Retirement Plans - Net Periodic Benefit Cost (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Settlements and curtailments	$ 0.2	$ 12.7	$ 2.4
Estimated amortization of net actuarial loss amount	1.5
Estimated amortization of net prior service credit	0.4
Estimated amortization of net obligation at transition	0.3
United States
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	0	0	0
Interest cost	3.3	3.3	3.2
Expected return on plan assets	(4.8)	(5.1)	(5.7)
Amortization of net actuarial loss	1.1	1.9	1.5
Amortization of prior service credit	0	0	0
Amortization of transition obligation	0	0	0
Net periodic pension cost (credit)	(0.4)	0.1	(1.0)
Settlements and curtailments	1.1	2.1	2.4
Total pension cost	0.7	2.2	1.4
International
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	0.3	0.5	0.6
Interest cost	0.9	2.0	2.2
Expected return on plan assets	(0.8)	(2.5)	(2.3)
Amortization of net actuarial loss	0.2	0.5	0.3
Amortization of prior service credit	(0.3)	(0.4)	(0.5)
Amortization of transition obligation	0.1	0.3	0.3
Net periodic pension cost (credit)	0.4	0.4	0.6
Settlements and curtailments	(0.9)	0	0
Total pension cost	(0.5)	0.4	0.6
Minimum | International
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Total pension cost for individual plan (less than)	0.1	0.1	0.1
Total pension credit for individual plan (less than)	0.1		0.1
Maximum | International
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Total pension cost for individual plan (less than)	0.4	0.5	0.6
Total pension credit for individual plan (less than)	$ 0.8		$ 0.8