Litigation (Details) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	3 Months Ended				3 Months Ended			3 Months Ended			3 Months Ended			15 Months Ended			3 Months Ended								3 Months Ended								0 Months Ended						3 Months Ended			3 Months Ended		3 Months Ended			3 Months Ended		3 Months Ended						3 Months Ended
	Mar. 31, 2012 Pending or Threatened Litigation [Member]	Mar. 31, 2011 Pending or Threatened Litigation [Member]	Mar. 31, 2012 Pending or Threatened Litigation [Member] Maximum [Member]	Mar. 31, 2012 Pending or Threatened Litigation [Member] Minimum [Member]	Mar. 31, 2012 Auction-Rate Securities Investigations and Litigation [Member]	Mar. 31, 2012 Auction-Rate Securities Investigations and Litigation [Member] Minimum [Member] agreements	May 30, 2007 Bear Stearns Hedge Fund Matters [Member] Plaintiff, Bank of America [Member]	Mar. 31, 2012 Bear Stearns Hedge Fund Matters [Member] Plaintiff, Bank of America [Member] Maximum [Member]	Mar. 31, 2012 Bear Stearns Hedge Fund Matters, Related to the Feeder Funds actions	Mar. 31, 2012 Bear Stearns Hedge Fund Matters, Feeder Funds, Enhanced Leverage Fund [Member] actions	Mar. 31, 2012 Bear Stearns Hedge Fund Matters, Feeder Funds, Enhanced Leverage Fund [Member] Maximum [Member]	Mar. 31, 2012 Bear Stearns Hedge Fund Matters, feeder funds, High Grade Fund [Member]	Mar. 31, 2012 Bear Stearns Shareholder Litigation and Related Matters [Member]	Mar. 14, 2008 Bear Stearns Shareholder Litigation and Related Matters [Member] Maximum [Member]	Mar. 14, 2008 Bear Stearns Shareholder Litigation and Related Matters [Member] Minimum [Member]	Mar. 31, 2012 Investment Management Litigation [Member] actions	Mar. 31, 2012 Investment Management Litigation [Member] Minimum [Member]	Mar. 31, 2012 Lehman Brothers Bankruptcy Proceedings [Member]	Mar. 31, 2012 Lehman Brothers Bankruptcy Proceedings [Member] Minimum [Member]	Mar. 31, 2012 CFTC Settlement [Member]	Mar. 31, 2012 Madoff Litigation [Member] causes	Mar. 31, 2012 Madoff Litigation [Member] Plaintiff, Madoff Litigation-related, liqudation trustee [Member]	Mar. 31, 2012 Madoff Litigation, related to Fairfield [Member]	Mar. 31, 2012 Mortgage-Backed Securities Litigation and Regulatory Investigations [Member] actions	Mar. 31, 2012 Mortgage-Backed Securities Litigation and Regulatory Investigations [Member] Minimum [Member]	Mar. 31, 2012 Mortgage Backed Securities Litigation Related to MBS Offerings Sponsored By EMC [Member] actions	Mar. 31, 2012 Mortgage Backed Securities Litigation Related to MBS Offerings Sponsored By EMC [Member] Minimum [Member] offerings	Mar. 31, 2012 Mortgage Backed Securities Litigation Related to MBS Offerings Sponsored By Washington Mutual [Member]	Mar. 31, 2012 Mortgage Backed Securities Litigation Related to MBS Offerings Sponsored By Washington Mutual [Member] Minimum [Member]	Mar. 31, 2012 Mortgage Backed Securities Litigation Related to MBS Offerings Sponsored By JPMorgan Chase [Member] Maximum [Member]	Mar. 31, 2012 Mortgage Backed Securities Litigation Related to MBS Offerings Sponsored By JPMorgan Chase [Member] Minimum [Member]	Mar. 31, 2012 Mortgage Foreclosure Investigations and Litigation [Member] actions	Feb. 09, 2012 Mortgage Foreclosure Investigations and Litigation [Member] Global settlement on servicing and origination of mortgages [Member] Settlement of Litigation, Cash Payments [Member]	Feb. 09, 2012 Mortgage Foreclosure Investigations and Litigation [Member] Global settlement on servicing and origination of mortgages [Member] Settlement of Litigation, Additional Relief Provided to Certain Borrowers [Member]	Feb. 09, 2012 Mortgage Foreclosure Investigations and Litigation [Member] Global settlement on servicing and origination of mortgages [Member] Settlement of Litigation, Refinancing Relief Provided to Certain Borrowers [Member]	Mar. 31, 2012 Municipal Derivatives Investigations and Litigation [Member] Maximum [Member]	Mar. 31, 2012 Municipal Derivatives Investigations and Litigation [Member] Minimum [Member]	Mar. 31, 2012 Municipal Derivatives Investigations and Litigation [Member] Plaintiff, Municipal Derivatives-related, one insurer [Member] Maximum [Member]	Mar. 31, 2012 Municipal Derivatives Investigations and Litigation [Member] Plaintiff, Municipal Derivatives-related, one insurer [Member] Minimum [Member]	Mar. 31, 2011 Municipal Derivatives Investigations and Litigation [Member] Plaintiff, Municipal Derivatives-related, the other insurer [Member]	Mar. 31, 2012 Municipal Derivatives Investigations and Litigation [Member] Plaintiff, Municipal Derivatives-related, the other insurer [Member] Minimum [Member]	Mar. 31, 2012 Municipal Derivatives Actions [Member]	Mar. 31, 2012 Jefferson County, Alabama [Member] Minimum [Member]	Mar. 31, 2012 Overdraft Fee/Debit Posting Order Litigation [Member]	Mar. 31, 2012 Petters Bankruptcy and Related Matters [Member]	Mar. 31, 2012 Securities Lending Litigation [Member] actions	Mar. 31, 2012 Securities Lending Litigation, related to medium-term notes of Sigma Finance [Member] actions	Mar. 31, 2012 Securities Lending Litigation, related to medium-term notes of Lehman Brothers [Member]	Mar. 31, 2012 Washington Mutual Litigations [Member] Plaintiff, Deutsche Bank National Trust Company [Member] Maximum [Member]	Mar. 31, 2012 Washington Mutual Litigations [Member] Plaintiff, Deutsche Bank National Trust Company [Member] Minimum [Member]	Mar. 31, 2012 Washington Mutual Litigations, in connection with disputed trust securities [Member]	Mar. 31, 2012 Washington Mutual Litigations, in connection with disputed deposit accounts [Member]	Mar. 31, 2012 Washington Mutual Litigations [Member]	Mar. 31, 2012 New York State Court [Member] Breach of Fiduciary Duty Litigation [Member] actions	Mar. 31, 2012 Western District Court of Washington [Member] Mortgage-Backed Securities Litigation and Regulatory Investigations [Member] tranches
Loss Contingency, Estimate [Abstract]
Loss Contingency, Range of Possible Loss, Portion Not Accrued			$ 4,200,000,000	$ 0
Litigation expense (benefit)	2,700,000,000	1,100,000,000
Loss Contingency, Information about Litigation Matters [Abstract]
Number of Legal Proceedings									3	1						4								3		7						5														4	3							5
Number of Tranches of Mortgage Backed Securities to Which Asserted Claims Are Limited																																																							13
Guaranteed payments of prinicipal and interest of certain classes of MBS offerings																										5,000,000,000
Number of Offerings by Entity Related to Filed Suit																										21
Number of Asserted Causes of Action Against Entity																					28
Number of Asserted Causes of Action Against Entity That Seek to Avoid Transfers to Entity																					20
Number of Finalized Consent Agreements with NASAA Member States						45
Number of Mortgage Loans Sought by Plaintiff for Repurchase																											1,300
Number of Trusts Related to an MBS Securitization																												52		191
Percentage of Voting Rights, MBS Trust Certificateholders																									25.00%
Loss Contingency, Damages Sought, Value								535,000,000	700,000,000								1,000,000,000					19,000,000,000																	400,000,000										10,000,000,000	6,000,000,000	4,000,000,000	4,000,000,000
Loss Contingency, Damages Sought, Recoveries, Value																		8,600,000,000				425,000,000	155,000,000																	4,000,000					450,000,000
Loss Contingency, Settlement Agreement, Consideration					25						18	19	10					700		20													1.1	3.7	500							45		110			150
Loss Contingency, Settlement Agreement, Consideration to Resolve Part But Not All of the Legal Matter					25						18	19	10					700		20													1.1	3.7	500							45		110			150
Loss Contingency, Damages Sought, Counterclaims, Value																			25,000,000,000
Loss Contingency, Information about related Resources or Markets [Abstract]
Loss Contingency, Insured Aggregate Principal Amount related to, Value																																						1,200,000,000			378,000,000
Loss Contingency, Investments in Medium-Term Notes related to, Value																																															500,000,000	500,000,000
Loss Contingency, Mortgage-Backed Securities Offerings related to, Value																										5,000,000,000
Loss Contingency, Mortgage-Backed Securities Trusts, Original Principal Amount Related To, Value																													58,000,000,000		174,000,000,000
Loss Contingency, Municipal Derivatives, Annual Market related to, Value																																				300,000,000,000	100,000,000,000
Loss Contingency, Securities Issued by Securitization Trusts related to, Value																								120,000,000,000
Loss Contingency, Securitization related to, Value							4,000,000,000
Loss Contingency, Shares related to, Outstanding														120	115
Loss Contingency, Shares related to, Price per Share														$ 172.61	$ 30
Loss Contingency, Warrants Issued related to, Value																																											3,000,000,000
Loss Contingency, Bonds, Value																																																					$ 38,000,000
Loss Contingency, Settlement [Abstract]
Loss Contingency, Settlement Agreement, Consideration					25						18	19	10					700		20													1.1	3.7	500							45		110			150