Reinsurance (Reinsurance Deposits Part B - Narrative) (Details) - USD ($) $ in Billions	Dec. 31, 2021	Dec. 31, 2020
Reinsurance Disclosures [Abstract]
Deposit Contracts, Assets	$ 3.1	$ 3.0
Deposit Contracts, Liabilities	$ 3.4	$ 2.7

Carrying amount of liabilities as of the balance sheet date pertaining to amounts received by the insurer or reinsurer from the insured (including a ceding company) under insurance or reinsurance contracts for which insurance risk is not transferred.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=99383045&loc=d3e9351-108337

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 30
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=99397363&loc=d3e9420-108338

Name:	us-gaap_DepositContractsLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant