CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net Income	$ 894.4	$ 284.2	$ 878.7
Change in Net Unrealized Gains on Securities Before Reclassification Adjustment:
Change in Net Unrealized Gains on Securities Not Other-Than-Temporarily Impaired (net of tax expense of $470.9; $812.4; $522.6)	926.4	1,544.4	989.0
Change in Net Unrealized Gains on Securities Other-Than-Temporarily Impaired (net of tax benefit of $-; $1.1; $0.5)	0	(2.1)	(0.9)
Total Change in Net Unrealized Gains on Securities Before Reclassification Adjustment (net of tax expense of $470.9; $811.3; $522.1)	926.4	1,542.3	988.1
Reclassification Adjustment for Net Realized Investment Gain (net of tax expense of $3.2; $13.0; $3.5)	(7.6)	(22.5)	(6.4)
Change in Net Gain on Cash Flow Hedges (net of tax expense (benefit) of $(4.3); $25.2; $(5.0))	(7.1)	47.7	(9.8)
Change in Adjustment to Reserves for Future Policy and Contract Benefits, Net of Reinsurance and Other (net of tax benefit of $325.6; $701.5; $499.6)	(660.1)	(1,321.1)	(948.3)
Change in Foreign Currency Translation Adjustment (net of tax expense of $ - ; $ - ; $0.6)	45.0	(10.5)	(31.8)
Change in Unrecognized Pension and Postretirement Benefit Costs (net of tax benefit of $68.0; $67.4; $12.7)	(130.4)	(125.5)	12.1
Total Other Comprehensive Income	166.2	110.4	3.9
Comprehensive Income	$ 1,060.6	$ 394.6	$ 882.6