Accumulated Other Comprehensive Loss - Reclassification out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Tax (expense) benefit	$ 15.2	$ (25.3)	$ (39.3)
Earnings from operations	219.1	199.2	159.9
Total before tax	2.4	(4.0)	(5.9)
Net of tax	1.5	(2.4)	(4.1)
Gains and losses on cash flow hedges:
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total before tax	4.4	(1.5)	(4.8)
Pension & Postretirement
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total before tax	(2.0)	(2.5)	(1.1)
Tax benefit	0.7	1.0	0.0
Net of tax	(1.3)	(1.5)	(1.1)
Amount Reclassified from Accumulated Other Comprehensive Income | Gains and losses on cash flow hedges:
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total before tax	4.4	(1.5)	(4.8)
Tax (expense) benefit	(1.6)	0.6	1.8
Earnings from operations	2.8	(0.9)	(3.0)
Amount Reclassified from Accumulated Other Comprehensive Income | Actuarial losses
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total before tax	(2.0)	(2.5)	(1.1)
Foreign currency exchange contracts | Amount Reclassified from Accumulated Other Comprehensive Income | Gains and losses on cash flow hedges:
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of sales	3.3	0.0	(1.4)
Commodity contracts | Amount Reclassified from Accumulated Other Comprehensive Income | Gains and losses on cash flow hedges:
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of sales	$ 1.1	$ (1.5)	$ (3.4)