Income Taxes Deferred Income Tax Asset and Liability Components (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Deferred income tax assets:
Inventory	$ 23.3	$ 22.8
Receivable allowances	1.4	1.9
Warranty, chargeback, and self - insurance liabilities	48.4	47.4
Other accrued liabilities	30.0	25.4
Deferred compensation	19.0	18.8
Stock-based compensation	21.2	18.9
Loss carryforwards—federal and state	7.0	6.5
Other, net	8.8	10.2
Total deferred income tax assets	159.1	151.9
Valuation allowance	(8.9)	(5.4)
Deferred income tax assets, net of valuation allowance	150.2	146.5
Deferred income tax liabilities:
Long-lived assets (intangibles assets and property)	(225.1)	(207.1)
Other, net	(14.9)	(11.3)
Total deferred income tax liabilities	(240.0)	(218.4)
Net deferred income tax liabilities	$ (89.8)	$ (71.9)