INCOME TAXES - Deferred Tax Assets Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Valuation Allowance [Line Items]
Valuation allowance	$ 9,258	$ 9,387
Foreign Tax Credit Carryforwards
Valuation Allowance [Line Items]
Valuation allowance	6,000
U.S. Residual Deferred Tax Asset Related to Non-U.S. Branches
Valuation Allowance [Line Items]
Valuation allowance	1,700
Local Non-U.S. Deferred Tax Assets
Valuation Allowance [Line Items]
Valuation allowance	1,500
State Net Operating Loss Carryforwards
Valuation Allowance [Line Items]
Valuation allowance	$ 100