CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue
Premium Income	$ 8,597.1	$ 8,357.7	$ 8,082.4
Net Investment Income	2,451.7	2,459.0	2,481.2
Realized Investment Gain (Loss)
Other-Than-Temporary Impairment Loss on Fixed Maturity Securities	(8.1)	(30.5)	(32.4)
Net Realized Investment Gain (Loss), Excluding Other-Than-Temporary Impairment Loss on Fixed Maturity Securities	48.4	54.7	(11.4)
Net Realized Investment Gain (Loss)	40.3	24.2	(43.8)
Other Income	197.7	205.6	211.5
Total Revenue	11,286.8	11,046.5	10,731.3
Benefits and Expenses
Benefits and Change in Reserves for Future Benefits	7,055.7	6,941.8	6,782.8
Commissions	1,060.8	1,026.7	996.3
Interest and Debt Expense	159.9	166.0	152.8
Deferral of Acquisition Costs	(628.0)	(592.4)	(569.7)
Amortization of Deferred Acquisition Costs	527.1	493.0	482.3
Compensation Expense	844.4	832.1	835.1
Other Expenses	862.9	831.6	813.4
Total Benefits and Expenses	9,882.8	9,698.8	9,493.0
Income Before Income Tax	1,404.0	1,347.7	1,238.3
Income Tax
Current	401.3	385.7	342.1
Deferred	8.5	30.6	29.1
Total Income Tax	409.8	416.3	371.2
Net Income	$ 994.2	$ 931.4	$ 867.1
Net Income Per Common Share
Basic	$ 4.39	$ 3.96	$ 3.51
Assuming Dilution	$ 4.37	$ 3.95	$ 3.50