Other Assets (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Other Assets [Abstract]
Receivable - securities lending	$ 19,404	$ 21,204
Derivative instruments, net	4,013	7,321
Bank-owned life insurance	3,242	3,158
Investments in joint ventures and other unconsolidated entities	2,259	2,363
Collateral, net	473	2,236
Prepaid expenses	364	333
Accounts receivable	348	886
Receivable for securities settlement	188	40
Deposits with clearing organizations	120	132
Deferred tax assets, net of valuation allowance	113	210
Income taxes receivable	97	106
Other	397	339
Total	$ 31,018	$ 38,328