Income Taxes (Significant Components of the Company's Net Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred income tax assets:
Postretirement benefit obligation	$ 2.0	$ 3.6
Inventory	9.9	13.7
Net operating loss and credit carryforwards	16.1	10.8
Warranty reserve	0.4	2.1
Accrued litigation	0.1	2.8
Compensation	4.2	4.1
Other	4.8	10.0
Total deferred income tax assets	37.5	47.1
Deferred income tax liabilities:
Depreciation and amortization	9.7	14.9
Pension	16.3	22.1
Intangible assets	16.6	23.3
Other	2.8	5.2
Total deferred income tax liabilities	45.4	65.5
Net deferred income tax liabilities prior to valuation allowances	(7.9)	(18.4)
Valuation allowances	(11.6)	(5.3)
Net deferred income tax liability	$ (19.5)	$ (23.7)