Deferred Policy Acquisition Costs, Value of Business Acquired and Other Policy-Related Intangibles (Deferred Sales Inducements) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred Policy Acquisition Costs and Present Value of Future Insurance Profits, Net [Abstract]
Beginning Balance of DSI	$ 362	$ 391	$ 411
Capitalization of DSI	2	2	2
Amortization of DSI	(69)	(36)	(39)
Unrealized investment gains (losses) of DSI	0	5	17
Ending Balance of DSI	$ 295	$ 362	$ 391

Amount of amortization expense (reversal of expense) for deferred sales inducement cost.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 30
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121638524&loc=d3e11332-158416

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6481654&loc=d3e11214-158414

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (g)(1)
-URI http://asc.fasb.org/extlink&oid=121370832&loc=SL117420844-207641

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 30
-Section 50
-Paragraph 2B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121638524&loc=SL117422543-158416

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration