PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Basis of Fair Value Measurements of Pension Plan Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 28,200	$ 26,400
Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	28,167	26,406	$ 24,908
Subtotal	21,258	20,128
Defined Benefit Pension Plans | Quoted Prices in Active Markets for Identical Items (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Subtotal	10,796	9,982
Defined Benefit Pension Plans | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Subtotal	10,450	10,119
Defined Benefit Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12	27	40
Subtotal	12	27
Cash and Cash Equivalents | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,463	1,298
Cash and Cash Equivalents | Defined Benefit Pension Plans | Quoted Prices in Active Markets for Identical Items (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,353	1,103
Cash and Cash Equivalents | Defined Benefit Pension Plans | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	110	195
Cash and Cash Equivalents | Defined Benefit Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. Equity [Member] | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	4,117	3,934
U.S. Equity [Member] | Defined Benefit Pension Plans | Quoted Prices in Active Markets for Identical Items (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	4,097	3,911
U.S. Equity [Member] | Defined Benefit Pension Plans | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	18	22
U.S. Equity [Member] | Defined Benefit Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	2	1
Non-U.S. Equity [Member] | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	4,559	5,186
Non-U.S. Equity [Member] | Defined Benefit Pension Plans | Quoted Prices in Active Markets for Identical Items (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	3,935	4,213
Non-U.S. Equity [Member] | Defined Benefit Pension Plans | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	620	964
Non-U.S. Equity [Member] | Defined Benefit Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	4	9
Equity securities | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8,676	9,120
Equity securities | Defined Benefit Pension Plans | Quoted Prices in Active Markets for Identical Items (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8,032	8,124
Equity securities | Defined Benefit Pension Plans | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	638	986
Equity securities | Defined Benefit Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6	10	27
Government debt | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	4,838	4,998
Government debt | Defined Benefit Pension Plans | Quoted Prices in Active Markets for Identical Items (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	242	128
Government debt | Defined Benefit Pension Plans | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	4,596	4,870
Government debt | Defined Benefit Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Corporate bonds | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	4,949	3,970
Corporate bonds | Defined Benefit Pension Plans | Quoted Prices in Active Markets for Identical Items (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	1,095	553
Corporate bonds | Defined Benefit Pension Plans | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	3,854	3,416
Corporate bonds | Defined Benefit Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	1
Debt - asset-backed | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	117	103
Debt - asset-backed | Defined Benefit Pension Plans | Quoted Prices in Active Markets for Identical Items (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Debt - asset-backed | Defined Benefit Pension Plans | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	116	102
Debt - asset-backed | Defined Benefit Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	1	1
Total fixed income securities | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9,904	9,071
Total fixed income securities | Defined Benefit Pension Plans | Quoted Prices in Active Markets for Identical Items (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,337	681
Total fixed income securities | Defined Benefit Pension Plans | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8,566	8,388
Total fixed income securities | Defined Benefit Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1	2	2
Private Equity Funds | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	5	13
Investments measured at NAV	3,857	3,135
Private Equity Funds | Defined Benefit Pension Plans | Quoted Prices in Active Markets for Identical Items (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Private Equity Funds | Defined Benefit Pension Plans | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Private Equity Funds | Defined Benefit Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	5	13
Real Estate | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	67	51
Investments measured at NAV	1,793	1,886
Real Estate | Defined Benefit Pension Plans | Quoted Prices in Active Markets for Identical Items (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	67	51
Real Estate | Defined Benefit Pension Plans | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Real Estate | Defined Benefit Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Derivatives - asset position | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	399	697
Derivatives - asset position | Defined Benefit Pension Plans | Quoted Prices in Active Markets for Identical Items (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	2	2
Derivatives - asset position | Defined Benefit Pension Plans | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	397	695
Derivatives - asset position | Defined Benefit Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Derivatives - liability position | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	324	594
Derivatives - liability position | Defined Benefit Pension Plans | Quoted Prices in Active Markets for Identical Items (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	2	1
Derivatives - liability position | Defined Benefit Pension Plans | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	322	593
Derivatives - liability position | Defined Benefit Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Alternative Investments | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	147	167
Alternative Investments | Defined Benefit Pension Plans | Quoted Prices in Active Markets for Identical Items (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	67	52
Alternative Investments | Defined Benefit Pension Plans | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	75	102
Alternative Investments | Defined Benefit Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5	13	11
Other Investments | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,068	472
Other Investments | Defined Benefit Pension Plans | Quoted Prices in Active Markets for Identical Items (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7	22
Other Investments | Defined Benefit Pension Plans | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,061	448
Other Investments | Defined Benefit Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	2	$ 0
Hedge Funds | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Investments measured at NAV	1,312	1,350
Plan Assets, Retirement Plan, Total investments measured at NAV [Member] | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6,962	6,371
Pension Trust Receivables [Member] | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	62	66
Pension Trust Payables [Member] | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ (115)	$ (159)