Condensed Consolidated Statement of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Net sales	$ 296,129	$ 278,233	$ 850,669	$ 853,499
Cost of products sold	163,630	149,471	464,842	468,177
Gross profit	132,499	128,762	385,827	385,322
Selling, general and administrative	72,409	72,945	222,334	227,856
Research and development	12,351	13,116	35,282	34,623
Restructuring charges (Note 4)	3,214	1,889	16,920	3,697
Currency exchange losses, net	562	790	3,994	2,498
Other operating expense (Note 18)	3,346	0	32,956	0
Operating income	40,617	40,022	74,341	116,648
Interest expense	3,961	4,412	10,566	12,515
Other income, net	(981)	(2,041)	(2,061)	(3,704)
Total other expense, net	2,980	2,371	8,505	8,811
Income from continuing operations before income taxes	37,637	37,651	65,836	107,837
Provision for income taxes (Note 10)	5,411	11,329	6,306	38,866
Income from continuing operations	32,226	26,322	59,530	68,971
(Loss) income from discontinued operations (Note 19)	0	(1,300)	0	55
Net income	32,226	25,022	59,530	69,026
Net income attributable to noncontrolling interests	(160)	(836)	(519)	(2,006)
Net income attributable to MSA Safety Incorporated	32,066	24,186	59,011	67,020
Amounts attributable to MSA Safety Incorporated common shareholders:
Income from continuing operations	32,066	25,486	59,011	67,475
Loss from discontinued operations (Note 19)	0	(1,300)	0	(455)
Net income attributable to MSA Safety Incorporated	$ 32,066	$ 24,186	$ 59,011	$ 67,020
Basic
Income from continuing operations, basic (dollars per share)	$ 0.84	$ 0.68	$ 1.55	$ 1.80
Income from discontinued operations, basic (dollars per share) (Note 19)	0.00	(0.04)	0.00	(0.01)
Net income, basic (dollars per share)	0.84	0.64	1.55	1.79
Diluted
Income from continuing operations, diluted (dollars per share)	0.83	0.67	1.52	1.77
Income from discontinued operations, diluted (dollars per share) (Note 19)	0.00	(0.04)	0.00	(0.01)
Net income, diluted (dollars per share)	0.83	0.63	1.52	1.76
Dividends per common share (dollars per share)	$ 0.35	$ 0.33	$ 1.03	$ 0.98