Financing Receivables Financing Receivables (Reinsurance Deposit Receivable) (Details) - USD ($) $ in Billions	3 Months Ended
Mar. 31, 2019	Dec. 31, 2019
Receivables [Abstract]
Deposit receivable		$ 1.5
Amount of fixed annuity policies reinsured	$ 1.7

Amount of the reinsurer's funds held on its behalf by the ceding insurer, including funds held in trust, under reinsurance treaties or contracts with the assuming insurer as security for the payment of the obligations thereunder.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.2,10)
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

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