Product Class Data (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net Sales:
Net sales	$ 854.2	$ 907.4	$ 908.8	$ 834.8	$ 829.7	$ 877.0	$ 874.0	$ 809.7	$ 3,505.2	$ 3,390.4	$ 3,359.4
Electrical Systems
Net Sales:
Net sales									1,514.4	1,476.7	1,538.7
Lighting
Net Sales:
Net sales									945.8	911.6	859.5
Power
Net Sales:
Net sales									$ 1,045.0	$ 1,002.1	$ 961.2