Fair Value Measurements (Details) (Fair Value, Measurements, Recurring [Member], USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Assets:
Total AFS securities	$ 22,371	$ 21,807
Trading fixed maturities	457	440
Assets of managed investment entities (MIE)	2,952	3,058
Total assets accounted for at fair value	27,577	26,852
Liabilities:
Liabilities of managed investment entities	2,672	2,787
Derivatives in annuity benefits accumulated	483	395
Other liabilities - derivatives	22	23
Total liabilities accounted for at fair value	3,177	3,205
Level 1 [Member]
Assets:
Total AFS securities	243	257
Assets of managed investment entities (MIE)	245	290
Total assets accounted for at fair value	1,443	1,435
Liabilities:
Liabilities of managed investment entities	118	194
Other liabilities - derivatives
Total liabilities accounted for at fair value	118	194
Level 2 [Member]
Assets:
Total AFS securities	21,207	20,568
Trading fixed maturities	456	439
Assets of managed investment entities (MIE)	2,643	2,724
Total assets accounted for at fair value	25,124	24,379
Liabilities:
Other liabilities - derivatives	22	23
Total liabilities accounted for at fair value	22	23
Level 3 [Member]
Assets:
Total AFS securities	921	982
Trading fixed maturities	1	1
Assets of managed investment entities (MIE)	64	44
Total assets accounted for at fair value	1,010	1,038
Liabilities:
Liabilities of managed investment entities	2,554	2,593
Derivatives in annuity benefits accumulated	483	395
Other liabilities - derivatives
Total liabilities accounted for at fair value	3,037	2,988
Variable Annuity Assets (separate accounts) [Member]
Assets:
Variable annuity assets	601	548
Variable Annuity Assets (separate accounts) [Member] | Level 2 [Member]
Assets:
Variable annuity assets	601	548
Other Investments [Member]
Assets:
Other Investments	142	71
Other Investments [Member] | Level 2 [Member]
Assets:
Other Investments	142	71
U.S. Government and government agencies [Member]
Assets:
Total AFS securities	390	382
U.S. Government and government agencies [Member] | Level 1 [Member]
Assets:
Total AFS securities	235	248
U.S. Government and government agencies [Member] | Level 2 [Member]
Assets:
Total AFS securities	155	134
States, municipalities and political subdivisions [Member]
Assets:
Total AFS securities	3,916	3,877
States, municipalities and political subdivisions [Member] | Level 2 [Member]
Assets:
Total AFS securities	3,844	3,794
States, municipalities and political subdivisions [Member] | Level 3 [Member]
Assets:
Total AFS securities	72	83
Foreign government [Member]
Assets:
Total AFS securities	260	254
Foreign government [Member] | Level 2 [Member]
Assets:
Total AFS securities	260	254
Residential Mortgage Backed Securities [Member]
Assets:
Total AFS securities	4,118	3,848
Residential Mortgage Backed Securities [Member] | Level 2 [Member]
Assets:
Total AFS securities	3,804	3,487
Residential Mortgage Backed Securities [Member] | Level 3 [Member]
Assets:
Total AFS securities	314	361
Commercial Mortgage Backed Securities [Member]
Assets:
Total AFS securities	2,900	2,840
Commercial Mortgage Backed Securities [Member] | Level 2 [Member]
Assets:
Total AFS securities	2,880	2,821
Commercial Mortgage Backed Securities [Member] | Level 3 [Member]
Assets:
Total AFS securities	20	19
All other corporate [Member]
Assets:
Total AFS securities	10,787	10,606
All other corporate [Member] | Level 1 [Member]
Assets:
Total AFS securities	8	9
All other corporate [Member] | Level 2 [Member]
Assets:
Total AFS securities	10,264	10,078
All other corporate [Member] | Level 3 [Member]
Assets:
Total AFS securities	515	519
Equity Securities [Member]
Assets:
Total AFS securities	1,054	928
Equity Securities [Member] | Level 1 [Member]
Assets:
Total AFS securities	955	888
Equity Securities [Member] | Level 2 [Member]
Assets:
Total AFS securities	75	29
Equity Securities [Member] | Level 3 [Member]
Assets:
Total AFS securities	$ 24	$ 11