Investments (Details 13) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013 item	Mar. 31, 2012 item
Mortgage Loan Modifications
Number of mortgage loans modified as a troubled debt restructuring	35	53
Recorded investment of mortgage loans modified as a troubled debt restructuring	$ 3.1	$ 65.4
Number of mortgage loans modified as a troubled debt restructuring in payment default	12	2
Brick and mortar
Mortgage Loan Modifications
Number of mortgage loans modified as a troubled debt restructuring	1	4
Recorded investment of mortgage loans modified as a troubled debt restructuring	0.8	63.2
Home equity
Mortgage Loan Modifications
Number of mortgage loans modified as a troubled debt restructuring	32	49
Recorded investment of mortgage loans modified as a troubled debt restructuring	1.9	2.2
Number of mortgage loans modified as a troubled debt restructuring in payment default	12	2
First liens
Mortgage Loan Modifications
Number of mortgage loans modified as a troubled debt restructuring	2
Recorded investment of mortgage loans modified as a troubled debt restructuring	$ 0.4