CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (UNAUDITED) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net Income (Loss)	$ 242.0	$ (284.7)	$ 804.1	$ 274.3
Other Comprehensive Income (Loss)
Change in Net Unrealized Gain (Loss) on Securities Before Adjustment (net of tax expense (benefit) of $209.5; $(80.6); $815.6; $(525.0))	800.4	(305.0)	3,093.2	(1,982.1)
Change in Adjustment to Deferred Acquisition Costs and Reserves for Future Policy and Contract Benefits, Net of Reinsurance (net of tax expense (benefit) of $(172.6); $(69.8); $(619.3); $276.1)	(665.2)	(260.2)	(2,358.7)	1,051.1
Change in Net Gain on Hedges (net of tax benefit of $3.7; $4.4; $12.3; $8.3)	(13.7)	(16.8)	(46.3)	(32.3)
Change in Foreign Currency Translation Adjustment (net of tax expense (benefit) of $0.8; $-; $1.2; $(0.3))	(37.6)	(15.2)	(40.0)	(29.5)
Change in Unrecognized Pension and Postretirement Benefit Costs (net of tax expense of $0.8; $1.3; $2.8; $4.0)	5.4	4.9	12.8	14.3
Total Other Comprehensive Income (Loss)	89.3	(592.3)	661.0	(978.5)
Comprehensive Income (Loss)	$ 331.3	$ (877.0)	$ 1,465.1	$ (704.2)