Income Taxes (Deferred Income Tax Assets And Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Allowance for doubtful accounts	$ 18.6	$ 22.4
Inventories	95.9	102.8
Pension and postretirement benefits	250.6	392.4
Environmental and regulatory compliance	26.8	29.9
Other accruals and prepayments	345.8	211.1
Stock-based compensation expense	63.9	89.3
Tax credit and loss carryforwards	673.4	1,095.9
Valuation allowances	(324.6)	(306.5)
Total deferred tax asset	1,150.4	1,637.3
Deferred tax liabilities:
Property, plant and equipment	(63.4)	(41.4)
Insurance, including self-insurance	(696.2)	(786.4)
Basis difference in LYONs	(12.9)	(13.1)
Goodwill and other intangibles	(2,711.2)	(3,645.3)
Unrealized gains on marketable securities	0.0	(2.9)
Total deferred tax liability	(3,483.7)	(4,489.1)
Net deferred tax liability	$ (2,333.3)	$ (2,851.8)