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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	Dec. 31, 2016
Group Insurance Policies [Member]
Effects of Reinsurance [Line Items]
Ceded Premiums Written	$ 9	$ 27	$ 40
Accident and Health Insurance Product Line [Member]
Effects of Reinsurance [Line Items]
Ceded Premiums Written	$ 25	70	$ 86
Other Insurance Product Line [Member]
Effects of Reinsurance [Line Items]
Ceded Premiums Written		90
Policyholder Benefits and Claims Incurred, Ceded		63
Gain (Loss) on Contract Termination		$ 27