Capital Stock - Schedule of Common Stock Activity (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Common Stock Activity [Roll Forward]
Beginning balance (in shares)	39,213,064
Stock options exercised (in shares)	31,394	103,545	122,087
Ending balance (in shares)	39,317,212	39,213,064
Common stock
Common Stock Activity [Roll Forward]
Beginning balance (in shares)	62,081,391	62,081,391	62,081,391
Acquisition of noncontrolling interest			$ (4,751)
Ending balance (in shares)	62,081,391	62,081,391	62,081,391
Total MSA Safety Incorporated shareholders’ equity	$ 312,324	$ 281,980	$ 260,121	$ 242,693
Treasury Stock, Common
Common Stock Activity [Roll Forward]
Beginning balance (in shares)	22,868,327	22,804,873	23,013,489
Ending balance (in shares)	22,764,179	22,868,327	22,804,873
Total MSA Safety Incorporated shareholders’ equity	$ (361,684)	$ (359,838)	$ (328,776)	$ (326,156)
Restricted Stock | Common stock
Common Stock Activity [Roll Forward]
Restricted stock awards	(643)	(711)	(762)
Restricted stock expense	9,476	7,715	6,562
Restricted stock forfeitures	$ (1,414)	$ (1,227)	$ (765)
Restricted Stock | Treasury Stock, Common
Common Stock Activity [Roll Forward]
Restricted stock awards (in shares)	40,856	52,810	53,934
Restricted stock awards	$ 643	$ 711	$ 762
Stock options | Common stock
Common Stock Activity [Roll Forward]
Restricted stock expense	11	49	90
Restricted stock forfeitures	(11)		(9)
Stock options exercised	$ 970	$ 3,021	$ 4,003
Stock options | Treasury Stock, Common
Common Stock Activity [Roll Forward]
Stock options exercised (in shares)	31,394	103,545	122,119
Stock options exercised	$ 503	$ 1,629	$ 1,767
Performance stock | Common stock
Common Stock Activity [Roll Forward]
Restricted stock expense	23,546	15,843	13,227
Restricted stock forfeitures	(1,585)	(2,730)
Performance stock issued	$ (855)	$ (880)	$ (939)
Performance stock | Treasury Stock, Common
Common Stock Activity [Roll Forward]
Performance stock issued (in shares)	53,407	55,447	64,543
Performance stock issued	$ 855	$ 880	$ 939
Employee Stock Purchase Plan | Common stock
Common Stock Activity [Roll Forward]
Employee stock purchase plan	$ 849	$ 779	$ 772
Employee Stock Purchase Plan | Treasury Stock, Common
Common Stock Activity [Roll Forward]
Employee stock purchase plan (in shares)	7,140	7,412	5,730
Employee stock purchase plan	$ 114	$ 112	$ 83
Treasury shares purchased | Treasury Stock, Common
Common Stock Activity [Roll Forward]
Purchase of treasury shares (in shares)	(28,649)	(31,260)	(37,710)
Treasury shares purchased	$ (3,961)	$ (4,021)	$ (6,171)
Share repurchase program | Treasury Stock, Common
Common Stock Activity [Roll Forward]
Purchase of treasury shares (in shares)		(251,408)
Treasury shares purchased		$ (30,373)