FEDERAL FUNDS, SECURITIES BORROWED, LOANED AND SUBJECT TO REPURCHASE AGREEMENTS - Offsetting (Details) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Securities purchased under agreements to resell
Gross amounts of recognized assets	$ 186,108	$ 176,284
Gross amounts offset on the Consolidated Balance Sheet	57,562	44,811
Net amounts of assets included on the Consolidated Balance Sheet	128,546	131,473
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	106,230	102,874
Net amounts	22,316	28,599
Deposits paid for securities borrowed
Gross amounts of recognized assets	105,519	105,340
Net amounts of assets included on the Consolidated Balance Sheet	105,519	105,340
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	22,633	16,200
Net amounts	82,886	89,140
Total
Total	291,627	281,624
Gross amounts offset on the Consolidated Balance Sheet	57,562	44,811
Net amounts of assets included on the Consolidated Balance Sheet	234,065	236,813
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	128,863	119,074
Net amounts	105,202	117,739
Securities sold under agreements to repurchase
Gross amounts of recognized liabilities	198,866	170,496
Gross amounts offset on the Consolidated Balance Sheet	57,562	44,811
Net amounts of liabilities included on the Consolidated Balance Sheet	141,304	125,685
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	64,748	63,517
Net amounts	76,556	62,168
Deposits received for securities loaned
Gross amounts of recognized liabilities	13,173	15,958
Net amounts of liabilities included on the Consolidated Balance Sheet	13,173	15,958
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	2,936	3,529
Net amounts	10,237	12,429
Total
Gross amounts of recognized liabilities	212,039	186,454
Gross amounts offset on the Consolidated Balance Sheet	57,562	44,811
Net amounts of liabilities included on the Consolidated Balance Sheet	154,477	141,643
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	67,684	67,046
Net amounts	$ 86,793	$ 74,597