Segment Information - Percentage of Total Sales by Product Group (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenue from External Customer [Line Items]
Revenues	$ 372,313	$ 341,289	$ 703,005	$ 649,717
Breathing Apparatus
Revenue from External Customer [Line Items]
Revenues	91,950	76,659	162,901	146,304
Fixed Gas & Flame Detection
Revenue from External Customer [Line Items]
Revenues	80,498	64,920	163,575	125,039
Firefighter Helmets & Protective Apparel
Revenue from External Customer [Line Items]
Revenues	47,899	53,121	96,360	99,131
Portable Gas Detection
Revenue from External Customer [Line Items]
Revenues	44,892	38,820	81,635	76,249
Industrial Head Protection
Revenue from External Customer [Line Items]
Revenues	43,724	38,155	79,881	70,851
Fall Protection
Revenue from External Customer [Line Items]
Revenues	26,614	30,809	51,275	56,876
Other
Revenue from External Customer [Line Items]
Revenues	$ 36,736	$ 38,805	$ 67,378	$ 75,267
Revenue Benchmark | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	100.00%	100.00%	100.00%	100.00%
Revenue Benchmark | Breathing Apparatus | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	25.00%	22.00%	23.00%	23.00%
Revenue Benchmark | Fixed Gas & Flame Detection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	22.00%	19.00%	23.00%	19.00%
Revenue Benchmark | Firefighter Helmets & Protective Apparel | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	13.00%	16.00%	14.00%	15.00%
Revenue Benchmark | Portable Gas Detection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	12.00%	11.00%	12.00%	12.00%
Revenue Benchmark | Industrial Head Protection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	12.00%	11.00%	11.00%	11.00%
Revenue Benchmark | Fall Protection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	7.00%	9.00%	7.00%	9.00%
Revenue Benchmark | Other | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	9.00%	12.00%	10.00%	11.00%
Americas
Revenue from External Customer [Line Items]
Revenues	$ 252,386	$ 217,707	$ 478,034	$ 426,046
Americas | Breathing Apparatus
Revenue from External Customer [Line Items]
Revenues	64,610	51,436	115,008	100,234
Americas | Fixed Gas & Flame Detection
Revenue from External Customer [Line Items]
Revenues	50,514	36,950	105,135	73,227
Americas | Firefighter Helmets & Protective Apparel
Revenue from External Customer [Line Items]
Revenues	35,037	36,424	68,513	71,413
Americas | Portable Gas Detection
Revenue from External Customer [Line Items]
Revenues	31,665	25,393	57,456	51,095
Americas | Industrial Head Protection
Revenue from External Customer [Line Items]
Revenues	34,023	28,820	62,188	53,931
Americas | Fall Protection
Revenue from External Customer [Line Items]
Revenues	17,005	17,677	33,282	33,349
Americas | Other
Revenue from External Customer [Line Items]
Revenues	$ 19,532	$ 21,007	$ 36,452	$ 42,797
Americas | Revenue Benchmark | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	100.00%	100.00%	100.00%	100.00%
Americas | Revenue Benchmark | Breathing Apparatus | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	26.00%	24.00%	24.00%	24.00%
Americas | Revenue Benchmark | Fixed Gas & Flame Detection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	20.00%	17.00%	22.00%	17.00%
Americas | Revenue Benchmark | Firefighter Helmets & Protective Apparel | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	14.00%	17.00%	14.00%	17.00%
Americas | Revenue Benchmark | Portable Gas Detection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	13.00%	12.00%	12.00%	12.00%
Americas | Revenue Benchmark | Industrial Head Protection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	13.00%	13.00%	13.00%	13.00%
Americas | Revenue Benchmark | Fall Protection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	7.00%	8.00%	7.00%	8.00%
Americas | Revenue Benchmark | Other | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	7.00%	9.00%	8.00%	9.00%
International
Revenue from External Customer [Line Items]
Revenues	$ 119,927	$ 123,582	$ 224,971	$ 223,671
International | Breathing Apparatus
Revenue from External Customer [Line Items]
Revenues	27,340	25,223	47,893	46,069
International | Fixed Gas & Flame Detection
Revenue from External Customer [Line Items]
Revenues	29,984	27,970	58,440	51,811
International | Firefighter Helmets & Protective Apparel
Revenue from External Customer [Line Items]
Revenues	12,862	16,697	27,847	27,719
International | Portable Gas Detection
Revenue from External Customer [Line Items]
Revenues	13,227	13,427	24,179	25,154
International | Industrial Head Protection
Revenue from External Customer [Line Items]
Revenues	9,701	9,335	17,693	16,920
International | Fall Protection
Revenue from External Customer [Line Items]
Revenues	9,609	13,132	17,993	23,526
International | Other
Revenue from External Customer [Line Items]
Revenues	$ 17,204	$ 17,798	$ 30,926	$ 32,472
International | Revenue Benchmark | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	100.00%	100.00%	100.00%	100.00%
International | Revenue Benchmark | Breathing Apparatus | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	23.00%	20.00%	21.00%	21.00%
International | Revenue Benchmark | Fixed Gas & Flame Detection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	25.00%	23.00%	26.00%	23.00%
International | Revenue Benchmark | Firefighter Helmets & Protective Apparel | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	11.00%	14.00%	12.00%	12.00%
International | Revenue Benchmark | Portable Gas Detection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	11.00%	11.00%	11.00%	11.00%
International | Revenue Benchmark | Industrial Head Protection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	8.00%	8.00%	8.00%	8.00%
International | Revenue Benchmark | Fall Protection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	8.00%	11.00%	8.00%	11.00%
International | Revenue Benchmark | Other | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	14.00%	13.00%	14.00%	14.00%