Segment Information - Financial Information by Reportable Segment (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Segment Reporting Information [Line Items]
Net sales	$ 3,893.1	$ 3,006.1	$ 2,668.9
Operating Income (Loss)	616.8	527.1	462.7
Identifiable assets	6,851.9	6,734.9
Depreciation	60.7	51.3	43.7
Capital expenditures	93.3	74.0	65.6
Cost of goods sold(1)	2,424.0	1,797.0	1,593.7
Selling, general and administrative	773.8	615.9	557.3
Research and development	78.5	66.1	55.2
Systems Protection
Segment Reporting Information [Line Items]
Net sales	2,592.9	1,823.3	1,605.9
Electrical Connections
Segment Reporting Information [Line Items]
Net sales	1,300.2	1,182.8	1,063.0
Operating Segments
Segment Reporting Information [Line Items]
Net sales	3,893.1	3,006.1	2,668.9
Operating Income (Loss)	909.6	757.6	677.2
Identifiable assets	6,623.2	5,284.0
Depreciation	56.0	47.5	38.7
Capital expenditures	86.5	69.1	58.8
Operating Segments | Systems Protection
Segment Reporting Information [Line Items]
Net sales	2,592.9	1,823.3	1,605.9
Operating Income (Loss)	537.0	403.1	346.6
Identifiable assets	3,342.2	2,129.3
Depreciation	31.9	25.7	22.4
Capital expenditures	66.8	45.9	38.1
Cost of goods sold(1)	1,686.5	1,143.4	1,011.6
Selling, general and administrative	320.1	239.1	218.0
Research and development	49.3	37.7	29.7
Operating Segments | Electrical Connections
Segment Reporting Information [Line Items]
Net sales	1,300.2	1,182.8	1,063.0
Operating Income (Loss)	372.6	354.5	330.6
Identifiable assets	3,281.0	3,154.7
Depreciation	24.1	21.8	16.3
Capital expenditures	19.7	23.2	20.7
Cost of goods sold(1)	721.0	637.1	549.5
Selling, general and administrative	184.8	167.5	163.1
Research and development	21.8	23.7	19.8
Other Reconciling Items
Segment Reporting Information [Line Items]
Capital expenditures	$ 6.8	$ 4.9	$ 6.8