Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Notes to Financial Statements [Abstract]
Federal income tax rate									35.00%
Reconciliation of Revenue from Segments to Consolidated [Abstract]
Total revenues	$ 2,570	$ 2,548	$ 2,804	$ 2,714	$ 2,662	$ 2,613	$ 2,605	$ 2,527	$ 10,636	$ 10,407	$ 8,499
Reconciliation of Net Income (Loss) from Segments to Consolidated [Abstract]
Income (loss) from continuing operations	(513)	151	325	339	196	248	252	255	302	951	(415)
Income (loss) from discontinued operations, after-tax	0	(8)	0	0	0	(2)	3	28	(8)	29	(70)
Net income (loss)	(513)	143	325	339	196	246	255	283	294	980	(485)
Net Investment Income [Abstract]
Total net investment income									4,652	4,541	4,178
Amortization of DAC and VOBA, Net of Interest
Total amortization of DAC and VOBA, net of interest									1,050	1,084	1,053
Reconciliation of Federal Income Tax Expense (Benefit) from Segments to Consolidated [Abstract]
Total federal income tax expense (benefit)									297	283	(106)
Assets
Total assets	202,906				193,824				202,906	193,824
Excluded Realized Gain Loss Tax Reconciling Item [Member]
Reconciliation of Federal Income Tax Expense (Benefit) from Segments to Consolidated [Abstract]
Total federal income tax expense (benefit)									(136)	(51)	(420)
Gain Loss On Early Extinguishment Of Debt Tax Reconciling Item [Member]
Reconciliation of Federal Income Tax Expense (Benefit) from Segments to Consolidated [Abstract]
Total federal income tax expense (benefit)									(3)	(2)	23
Amortization Of Deferred Gain Loss On Reinsurance Related To Reserve Changes Tax Reconciling Item [Member]
Reconciliation of Federal Income Tax Expense (Benefit) from Segments to Consolidated [Abstract]
Total federal income tax expense (benefit)									1	1	1
Impairment Of Intangibles Tax Reconciling Item [Member]
Reconciliation of Federal Income Tax Expense (Benefit) from Segments to Consolidated [Abstract]
Total federal income tax expense (benefit)									0	0	(16)
Benefit Ratio Unlocking Tax Reconciling Item [Member]
Reconciliation of Federal Income Tax Expense (Benefit) from Segments to Consolidated [Abstract]
Total federal income tax expense (benefit)									(7)	6	46
Excluded Realized Gain (Loss), After Tax, Reconciling Item [Member]
Reconciliation of Net Income (Loss) from Segments to Consolidated [Abstract]
Net income (loss)									(252)	(95)	(780)
Gain (loss) on early extinguishment of debt, After Tax, Reconcilling Item [Member]
Reconciliation of Net Income (Loss) from Segments to Consolidated [Abstract]
Net income (loss)									(5)	(3)	42
Income (loss) from reserve changes (net of related amortization) on business sold through reinsurance, After Tax, Reconciling Item [Member]
Reconciliation of Net Income (Loss) from Segments to Consolidated [Abstract]
Net income (loss)									2	2	2
Impairment of intangibles, After Tax, Reconciling Item [Member]
Reconciliation of Net Income (Loss) from Segments to Consolidated [Abstract]
Net income (loss)									(747)	0	(710)
Benefit ratio unlocking, After Tax, Reconciling Item [Member]
Reconciliation of Net Income (Loss) from Segments to Consolidated [Abstract]
Net income (loss)									(14)	10	89
Excluded Realized Gain (Loss), Pre Tax, Reconciling Item [Member]
Reconciliation of Revenue from Segments to Consolidated [Abstract]
Total revenues									(388)	(146)	(1,200)
Amortization of Deferred Gains From Reserve Changes On Business Sold Through Reinsurance, Pre Tax, Reconciling Item [Member]
Reconciliation of Revenue from Segments to Consolidated [Abstract]
Total revenues									3	3	3
Amortization Income of DFEL Associated With Benefit Ratio Unlocking, Pre Tax, Reconciling Item [Member]
Reconciliation of Revenue from Segments to Consolidated [Abstract]
Total revenues									0	0	(4)
Annuities Segment [Member]
Reconciliation of Revenue from Segments to Consolidated [Abstract]
Total revenues									2,865	2,654	2,301
Reconciliation of Net Income (Loss) from Segments to Consolidated [Abstract]
Net income (loss)									592	484	353
Net Investment Income [Abstract]
Total net investment income									1,106	1,119	1,037
Amortization of DAC and VOBA, Net of Interest
Total amortization of DAC and VOBA, net of interest									405	421	360
Reconciliation of Federal Income Tax Expense (Benefit) from Segments to Consolidated [Abstract]
Total federal income tax expense (benefit)									114	102	41
Assets
Total assets	97,272				91,435				97,272	91,435
Retirement Plan Services Segment [Member]
Reconciliation of Revenue from Segments to Consolidated [Abstract]
Total revenues									1,017	988	926
Reconciliation of Net Income (Loss) from Segments to Consolidated [Abstract]
Net income (loss)									167	154	133
Net Investment Income [Abstract]
Total net investment income									793	769	732
Amortization of DAC and VOBA, Net of Interest
Total amortization of DAC and VOBA, net of interest									60	79	75
Reconciliation of Federal Income Tax Expense (Benefit) from Segments to Consolidated [Abstract]
Total federal income tax expense (benefit)									67	60	50
Assets
Total assets	28,774				28,562				28,774	28,562
Life Insurance Segment [Member]
Reconciliation of Revenue from Segments to Consolidated [Abstract]
Total revenues									4,739	4,590	4,295
Reconciliation of Net Income (Loss) from Segments to Consolidated [Abstract]
Net income (loss)									604	513	569
Net Investment Income [Abstract]
Total net investment income									2,294	2,186	1,975
Amortization of DAC and VOBA, Net of Interest
Total amortization of DAC and VOBA, net of interest									539	538	571
Reconciliation of Federal Income Tax Expense (Benefit) from Segments to Consolidated [Abstract]
Total federal income tax expense (benefit)									283	236	245
Assets
Total assets	60,544				56,713				60,544	56,713
Group Protection Segment [Member]
Reconciliation of Revenue from Segments to Consolidated [Abstract]
Total revenues									1,939	1,831	1,713
Reconciliation of Net Income (Loss) from Segments to Consolidated [Abstract]
Net income (loss)									101	72	124
Net Investment Income [Abstract]
Total net investment income									152	141	127
Amortization of DAC and VOBA, Net of Interest
Total amortization of DAC and VOBA, net of interest									46	46	47
Reconciliation of Federal Income Tax Expense (Benefit) from Segments to Consolidated [Abstract]
Total federal income tax expense (benefit)									54	38	67
Assets
Total assets	3,458				3,254				3,458	3,254
Other Operations [Member]
Reconciliation of Revenue from Segments to Consolidated [Abstract]
Total revenues									461	487	465
Reconciliation of Net Income (Loss) from Segments to Consolidated [Abstract]
Net income (loss)									(146)	(186)	(237)
Net Investment Income [Abstract]
Total net investment income									307	326	307
Reconciliation of Federal Income Tax Expense (Benefit) from Segments to Consolidated [Abstract]
Total federal income tax expense (benefit)									(76)	(107)	(143)
Assets
Total assets	$ 12,858				$ 13,860				$ 12,858	$ 13,860