Derivative Financial Instruments (Changes In AOCI Relating To Derivatives) (Details) - Qualifying Hedges - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives — effective portion reclassified from AOCI to income	$ 13.4	$ 1.8	$ 33.8
Total income statement impact	13.4	1.8	33.8
Derivatives — effective portion recorded in OCI	(74.7)	2.7	128.4
Total change in OCI for period	(88.1)	0.9	94.6
Foreign currency forward contracts
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives — effective portion reclassified from AOCI to income	13.4	1.8	33.8
Total income statement impact	13.4	1.8	33.8
Derivatives — effective portion recorded in OCI	(74.7)	2.7	128.4
Total change in OCI for period	$ (88.1)	$ 0.9	$ 94.6