Other Assets - Components of Other Assets (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Other Assets [Line Items]
Total	$ 37,549	$ 32,600
Real estate acquired through foreclosure	63	62
Reported Amount | Other assets
Other Assets [Line Items]
Collateral deposits, net	22,094	18,134
Unrealized gains on derivative financial instruments, net	8,048	7,934
Bank-owned life insurance	2,419	2,402
Investments in joint ventures and other unconsolidated entities	1,875	1,798
Accounts receivable	1,087	513
Receivable for securities settlement	419	218
Prepaid expenses	376	259
Income taxes receivable	295	396
Deferred tax assets, net of valuation allowance	189	214
Deposits with clearing organizations	181	197
Receivable for securities sold	45	0
Other	521	535
Total	$ 37,549	$ 32,600