Derivative Financial Instruments (Details 6) (Cash Flow Hedges [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Cash Flow Hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Accumulated other comprehensive income (loss), balance at beginning of period	$ 1,832	$ (165)	$ 1,514	$ (59)
Gains (losses) deferred in other comprehensive income (loss) on the effective portion of cash flow hedges	(324)	1,630	(4)	1,527
Amounts reclassified to net derivatives gains (losses)	1	17	(3)	9
Amounts reclassified to net investment income	(1)	1	(1)	2
Amounts reclassified to other expenses	0	3	2	7
Amortization of transition adjustment	0	0	0	0
Accumulated other comprehensive income (loss), balance at end of period	$ 1,508	$ 1,486	$ 1,508	$ 1,486