Contingencies - Accrual for Probable Losses (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Loss Contingency Accrual [Roll Forward]
Litigation contingency accrual - Beginning of period	$ 0.4	$ 3.2	$ 8.1
Cash payments	(0.3)	(5.0)	(14.0)
Litigation contingency accrual - End of period	1.9	0.4	3.2
Continuing Operations
Loss Contingency Accrual [Roll Forward]
Adjustment to accruals - expense (income)	1.8	0.6	7.1
Discontinued Operations
Loss Contingency Accrual [Roll Forward]
Adjustment to accruals - expense (income)	$ 0.0	$ 1.6	$ 2.0