Guaranteed Benefit Features (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Net Amount at Risk by Product and Guarantee [Line Items]
Average attained age of contract holders	72		72
Summary of guaranteed death benefit liabilities
Balance as of beginning-of-year	$ 84	$ 44	$ 44
Changes in reserves	(17)	4
Benefits paid	(12)	(10)
Balance as of end-of-period	55	38	84
Asset type
Total	74,666		71,008
Percent of total variable annuity separate account values	94.00%		98.00%
Percent of permanent life insurance in force	38.00%
Percent of permanent life insurance sales	33.00%
Domestic Equity [Member]
Asset type
Total	36,577		34,286
International Equity [Member]
Asset type
Total	14,045		13,095
Bonds [Member]
Asset type
Total	18,000		17,735
Money Market [Member]
Asset type
Total	6,044		5,892
Return of Net Deposits [Member]
Net Amount at Risk by Product and Guarantee [Line Items]
Total Account Value	58,847		54,004
Net amount at risk	528		1,379
Average attained age of contract holders	59		59
Minimum Return [Member]
Net Amount at Risk by Product and Guarantee [Line Items]
Total Account Value	159		155
Net amount at risk	41		48
Guaranteed minimum return	5.00%		5.00%
Anniversary Contract Value [Member]
Net Amount at Risk by Product and Guarantee [Line Items]
Total Account Value	23,223		21,648
Net amount at risk	$ 1,471		$ 2,939
Average attained age of contract holders	67		67