Condensed Consolidated Statement of Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Net sales	$ 341,145	$ 326,038
Cost of products sold	183,786	176,056
Gross profit	157,359	149,982
Selling, general and administrative	80,237	78,429
Research and development	14,112	13,705
Restructuring charges (Note 4)	2,007	5,831
Currency exchange losses, net (Note 6)	270	16,961
Product liability expense (Note 17)	1,951	2,896
Operating income	58,782	32,160
Interest expense	3,144	2,360
Other income, net	(1,259)	(2,579)
Total other expense (income), net	1,885	(219)
Income before income taxes	56,897	32,379
Provision for income taxes (Note 10)	13,095	9,003
Net income	43,802	23,376
Net income attributable to noncontrolling interests	(128)	(144)
Net income attributable to MSA Safety Incorporated	$ 43,674	$ 23,232
Earnings per share attributable to MSA Safety Incorporated common shareholders (Note 9):
Basic (in dollars per share)	$ 1.12	$ 0.60
Diluted (in dollars per share)	1.11	0.59
Dividends per common share (in dollars per share)	$ 0.42	$ 0.38