Supplemental Data (Details 2) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment - Net
Gross property, plant and equipment	$ 694.5	$ 598.9
Less accumulated depreciation	371.5	357.2
Property, plant and equipment-net	323.0	241.7
Depreciation expense	24.8	23.2	$ 23.2
Interest expense capitalized	0.2	0.1	$ 0.2
Accrued Expenses
Accrued salaries and employee benefits	25.2	23.2
Amounts due to customers	9.5	8.8
Accrued interest	1.2	1.2
Accrued income taxes	0.7	1.0
Other	14.6	9.6
Total	51.2	43.8
Noncurrent Employee Benefits
Pension benefits	51.2	41.4
Post-employment benefits other than pensions	38.5	39.5
Total (a)	89.7	80.9
Long-term disability benefits due to Terrace Bay retirees	2.7	3.4
Land and land improvements
Property, Plant and Equipment - Net
Gross property, plant and equipment	19.6	15.7
Buildings
Property, Plant and Equipment - Net
Gross property, plant and equipment	121.4	107.5
Machinery and equipment
Property, Plant and Equipment - Net
Gross property, plant and equipment	512.2	461.4
Construction in progress
Property, Plant and Equipment - Net
Gross property, plant and equipment	$ 41.3	$ 14.3