Segment Information - Percentage of Total Sales by Product Group (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenue from External Customer [Line Items]
Revenues	$ 446,728	$ 381,694	$ 1,292,290	$ 1,084,699
Breathing Apparatus
Revenue from External Customer [Line Items]
Revenues	111,024	91,977	288,976	254,878
Fixed Gas & Flame Detection
Revenue from External Customer [Line Items]
Revenues	112,012	87,746	311,502	251,321
Firefighter Helmets & Protective Apparel
Revenue from External Customer [Line Items]
Revenues	64,707	54,738	192,634	151,097
Portable Gas Detection
Revenue from External Customer [Line Items]
Revenues	43,682	39,481	149,036	121,116
Industrial Head Protection
Revenue from External Customer [Line Items]
Revenues	45,780	43,608	135,851	123,489
Fall Protection
Revenue from External Customer [Line Items]
Revenues	31,980	27,839	97,019	79,114
Other
Revenue from External Customer [Line Items]
Revenues	$ 37,543	$ 36,305	$ 117,272	$ 103,684
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%	24.00%	22.00%	23.00%
Revenue Benchmark | Fixed Gas & Flame Detection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	25.00%	23.00%	24.00%	23.00%
Revenue Benchmark | Firefighter Helmets & Protective Apparel | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	15.00%	14.00%	15.00%	14.00%
Revenue Benchmark | Portable Gas Detection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	10.00%	10.00%	12.00%	11.00%
Revenue Benchmark | Industrial Head Protection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	10.00%	11.00%	11.00%	11.00%
Revenue Benchmark | Fall Protection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	7.00%	7.00%	7.00%	7.00%
Revenue Benchmark | Other | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	8.00%	11.00%	9.00%	11.00%
Americas
Revenue from External Customer [Line Items]
Revenues	$ 314,273	$ 276,082	$ 902,918	$ 754,116
Americas | Breathing Apparatus
Revenue from External Customer [Line Items]
Revenues	79,908	70,482	201,945	185,490
Americas | Fixed Gas & Flame Detection
Revenue from External Customer [Line Items]
Revenues	73,074	62,134	200,604	167,269
Americas | Firefighter Helmets & Protective Apparel
Revenue from External Customer [Line Items]
Revenues	51,608	41,958	152,784	110,471
Americas | Portable Gas Detection
Revenue from External Customer [Line Items]
Revenues	31,933	28,358	108,088	85,815
Americas | Industrial Head Protection
Revenue from External Customer [Line Items]
Revenues	36,402	34,620	106,120	96,808
Americas | Fall Protection
Revenue from External Customer [Line Items]
Revenues	20,235	17,658	63,168	50,940
Americas | Other
Revenue from External Customer [Line Items]
Revenues	$ 21,113	$ 20,872	$ 70,209	$ 57,323
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	25.00%	26.00%	22.00%	25.00%
Americas | Revenue Benchmark | Fixed Gas & Flame Detection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	23.00%	23.00%	22.00%	22.00%
Americas | Revenue Benchmark | Firefighter Helmets & Protective Apparel | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	16.00%	15.00%	17.00%	15.00%
Americas | Revenue Benchmark | Portable Gas Detection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	10.00%	10.00%	12.00%	11.00%
Americas | Revenue Benchmark | Industrial Head Protection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	12.00%	13.00%	12.00%	13.00%
Americas | Revenue Benchmark | Fall Protection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	7.00%	6.00%	7.00%	7.00%
Americas | Revenue Benchmark | Other | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	7.00%	7.00%	8.00%	7.00%
International
Revenue from External Customer [Line Items]
Revenues	$ 132,455	$ 105,612	$ 389,372	$ 330,583
International | Breathing Apparatus
Revenue from External Customer [Line Items]
Revenues	31,116	21,495	87,031	69,388
International | Fixed Gas & Flame Detection
Revenue from External Customer [Line Items]
Revenues	38,938	25,612	110,898	84,052
International | Firefighter Helmets & Protective Apparel
Revenue from External Customer [Line Items]
Revenues	13,099	12,780	39,850	40,626
International | Portable Gas Detection
Revenue from External Customer [Line Items]
Revenues	11,749	11,123	40,948	35,301
International | Industrial Head Protection
Revenue from External Customer [Line Items]
Revenues	9,378	8,988	29,731	26,681
International | Fall Protection
Revenue from External Customer [Line Items]
Revenues	11,745	10,181	33,851	28,174
International | Other
Revenue from External Customer [Line Items]
Revenues	$ 16,430	$ 15,433	$ 47,063	$ 46,361
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	24.00%	20.00%	22.00%	21.00%
International | Revenue Benchmark | Fixed Gas & Flame Detection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	29.00%	24.00%	28.00%	25.00%
International | Revenue Benchmark | Firefighter Helmets & Protective Apparel | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	10.00%	12.00%	10.00%	12.00%
International | Revenue Benchmark | Portable Gas Detection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	9.00%	11.00%	11.00%	11.00%
International | Revenue Benchmark | Industrial Head Protection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	7.00%	9.00%	8.00%	8.00%
International | Revenue Benchmark | Fall Protection | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	9.00%	10.00%	9.00%	9.00%
International | Revenue Benchmark | Other | Product Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk percentage	12.00%	14.00%	12.00%	14.00%