Condensed Consolidated Statement of Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement [Abstract]
Net sales	$ 314,438	$ 349,675	$ 655,583	$ 675,713
Cost of products sold	172,841	188,591	356,627	364,647
Gross profit	141,597	161,084	298,956	311,066
Selling, general and administrative	69,034	84,009	149,271	162,437
Research and development	13,760	14,256	27,872	27,962
Restructuring charges (Note 4)	8,865	3,522	10,872	9,353
Currency exchange losses, net (Note 6)	793	1,290	1,063	18,251
Product liability expense (Note 17)	851	3,529	2,802	6,425
Operating income	48,294	54,478	107,076	86,638
Interest expense	2,459	4,470	5,602	6,830
Other income, net	(2,000)	(3,342)	(3,258)	(5,921)
Total other expense, net	459	1,128	2,344	909
Income before income taxes	47,835	53,350	104,732	85,729
Provision for income taxes (Note 10)	11,429	13,238	24,523	22,241
Net income	36,406	40,112	80,209	63,488
Net income attributable to noncontrolling interests	(340)	(306)	(468)	(450)
Net income attributable to MSA Safety Incorporated	$ 36,066	$ 39,806	$ 79,741	$ 63,038
Earnings per share attributable to MSA Safety Incorporated common shareholders (Note 9):
Basic (in dollars per share)	$ 0.93	$ 1.03	$ 2.05	$ 1.63
Diluted (in dollars per share)	0.92	1.01	2.03	1.61
Dividends per common share (in dollars per share)	$ 0.43	$ 0.42	$ 0.85	$ 0.80