Fair Value Measurements (Narrative) (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
Fair Value Measurements Of Financial Instruments [Line Items]
Level 1 to Level 2 Transfers	$ 0	$ 6	$ 0	$ 19
Level 2 to Level 1 Transfers	0	0	0	0
Guaranteed Living Benefits, Net Income Impact From Model Refinement	$ 1		$ (2)
Redemption Notice Periods Lower Range [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Notice period for redemption for alternative investments investment funds, days			5 days
Redemption Notice Periods Upper Range [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Notice period for redemption for alternative investments investment funds, days			120 days