Shareholders' Equity (Common Stock Issued With The Exercise Of Stock Options) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Stockholders' Equity Note [Abstract]
Shares issued (in shares)	0.1	0.1	0.2	0.4
Proceeds from the exercise of stock options	$ 4.9	$ 1.8	$ 8.0	$ 16.0
Average exercise price per share (in dollars per share)	$ 35.61	$ 16.67	$ 33.70	$ 39.20