Foreign Operations (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
Foreign operations data
Revenues	$ 362.1	$ 362.9	$ 358.9	$ 334.4	$ 378.7	$ 386.2	$ 365.3	$ 319.7	$ 1,418.3	$ 1,449.9	$ 1,451.0
Identifiable assets	$ 7,105.4				6,894.2				$ 7,105.4	6,894.2	6,919.9
Foreign Operations (Textual) [Abstract]
Maximum percentage of consolidated revenues derive from any individual foreign country									10.00%
Percentage of company's identifiable assets	10.00%								10.00%
Foreign [Member]
Foreign operations data
Revenues									$ 320.7	329.4	346.2
Identifiable assets	$ 2,098.2				1,992.3				2,098.2	1,992.3	2,133.3
United States [Member]
Foreign operations data
Revenues									1,097.6	1,120.5	1,104.8
Identifiable assets	$ 5,007.2				$ 4,901.9				$ 5,007.2	$ 4,901.9	$ 4,786.6