POSTRETIREMENT BENEFIT PLANS - Schedule of Defined Benefit Plans (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Jan. 01, 2023	Dec. 31, 2022
Accumulated Benefit Obligations and Unrecognized Gain
Accumulated benefit obligation	$ 22,185	$ 23,841	$ 22,906
Unrecognized gain recorded in AOCI			2,481
Net Benefit Liability
Projected benefit obligations			22,953
Fair value of plan assets			18,908
Net liability			4,045
Pension Plans
Accumulated Benefit Obligations and Unrecognized Gain
Accumulated benefit obligation			21,696
Unrecognized gain recorded in AOCI			1,258
Net Benefit Liability
Projected benefit obligations			21,743
Fair value of plan assets			18,908
Net liability			2,835
Other Postretirement Benefits Plan
Accumulated Benefit Obligations and Unrecognized Gain
Accumulated benefit obligation			1,210
Unrecognized gain recorded in AOCI			1,223
Net Benefit Liability
Projected benefit obligations	1,016	1,133	1,210	$ 0
Fair value of plan assets	0	0	0	$ 0
Net liability	$ 1,016	$ 1,133	$ 1,210