Income Taxes (Deferred Tax Assets (Liabilities) Resulting From Temporary Differences) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Tax loss and deduction carryforwards	$ 2,144.3	$ 2,022.1
Tax credit carryforwards	830.5	981.0
All other future deductions	560.8	471.0
Valuation allowance	(3,257.5)	(3,217.7)
Total deferred tax assets	278.1	256.4
Deferred tax liabilities:
Total deferred tax liabilities	(85.1)	(74.9)
Net deferred tax assets	$ 193.0	$ 181.5