Investments and Derivative Instruments (Details 16) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Derivative Instruments Gain (Loss) [Line Items]
Document Period End Date	Mar. 31, 2013
Cash flow hedges [Member]
Derivative Instruments Gain (Loss) [Line Items]
Gain or (Loss) Reclassified from AOCI into Income (Effective Portion)	$ 94
Interest Rate Swap [Member] | Cash flow hedges [Member]
Derivative Instruments Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	(71)		(33)
Net Realized Capital Gains (Losses) Recognized in Income on Derivative (Ineffective Portion)
Interest Rate Swap [Member] | Net realized capital gains (losses) [Member] | Cash flow hedges [Member]
Derivative Instruments Gain (Loss) [Line Items]
Gain or (Loss) Reclassified from AOCI into Income (Effective Portion)	73	[1]	5
Interest Rate Swap [Member] | Net Investment Income [Member] | Cash flow hedges [Member]
Derivative Instruments Gain (Loss) [Line Items]
Gain or (Loss) Reclassified from AOCI into Income (Effective Portion)	24		36
Foreign Currency Swap [Member] | Cash flow hedges [Member]
Derivative Instruments Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	1		(5)
Net Realized Capital Gains (Losses) Recognized in Income on Derivative (Ineffective Portion)
Foreign Currency Swap [Member] | Net realized capital gains (losses) [Member] | Cash flow hedges [Member]
Derivative Instruments Gain (Loss) [Line Items]
Gain or (Loss) Reclassified from AOCI into Income (Effective Portion)	$ (3)		$ 3

[1] [2] Includes $71 of net gains on cash flow hedging instruments relating to the sales of the Retirement Plans and Individual Life businesses.