PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Basis of Fair Value Measurements) (Details) - USD ($) $ in Millions | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | $ 3,148 | $ 3,005 | |
Defined Benefit Plan, Alternative Investments, Fair Value Of Plan Assets | 996 | 949 | |
Defined Benefit Plan, Fair Value of Plan Assets, Reconciling Items, Pension Trust Receivables | 0 | 2 | |
Defined Benefit Plan, Fair Value of Plan Assets, Reconciling Items, Pension Trust Payables | 7 | 0 | |
Pension Plan [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 3,148 | 3,005 | $ 3,307 |
Defined Benefit Plan, Fair Value of Plan Assets Subtotal | 2,159 | 2,054 | |
Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Fair Value of Plan Assets Subtotal | 838 | 752 | |
Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Fair Value of Plan Assets Subtotal | 1,312 | 1,296 | |
Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 9 | 6 | 7 |
Defined Benefit Plan, Fair Value of Plan Assets Subtotal | 9 | 6 | |
Pension Plan [Member] | Cash and Cash Equivalents [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 160 | 189 | |
Pension Plan [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 148 | 189 | |
Pension Plan [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 12 | 0 | |
Pension Plan [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 0 | 0 | |
Pension Plan [Member] | U.S. Equity [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 346 | 277 | |
Pension Plan [Member] | U.S. Equity [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 344 | 275 | |
Pension Plan [Member] | U.S. Equity [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 2 | 2 | |
Pension Plan [Member] | U.S. Equity [Member] | Fair Value, Inputs, Level 3 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 0 | 0 | |
Pension Plan [Member] | Non-U.S. Equity - Developed Countries [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 369 | 321 | |
Pension Plan [Member] | Non-U.S. Equity - Developed Countries [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 325 | 269 | |
Pension Plan [Member] | Non-U.S. Equity - Developed Countries [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 40 | 46 | |
Pension Plan [Member] | Non-U.S. Equity - Developed Countries [Member] | Fair Value, Inputs, Level 3 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 4 | 6 | |
Pension Plan [Member] | Equity Securities [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 715 | 598 | |
Pension Plan [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 669 | 544 | |
Pension Plan [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 42 | 48 | |
Pension Plan [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 4 | 6 | 7 |
Pension Plan [Member] | US Treasury and Government [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 812 | 812 | |
Pension Plan [Member] | US Treasury and Government [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 7 | 8 | |
Pension Plan [Member] | US Treasury and Government [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 805 | 804 | |
Pension Plan [Member] | US Treasury and Government [Member] | Fair Value, Inputs, Level 3 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 0 | 0 | |
Pension Plan [Member] | Corporate Debt Securities [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 455 | 413 | |
Pension Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 9 | 11 | |
Pension Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 446 | 402 | |
Pension Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 0 | 0 | |
Pension Plan [Member] | Asset-backed Securities [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 13 | 30 | |
Pension Plan [Member] | Asset-backed Securities [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 0 | 0 | |
Pension Plan [Member] | Asset-backed Securities [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 13 | 30 | |
Pension Plan [Member] | Asset-backed Securities [Member] | Fair Value, Inputs, Level 3 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 0 | 0 | |
Pension Plan [Member] | Debt Securities [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 1,280 | 1,255 | |
Pension Plan [Member] | Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 16 | 19 | |
Pension Plan [Member] | Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 1,264 | 1,236 | |
Pension Plan [Member] | Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 0 | 0 | |
Pension Plan [Member] | Private Equity Funds [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 5 | 0 | |
Pension Plan [Member] | Private Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 0 | 0 | |
Pension Plan [Member] | Private Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 0 | 0 | |
Pension Plan [Member] | Private Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 5 | 0 | |
Pension Plan [Member] | Derivative Financial Instruments, Assets [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 0 | 12 | |
Pension Plan [Member] | Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 0 | 0 | |
Pension Plan [Member] | Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 0 | 12 | |
Pension Plan [Member] | Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 3 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 0 | 0 | |
Pension Plan [Member] | Derivative Financial Instruments, Liabilities [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | (3) | 0 | |
Pension Plan [Member] | Derivative Financial Instruments, Liabilities [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 0 | 0 | |
Pension Plan [Member] | Derivative Financial Instruments, Liabilities [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | (3) | 0 | |
Pension Plan [Member] | Derivative Financial Instruments, Liabilities [Member] | Fair Value, Inputs, Level 3 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 0 | 0 | |
Pension Plan [Member] | Alternative Investments [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 2 | 12 | |
Pension Plan [Member] | Alternative Investments [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 0 | 0 | |
Pension Plan [Member] | Alternative Investments [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | (3) | 12 | |
Pension Plan [Member] | Alternative Investments [Member] | Fair Value, Inputs, Level 3 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 5 | 0 | $ 0 |
Pension Plan [Member] | Other [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 2 | 0 | |
Pension Plan [Member] | Other [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 5 | 0 | |
Pension Plan [Member] | Other [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | (3) | 0 | |
Pension Plan [Member] | Other [Member] | Fair Value, Inputs, Level 3 [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Plan Assets, Amount | 0 | 0 | |
Pension Plan [Member] | Hedge Funds [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Alternative Investments, Fair Value Of Plan Assets | 266 | 287 | |
Pension Plan [Member] | Private Market Funds [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Alternative Investments, Fair Value Of Plan Assets | 389 | 335 | |
Pension Plan [Member] | Real Estate [Member] | | | |
Defined Benefit Plan Disclosure [Line Items] | | | |
Defined Benefit Plan, Alternative Investments, Fair Value Of Plan Assets | $ 341 | $ 327 | |