Reserves in Addition to Account Balance, Based on Expected No-Lapse Guarantee Benefits and Expected Policy Assessments (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Liability for Future Policy Benefit, by Product Segment [Line Items]
Life policy and investment contract reserves	$ 2,435	$ 2,390
Ordinary/Traditional Life
Liability for Future Policy Benefit, by Product Segment [Line Items]
Life policy and investment contract reserves	830	815
Universal Life
Liability for Future Policy Benefit, by Product Segment [Line Items]
Life policy and investment contract reserves	509	508
Deferred Annuities
Liability for Future Policy Benefit, by Product Segment [Line Items]
Life policy and investment contract reserves	864	862
Structured Settlements
Liability for Future Policy Benefit, by Product Segment [Line Items]
Life policy and investment contract reserves	187	189
Other
Liability for Future Policy Benefit, by Product Segment [Line Items]
Life policy and investment contract reserves	$ 45	$ 16