Investments - Schedule of Summarized Financial Information, Amerifund (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Jun. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 15, 2020	Dec. 31, 2019
Condensed Combined Balance Sheets
Total current assets	$ 493.1				$ 493.1			$ 630.9
Total assets	3,868.6			$ 1,893.7	3,868.6	$ 1,893.7	$ 2,000.0	2,092.2
Current liabilities	159.0				159.0			198.7
Long-term debt	70.3				70.3			127.1
Total liabilities	596.6				596.6			562.4
Total liabilities and equity	3,868.6				3,868.6			$ 2,092.2
Equity Method Investment, Financial Statement, Reported Amounts [Abstract]
Total revenues	334.0			351.2	2,113.3	974.8
Operating income (loss)	(28.4)			(21.5)	(127.4)	(54.0)
Net loss	128.0			41.6	1,232.2	40.6
Income attributable to noncontrolling interests	$ (3.9)			$ (4.6)	$ (22.7)	$ (12.2)
AmeriLife | Unconsolidated affiliates
Condensed Combined Balance Sheets
Total current assets		$ 86.5	$ 86.5
Goodwill and other intangible assets, net		1,100.6	1,100.6
Other assets		15.2	15.2
Total assets		1,202.3	1,202.3
Current liabilities		39.3	39.3
Long-term debt		500.2	500.2
Other non-current liabilities		5.9	5.9
Total liabilities		545.4	545.4
Member's equity		594.5	594.5
Noncontrolling interest - nonredeemable		62.4	62.4
Total member's equity		656.9	656.9
Total liabilities and equity		1,202.3	1,202.3
Equity Method Investment, Financial Statement, Reported Amounts [Abstract]
Total revenues		79.4	93.1
Operating income (loss)		5.1	(4.8)
Net loss		(5.4)	(16.1)
Income attributable to noncontrolling interests		3.9	4.3
Net loss		$ (9.3)	$ (20.4)