Accrued Warranty Costs (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Changes in product warranty liability [Roll Forward]
Balance at beginning of period	$ 7.1	$ 6.1
Claims paid	(3.0)	(1.7)
Warranty expense, net	3.6	1.1
Balance at end of period	$ 7.7	$ 5.5