Reinsurance - Earned Life Insurance Premiums on Ceded Business (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct earned premiums	$ 1,048	$ 958	$ 2,067	$ 1,893
Ceded earned premiums	(44)	(51)	(87)	(99)
Life Insurance Segment
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct earned premiums	68	58	130	114
Ceded earned premiums	(15)	(14)	(29)	(28)
Net earned premiums	$ 53	$ 44	$ 101	$ 86