RETIREMENT BENEFITS PLANS - Obligations and Funded Status (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Funded status
Fair value of plan assets	$ 5,919	$ 5,600
Pension plans | United States
Funded status
Fair value of plan assets	3,672	3,463	$ 3,433
Benefit obligations	(3,760)	(4,121)	(4,028)
Funded status	(88)	(658)
Amounts recognized in the Consolidated Balance Sheets
Non-current assets	59	0
Current liabilities	(16)	(36)
Non-current liabilities	(131)	(622)
Total	(88)	(658)
Amounts recognized in Accumulated other comprehensive loss (pre-tax)
Net actuarial (gain) loss	708	1,046
Prior service cost (credit)	5	5
Total	713	1,051	1,103
Pension plans | Foreign Plan
Funded status
Fair value of plan assets	2,247	2,137	1,903
Benefit obligations	(2,837)	(3,036)	(2,747)
Funded status	(590)	(899)
Amounts recognized in the Consolidated Balance Sheets
Non-current assets	179	95
Current liabilities	(28)	(28)
Non-current liabilities	(741)	(966)
Total	(590)	(899)
Amounts recognized in Accumulated other comprehensive loss (pre-tax)
Net actuarial (gain) loss	745	1,005
Prior service cost (credit)	18	21
Total	763	1,026	904
Other postretirement benefits plans
Funded status
Fair value of plan assets	19	20	23
Benefit obligations	(304)	(375)	(378)
Funded status	(285)	(355)
Amounts recognized in the Consolidated Balance Sheets
Non-current assets	0	0
Current liabilities	(22)	(25)
Non-current liabilities	(263)	(330)
Total	(285)	(355)
Amounts recognized in Accumulated other comprehensive loss (pre-tax)
Net actuarial (gain) loss	(55)	1
Prior service cost (credit)	0	(3)
Total	$ (55)	$ (2)	$ (25)