Investments (Net Investment Income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net Investment Income [Line Items]
Gross Investment Income, Operating	$ 645	$ 633	$ 2,028	$ 2,030
Investment Income, Investment Expense	30	27	86	75
Net investment income	678	675	2,132	2,223
Securities Investment [Member]
Net Investment Income [Line Items]
Gross Investment Income, Operating	675	660	2,114	2,105
Debt Securities [Member]
Net Investment Income [Line Items]
Gross Investment Income, Operating	523	531	1,589	1,595
Equity Securities [Member]
Net Investment Income [Line Items]
Gross Investment Income, Operating	3	(1)	8	6
FVO general account securities [Member]
Net Investment Income [Line Items]
Gross Investment Income, Operating	0	2	1	2
Trading Securities, Change in Unrealized Holding Gain (Loss)	1	0	0	0
Mortgage Loans on Real Estate [Member]
Net Investment Income [Line Items]
Gross Investment Income, Operating	82	85	247	262
Policy Loans [Member]
Net Investment Income [Line Items]
Gross Investment Income, Operating	14	14	42	44
Real Estate Investment [Member]
Net Investment Income [Line Items]
Gross Investment Income, Operating	10	9	36	77
Partnership Interest [Member]
Net Investment Income [Line Items]
Gross Investment Income, Operating	41	18	195	115
Cash and Cash Equivalents [Member]
Net Investment Income [Line Items]
Gross Investment Income, Operating	0	1	3	3
International Joint Venture [Member]
Net Investment Income [Line Items]
Gross Investment Income, Operating	6	0	(4)	(3)
Other Investments [Member]
Net Investment Income [Line Items]
Gross Investment Income, Operating	(4)	1	(3)	4
Consolidated Securitization Entities And Fair Value Option Contractholder-Directed Unit-Linked [Member]
Net Investment Income [Line Items]
Gross Investment Income, Operating	33	42	104	193
Fair Value Option Contractholder Directed Unit Linked Investments [Member]
Net Investment Income [Line Items]
Gross Investment Income, Operating	0	0	0	62
Commercial Loan [Member] | Variable Interest Entity, Primary Beneficiary, Consolidated Securitization Entities [Member]
Net Investment Income [Line Items]
Gross Investment Income, Operating	$ 33	$ 42	$ 104	$ 131