CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Net Income	$ 213.9	$ 223.6
Change in Net Unrealized Gain on Securities Before Reclassification Adjustment:
Change in Net Unrealized Gain on Securities Not Other-Than-Temporarily Impaired (net of tax benefit of $110.2; $40.7)	(196.5)	(77.3)
Change in Net Unrealized Gain on Securities Other-Than-Temporarily Impaired (net of tax benefit of $-; $1.1)	0	(2.1)
Total Change in Net Unrealized Gain on Securities Before Reclassification Adjustment (net of tax benefit of $110.2; $41.8)	(196.5)	(79.4)
Reclassification Adjustment for Net Realized Investment Gain (net of tax expense of $0.3; $0.5)	(0.7)	(0.6)
Change in Net Gain on Cash Flow Hedges (net of tax benefit of $5.9; $5.4)	(10.7)	(9.9)
Change in Adjustment to Reserves for Future Policy and Contract Benefits, Net of Reinsurance and Other (net of tax expense of $97.2; $59.8)	166.8	113.2
Change in Foreign Currency Translation Adjustment	28.2	26.5
Change in Unrecognized Pension and Postretirement Benefit Costs (net of tax expense of $3.5; $1.6)	6.5	5.1
Total Other Comprehensive Income (Loss)	(6.4)	54.9
Comprehensive Income	$ 207.5	$ 278.5