Fair Value Measurements (Details) (Fair Value, Measurements, Recurring [Member], USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Assets:
Total AFS securities	$ 20,500	$ 19,328
Trading fixed maturities	395	393
Assets of managed investment entities (MIE)	2,591	2,537
Total assets accounted for at fair value	25,002	23,662
Liabilities:
Liabilities of managed investment entities	2,430	2,323
Derivatives in annuity benefits accumulated	299	190
Total liabilities accounted for at fair value	2,729	2,513
Variable Annuity Assets (separate accounts) [Member]
Assets:
Variable annuity assets	624	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	624	616
Variable Annuity Assets (separate accounts) [Member] | Level 3 [Member]
Assets:
Variable annuity assets	0	0
Other Investments [Member]
Assets:
Other Investments	113	98
Other Investments [Member] | Level 1 [Member]
Assets:
Other Investments	0	0
Other Investments [Member] | Level 2 [Member]
Assets:
Other Investments	113	98
Other Investments [Member] | Level 3 [Member]
Assets:
Other Investments	0	0
U.S. Government and government agencies [Member]
Assets:
Total AFS securities	405	467
U.S. Government and government agencies [Member] | Level 1 [Member]
Assets:
Total AFS securities	242	249
U.S. Government and government agencies [Member] | Level 2 [Member]
Assets:
Total AFS securities	163	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	3,475	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	3,391	2,919
States, municipalities and political subdivisions [Member] | Level 3 [Member]
Assets:
Total AFS securities	84	20
Foreign government [Member]
Assets:
Total AFS securities	271	278
Foreign government [Member] | Level 1 [Member]
Assets:
Total AFS securities	0	0
Foreign government [Member] | Level 2 [Member]
Assets:
Total AFS securities	271	278
Foreign government [Member] | Level 3 [Member]
Assets:
Total AFS securities	0	0
Residential Mortgage Backed Securities [Member]
Assets:
Total AFS securities	3,842	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	3,587	3,563
Residential Mortgage Backed Securities [Member] | Level 3 [Member]
Assets:
Total AFS securities	255	312
Commercial Mortgage Backed Securities [Member]
Assets:
Total AFS securities	2,371	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	2,361	2,117
Commercial Mortgage Backed Securities [Member] | Level 3 [Member]
Assets:
Total AFS securities	10	6
All other corporate [Member]
Assets:
Total AFS securities	10,136	9,646
All other corporate [Member] | Level 1 [Member]
Assets:
Total AFS securities	10	9
All other corporate [Member] | Level 2 [Member]
Assets:
Total AFS securities	9,744	9,201
All other corporate [Member] | Level 3 [Member]
Assets:
Total AFS securities	382	436
Equity Securities [Member]
Assets:
Total AFS securities	779	690
Equity Securities [Member] | Level 1 [Member]
Assets:
Total AFS securities	629	461
Equity Securities [Member] | Level 2 [Member]
Assets:
Total AFS securities	129	208
Equity Securities [Member] | Level 3 [Member]
Assets:
Total AFS securities	21	21
Level 1 [Member]
Assets:
Total AFS securities	252	258
Trading fixed maturities	0	0
Assets of managed investment entities (MIE)	125	96
Total assets accounted for at fair value	1,006	815
Liabilities:
Liabilities of managed investment entities	108	65
Derivatives in annuity benefits accumulated	0	0
Total liabilities accounted for at fair value	108	65
Level 2 [Member]
Assets:
Total AFS securities	19,517	18,296
Trading fixed maturities	394	390
Assets of managed investment entities (MIE)	2,413	2,393
Total assets accounted for at fair value	23,190	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	731	774
Trading fixed maturities	1	3
Assets of managed investment entities (MIE)	53	48
Total assets accounted for at fair value	806	846
Liabilities:
Liabilities of managed investment entities	2,322	2,258
Derivatives in annuity benefits accumulated	299	190
Total liabilities accounted for at fair value	$ 2,621	$ 2,448