Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Available for sale:
Fixed maturity securities (amortized costs)	$ 8,051.3	$ 8,477.3
Equity securities - cost	1,146.0	632.0
Trading securities:
Equity securities - cost	$ 34.1	$ 0
Preferred Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred Stock, authorized shares (in shares)	75,000,000	75,000,000
Preferred Stock, outstanding shares (in shares)	0	0
Common Stock, par value (in dollars per share)	$ 1.00	$ 1.00
Common Stock, authorized shares (in shares)	500,000,000	500,000,000
Common Stock, issued shares (in shares)	260,827,571	260,462,217
Common Class B [Member]
Trading securities:
Common Stock, par value (in dollars per share)	$ 1.00	$ 1.00
Common Stock, authorized shares (in shares)	100,000,000	100,000,000
Common Stock, issued shares (in shares)	0	0