Assumed Life Reinsurance Programs Involving Minimum Benefit Guarantees Under Annuity Contracts (Schedule Of Guaranteed Minimum Benefits Income And Expense) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Guaranteed Minimum Benefits [Line Items]
Net premiums earned	$ 4,754	$ 4,610	$ 13,056	$ 12,250
Policy benefits and other reserve adjustments	125	138	383	379
Net realized gains (losses)	(120)	40	(297)	350
Guaranteed Minimum Death Benefit [Member]
Guaranteed Minimum Benefits [Line Items]
Net premiums earned	17	19	54	59
Policy benefits and other reserve adjustments	12	14	40	58
Guaranteed Minimum Income Benefit [Member]
Guaranteed Minimum Benefits [Line Items]
Net premiums earned	35	36	105	112
Policy benefits and other reserve adjustments	8	9	27	20
Net realized gains (losses)	(76)	138	(124)	608
Gain (loss) recognized in income	(49)	165	(46)	700
Net cash received	31	31	93	94
Net (increase) decrease in liability	$ (80)	$ 134	$ (139)	$ 606