INCOME TAXES - NET OPERATING LOSSES AND TAX CREDIT CARRYFORWARDS (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
Valuation allowances	$ 174	$ 144
U.S. Federal [Member]
Operating Loss Carryforwards [Line Items]
NOLs	5,284
Valuation allowances	118	90
U.S. Federal [Member] | General business tax credits [Member]
Operating Loss Carryforwards [Line Items]
Tax credits	428
U.S. Federal [Member] | Foreign tax credits [Member]
Operating Loss Carryforwards [Line Items]
Tax credits	694
U.S. state [Member]
Operating Loss Carryforwards [Line Items]
NOLs	3,047
Valuation allowances	32	33
U.S. state [Member] | General business tax credits [Member]
Operating Loss Carryforwards [Line Items]
Tax credits	39
Non-U.S. [Member]
Operating Loss Carryforwards [Line Items]
NOLs	126
Valuation allowances	$ 24	$ 21