Retirement Benefits Narrative (Details) $ in Millions	1 Months Ended	12 Months Ended
	Jan. 31, 2015 USD ($)	Dec. 31, 2015 USD ($) benefit_plan	Dec. 31, 2014 USD ($) benefit_plan	Dec. 31, 2013 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation		$ 842.1	$ 907.1
Number of defined contribution pension plans (benefit plan) | benefit_plan		6
Defined contribution pension plans, total costs		$ 13.3	$ 12.9	$ 11.2
Number of multiemployer defined benefit pension plans (benefit_plan) | benefit_plan		2	3
Multiemployer plan total employer contributions		$ 0.8	$ 0.8	0.9
Employer stock included in plan assets		34.7	37.6
Fair value of plan assets		$ 757.6	$ 835.7
Employer stock as percentage of plan assets		5.30%	5.20%
Carrying Value
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ 92.4	$ 78.1
Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		62.0	152.8
Cash and cash equivalents | Reclassification Adjustment
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets			126.6
Alternative Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		158.3	188.2
Alternative Investments | Carrying Value
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		92.4	78.1
Equity/Debt Futures
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		2.5	8.1
Equity/Debt Futures | Reclassification Adjustment
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets			(142.0)
Derivative Liability
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		(0.7)	(0.5)
Derivative Liability | Reclassification Adjustment
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets			$ (15.4)
US Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Voluntary lump sum program payment		$ 27.7
Defined benefit obligation per plan, as a percent of total benefit obligation		89.00%
Discount rate		4.80%	4.30%
Effect on defined benefit obligation, due to change in mortality table utilized			$ 40.0
Employer contributions	$ 20.0
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation		$ 912.3	$ 976.3	$ 828.2
Number of multiemployer defined benefit pension plans (benefit_plan) | benefit_plan		2
Multiemployer plan, number of plans under 65% funded (benefit_plan) | benefit_plan		1
Defined benefit plan, funded percentage		65.00%
Discount rate		4.71%	4.23%	5.04%
Fair value of plan assets		$ 757.6	$ 835.7	$ 764.0
Employer contributions		27.9	$ 27.6
Foreign Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Estimated future employer contributions in next fiscal year		$ 2.2
Foreign Pension Plan | CANADA
Defined Benefit Plan Disclosure [Line Items]
Discount rate		3.90%	3.95%
Foreign Pension Plan | UNITED KINGDOM
Defined Benefit Plan Disclosure [Line Items]
Discount rate		4.00%	3.70%