Product Class Data (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net Sales:
Net sales	$ 848.8	$ 895.3	$ 855.8	$ 759.5	$ 806.6	$ 835.9	$ 801.3	$ 740.1	$ 3,359.4	$ 3,183.9	$ 3,044.4
Electrical Systems
Net Sales:
Net sales									1,538.7	1,466.4	1,376.1
Lighting
Net Sales:
Net sales									859.5	796.2	738.5
Power
Net Sales:
Net sales									$ 961.2	$ 921.3	$ 929.8