Reinsurance - Earned Life Insurance Premiums on Ceded Business (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct earned premiums	$ 1,019	$ 935
Assumed earned premiums	3	2
Ceded earned premiums	(43)	(48)
Life Insurance Segment
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct earned premiums	62	56
Ceded earned premiums	(14)	(14)
Net earned premiums	$ 48	$ 42