Investments (Details 13) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013 item	Sep. 30, 2012 item	Sep. 30, 2013 item	Sep. 30, 2012 item
Mortgage Loan Modifications
Number of mortgage loans modified as a troubled debt restructuring	12	136	65	240
Recorded investment of mortgage loans modified as a troubled debt restructuring	$ 0.8	$ 14.6	$ 4.6	$ 32.8
Number of mortgage loans modified as a troubled debt restructuring in payment default	1	1	16	4
Recorded investment of mortgage loans modified as a troubled debt restructuring in payment default	0.1		0.8
Brick and mortar
Mortgage Loan Modifications
Number of mortgage loans modified as a troubled debt restructuring		2	2	3
Recorded investment of mortgage loans modified as a troubled debt restructuring		8.2	0.9	22.0
Home equity
Mortgage Loan Modifications
Number of mortgage loans modified as a troubled debt restructuring	12	134	60	237
Recorded investment of mortgage loans modified as a troubled debt restructuring	0.8	6.4	3.1	10.8
Number of mortgage loans modified as a troubled debt restructuring in payment default		1	13	4
First liens
Mortgage Loan Modifications
Number of mortgage loans modified as a troubled debt restructuring			3
Recorded investment of mortgage loans modified as a troubled debt restructuring			0.6
Number of mortgage loans modified as a troubled debt restructuring in payment default	1		3
Recorded investment of mortgage loans modified as a troubled debt restructuring in payment default	$ 0.1		$ 0.8