Investments (Details - Impaired commercial loans) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Impaired Commercial Mortgage Loans And Valuation Reserves [Line Items]
Impaired Financing Receivable, Recorded Investment	$ 125	$ 195
Commercial Mortgage Loans Financing Receivable With Related Allowance [Member]
Impaired Commercial Mortgage Loans And Valuation Reserves [Line Items]
Impaired Financing Receivable, Recorded Investment	65	135
Commercial Mortgage Loans Financing Receivable With No Related Allowance [Member]
Impaired Commercial Mortgage Loans And Valuation Reserves [Line Items]
Impaired Financing Receivable, Recorded Investment	60	60
Impaired Commercial Mortgage Loans Gross [Member]
Impaired Commercial Mortgage Loans And Valuation Reserves [Line Items]
Impaired Financing Receivable, Recorded Investment	132	214
Impaired Commercial Mortgage Loans Gross [Member] | Commercial Mortgage Loans Financing Receivable With Related Allowance [Member]
Impaired Commercial Mortgage Loans And Valuation Reserves [Line Items]
Impaired Financing Receivable, Recorded Investment	72	154
Impaired Commercial Mortgage Loans Gross [Member] | Commercial Mortgage Loans Financing Receivable With No Related Allowance [Member]
Impaired Commercial Mortgage Loans And Valuation Reserves [Line Items]
Impaired Financing Receivable, Recorded Investment	60	60
Impaired Commercial Mortgage Loans Reserves [Member]
Impaired Commercial Mortgage Loans And Valuation Reserves [Line Items]
Impaired Financing Receivable, Recorded Investment	(7)	(19)
Impaired Commercial Mortgage Loans Reserves [Member] | Commercial Mortgage Loans Financing Receivable With Related Allowance [Member]
Impaired Commercial Mortgage Loans And Valuation Reserves [Line Items]
Impaired Financing Receivable, Recorded Investment	(7)	(19)
Impaired Commercial Mortgage Loans Reserves [Member] | Commercial Mortgage Loans Financing Receivable With No Related Allowance [Member]
Impaired Commercial Mortgage Loans And Valuation Reserves [Line Items]
Impaired Financing Receivable, Recorded Investment	$ 0	$ 0