RETIREMENT BENEFITS - Schedule of Net Benefit Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Net periodic pension benefit cost	$ (15)	$ (13)	$ 1,599
Pension Plans, Defined Benefit
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Service cost — benefits earned during the year	51	48	26
Interest cost on projected benefit obligation	35	42	115
Expected return on plan assets	(99)	(98)	(200)
Amortization of prior service credits	(4)	(4)	(4)
Amortization of net actuarial loss	50	44	59
Settlements and Curtailments	(5)	10	1,640
Net periodic pension benefit cost	$ 28	$ 42	$ 1,636