Estimated amount after valuation allowance of reinsurance recoverables, due from reinsurers for incurred claims not yet reported, and claims settlement expenses.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 310
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=99404803&loc=d3e21409-158489

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 310
-Section 45
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=99404803&loc=d3e21412-158489

Name:	us-gaap_ReinsuranceReceivablesIncurredButNotReportedClaims
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Liability for Unpaid Claims and CAE - Additional Information (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Liability for Unpaid Claims and CAE
Reinsurance Recoverables, Incurred but Not Reported Claims	$ 9,042.2	$ 8,378.9	$ 2,260.2	$ 2,246.8
Phase 2 \| Closed Block Individual Disability Reinsurance Transaction
Liability for Unpaid Claims and CAE
Increase in Benefits and Change in Reserves for Future Benefits	133.1
Reinsurance Recoverables, Incurred but Not Reported Claims	$ 990.0