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BASIS OF PRESENTATION AND ACCOUNTING CHANGES - Accounting Changes (Details) - USD ($) $ in Millions	Mar. 31, 2016	Jan. 01, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle
Increase (decrease) in AOCI	$ (26,626)		$ (29,344)
Retained earnings	136,998		133,841
Other	$ 121,621		125,002
Accounting Standards Update 2016-01 \| New Accounting Pronouncement, Early Adoption, Effect
New Accounting Pronouncements or Change in Accounting Principle
Increase (decrease) in AOCI		$ (15)
Retained earnings		$ 15
Accounting Standards Update 2014-01
New Accounting Pronouncements or Change in Accounting Principle
Retained earnings			(349)
Other			(178)
Addition (reduction) in deferred tax assets			$ (171)