Investments (Amortized Cost and Fair Value of Fixed Maturities by Contractual Maturities) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Available for Sale Amortized Cost
Due in one year or less	$ 9,160
Due after one year through five years	47,219
Due after five years through ten years	57,745
Due after ten years	123,914
Debt Maturities, without single maturity date	30,689
Total	268,727		277,654
Available for Sale Securities Fair Value
Due in one year or less	9,591
Due after one year through five years	51,622
Due after five years through ten years	62,682
Due after ten years	131,806
Debt Maturities, without Single Maturity Date	31,165
Total	286,866	[1]	301,336	[1]
Held to Maturity Securities Amortized Cost
Due in one year or less	0
Due after one year through five years	55
Due after five years through ten years	323
Due after ten years	1,464	[2]
Debt Maturities, without Single Maturity Date	1,470
Total	3,312	[1]	4,268	[1]
Held to Maturity Securities Fair Value
Due in one year or less	0
Due after one year through five years	56
Due after five years through ten years	331
Due after ten years	1,597	[2]
Debt Maturities, without Single Maturity Date	1,569
Total	3,553		4,511
Residential Mortgage Backed Securities [Member]
Available for Sale Amortized Cost
Debt Maturities, without single maturity date	6,365
Available for Sale Securities Fair Value
Debt Maturities, without Single Maturity Date	6,703
Held to Maturity Securities Amortized Cost
Debt Maturities, without Single Maturity Date	611
Held to Maturity Securities Fair Value
Debt Maturities, without Single Maturity Date	646
Commercial Mortgage Backed Securities [Member]
Available for Sale Amortized Cost
Debt Maturities, without single maturity date	13,633
Available for Sale Securities Fair Value
Debt Maturities, without Single Maturity Date	13,873
Held to Maturity Securities Amortized Cost
Debt Maturities, without Single Maturity Date	166
Held to Maturity Securities Fair Value
Debt Maturities, without Single Maturity Date	184
Asset-backed Securities [Member]
Available for Sale Amortized Cost
Debt Maturities, without single maturity date	10,691
Available for Sale Securities Fair Value
Debt Maturities, without Single Maturity Date	10,589
Held to Maturity Securities Amortized Cost
Debt Maturities, without Single Maturity Date	693
Held to Maturity Securities Fair Value
Debt Maturities, without Single Maturity Date	$ 739

[1] (1) See Note 5 for details of balances associated with variable interest entities.

[2] Excludes notes with amortized cost of $2,400 million (fair value, $2,461 million) which have been offset with the associated payables under a netting agreement.