Fair Value Measurements (Details - Assets by level) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Fixed maturities:
Total fixed maturities	$ 17,327	$ 16,217
Equity securities	102	100
Short-term investments	215	225
Separate account assets
Total separate account assets	8,354	8,093
Level 3 Financial Assets Carried At Fair Value [Abstract]
Corporate bonds valued at transaction price	66	72
Equity securities valued at transaction price	33	30
Other asset and mortgage-backed securities
Level 3 Fair Value And Significant Unobservable Inputs Deveopled Directly By Company [Line Items]
Fair Value	575
Liquidity Adjustment to Discount Rates Low	60
Liquidity Adjustment to Discount Rates High	430
Liquidity Adjustment to Discount Rates Weighted Average	90
Weighting of Credit Spreads Adjustment to Discount Rates Low	80
Weighting of Credit Spreads Adjustment to Discount Rates High	4,900
Weighting of Credit Spreads Adjustment to Discount Rate Weighted Average	510
Corporate and government bonds
Level 3 Fair Value And Significant Unobservable Inputs Deveopled Directly By Company [Line Items]
Fair Value	309
Liquidity Adjustment to Discount Rates Low	10
Liquidity Adjustment to Discount Rates High	500
Liquidity Adjustment to Discount Rates Weighted Average	240
Fair Value, Inputs, Level 1 [Member]
Fixed maturities:
Federal government and agency	146	217
State and local government	0	0
Foreign government	0	0
Corporate	0	0
Federal agency mortgage-backed	0	0
Other mortgage-backed	0	0
Other asset-backed	0	0
Total fixed maturities	146	217
Equity securities	4	3
Subtotal	150	220
Short-term investments	0	0
GMIB assets	0	0
Other derivative assets	0	0
Total financial assets at fair value, excluding separate accounts	150	220
Financial liabilities at fair value:
GMIB liabilities	0	0
Other derivative liabilities	0	0
Total financial liabilities at fair value	0	0
Separate account assets
Guaranteed separate accounts	245	249
Non-guaranteed separate accounts	1,829	1,804
Total separate account assets	2,074	2,053
Fair Value, Inputs, Level 2 [Member]
Fixed maturities:
Federal government and agency	763	738
State and local government	2,503	2,456
Foreign government	1,299	1,251
Corporate	10,915	10,132
Federal agency mortgage-backed	152	9
Other mortgage-backed	92	79
Other asset-backed	362	363
Total fixed maturities	16,086	15,028
Equity securities	65	67
Subtotal	16,151	15,095
Short-term investments	215	225
GMIB assets	0	0
Other derivative assets	47	45
Total financial assets at fair value, excluding separate accounts	16,413	15,365
Financial liabilities at fair value:
GMIB liabilities	0	0
Other derivative liabilities	28	30
Total financial liabilities at fair value	28	30
Separate account assets
Guaranteed separate accounts	1,422	1,439
Non-guaranteed separate accounts	3,906	3,851
Total separate account assets	5,328	5,290
Fair Value, Inputs, Level 3 [Member]
Fixed maturities:
Federal government and agency	1	3
State and local government	0	0
Foreign government	23	23
Corporate	493	381
Federal agency mortgage-backed	0	0
Other mortgage-backed	1	1
Other asset-backed	577	564
Total fixed maturities	1,095	972
Equity securities	33	30
Subtotal	1,128	1,002
Short-term investments	0	0
GMIB assets	707	712
Other derivative assets	0	0
Total financial assets at fair value, excluding separate accounts	1,835	1,714
Financial liabilities at fair value:
GMIB liabilities	1,332	1,333
Other derivative liabilities	0	0
Total financial liabilities at fair value	1,332	1,333
Separate account assets
Guaranteed separate accounts	0	0
Non-guaranteed separate accounts	952	750
Total separate account assets	952	750
Level 3 Financial Assets Carried At Fair Value [Abstract]
Other asset and mortgage-backed securities valued using pricing models	578	565
Corporate and government bonds valued using pricing models	$ 451	$ 335