BASIS OF PRESENTATION AND ACCOUNTING CHANGES - Accounting Changes (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2014	Jun. 30, 2015	Mar. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle
Addition (reduction) in Retained earnings	$ 117,852	$ 126,954
Other assets	122,122	135,929
Accounting Standards Update 2014-01
New Accounting Pronouncements or Change in Accounting Principle
Addition (reduction) in Retained earnings			$ (349)
Other assets			(178)
Addition (reduction) in deferred tax assets			$ (171)
Accounting Standards Update 2014-14
New Accounting Pronouncements or Change in Accounting Principle
Reclassification adjustment	130
New Accounting Pronouncement, Early Adoption, Effect | Accounting Standards Update 2015-07
New Accounting Pronouncements or Change in Accounting Principle
Level 3 assets	$ (1,100)	$ (1,000)