Reinsurance Level 4 Reinsurance Revenues (Details) - USD ($) $ in Millions	5 Months Ended	7 Months Ended	12 Months Ended
	May 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Assumed Premiums Earned	$ 48	$ 66	$ 116	$ 129
Ceded Premiums Earned	(684)	(972)	(1,539)	(1,616)
Life Annuity Accident and Health Insurance Product Line [Member]
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Gross Fee Income Earned Premium and Other Life	1,059	1,439	2,434	2,659
Assumed Premiums Earned	48	66	116	129
Ceded Premiums Earned	(684)	(972)	(1,539)	(1,616)
Net Fee Income Earned Premium and Other Life	$ 423	$ 533	$ 1,011	$ 1,172