Derivative Financial Instruments (Details 6) (Cash Flow Hedges [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Cash Flow Hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Accumulated other comprehensive income (loss), balance at beginning of period	$ 1,019	$ (237)	$ 1,514	$ (59)
Gains (losses) deferred in other comprehensive income (loss) on the effective portion of cash flow hedges	805	82	320	(103)
Amounts reclassified to net derivatives gains (losses)	8	(12)	(4)	(8)
Amounts reclassified to net investment income	0	0	0	1
Amounts reclassified to other expenses	0	2	2	4
Amortization of transition adjustment	0	0	0	0
Accumulated other comprehensive income (loss), balance at end of period	$ 1,832	$ (165)	$ 1,832	$ (165)