FEDERAL FUNDS, SECURITIES BORROWED, LOANED AND SUBJECT TO REPURCHASE AGREEMENTS - Offsetting (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Securities purchased under agreements to resell
Gross amounts of recognized assets	$ 185,844	$ 176,284
Gross amounts offset on the Consolidated Balance Sheet	50,920	44,811
Net amounts of assets included on the Consolidated Balance Sheet	134,924	131,473
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	102,227	102,874
Net amounts	32,697	28,599
Deposits paid for securities borrowed
Gross amounts of recognized assets	108,005	105,340
Net amounts of assets included on the Consolidated Balance Sheet	108,005	105,340
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	20,622	16,200
Net amounts	87,383	89,140
Total
Total	293,849	281,624
Gross amounts offset on the Consolidated Balance Sheet	50,920	44,811
Net amounts of assets included on the Consolidated Balance Sheet	242,929	236,813
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	122,849	119,074
Net amounts	120,080	117,739
Securities sold under agreements to repurchase
Gross amounts of recognized liabilities	184,049	170,496
Gross amounts offset on the Consolidated Balance Sheet	50,920	44,811
Net amounts of liabilities included on the Consolidated Balance Sheet	133,129	125,685
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	66,956	63,517
Net amounts	66,173	62,168
Deposits received for securities loaned
Gross amounts of recognized liabilities	14,968	15,958
Net amounts of liabilities included on the Consolidated Balance Sheet	14,968	15,958
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	3,447	3,529
Net amounts	11,521	12,429
Total
Gross amounts of recognized liabilities	199,017	186,454
Gross amounts offset on the Consolidated Balance Sheet	50,920	44,811
Net amounts of liabilities included on the Consolidated Balance Sheet	148,097	141,643
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	70,403	67,046
Net amounts	$ 77,694	$ 74,597