Employee Benefit Plans - Amounts Recognized in Consolidated Balance Sheets and Accumulated Other Comprehensive Loss (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Amounts recognized on the consolidated balance sheets [Abstract]
Non-current liabilities	$ (37.3)	$ (58.9)
Pension Benefits
Amounts recognized on the consolidated balance sheets [Abstract]
Non-current assets	3.3	1.4
Current liabilities	0	0
Non-current liabilities	(25.3)	(48.8)
Total	(22.0)	(47.4)
Amounts recognized in accumulated other comprehensive loss [Abstract]
Net loss (gain) (net of taxes)	33.2	53.0
Unrecognized prior service credit (net of taxes)	(3.9)	(4.4)
Total	29.3	48.6
Other Post-retirement Benefits
Amounts recognized on the consolidated balance sheets [Abstract]
Non-current assets	0	0
Current liabilities	(0.9)	(0.8)
Non-current liabilities	(12.0)	(10.1)
Total	(12.9)	(10.9)
Amounts recognized in accumulated other comprehensive loss [Abstract]
Net loss (gain) (net of taxes)	1.1	(1.4)
Unrecognized prior service credit (net of taxes)	0	0
Total	$ 1.1	$ (1.4)