Retirement Benefits (Details 6) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	$ (5.2)	$ (9.8)
Noncurrent liabilities	(827.9)	(833.8)
Total amount recognized	(833.1)	(843.6)
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	(36.4)	(39.8)
Noncurrent liabilities	(317.7)	(359.2)
Total amount recognized	$ (354.1)	$ (399.0)