Invested Assets and Related Income - Fair Value and Amortized Cost of Fixed Maturities by Contractual Maturity (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Schedule of Available-For-Sale Securities [Line Items]
Due in one year or less, Fair Value	$ 2,241
Due after one year through five years, Fair Value	13,769
Due after five years through ten years, Fair Value	11,743
Due after ten years, Fair Value	7,674
Subtotal fixed maturities, Fair Value	35,427
Total fixed maturities, Fair Value	37,091	38,076
Due in one year or less, Amortized Cost	2,212
Due after one year through five years, Amortized Cost	13,202
Due after five years through ten years, Amortized Cost	11,294
Due after ten years, Amortized Cost	7,635
Subtotal fixed maturities, Amortized Cost	34,343
Total fixed maturities, Amortized Cost	35,959	35,398
Residential Mortgage-backed Securities [Member]
Schedule of Available-For-Sale Securities [Line Items]
Taxable, Fair Value	299
Taxable, Amortized Cost	277
Commercial Mortgage-backed Securities [Member]
Schedule of Available-For-Sale Securities [Line Items]
Taxable, Fair Value	1,365
Taxable, Amortized Cost	$ 1,339