Stock Transactions And Stock-Based Compensation (Components Of Share-Based Compensation Program) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Pretax compensation expense	$ 139.4	$ 129.8	$ 103.8
Income tax benefit	(43.3)	(38.9)	(32.8)
Total stock-based compensation expense, net of income taxes	96.1	90.9	71.0
RSUs/PSUs:
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Pretax compensation expense	90.2	85.9	69.7
Income tax benefit	(27.7)	(25.3)	(22.1)
Total stock-based compensation expense, net of income taxes	62.5	60.6	47.6
Stock options
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Pretax compensation expense	49.2	43.9	34.1
Income tax benefit	(15.6)	(13.6)	(10.7)
Total stock-based compensation expense, net of income taxes	$ 33.6	$ 30.3	$ 23.4