Segment Information - Percentage of Total Sales by Product Group (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Revenue from External Customer [Line Items]
Revenues	$ 330,692	$ 308,428
Breathing Apparatus
Revenue from External Customer [Line Items]
Revenues	70,951	69,644
Fixed Gas & Flame Detection
Revenue from External Customer [Line Items]
Revenues	83,077	60,119
Firefighter Helmets & Protective Apparel
Revenue from External Customer [Line Items]
Revenues	48,461	46,010
Portable Gas Detection
Revenue from External Customer [Line Items]
Revenues	36,744	37,429
Industrial Head Protection
Revenue from External Customer [Line Items]
Revenues	36,157	32,696
Fall Protection
Revenue from External Customer [Line Items]
Revenues	24,662	26,067
Other
Revenue from External Customer [Line Items]
Revenues	$ 30,640	$ 36,463
Revenue Benchmark | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	100.00%	100.00%
Revenue Benchmark | Breathing Apparatus | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	22.00%	23.00%
Revenue Benchmark | Fixed Gas & Flame Detection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	25.00%	19.00%
Revenue Benchmark | Firefighter Helmets & Protective Apparel | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	15.00%	15.00%
Revenue Benchmark | Portable Gas Detection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	11.00%	12.00%
Revenue Benchmark | Industrial Head Protection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	11.00%	11.00%
Revenue Benchmark | Fall Protection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	7.00%	8.00%
Revenue Benchmark | Other | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	9.00%	12.00%
Americas
Revenue from External Customer [Line Items]
Revenues	$ 225,648	$ 208,340
Americas | Breathing Apparatus
Revenue from External Customer [Line Items]
Revenues	50,398	48,798
Americas | Fixed Gas & Flame Detection
Revenue from External Customer [Line Items]
Revenues	54,621	36,277
Americas | Firefighter Helmets & Protective Apparel
Revenue from External Customer [Line Items]
Revenues	33,476	34,988
Americas | Portable Gas Detection
Revenue from External Customer [Line Items]
Revenues	25,791	25,702
Americas | Industrial Head Protection
Revenue from External Customer [Line Items]
Revenues	28,165	25,111
Americas | Fall Protection
Revenue from External Customer [Line Items]
Revenues	16,277	15,672
Americas | Other
Revenue from External Customer [Line Items]
Revenues	$ 16,920	$ 21,792
Americas | Revenue Benchmark | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	100.00%	100.00%
Americas | Revenue Benchmark | Breathing Apparatus | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	22.00%	23.00%
Americas | Revenue Benchmark | Fixed Gas & Flame Detection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	24.00%	17.00%
Americas | Revenue Benchmark | Firefighter Helmets & Protective Apparel | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	15.00%	17.00%
Americas | Revenue Benchmark | Portable Gas Detection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	11.00%	12.00%
Americas | Revenue Benchmark | Industrial Head Protection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	13.00%	12.00%
Americas | Revenue Benchmark | Fall Protection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	7.00%	8.00%
Americas | Revenue Benchmark | Other | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	8.00%	11.00%
International
Revenue from External Customer [Line Items]
Revenues	$ 105,044	$ 100,088
International | Breathing Apparatus
Revenue from External Customer [Line Items]
Revenues	20,553	20,846
International | Fixed Gas & Flame Detection
Revenue from External Customer [Line Items]
Revenues	28,456	23,842
International | Firefighter Helmets & Protective Apparel
Revenue from External Customer [Line Items]
Revenues	14,985	11,022
International | Portable Gas Detection
Revenue from External Customer [Line Items]
Revenues	10,953	11,727
International | Industrial Head Protection
Revenue from External Customer [Line Items]
Revenues	7,992	7,585
International | Fall Protection
Revenue from External Customer [Line Items]
Revenues	8,385	10,395
International | Other
Revenue from External Customer [Line Items]
Revenues	$ 13,720	$ 14,671
International | Revenue Benchmark | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	100.00%	100.00%
International | Revenue Benchmark | Breathing Apparatus | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	20.00%	21.00%
International | Revenue Benchmark | Fixed Gas & Flame Detection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	27.00%	24.00%
International | Revenue Benchmark | Firefighter Helmets & Protective Apparel | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	14.00%	11.00%
International | Revenue Benchmark | Portable Gas Detection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	10.00%	12.00%
International | Revenue Benchmark | Industrial Head Protection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	8.00%	8.00%
International | Revenue Benchmark | Fall Protection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	8.00%	10.00%
International | Revenue Benchmark | Other | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	13.00%	14.00%