Accumulated Other Comprehensive Income (Loss) - Reclassification out of AOCI (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of actuarial losses	$ 0.3	$ (0.3)
Tax benefit	(3.1)	(5.1)
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications for the period	0.3	0.2
Reclassification out of Accumulated Other Comprehensive Income | Selling, general and administrative
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of actuarial losses	(0.4)	(0.3)
Reclassification out of Accumulated Other Comprehensive Income | Income tax benefit
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax benefit	$ (0.1)	$ (0.1)