Reinsurance Level 4 Reinsurance Revenue (Details) - Life Annuity Accident and Health Insurance Product Line [Member] - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Gross Fee Income Earned Premium and Other Life	$ 576	$ 640
Assumed Premiums Earned	30	29
Ceded Premiums Earned	395	411
Net Fee Income Earned Premium and Other Life	$ 211	$ 258

Amount of earned premiums ceded to other entities.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Name:	us-gaap_CededPremiumsEarned
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration