Discontinued Operations - Summarized Assets and Liabilities of the of Discontinued Operations (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Current assets
Total assets held for sale	$ 2.2	$ 5,942.1
Current liabilities
Total liabilities held for sale	0.0	5,306.7
Discontinued Operations
Current assets
Cash and cash equivalents	0.0	195.2	$ 135.6	$ 216.0
Accounts receivable, net	0.0	13.6
Other current assets	1.5	8.7
Total current assets	1.5	217.5
Investments	0.0	4,610.2
Recoverable from reinsurers	0.0	957.5
Deferred tax asset	0.0	1.4
Property, plant and equipment, net	0.0	90.5
Goodwill	0.0	2.1
Intangibles, net	0.0	11.7
Other assets	0.0	51.2
Total assets held for sale	1.5	5,942.1
Current liabilities
Accounts payable	0.0	2.6
Accrued liabilities	0.0	35.8
Current portion of debt obligations	0.0	5.7
Other current liabilities	0.0	7.4
Total current liabilities	0.0	51.5
Life, accident and health reserves	0.0	4,627.5
Annuity reserves	0.0	228.8
Value of business acquired	0.0	199.8
Deferred tax liability	0.0	136.5
Debt obligations	0.0	50.6
Other liabilities	0.0	12.0
Total liabilities held for sale	$ 0.0	$ 5,306.7