Retirement and Other Postretirement Benefit Plans - Schedule of Pension Assets Measured at Fair Value (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Fair value measurements	$ 165.6	$ 149.3
Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value measurements	120.6
Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value measurements	39.3	142.8
Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value measurements	5.7	6.5	5.9
Actual return on plan assets	0.2	0.3
Purchases,sales and settlements	(0.2)
Changes due to exchange rates	(0.8)	0.3
Equity Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value measurements	53.9	83.3
Equity Funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value measurements	53.9
Equity Funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value measurements		83.3
Diversified Growth Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value measurements	45.8
Diversified Growth Funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value measurements	45.8
Liability Driven Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value measurements	38.7
Liability Driven Investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value measurements	38.7
Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value measurements	14.8	58.5
Debt Securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value measurements	14.8
Debt Securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value measurements		58.5
Index Linked Gilts
Defined Benefit Plan Disclosure [Line Items]
Fair value measurements	6.1
Index Linked Gilts | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value measurements	6.1
Other Insurance Product Line
Defined Benefit Plan Disclosure [Line Items]
Fair value measurements	3.2	3.6
Other Insurance Product Line | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value measurements	3.2	3.6	3.1
Actual return on plan assets	0.1	0.1
Purchases,sales and settlements		0.2
Changes due to exchange rates	(0.5)	0.2
Diversified Investment, Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value measurements	2.5	2.9
Diversified Investment, Funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value measurements	2.5	2.9	2.8
Actual return on plan assets	0.1	0.2
Purchases,sales and settlements	(0.2)	(0.2)
Changes due to exchange rates	(0.3)	0.1
Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value measurements	0.6	1.0
Cash and Cash Equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value measurements	$ 0.6	$ 1.0