Investments - Reverse Repurchase Agreements (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Schedule of Resale Agreements [Line Items]
Securities Purchased under Agreements to Resell		$ 0
Securities Purchased under Agreements to Resell, Fair Value of Collateral	$ 630	$ 0
Consolidated Entity Excluding Variable Interest Entities (VIE)
Schedule of Resale Agreements [Line Items]
Securities Purchased under Agreements to Resell	$ 190

Amount, after the effects of master netting arrangements, of funds outstanding loaned in the form of a security resale agreement between the entity and another party for the purchase and resale of identical or substantially the same securities at a date certain for a specified price. Includes purchases of participations in pools of securities that are subject to a resale agreement, assets not subject to a master netting arrangement and not elected to be offset.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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Name:	us-gaap_SecuritiesPurchasedUnderAgreementsToResell
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant