Equity - Reconciliation for the reclassifications out of accumulated other comprehensive income, net of tax (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales									$ (2,602.6)	$ (2,906.0)	$ (3,026.3)
Total before tax	$ 12.4	$ 15.8	$ 37.9	$ (9.5)	$ 38.4	$ 56.3	$ 66.1	$ 8.6	56.6	169.4	225.2
Tax expense (benefit)									(6.7)	8.6	36.1
Net of tax	$ 43.8	$ 4.8	$ 23.3	$ (8.4)	$ 33.6	$ 73.1	$ 46.6	$ (8.8)	63.5	144.5	$ 141.8
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net of tax									(17.0)	(5.7)
Gains and Losses on Cash Flow Hedges | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax									(18.3)	(4.1)
Tax expense (benefit)									(6.8)	(1.5)
Net of tax									(11.5)	(2.6)
Amortization of prior service cost | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of pension and postretirement									(0.1)	0.2
Pension & Postretirement | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax									(7.6)	(4.1)
Tax expense (benefit)									(2.1)	(1.0)
Amortization of pension and postretirement									(7.5)	(4.3)
Net of tax									(5.5)	(3.1)
Foreign currency exchange contracts | Gains and Losses on Cash Flow Hedges | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales									(11.7)	(2.2)
Commodity contracts | Gains and Losses on Cash Flow Hedges | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales									(4.0)	(0.1)
Interest Rate Swap | Gains and Losses on Cash Flow Hedges | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales									$ (2.6)	$ (1.8)