Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 35,542	$ 36,636
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments (Note 6)	5,892	(10,223)
Pension and post-retirement plan actuarial gains, net of tax (Note 6)	2,264	3,712
Unrealized losses on available-for-sale securities (Note 6)	(9)	(5)
Total other comprehensive income (loss), net of tax	8,147	(6,516)
Comprehensive income	43,689	30,120
Less: Comprehensive income attributable to noncontrolling interests	0	(221)
Comprehensive income attributable to MSA Safety Incorporated	$ 43,689	$ 29,899