Segment Information (Reportable Segment Information) (Details) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Segment Reporting Information [Line Items]
Sales to external customers	$ 298,241	$ 242,019	$ 869,473	$ 691,626
Intercompany sales
Net income (loss) attributable to Mine Safety Appliances Company	19,972	9,603	52,873	26,336
North America [Member]
Segment Reporting Information [Line Items]
Sales to external customers	143,547	111,915	412,154	327,803
Intercompany sales	26,077	22,987	76,537	61,659
Net income (loss) attributable to Mine Safety Appliances Company	18,839	12,621	44,773	31,133
Europe [Member]
Segment Reporting Information [Line Items]
Sales to external customers	71,696	61,539	211,403	174,569
Intercompany sales	27,515	21,242	86,213	64,908
Net income (loss) attributable to Mine Safety Appliances Company	1,859	280	5,540	(5,483)
International [Member]
Segment Reporting Information [Line Items]
Sales to external customers	82,998	68,565	245,916	189,254
Intercompany sales	5,703	4,450	13,720	11,920
Net income (loss) attributable to Mine Safety Appliances Company	6,666	3,800	20,509	11,727
Reconciling Items [Member]
Segment Reporting Information [Line Items]
Sales to external customers
Intercompany sales	(59,295)	(48,679)	(176,470)	(138,487)
Net income (loss) attributable to Mine Safety Appliances Company	$ (7,392)	$ (7,098)	$ (17,949)	$ (11,041)