Guaranteed Benefit Features (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Summary of guaranteed death benefit liabilities
Balance as of beginning-of-year	$ 44	$ 71	$ 277
Changes in reserves	93	57	(33)
Benefits paid	(53)	(84)	(173)
Balance as of end-of-year	84	44	71
Asset type
Total	71,008	71,469
Percent of total variable annuity separate account values	98.00%	98.00%
Percent of permanent life insurance in force	38.00%
Percent of permanent life insurance sales	43.00%
Domestic equity
Asset type
Total	34,286	35,659
International equity
Asset type
Total	13,095	14,172
Bonds
Asset type
Total	17,735	15,913
Money Market
Asset type
Total	5,892	5,725
Return of Net Deposits [Member]
Net Amount at Risk by Product and Guarantee [Line Items]
Total Account Value	54,004	52,211
Net amount at risk	1,379	816
Average attained age of contract holders	59	58
Minimum Return [Member]
Net Amount at Risk by Product and Guarantee [Line Items]
Total Account Value	155	187
Net amount at risk	48	46
Average attained age of contract holders	72	70
Guaranteed minimum return	5.00%	5.00%
Anniversary Contract Value [Member]
Net Amount at Risk by Product and Guarantee [Line Items]
Total Account Value	21,648	23,483
Net amount at risk	$ 2,939	$ 2,183
Average attained age of contract holders	67	66