FEDERAL FUNDS, SECURITIES BORROWED, LOANED, AND SUBJECT TO REPURCHASE AGREEMENTS - Offsetting (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Securities purchased under agreements to resell
Gross amounts of recognized assets	$ 179,973	$ 180,318
Gross amounts offset on the Consolidated Balance Sheet	47,890	56,339
Net amounts of assets included on the Consolidated Balance Sheet	132,083	123,979
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	99,055	94,353
Net amounts	33,028	29,626
Deposits paid for securities borrowed
Gross amounts of recognized assets	104,971	118,591
Net amounts of assets included on the Consolidated Balance Sheet	104,971	118,591
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	14,982	15,139
Net amounts	89,989	103,452
Total
Total	284,944	298,909
Gross amounts offset on the Consolidated Balance Sheet	47,890	56,339
Net amounts of assets included on the Consolidated Balance Sheet	237,054	242,570
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	114,037	109,492
Net amounts	123,017	133,078
Securities sold under agreements to repurchase
Gross amounts of recognized liabilities	202,436	203,543
Gross amounts offset on the Consolidated Balance Sheet	47,890	56,339
Net amounts of liabilities included on the Consolidated Balance Sheet	154,546	147,204
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	77,855	72,928
Net amounts	76,691	74,276
Deposits received for securities loaned
Gross amounts of recognized liabilities	21,690	25,900
Net amounts of liabilities included on the Consolidated Balance Sheet	21,690	25,900
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	2,688	5,190
Net amounts	19,002	20,710
Total
Gross amounts of recognized liabilities	224,126	229,443
Gross amounts offset on the Consolidated Balance Sheet	47,890	56,339
Net amounts of liabilities included on the Consolidated Balance Sheet	176,236	173,104
Amounts not offset on the Consolidated Balance Sheet but eligible for offsetting upon counterparty default	80,543	78,118
Net amounts	$ 95,693	$ 94,986