Significant Accounting Policies (Health Plan Services Health Care Cost) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Health Care Organization Revenue and Expense [Line Items]
Prior Year Claims and Claims Adjustment Expense	$ (9.8)	$ 9.7	$ (109.4)	$ (16.9)
Provision For Adverse Deviation	84.3		84.3		$ 77.7
Favorable prior period development [Member]
Health Care Organization Revenue and Expense [Line Items]
Prior Year Claims and Claims Adjustment Expense	(8.8)		(31.7)
Unfavorable Development [Member]
Health Care Organization Revenue and Expense [Line Items]
Prior Year Claims and Claims Adjustment Expense		10.4		34.5
Provision for Adverse Deviation, Release [Member]
Health Care Organization Revenue and Expense [Line Items]
Prior Year Claims and Claims Adjustment Expense	$ (1.0)	$ (0.7)	$ (77.7)	$ (51.4)