Trading Assets and Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	$ 22,823	$ 16,850
Trading liabilities	4,024	4,908
U.S. Treasury [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	3,576	3,560
US Government agency issued or guaranteed [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	23	24
US Government sponsored enterprises [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	216	222
Asset backed securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	357	365
Corporate and foreign bonds [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	7,288	6,481
Other securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	12	15
Precious metals [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	7,770	1,772
Trading liabilities	0	62
Securities sold, not yet purchased [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading liabilities	855	1,060
Derivatives [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	3,581	4,411
Derivatives [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading liabilities	$ 3,169	$ 3,786