Accumulated Other Comprehensive Loss Reclassification Adjustment (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Interest expense		$ (117.3)		$ (101.4)		$ (32.5)
Net prior service benefit amortization, tax		0.0		0.0		0.1
Net actuarial loss amortization recognized during the year, tax		(3.3)		(1.8)		(2.7)
Net actuarial gains (losses) recognized due to settlement (net of tax of $0.4 and $0.0, respectively)		(0.2)	[1]	0.0	[1]	0.0
Net actuarial losses recognized due to settlement, tax		0.4		0.0		0.0
Curtailment gain		0.0		3.3		0.0
Net prior service benefit amortization due to curtailment, tax		0.0		1.5		0.0
Currency impact (net of tax of $(1.9) and $0.4, respectively)	[1]	(1.3)		0.7		0.0
Currency impact, tax		(1.9)		0.4		0.0
Derivatives, reclassification adjustment for amounts recognized in net income, tax		0.0		(0.2)		(0.1)
Interest income		20.3		21.5		$ 26.0
Total reclassifications for the period		2.9		(0.2)
Interest Rate Hedges
Total reclassifications for the period		(0.4)		(0.2)
Interest Rate Hedges | Reclassification out of Accumulated Other Comprehensive Income [Member]
Interest expense		(0.4)		(0.2)
Derivatives, reclassification adjustment for amounts recognized in net income, tax		(0.1)		0.0
Pension and Other Post-Retirement Benefits
Total reclassifications for the period		3.3		0.0
Pension and Other Post-Retirement Benefits | Reclassification out of Accumulated Other Comprehensive Income [Member]
Recognized net actuarial loss	[1]	2.2		4.0
Net actuarial loss amortization recognized during the year, tax		(3.3)		(1.8)
Net actuarial gains (losses) recognized due to settlement (net of tax of $0.4 and $0.0, respectively)		(0.2)		0.0
Net actuarial losses recognized due to settlement, tax		0.4		0.0
Curtailment gain	[1]	0.0		3.3
Net prior service benefit amortization due to curtailment, tax		0.0		1.5
Currency impact (net of tax of $(1.9) and $0.4, respectively)		1.3		(0.7)
Currency impact, tax		(1.9)		0.4
Amounts reclassified from AOCI		$ 3.3		$ 0.0

[1] Pension and other post-retirement benefits AOCI components are included in the computation of net periodic benefit cost (refer to note 15 to the consolidated financial statements).