cumu

Contingencies - Summary of Cumulative Trauma Product Liability Claims Activity (Detail)	12 Months Ended
	Dec. 31, 2020lawsuittrauma_claim	Dec. 31, 2019lawsuittrauma_claim	Dec. 31, 2018trauma_claimlawsuit
Lawsuits
Loss Contingency, Quantities [Roll Forward]
Open lawsuits/Pending claims, January 1 | lawsuit	1,605	1,481	1,420
New lawsuits/claims | lawsuit	402	346	369
Settled and dismissed lawsuits/claims | lawsuit	(385)	(222)	(308)
Open lawsuits/Pending claims, December 31 | lawsuit	1,622	1,605	1,481
Pending claims
Loss Contingency, Quantities [Roll Forward]
Open lawsuits/Pending claims, January 1 | trauma_claim	2,456	2,355	2,242
New lawsuits/claims | trauma_claim	917	486	479
Settled and dismissed lawsuits/claims | trauma_claim	(495)	(385)	(366)
Open lawsuits/Pending claims, December 31 | trauma_claim	2,878	2,456	2,355

Contingencies - Summary of Insu

Contingencies - Summary of Insurance Receivable Balances and Activity Related to Cumulative Trauma Product Liability Losses (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Movement in Loss Contingency Receivable, Increase (Decrease) [Roll Forward]
Balance beginning of period	$ 63.8	$ 71.7
Additions	39	9.1
Collections and other adjustments	(5.8)	(17)
Balance end of period	$ 97	$ 63.8

Contingencies - Summary of Note

Contingencies - Summary of Notes Receivable from Insurance Companies and Activity During the Year (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Movement in Loss Contingency Receivable, Increase (Decrease) [Roll Forward]
Balance beginning of period	$ 56	$ 59.6
Additions	1.4	1.5
Collections	(5.1)	(5.1)
Balance end of period	$ 52.3	$ 56

Contingencies Warranty Reserve

Contingencies Warranty Reserve (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Warranty Expense [Rollforward]
Beginning warranty reserve	$ 12,715	$ 14,214	$ 14,753
Warranty payments	(10,861)	(12,664)	(9,955)
Warranty claims	10,233	12,033	10,585
Provision for product warranties and other adjustments	(659)	(868)	(1,169)
Ending warranty reserve	$ 11,428	$ 12,715	$ 14,214

Quarterly Financial Informati_3

Quarterly Financial Information (Unaudited) - Schedule of Quarterly Financial Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 388,248	$ 304,392	$ 314,438	$ 341,145	$ 375,254	$ 351,014	$ 349,675	$ 326,038	$ 1,348,223	$ 1,401,981	$ 1,358,104
Gross profit	159,272	132,232	141,585	157,359	166,845	158,701	161,084	149,982	590,448	636,612	611,863
Net income	$ 12,338	$ 28,034	$ 36,055	$ 43,674	$ 31,163	$ 42,239	$ 39,806	$ 23,232	$ 120,101	$ 136,440	$ 124,150
Basic (dollars per share)	$ 0.32	$ 0.72	$ 0.93	$ 1.12	$ 0.80	$ 1.09	$ 1.03	$ 0.60	$ 3.09	$ 3.52	$ 3.23
Diluted (dollars per share)	$ 0.31	$ 0.71	$ 0.92	$ 1.11	$ 0.79	$ 1.08	$ 1.01	$ 0.59	$ 3.05	$ 3.48	$ 3.18

Subsequent Event (Details)

Subsequent Event (Details) - Bristol - USD ($)	Jan. 25, 2021	Dec. 31, 2020
Subsequent Event [Line Items]
Integration costs		$ 500,000
Subsequent Event
Subsequent Event [Line Items]
Common stock acquired (as a percent)	100.00%
Purchase price of business combination	$ 62,400,000
Contingent consideration	$ 0

Schedule II - Valuation and Q_2

Schedule II - Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Allowance for Doubtful Accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	$ 4,860	$ 5,369	$ 5,540
Charged to costs and expenses	1,172	2,015	375
Deductions from reserves, net	688	2,524	546
Balance at end of year	5,344	4,860	5,369
Income Tax Valuation Allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	5,936	5,039	4,559
Charged to costs and expenses	2,854	1,138	859
Deductions from reserves, net	1,602	241	379
Balance at end of year	$ 7,188	$ 5,936	$ 5,039

Schedule II - Valuation and Q_3

Schedule II - Valuation and Qualifying Accounts - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Allowance for Doubtful Accounts
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Currency translation gains (losses)	$ (107)	$ (1,058)	$ (291)
Income Tax Valuation Allowance
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Currency translation gains (losses)	$ (41)	$ 104	$ (367)