Investments Equity Securities (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Equity securities - cost	$ 1,146.0	$ 632.0
Available-for-sale Securities, Equity Securities	1,390.2	1,004.2
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Equity securities, OTTI adjustments	0	0
Equity securities - cost	1,146.0	632.0
Equity securities, gross unrealized gains	245.5	372.7
Equity securities, gross unrealized losses	1.3	0.5
Available-for-sale Securities, Equity Securities	$ 1,390.2	$ 1,004.2