Derivatives and Hedging Activities (Details 4) (USD $) In Millions, unless otherwise specified	12 Months Ended			3 Months Ended	12 Months Ended																		12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Jun. 30, 2011 Cash flow hedges	Dec. 31, 2011 Cash flow hedges	Dec. 31, 2010 Cash flow hedges	Dec. 31, 2009 Cash flow hedges	Dec. 31, 2011 Cash flow hedges Other revenues	Dec. 31, 2011 Cash flow hedges Interest and debt expense	Dec. 31, 2010 Cash flow hedges Interest and debt expense	Dec. 31, 2009 Cash flow hedges Interest and debt expense	Dec. 31, 2011 Cash flow hedges Distribution fees	Dec. 31, 2010 Cash flow hedges Distribution fees	Dec. 31, 2011 Cash flow hedges Net investment income	Dec. 31, 2010 Cash flow hedges Net investment income	Dec. 31, 2009 Cash flow hedges Net investment income	Dec. 31, 2011 Cash flow hedges Interest on debt	Dec. 31, 2010 Cash flow hedges Interest on debt	Dec. 31, 2009 Cash flow hedges Interest on debt	Dec. 31, 2011 Cash flow hedges Asset-based distribution fees	Dec. 31, 2010 Cash flow hedges Asset-based distribution fees	Mar. 31, 2010 Fair value hedges Swaps	Dec. 31, 2011 Fair value hedges Fixed rate debt Interest and debt expense	Dec. 31, 2010 Fair value hedges Fixed rate debt Interest and debt expense
Derivative Instruments Gain (Loss)
Cash flow hedge, Gain (Loss) Reclassified from Accumulated Other Comprehensive Income to Other revenues				$ 27
Probable reclassification of unrealized gains on cash flow hedges from accumulated other comprehensive income to earnings during the next 12 months					2
Reclassification of net pretax gains, to be recorded as a reduction to interest and debt expense in the next 12 months					4
Reclassification of net pretax losses, to be recorded in net investment income in the next 12 months					6
Amount of Gain (Loss) Recognized in Other Comprehensive Income on Derivatives					(10)	36	19										(11)	16	19	1	20
Amount of Gain (Loss) Reclassified from Accumulated other Comprehensive Income into Income					34	13	2	27	4	8	8	9	11	(6)	(6)	(6)
Hedging exposure to the variability in future cash flows (in years)					24 years
Number of interest rate swaps held																						3
Amount of Gain Recognized in Income on Derivatives																							41	36
Summary of unrealized derivatives gains (losses) included in accumulated other comprehensive income (loss) related to cash flow hedges
Net unrealized derivatives gains (losses), at the beginning of the period	18	3	(8)
Holding gains (losses)	(10)	36	19
Reclassification of realized gains	(34)	(13)	(2)
Income tax benefit (provision)	15	(8)	(6)
Net unrealized derivatives gains (losses), at the end of the period	$ (11)	$ 18	$ 3