Segment Information - Revenue from External Customers by Products and Services (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenue from External Customer [Line Items]
Revenues	$ 1,527,953	$ 1,400,182	$ 1,348,223
Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	100.00%	100.00%	100.00%
Breathing Apparatus
Revenue from External Customer [Line Items]
Revenues	$ 371,176	$ 322,412	$ 329,179
Breathing Apparatus | Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	24.00%	23.00%	24.00%
Fixed Gas & Flame Detection (a)
Revenue from External Customer [Line Items]
Revenues	$ 356,075	$ 299,018	$ 287,414
Fixed Gas & Flame Detection (a) | Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	23.00%	21.00%	21.00%
Firefighter Helmets & Protective Apparel (b)
Revenue from External Customer [Line Items]
Revenues	$ 207,759	$ 203,914	$ 162,207
Firefighter Helmets & Protective Apparel (b) | Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	14.00%	15.00%	12.00%
Portable Gas Detection
Revenue from External Customer [Line Items]
Revenues	$ 173,660	$ 162,761	$ 142,581
Portable Gas Detection | Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	11.00%	12.00%	11.00%
Industrial Head Protection
Revenue from External Customer [Line Items]
Revenues	$ 163,253	$ 143,601	$ 125,921
Industrial Head Protection | Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	11.00%	10.00%	9.00%
Fall Protection
Revenue from External Customer [Line Items]
Revenues	$ 110,094	$ 117,731	$ 103,075
Fall Protection | Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	7.00%	8.00%	8.00%
Other
Revenue from External Customer [Line Items]
Revenues	$ 145,936	$ 150,745	$ 197,846
Other | Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	10.00%	11.00%	15.00%
Americas
Revenue from External Customer [Line Items]
Revenues	$ 1,043,238	$ 908,068	$ 874,305
Americas | Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	100.00%	100.00%	100.00%
Americas | Breathing Apparatus
Revenue from External Customer [Line Items]
Revenues	$ 265,558	$ 217,340	$ 220,650
Americas | Breathing Apparatus | Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	25.00%	24.00%	25.00%
Americas | Fixed Gas & Flame Detection (a)
Revenue from External Customer [Line Items]
Revenues	$ 227,609	$ 182,515	$ 158,924
Americas | Fixed Gas & Flame Detection (a) | Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	22.00%	20.00%	18.00%
Americas | Firefighter Helmets & Protective Apparel (b)
Revenue from External Customer [Line Items]
Revenues	$ 150,869	$ 137,086	$ 133,653
Americas | Firefighter Helmets & Protective Apparel (b) | Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	14.00%	15.00%	15.00%
Americas | Portable Gas Detection
Revenue from External Customer [Line Items]
Revenues	$ 121,934	$ 109,543	$ 90,545
Americas | Portable Gas Detection | Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	12.00%	12.00%	10.00%
Americas | Industrial Head Protection
Revenue from External Customer [Line Items]
Revenues	$ 127,485	$ 108,869	$ 92,075
Americas | Industrial Head Protection | Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	12.00%	12.00%	11.00%
Americas | Fall Protection
Revenue from External Customer [Line Items]
Revenues	$ 69,225	$ 69,108	$ 58,060
Americas | Fall Protection | Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	7.00%	8.00%	7.00%
Americas | Other
Revenue from External Customer [Line Items]
Revenues	$ 80,558	$ 83,607	$ 120,398
Americas | Other | Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	8.00%	9.00%	14.00%
International
Revenue from External Customer [Line Items]
Revenues	$ 484,715	$ 492,114	$ 473,918
International | Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	100.00%	100.00%	100.00%
International | Breathing Apparatus
Revenue from External Customer [Line Items]
Revenues	$ 105,618	$ 105,072	$ 108,529
International | Breathing Apparatus | Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	22.00%	21.00%	23.00%
International | Fixed Gas & Flame Detection (a)
Revenue from External Customer [Line Items]
Revenues	$ 128,466	$ 116,503	$ 128,490
International | Fixed Gas & Flame Detection (a) | Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	27.00%	24.00%	27.00%
International | Firefighter Helmets & Protective Apparel (b)
Revenue from External Customer [Line Items]
Revenues	$ 56,890	$ 66,828	$ 28,554
International | Firefighter Helmets & Protective Apparel (b) | Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	12.00%	14.00%	6.00%
International | Portable Gas Detection
Revenue from External Customer [Line Items]
Revenues	$ 51,726	$ 53,218	$ 52,036
International | Portable Gas Detection | Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	11.00%	11.00%	11.00%
International | Industrial Head Protection
Revenue from External Customer [Line Items]
Revenues	$ 35,768	$ 34,732	$ 33,846
International | Industrial Head Protection | Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	7.00%	7.00%	7.00%
International | Fall Protection
Revenue from External Customer [Line Items]
Revenues	$ 40,869	$ 48,623	$ 45,015
International | Fall Protection | Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	8.00%	10.00%	10.00%
International | Other
Revenue from External Customer [Line Items]
Revenues	$ 65,378	$ 67,138	$ 77,448
International | Other | Sales | Product concentration risk
Revenue from External Customer [Line Items]
Concentration risk (percentage)	13.00%	13.00%	16.00%