Transactions with Affiliates Level 4 Reinsurance Disclosures (Details) - Hartford Life and Accident Insurance Company [Member] - USD ($) $ in Millions	5 Months Ended	12 Months Ended
May 31, 2018	Dec. 31, 2017
Group Insurance Policies [Member]
Effects of Reinsurance [Line Items]
Ceded Premiums Written	$ 9	$ 27
Accident and Health Insurance Product Line [Member]
Effects of Reinsurance [Line Items]
Ceded Premiums Written	$ 25	$ 70

Amount of written premiums ceded to other entities.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 605
-Section 50
-Paragraph 1
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=6486672&loc=d3e27261-158547

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 605
-Section 50
-Paragraph 1
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=6486672&loc=d3e27261-158547

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