Securities Financing Activities - Schedule of securities sold under repurchase agreements, netting & securities loaned (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements with an appropriate legal opinion, Gross liability	$ 289,619,000,000	$ 257,630,000,000
Amounts netted on the Consolidated balance sheets	(142,719,000,000)	(115,408,000,000)
Securities sold under repurchase agreements with an appropriate legal opinion, Net liability	146,900,000,000	142,222,000,000
Securities sold under repurchase agreements where an appropriate legal opinion has not been either sought or obtained(a)	22,906,000,000	18,143,000,000
Total securities sold under repurchase agreements, gross liability balance	312,525,000,000	275,773,000,000
Total securities sold under repurchase agreements, net liability balance	169,806,000,000	160,365,000,000
Securities loaned including not subject to master netting arrangement	25,927,000,000	25,769,000,000
Securities loaned where an appropriate legal opinion has not been either sought or obtained	537,000,000	397,000,000
Securities-For-Securities Borrow Versus Pledge Transactions
Securities Financing Transaction [Line Items]
Securities loaned	4,100,000,000	5,800,000,000
Securities Financing Transaction, Fair Value
Securities Financing Transaction [Line Items]
Total securities sold under repurchase agreements, net liability balance	3,000,000,000	4,900,000,000
Securities loaned	$ 0	$ 483,000,000