Segment Information (Reconciliation Of Reportable Segments Operating Revenues To Total Revenues Reported In The Consolidated Statements Of Income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting [Abstract]
Document Fiscal Year Focus			2014
Reportable segments operating revenues	$ 18,370.7	$ 17,618.7	$ 54,245.5	$ 52,545.7
Net investment income	174.4	167.6	546.6	482.8
Net realized gains on investments	25.7	95.4	133.2	166.4
Other-than-temporary impairment losses recognized in income	(13.8)	(26.2)	(35.5)	(73.1)
Total revenues	$ 18,557.0	$ 17,855.5	$ 54,889.8	$ 53,121.8