CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net Income	$ 212.9	$ 225.8
Other Comprehensive Income (Loss)
Change in Net Unrealized Gain on Securities Before Adjustment (net of tax expense of $182.8; $371.1)	350.2	710.0
Change in Adjustment to Deferred Acquisition Costs and Reserves for Future Policy and Contract Benefits, Net of Reinsurance (net of tax benefit of $120.3; $272.0)	(226.2)	(520.4)
Change in Net Gain on Cash Flow Hedges (net of tax expense of $9.0; $1.0)	20.9	1.7
Change in Foreign Currency Translation Adjustment (net of tax benefit of $0.1; $0.0)	(54.0)	7.6
Change in Unrecognized Pension and Postretirement Benefit Costs (net of tax expense of $1.5; $0.3)	3.1	0.5
Total Other Comprehensive Income	94.0	199.4
Comprehensive Income	$ 306.9	$ 425.2