Pension, Post-Retirement and Post-Employment Plans - Amounts Included in Consolidated Balance Sheets (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Prepaid pension assets
Total included in other assets	$ 4.0	$ 0.0
Other current liabilities
Total included in accrued expenses and other current liabilities	2.1	8.0
Retirement benefits, less current portion
Total included in long-term retirement benefits, less current portion	69.5	67.8
Foreign pension
Prepaid pension assets
Total included in other assets	4.0	0.0
Other current liabilities
Total included in accrued expenses and other current liabilities	0.6	0.6
Retirement benefits, less current portion
Total included in long-term retirement benefits, less current portion	21.4	18.4
Domestic
Other current liabilities
Total included in accrued expenses and other current liabilities	0.7	6.7
Retirement benefits, less current portion
Total included in long-term retirement benefits, less current portion	36.2	39.3
Domestic post-retirement medical benefits
Other current liabilities
Total included in accrued expenses and other current liabilities	0.6	0.6
Retirement benefits, less current portion
Total included in long-term retirement benefits, less current portion	9.0	8.8
Foreign post-retirement medical benefits
Other current liabilities
Total included in accrued expenses and other current liabilities	0.2	0.1
Retirement benefits, less current portion
Total included in long-term retirement benefits, less current portion	$ 2.9	$ 1.3