Stock Transactions and Stock-Based Compensation (Components Of Share-Based Compensation Program) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Pretax compensation expense	$ 129.8	$ 103.8	$ 84.7
Income tax benefit	(38.9)	(32.8)	(24.1)
Total stock-based compensation expense, net of income taxes	90.9	71.0	60.6
RSUs/PSUs:
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Pretax compensation expense	85.9	69.7	52.1
Income tax benefit	(25.3)	(22.1)	(14.7)
Total stock-based compensation expense, net of income taxes	60.6	47.6	37.4
Stock options
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Pretax compensation expense	43.9	34.1	32.6
Income tax benefit	(13.6)	(10.7)	(9.4)
Total stock-based compensation expense, net of income taxes	$ 30.3	$ 23.4	$ 23.2