Schedule 2 - Parent Company Financial Statements - Balance Sheets (Parenthetical) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Amortized Cost of Fixed Maturity Securities	$ 4,370.5	$ 4,283.8
Fair Value of Notes Payable	667.1	675.5
Senior Notes [Member] | Senior Notes Payable, 6.00% due 2017 [Member]
Senior Notes Payable, Interest Rate	6.00%
Senior Notes [Member] | Senior Notes Payable, 6.00% due 2015 [Member]
Senior Notes Payable, Interest Rate	6.00%
Parent Company [Member]
Amortized Cost of Fixed Maturity Securities	0	0
Trading Securities, Cost	4.7	4.9
Parent Company [Member] | Senior Notes [Member] | Senior Notes Payable, 6.00% due 2017 [Member]
Fair Value of Notes Payable	395.5	393.7
Senior Notes Payable, Interest Rate	6.00%	6.00%
Parent Company [Member] | Senior Notes [Member] | Senior Notes Payable, 6.00% due 2015 [Member]
Fair Value of Notes Payable	$ 271.6	$ 276.3
Senior Notes Payable, Interest Rate	6.00%	6.00%