Derivative Financial Instruments (Details 7) (Cash Flow Hedges, USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Derivatives in cash flow hedging relationships [Abstract]
Amount of Gains (Losses) Deferred in Accumulated Other Comprehensive Income (Loss) on Derivatives (Effective Portion)	$ 82	$ 566	$ (103)	$ 617
Credit forwards [Member]
Derivatives in cash flow hedging relationships [Abstract]
Amount of Gains (Losses) Deferred in Accumulated Other Comprehensive Income (Loss) on Derivatives (Effective Portion)	5	14	2	17
Credit forwards [Member] | Net Investment Income [Member]
Derivatives in cash flow hedging relationships [Abstract]
Amount and Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Effective Portion)	0	0	0	0
Amount and Location of Gains (Losses) Recognized In Income on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)	0	0	0	0
Credit forwards [Member] | Other Expenses [Member]
Derivatives in cash flow hedging relationships [Abstract]
Amount and Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Effective Portion)	0	0	0	0
Credit forwards [Member] | Net Derivatives Gains (Losses) [Member]
Derivatives in cash flow hedging relationships [Abstract]
Amount and Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Effective Portion)	0	0	0	0
Amount and Location of Gains (Losses) Recognized In Income on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)	0	0	0	0
Foreign currency swaps [Member]
Derivatives in cash flow hedging relationships [Abstract]
Amount of Gains (Losses) Deferred in Accumulated Other Comprehensive Income (Loss) on Derivatives (Effective Portion)	(36)	292	(140)	339
Foreign currency swaps [Member] | Net Investment Income [Member]
Derivatives in cash flow hedging relationships [Abstract]
Amount and Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Effective Portion)	(1)	(1)	(3)	(3)
Amount and Location of Gains (Losses) Recognized In Income on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)	0	0	0	0
Foreign currency swaps [Member] | Other Expenses [Member]
Derivatives in cash flow hedging relationships [Abstract]
Amount and Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Effective Portion)	0	1	1	1
Foreign currency swaps [Member] | Net Derivatives Gains (Losses) [Member]
Derivatives in cash flow hedging relationships [Abstract]
Amount and Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Effective Portion)	(11)	6	(15)	(62)
Amount and Location of Gains (Losses) Recognized In Income on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)	(1)	2	(2)	3
Interest rate forwards [Member]
Derivatives in cash flow hedging relationships [Abstract]
Amount of Gains (Losses) Deferred in Accumulated Other Comprehensive Income (Loss) on Derivatives (Effective Portion)	33	(15)	18	(15)
Interest rate forwards [Member] | Net Investment Income [Member]
Derivatives in cash flow hedging relationships [Abstract]
Amount and Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Effective Portion)	0	0	1	1
Amount and Location of Gains (Losses) Recognized In Income on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)	0	0	0	0
Interest rate forwards [Member] | Other Expenses [Member]
Derivatives in cash flow hedging relationships [Abstract]
Amount and Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Effective Portion)	0	0	(1)	0
Interest rate forwards [Member] | Net Derivatives Gains (Losses) [Member]
Derivatives in cash flow hedging relationships [Abstract]
Amount and Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Effective Portion)	22	11	22	11
Amount and Location of Gains (Losses) Recognized In Income on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)	(13)	0	(11)	0
Interest rate swaps [Member]
Derivatives in cash flow hedging relationships [Abstract]
Amount of Gains (Losses) Deferred in Accumulated Other Comprehensive Income (Loss) on Derivatives (Effective Portion)	80	275	17	276
Interest rate swaps [Member] | Net Investment Income [Member]
Derivatives in cash flow hedging relationships [Abstract]
Amount and Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Effective Portion)	1	0	1	0
Amount and Location of Gains (Losses) Recognized In Income on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)	0	0	0	0
Interest rate swaps [Member] | Other Expenses [Member]
Derivatives in cash flow hedging relationships [Abstract]
Amount and Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Effective Portion)	(2)	0	(4)	0
Interest rate swaps [Member] | Net Derivatives Gains (Losses) [Member]
Derivatives in cash flow hedging relationships [Abstract]
Amount and Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Effective Portion)	1	0	1	0
Amount and Location of Gains (Losses) Recognized In Income on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)	2	0	2	2
Net Investment Income [Member]
Derivatives in cash flow hedging relationships [Abstract]
Amount and Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Effective Portion)	0	(1)	(1)	(2)
Amount and Location of Gains (Losses) Recognized In Income on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)	0	0	0	0
Other Expenses [Member]
Derivatives in cash flow hedging relationships [Abstract]
Amount and Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Effective Portion)	(2)	1	(4)	1
Net Derivatives Gains (Losses) [Member]
Derivatives in cash flow hedging relationships [Abstract]
Amount and Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Effective Portion)	12	17	8	(51)
Amount and Location of Gains (Losses) Recognized In Income on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)	$ (12)	$ 2	$ (11)	$ 5