Business Segments (Schedule Of Reportable Segments) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Apr. 02, 2011	Dec. 31, 2011
Segment Reporting Information [Line Items]
External sales	$ 807.9	$ 662.7
Total sales	807.9	662.7
Segment income from operations	79.1	64.1
Identifiable assets	3,467.5	2,544.1	3,266.5
Depreciation and amortization	30.9	21.6
Electrical Segment [Member]
Segment Reporting Information [Line Items]
External sales	731.4	594.3
Intersegment sales	0.8	2.4
Total sales	732.2	596.7
Segment income from operations	69.4	55.5
Identifiable assets	3,238.4	2,371.6
Depreciation and amortization	28.3	20.1
Mechanical Segment [Member]
Segment Reporting Information [Line Items]
External sales	76.5	68.4
Intersegment sales	0.8	0.6
Total sales	77.3	69.0
Segment income from operations	9.7	8.6
Identifiable assets	229.1	172.5
Depreciation and amortization	2.6	1.5
Eliminations [Member]
Segment Reporting Information [Line Items]
Intersegment sales	(1.6)	(3.0)
Total sales	$ (1.6)	$ (3.0)