Fair Value Measurements (Details - Separate Account Assets) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011
Financial assets and financial liabilities carried at fair value [Line Items]
Guaranteed separate accounts	$ 569		$ 1,688
Non-guaranteed separate accounts	7,188	[1]	6,405	[2]
Total separate account assets	7,757		8,093
Separate Accounts [Member]
Changes in Level 3 Financial Assets and Financial Liabilities Caried at Fair Value [Line Items]
Balance at January 1,	750		594
Policyholder gains (losses)	55	[3]	114	[4]
Purchases, issuances, settlements:
Purchases	283		257
Sales	(6)		(51)
Settlements	(90)		(152)
Total purchases, sales, settlements	187		54
Transfers into/(out of) Level 3:
Transfers into Level 3	17		4
Transfers out of Level 3	(4)		(16)
Total transfers into/(out of) Level 3	13		(12)
Balance at December 31,	1,005		750
Policyholder Gains Losses Attributable To Instruments Still Held	49		96
Pension Benefits [Member]
Financial assets and financial liabilities carried at fair value [Line Items]
Non-guaranteed separate accounts	3,400		3,000
Fair Value Inputs Level 1 [Member]
Financial assets and financial liabilities carried at fair value [Line Items]
Guaranteed separate accounts	245		249
Non-guaranteed separate accounts	1,925	[1]	1,804	[2]
Total separate account assets	2,170		2,053
Fair Value Inputs Level 2 [Member]
Financial assets and financial liabilities carried at fair value [Line Items]
Guaranteed separate accounts	324		1,439
Non-guaranteed separate accounts	4,258	[1]	3,851	[2]
Total separate account assets	4,582		5,290
Fair Value Inputs Level 3 [Member]
Financial assets and financial liabilities carried at fair value [Line Items]
Guaranteed separate accounts	0		0
Non-guaranteed separate accounts	1,005	[1]	750	[2]
Total separate account assets	1,005		750
Fair Value Inputs Level 3 [Member] | Pension Benefits [Member]
Financial assets and financial liabilities carried at fair value [Line Items]
Non-guaranteed separate accounts	$ 956		$ 702

[1] As of December 31, 2012, non-guaranteed separate accounts included $3.4 billion in assets supporting the Company's pension plans, including $956 million classified in Level 3.

[2] As of December 31, 2011, non-guaranteed separate accounts included $3.0 billion in assets supporting the Company's pension plans, including $702 million classified in Level 3.

[3] Included in this amount are gains of $49 million attributable to instruments still held at the reporting date.

[4] Included in this amount are gains of $96 million attributable to instruments still held at the reporting date.