Significant Accounting Policies (Health Plan Services Health Care Cost) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Health Care Organization Revenue and Expense [Line Items]
Prior Year Claims and Claims Adjustment Expense	$ (85.3)	$ (22.9)
Provision For Adverse Deviation	73.5		77.7
Favorable prior period development [Member]
Health Care Organization Revenue and Expense [Line Items]
Prior Year Claims and Claims Adjustment Expense	(20.6)
Unfavorable Development [Member]
Health Care Organization Revenue and Expense [Line Items]
Prior Year Claims and Claims Adjustment Expense		23.0
Provision for Adverse Deviation, Release [Member]
Health Care Organization Revenue and Expense [Line Items]
Prior Year Claims and Claims Adjustment Expense	$ (64.7)	$ (45.9)