CONSOLIDATED STATEMENTS OF INCOME (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Revenue
Premium Income	$ 7,514.2	$ 7,431.4	$ 7,475.5
Net Investment Income	2,519.6	2,495.5	2,346.6
Realized Investment Gain (Loss)
Total Other-Than-Temporary Impairment Loss on Fixed Maturity Securities	(19.9)	(15.9)	(215.5)
Other-Than-Temporary Impairment Loss Recognized in Other Comprehensive Income	0	0	3.7
Net Impairment Loss Recognized in Earnings	(19.9)	(15.9)	(211.8)
Other Net Realized Investment Gain	15.0	40.6	223.5
Net Realized Investment Gain (Loss)	(4.9)	24.7	11.7
Other Income	249.1	241.6	257.2
Total Revenue	10,278.0	10,193.2	10,091.0
Benefits and Expenses
Benefits and Change in Reserves for Future Benefits	7,209.5	6,354.1	6,291.6
Commissions	879.2	855.4	837.1
Interest and Debt Expense	143.3	141.8	125.4
Deferral of Acquisition Costs	(628.3)	(607.7)	(593.6)
Amortization of Deferred Acquisition Costs	533.8	547.1	526.2
Impairment of Deferred Acquisition Costs	289.8	0	0
Compensation Expense	808.0	776.3	793.3
Other Expenses	785.5	794.9	818.7
Total Benefits and Expenses	10,020.8	8,861.9	8,798.7
Income Before Income Tax	257.2	1,331.3	1,292.3
Income Tax (Benefit)
Current	230.5	301.0	377.9
Deferred	(208.7)	144.2	61.8
Total Income Tax	21.8	445.2	439.7
Net Income	$ 235.4	$ 886.1	$ 852.6
Net Income Per Common Share
Earnings Per Share, Basic	$ 0.78	$ 2.72	$ 2.57
Earnings Per Share, Diluted	$ 0.78	$ 2.71	$ 2.57