Fair Value Measurements (Details) (Fair Value, Measurements, Recurring [Member], USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Assets:
Total AFS securities	$ 21,552	$ 19,328
Trading fixed maturities	441	393
Assets of managed investment entities (MIE)	2,439	2,537
Total assets accounted for at fair value	25,924	23,662
Liabilities:
Liabilities of managed investment entities	2,229	2,323
Derivatives in annuity benefits accumulated	332	190
Total liabilities accounted for at fair value	2,561	2,513
Variable Annuity Assets (separate accounts) [Member]
Assets:
Variable annuity assets	515	616
Variable Annuity Assets (separate accounts) [Member] | Level 1 [Member]
Assets:
Variable annuity assets	0	0
Variable Annuity Assets (separate accounts) [Member] | Level 2 [Member]
Assets:
Variable annuity assets	515	616
Variable Annuity Assets (separate accounts) [Member] | Level 3 [Member]
Assets:
Variable annuity assets	0	0
Other Investments [Member]
Assets:
Other Investments	47	98
Other Investments [Member] | Level 1 [Member]
Assets:
Other Investments	0	0
Other Investments [Member] | Level 2 [Member]
Assets:
Other Investments	47	98
Other Investments [Member] | Level 3 [Member]
Assets:
Other Investments	0	0
U.S. Government and government agencies [Member]
Assets:
Total AFS securities	422	467
U.S. Government and government agencies [Member] | Level 1 [Member]
Assets:
Total AFS securities	234	249
U.S. Government and government agencies [Member] | Level 2 [Member]
Assets:
Total AFS securities	188	218
U.S. Government and government agencies [Member] | Level 3 [Member]
Assets:
Total AFS securities	0	0
States, municipalities and political subdivisions [Member]
Assets:
Total AFS securities	3,769	2,939
States, municipalities and political subdivisions [Member] | Level 1 [Member]
Assets:
Total AFS securities	0	0
States, municipalities and political subdivisions [Member] | Level 2 [Member]
Assets:
Total AFS securities	3,697	2,919
States, municipalities and political subdivisions [Member] | Level 3 [Member]
Assets:
Total AFS securities	72	20
Foreign government [Member]
Assets:
Total AFS securities	267	278
Foreign government [Member] | Level 1 [Member]
Assets:
Total AFS securities	0	0
Foreign government [Member] | Level 2 [Member]
Assets:
Total AFS securities	267	278
Foreign government [Member] | Level 3 [Member]
Assets:
Total AFS securities	0	0
Residential Mortgage Backed Securities [Member]
Assets:
Total AFS securities	3,824	3,875
Residential Mortgage Backed Securities [Member] | Level 1 [Member]
Assets:
Total AFS securities	0	0
Residential Mortgage Backed Securities [Member] | Level 2 [Member]
Assets:
Total AFS securities	3,540	3,563
Residential Mortgage Backed Securities [Member] | Level 3 [Member]
Assets:
Total AFS securities	284	312
Commercial Mortgage Backed Securities [Member]
Assets:
Total AFS securities	2,802	2,123
Commercial Mortgage Backed Securities [Member] | Level 1 [Member]
Assets:
Total AFS securities	0	0
Commercial Mortgage Backed Securities [Member] | Level 2 [Member]
Assets:
Total AFS securities	2,774	2,117
Commercial Mortgage Backed Securities [Member] | Level 3 [Member]
Assets:
Total AFS securities	28	6
All other corporate [Member]
Assets:
Total AFS securities	10,468	9,646
All other corporate [Member] | Level 1 [Member]
Assets:
Total AFS securities	9	9
All other corporate [Member] | Level 2 [Member]
Assets:
Total AFS securities	10,023	9,201
All other corporate [Member] | Level 3 [Member]
Assets:
Total AFS securities	436	436
Equity Securities [Member]
Assets:
Total AFS securities	930	690
Equity Securities [Member] | Level 1 [Member]
Assets:
Total AFS securities	777	461
Equity Securities [Member] | Level 2 [Member]
Assets:
Total AFS securities	129	208
Equity Securities [Member] | Level 3 [Member]
Assets:
Total AFS securities	24	21
Level 1 [Member]
Assets:
Total AFS securities	243	258
Trading fixed maturities	0	0
Assets of managed investment entities (MIE)	132	96
Total assets accounted for at fair value	1,152	815
Liabilities:
Liabilities of managed investment entities	47	65
Derivatives in annuity benefits accumulated	0	0
Total liabilities accounted for at fair value	47	65
Level 2 [Member]
Assets:
Total AFS securities	20,489	18,296
Trading fixed maturities	440	390
Assets of managed investment entities (MIE)	2,267	2,393
Total assets accounted for at fair value	23,887	22,001
Liabilities:
Liabilities of managed investment entities	0	0
Derivatives in annuity benefits accumulated	0	0
Total liabilities accounted for at fair value	0	0
Level 3 [Member]
Assets:
Total AFS securities	820	774
Trading fixed maturities	1	3
Assets of managed investment entities (MIE)	40	48
Total assets accounted for at fair value	885	846
Liabilities:
Liabilities of managed investment entities	2,182	2,258
Derivatives in annuity benefits accumulated	332	190
Total liabilities accounted for at fair value	$ 2,514	$ 2,448