CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Change in Net Unrealized Gain on Securities Before Adjustment, Tax Benefit	$ (434.2)	$ (436.5)
Change in Adjustment to Deferred Acquisition Costs and Reserves for Future Policy and Contract Benefits, Net of Reinsurance, Tax Expense	331.8	380.8
Change in Net Gain on Hedges, Tax Expense (Benefit)	(5.4)	6.6
Change in Foreign Currency Translation Adjustment, Tax Expense	1.8	2.1
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	$ 1.2	$ 1.9