Condensed Consolidated Statement of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 32,226	$ 25,022	$ 59,530	$ 69,026
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments (Note 6)	10,021	(2,411)	34,888	(3,519)
Pension and post-retirement plan adjustments, net of tax (Note 6)	2,180	1,893	6,321	5,679
Total amount reclassified from Accumulated other comprehensive loss, net of tax	0	0	0	4,125
Total other comprehensive income (loss), net of tax	12,201	(518)	41,209	6,285
Comprehensive income	44,427	24,504	100,739	75,311
Comprehensive income attributable to noncontrolling interests	(4,289)	(1,021)	(3,185)	(3,271)
Comprehensive income attributable to MSA Safety Incorporated	$ 40,138	$ 23,483	$ 97,554	$ 72,040