Guarantees, Pledged Assets and Collateral Textuals (Details) (USD $)	3 Months Ended										9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013 Fed Funds Sold, Securities Purchased under Resale Agreements and Other Short-Term Investments [Member]	Dec. 31, 2012 Fed Funds Sold, Securities Purchased under Resale Agreements and Other Short-Term Investments [Member]	Sep. 30, 2013 Loans [Member]	Dec. 31, 2012 Loans [Member]	Sep. 30, 2013 Direct pay letters of credit (DPLCs) [Member]	Dec. 31, 2012 Direct pay letters of credit (DPLCs) [Member]	Sep. 30, 2013 Third party clearing indemnifications [Member]	Dec. 31, 2012 Third party clearing indemnifications [Member]	Sep. 30, 2013 Securities lending and other indemnifications [Member]	Dec. 31, 2012 Securities lending and other indemnifications [Member]	Sep. 30, 2013 Loans and MHFS sold with recourse [Member]	Sep. 30, 2012 Loans and MHFS sold with recourse [Member]	Sep. 30, 2013 Loans and MHFS sold with recourse [Member]	Sep. 30, 2012 Loans and MHFS sold with recourse [Member]	Sep. 30, 2013 Trading assets and other [Member]	Dec. 31, 2012 Trading assets and other [Member]	Sep. 30, 2013 Available for sale Securities [Member]	Dec. 31, 2012 Available for sale Securities [Member]
Guarantees (Textuals) [Abstract]
Maximum exposure to loss	$ 59,435,000,000	$ 61,600,000,000					$ 16,400,000,000	$ 18,500,000,000	$ 2,900,000,000	$ 2,100,000,000	$ 3,282,000,000	$ 2,541,000,000
Guarantor Obligations, Term											These arrangements are for an indefinite period of time whereby we indemnify our clients against default by the borrower in returning these lent securities. This indemnity is supported by collateral received from the borrowers and is generally in the form of cash or highly liquid securities that are marked to market daily.
Collateral	412,000,000	443,000,000
Securities Loaned	399,000,000	436,000,000
Third-party clearing customer obligations									717,000,000	579,000,000
Collateral provided to third-party clearing agents									3,600,000,000	3,100,000,000
Percentage share of losses owed on loans and MHFS sold with recourse	Primarily all of these programs and arrangements require that we share in the loans’ credit exposure for their remaining life by providing recourse to the GSE, up to 33.33% of actual losses incurred on a pro-rata basis.
Loans repurchased													8,000,000	5,000,000	26,000,000	21,000,000
Pledged collateral assets related to consolidated VIEs	10,200,000,000	14,600,000,000
Securities owned and pledged as collateral available to be repledged, Fair Value																	32,500,000,000	27,400,000,000
Securities owned and pledged as collateral related to repurchase agreements not available to be repledged, Fair Value	9,600,000,000	9,100,000,000																	8,300,000,000	8,400,000,000
Net amounts in consolidated balance sheet	38,224,000,000	43,286,000,000	27,000,000,000	33,800,000,000	11,200,000,000	9,500,000,000
Non-cash collateral received, fair value	48,200,000,000	46,600,000,000
Collateral received with the right to sell or repledge	48,200,000,000	46,600,000,000
Collateral sold or repledged	27,500,000,000	29,700,000,000
Non-cash collateral pledged, fair value	$ 42,100,000,000	$ 36,400,000,000