Derivative Instruments (Credit Derivatives Sold) (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Derivative [Line Items]
Derivative notional amount	$ 31,316	$ 58,640
Insurance Operations [Member]
Derivative [Line Items]
Derivative notional amount	28,935	53,014
Total fair value of credit derivatives	(1,152)	(2,934)
Insurance Operations [Member] | Credit Default Swap [Member]
Derivative [Line Items]
Weighted average remaining expected maturity	2 years 7 months 6 days	5 years 1 month 6 days
Derivative notional amount	23,954	47,002
Total fair value of credit derivatives	(1,132)	(2,858)
Insurance Operations [Member] | Insured Swaps [Member]
Derivative [Line Items]
Weighted average remaining expected maturity	18 years 6 months 0 days	19 years 4 months 24 days
Derivative notional amount	4,945	5,817
Total fair value of credit derivatives	(5)	(8)
Insurance Operations [Member] | Other Credit Derivatives [Member]
Derivative [Line Items]
Weighted average remaining expected maturity	28 years 0 months 0 days	1 year 9 months 18 days
Derivative notional amount	36	195
Total fair value of credit derivatives	(15)	(68)
Credit Rating Aaa [Member] | Insurance Operations [Member]
Derivative [Line Items]
Derivative notional amount	7,406	10,457
Total fair value of credit derivatives	(2)	(7)
Credit Rating Aaa [Member] | Insurance Operations [Member] | Credit Default Swap [Member]
Derivative [Line Items]
Derivative notional amount	7,406	10,457
Credit Rating Aaa [Member] | Insurance Operations [Member] | Insured Swaps [Member]
Derivative [Line Items]
Derivative notional amount	0	0
Credit Rating Aaa [Member] | Insurance Operations [Member] | Other Credit Derivatives [Member]
Derivative [Line Items]
Derivative notional amount	0	0
Credit Rating Aa [Member] | Insurance Operations [Member]
Derivative [Line Items]
Derivative notional amount	2,049	5,965
Total fair value of credit derivatives	0	(70)
Credit Rating Aa [Member] | Insurance Operations [Member] | Credit Default Swap [Member]
Derivative [Line Items]
Derivative notional amount	1,972	5,862
Credit Rating Aa [Member] | Insurance Operations [Member] | Insured Swaps [Member]
Derivative [Line Items]
Derivative notional amount	77	103
Credit Rating Aa [Member] | Insurance Operations [Member] | Other Credit Derivatives [Member]
Derivative [Line Items]
Derivative notional amount	0	0
Credit Rating A [Member] | Insurance Operations [Member]
Derivative [Line Items]
Derivative notional amount	4,350	8,914
Total fair value of credit derivatives	(3)	(72)
Credit Rating A [Member] | Insurance Operations [Member] | Credit Default Swap [Member]
Derivative [Line Items]
Derivative notional amount	1,068	5,253
Credit Rating A [Member] | Insurance Operations [Member] | Insured Swaps [Member]
Derivative [Line Items]
Derivative notional amount	3,282	3,661
Credit Rating A [Member] | Insurance Operations [Member] | Other Credit Derivatives [Member]
Derivative [Line Items]
Derivative notional amount	0	0
Credit Rating Bbb [Member] | Insurance Operations [Member]
Derivative [Line Items]
Derivative notional amount	9,138	13,553
Total fair value of credit derivatives	(78)	(732)
Credit Rating Bbb [Member] | Insurance Operations [Member] | Credit Default Swap [Member]
Derivative [Line Items]
Derivative notional amount	7,552	11,571
Credit Rating Bbb [Member] | Insurance Operations [Member] | Insured Swaps [Member]
Derivative [Line Items]
Derivative notional amount	1,586	1,982
Credit Rating Bbb [Member] | Insurance Operations [Member] | Other Credit Derivatives [Member]
Derivative [Line Items]
Derivative notional amount	0	0
Credit Rating Below Investment Grade [Member] | Insurance Operations [Member]
Derivative [Line Items]
Derivative notional amount	5,992	14,125
Total fair value of credit derivatives	(1,069)	(2,053)
Credit Rating Below Investment Grade [Member] | Insurance Operations [Member] | Credit Default Swap [Member]
Derivative [Line Items]
Derivative notional amount	5,956	13,859
Credit Rating Below Investment Grade [Member] | Insurance Operations [Member] | Insured Swaps [Member]
Derivative [Line Items]
Derivative notional amount	0	71
Credit Rating Below Investment Grade [Member] | Insurance Operations [Member] | Other Credit Derivatives [Member]
Derivative [Line Items]
Derivative notional amount	$ 36	$ 195