Fair Value Measurements (Details - Assets by level) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Fixed maturities:
Total fixed maturities	$ 17,049	$ 16,217
Equity securities	107	100
Short-term investments	187	225
Separate account assets
Total separate account assets	8,481	8,093
Level 3 Financial Assets Carried At Fair Value [Abstract]
Corporate bonds valued at transaction price	77	72
Equity securities valued at transaction price	31	30
Other asset and mortgage-backed securities
Level 3 Fair Value And Significant Unobservable Inputs Deveopled Directly By Company [Line Items]
Fair Value	577
Liquidity Adjustment to Discount Rates Low	60
Liquidity Adjustment to Discount Rates High	680
Liquidity Adjustment to Discount Rates Weighted Average	80
Weighting of Credit Spreads Adjustment to Discount Rates Low	60
Weighting of Credit Spreads Adjustment to Discount Rates High	5,200
Weighting of Credit Spreads Adjustment to Discount Rate Weighted Average	465
Corporate and government bonds
Level 3 Fair Value And Significant Unobservable Inputs Deveopled Directly By Company [Line Items]
Fair Value	242
Liquidity Adjustment to Discount Rates Low	10
Liquidity Adjustment to Discount Rates High	475
Liquidity Adjustment to Discount Rates Weighted Average	235
Fair Value, Inputs, Level 1 [Member]
Fixed maturities:
Federal government and agency	141	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	141	217
Equity securities	4	3
Subtotal	145	220
Short-term investments	0	0
GMIB assets	0	0
Other derivative assets	0	0
Total financial assets at fair value, excluding separate accounts	145	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	269	249
Non-guaranteed separate accounts	1,864	1,804
Total separate account assets	2,133	2,053
Fair Value, Inputs, Level 2 [Member]
Fixed maturities:
Federal government and agency	705	738
State and local government	2,524	2,456
Foreign government	1,254	1,251
Corporate	10,770	10,132
Federal agency mortgage-backed	158	9
Other mortgage-backed	88	79
Other asset-backed	368	363
Total fixed maturities	15,867	15,028
Equity securities	72	67
Subtotal	15,939	15,095
Short-term investments	187	225
GMIB assets	0	0
Other derivative assets	37	45
Total financial assets at fair value, excluding separate accounts	16,163	15,365
Financial liabilities at fair value:
GMIB liabilities	0	0
Other derivative liabilities	31	30
Total financial liabilities at fair value	31	30
Separate account assets
Guaranteed separate accounts	1,400	1,439
Non-guaranteed separate accounts	4,005	3,851
Total separate account assets	5,405	5,290
Fair Value, Inputs, Level 3 [Member]
Fixed maturities:
Federal government and agency	2	3
State and local government	0	0
Foreign government	21	23
Corporate	438	381
Federal agency mortgage-backed	0	0
Other mortgage-backed	1	1
Other asset-backed	579	564
Total fixed maturities	1,041	972
Equity securities	31	30
Subtotal	1,072	1,002
Short-term investments	0	0
GMIB assets	617	712
Other derivative assets	0	0
Total financial assets at fair value, excluding separate accounts	1,689	1,714
Financial liabilities at fair value:
GMIB liabilities	1,162	1,333
Other derivative liabilities	0	0
Total financial liabilities at fair value	1,162	1,333
Separate account assets
Guaranteed separate accounts	0	0
Non-guaranteed separate accounts	943	750
Total separate account assets	943	750
Level 3 Financial Assets Carried At Fair Value [Abstract]
Other asset and mortgage-backed securities valued using pricing models	580	565
Corporate and government bonds valued using pricing models	$ 384	$ 335