Reinsurance - Earned Life Insurance Premiums on Ceded Business (Detail) - Life Insurance Segment - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct earned premiums	$ 68	$ 68	$ 133	$ 130
Ceded earned premiums	(16)	(15)	(28)	(29)
Earned premiums	$ 52	$ 53	$ 105	$ 101

Amount of earned premiums ceded to other entities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

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