Employee Benefit Plans (Narrative) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2018
Unrecognized net actuarial losses		$ 380.6	$ 404.8	$ 336.6
Reduction in equity		$ 285.1	304.5	249.0
Defined benefit plan, target allocation percentage of assets, near-term benefit payments		30.00%
Defined benefit plan, target allocation percentage of assets, long-term growth		70.00%
Company contributions		$ 12.3	11.6	12.0
Alternative Investments
Defined benefit plan, target plan asset allocations		5.00%
Equity Securities
Defined benefit plan, target plan asset allocations		40.00%
Fixed Income Investments
Defined benefit plan, target plan asset allocations		55.00%
Minimum
Percentage of joint venture's unrecognized net actuarial losses and unrecognized prior service cost		20.00%
ENPP
Minimum age for vesting		50 years
Minimum participation period to qualify for payment		10 years
Minimum service period to vest		5 years
Minimum age to receive benefits		65 years
Period over which retirement benefits are paid		15 years
Period considered when determining retirement benefits		3 years
Minimum service period		20 years
Final years of service		10 years
Pension and Other Postretirement Benefit Plans [Member]
Aggregate projected benefit obligation		$ 946.0	877.6
Accumulated benefit obligation		891.2	823.8
Fair value of plan assets		690.8	600.9
Reduction in equity		379.3	403.5
Tax effect of benefit plans		$ 95.0	$ 99.8
Pension Benefits
Percentage of fixed income securities consisting of high-yield securities		13.00%	13.00%
Percentage of Fixed Income Securities Consisting of Foreign Securities		15.00%	31.00%
Unrecognized net actuarial losses		$ 360.1	$ 384.7
Net prior service (credit) cost		12.2	13.4
Net loss recognized due to settlement		$ 0.2	$ 0.4	$ 0.2
Weighted average discount rate		2.50%	2.70%
Benefit payments in 2018 (less than)		$ 47.6
Benefit payments made to defined benefit pension plans and ENPP		43.3
Benefits paid		$ 42.6	$ 44.1
Weighted average expected long-term rate of return on plan assets		5.80%	6.80%	6.80%
Pension Benefits | Forecast
Net actuarial (gain) loss that will be amortized from accumulated other comprehensive loss					$ 12.2
Net prior service (credit) cost that will be amortized from accumulated other comprehensive loss					$ (1.2)
Postretirement Benefits
Unrecognized net actuarial losses		$ 3.8	$ 2.0
Net prior service (credit) cost		3.2	$ 3.4
Net actuarial (gain) loss that will be amortized from accumulated other comprehensive loss		0.1
Net prior service (credit) cost that will be amortized from accumulated other comprehensive loss		$ (0.2)
Weighted average discount rate		4.90%	5.30%
Benefit payments in 2018 (less than)		$ 1.6
Benefits paid		$ 1.6	$ 1.2
Brazilian Postretirement Benefit Obligation, Defined Benefit [Member]
Health care cost trend rate assumed		11.00%	11.80%
Ultimate health care cost trend rate		5.30%	6.10%
Benefit payments in 2018 (less than)		$ 0.1
U.S Based Postretirement Health Care and Life Insurance Benefit Plans
Health care cost trend rate assumed		6.75%	7.00%
Ultimate health care cost trend rate		5.00%	5.00%
Benefit payments in 2018 (less than)		$ 1.6
UNITED STATES | Pension Benefits
Aggregate projected benefit obligation		129.6	$ 118.1
Accumulated benefit obligation		111.5	101.9
Fair value of plan assets		$ 36.6	$ 36.2
Weighted average discount rate		3.70%	4.25%
Expected minimum contribution		$ 3.1
Defined benefit plan, target allocation percentage of assets, near-term benefit payments		15.00%
Defined benefit plan, target allocation percentage of assets, long-term growth		85.00%
Defined benefit plan, assumptions used in investment strategy, expected return next fiscal year		6.40%
Weighted average expected long-term rate of return on plan assets	[1]	6.00%	6.00%	6.00%
UNITED STATES | Pension Benefits | Large and small cap domestic equity securities
Defined benefit plan, target plan asset allocations		30.00%
UNITED STATES | Pension Benefits | International equity securities
Defined benefit plan, target plan asset allocations		12.00%
UNITED STATES | Pension Benefits | Fixed Income Securities
Defined benefit plan, target plan asset allocations		44.00%
UNITED STATES | Pension Benefits | Alternative Investments
Defined benefit plan, target plan asset allocations		14.00%
Foreign Plan [Member] | U.K. Pension Plans, Defined Benefit
Expected minimum contribution		$ 20.6
Weighted average expected long-term rate of return on plan assets		5.50%
Foreign Plan [Member] | Pension Benefits
Expected minimum contribution		$ 29.8
Defined benefit plan, historical average return on asset mix		6.00%
Corporate Joint Venture | GIMA
Reduction in equity		$ (1.3)	$ (1.3)
Tax effect of benefit plans		$ 0.5	$ 0.5
Percentage of joint venture's unrecognized net actuarial losses and unrecognized prior service cost		50.00%	50.00%
Net loss recognized due to settlement		$ 0.1	$ 0.1

[1] Applicable for U.S. funded, qualified plans.