Employee and Agent Benefits (Details 2) (USD $) In Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2011
Pension benefits
Impact from Exit of Group Medical Insurance Business
Curtailment (gain) loss	$ (0.3)	$ (1.0)
Contributions
Minimum annual contribution required in current fiscal year for qualified pension plan		0
The low end of the range of possible contributions to be made during the current fiscal year to the qualified and nonqualified pension plans combined	60.0	60.0
The high end of the range of possible contributions to be made during the current fiscal year to the qualified and nonqualified pension plans combined	90.0	90.0
Contributions made by employer to fund qualified and nonqualified pension plans	16.2	48.6
Other postretirement benefits
Impact from Exit of Group Medical Insurance Business
Curtailment (gain) loss	$ (1.1)	$ (4.0)