Income Taxes (Summary Of Temporary Differences That Give Rise To Deferred Income Tax Assets And Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Deferred income tax assets (liabilities):
Inventory costing and valuation methods	$ 4.2	$ 3.6
Allowance for doubtful accounts	3.2	3.0
Insurance reserves	8.1	8.4
Customer promotions	1.9	1.3
Stock-based compensation	5.6	5.2
Federal and state benefit of uncertain tax positions	0.8	0.9
Foreign net operating loss and credit carryforwards	3.2	4.2
Foreign valuation allowances	(2.7)	(2.8)
Other, net	1.3	0.8
Total deferred income tax assets	25.6	24.6
Property and equipment	(104.7)	(75.2)
Total deferred income tax liabilities	(104.7)	(75.2)
Deferred income tax liabilities	$ (79.1)	$ (50.6)