Condensed Consolidated Statement of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 12,614	$ 31,931	$ 27,304	$ 44,004
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments (Note 6)	14,123	(15,056)	24,867	(1,108)
Pension and post-retirement plan adjustments, net of tax (Note 6)	2,157	1,894	4,141	3,786
Total amount reclassified from Accumulated other comprehensive loss, net of tax	0	2,022	0	4,125
Total other comprehensive income (loss), net of tax	16,280	(11,140)	29,008	6,803
Comprehensive income	28,894	20,791	56,312	50,807
Comprehensive loss (income) attributable to noncontrolling interests	755	(2,252)	1,104	(2,250)
Comprehensive income attributable to MSA Safety Incorporated	$ 29,649	$ 18,539	$ 57,416	$ 48,557