Retirement Benefit Plans - Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Amounts recognized on the Consolidated Balance Sheets:
Non-current assets	$ 32.1	$ 86.3
Current liabilities	5.7	9.1
Pension Plan, Defined Benefit [Member]
Amounts recognized on the Consolidated Balance Sheets:
Non-current assets	26.4	69.0
Current liabilities	4.3	4.2
Non-current liabilities	(104.9)	(101.0)
Total	(82.8)	(36.2)
International Plans [Member]
Amounts recognized on the Consolidated Balance Sheets:
Non-current assets	5.7	17.3
Current liabilities	1.4	4.9
Non-current liabilities	(49.8)	(45.9)
Total	$ (45.5)	$ (33.5)