Reserve for Life-Contingent Contract Benefits and Contractholder Funds (Details 5) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Liabilities for guarantees:
Balance at beginning of period	$ 644	$ 599
Less reinsurance recoverables	453	438
Net balance at beginning of period	191	161
Incurred guaranteed benefits	26	30
Paid guarantee benefits	(2)
Net change	24	30
Net balance at end of period	215	191
Plus reinsurance recoverables	458	453
Balance at end of period	673	644
Liability for guarantees related to death benefits and interest-sensitive life products
Liabilities for guarantees:
Balance at beginning of period	289	236
Less reinsurance recoverables	116	93
Net balance at beginning of period	173	143
Incurred guaranteed benefits	25	30
Paid guarantee benefits	(2)
Net change	23	30
Net balance at end of period	196	173
Plus reinsurance recoverables	113	116
Balance at end of period	309	289
Liability for guarantees related to income benefits
Liabilities for guarantees:
Balance at beginning of period	191	227
Less reinsurance recoverables	175	210
Net balance at beginning of period	16	17
Incurred guaranteed benefits	(1)	(1)
Net change	(1)	(1)
Net balance at end of period	15	16
Plus reinsurance recoverables	220	175
Balance at end of period	235	191
Liability for guarantees related to accumulation and withdrawal benefits
Liabilities for guarantees:
Balance at beginning of period	164	136
Less reinsurance recoverables	162	135
Net balance at beginning of period	2	1
Incurred guaranteed benefits	2	1
Net change	2	1
Net balance at end of period	4	2
Plus reinsurance recoverables	125	162
Balance at end of period	$ 129	$ 164