Investments and Derivative Instruments (Maximum Exposure to VIEs) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Variable Interest Entities Primary Beneficiary
Total Liabilities	$ 111	[1]	$ 477	[1]
Variable Interest Entity Assets Included in Limited Partnerships and Other Alternative Investments	6		7
Consolidated VIEs [Member]
Variable Interest Entities Primary Beneficiary
Total Assets	227		498
Maximum Exposure to Loss	120	[2]	29	[2]
Collateralized Debt Obligations [Member] | Consolidated VIEs [Member]
Variable Interest Entities Primary Beneficiary
Total Assets	89	[3]	491	[3]
Total Liabilities	88	[1],[3]	474	[1],[3]
Maximum Exposure to Loss	7	[2],[3]	25	[2],[3]
Investment Fund [Member] | Consolidated VIEs [Member]
Variable Interest Entities Primary Beneficiary
Total Assets	132	[4]	0	[4]
Total Liabilities	20	[1],[4]	0	[1],[4]
Maximum Exposure to Loss	110	[2],[4]	0	[2],[4]
Limited partnerships [Member] | Consolidated VIEs [Member]
Variable Interest Entities Primary Beneficiary
Total Liabilities	3	[1]	3	[1]
Maximum Exposure to Loss	$ 3	[2]	$ 4	[2]

[1] Included in other liabilities in the Company’s Consolidated Balance Sheets.

[2] The maximum exposure to loss represents the maximum loss amount that the Company could recognize as a reduction in net investment income or as a realized capital loss and is the cost basis of the Company’s investment.

[3] Total assets included in fixed maturities, AFS in the Company’s Consolidated Balance Sheets.

[4] Total assets included in fixed maturities, FVO in the Company's Consolidated Balances Sheets.