PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Schedule of Changes in Benefit Obligation (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Other Postretirement Benefits
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation, beginning of year	$ 191	$ 191	$ 355
Service cost		0	4	$ 6
Interest cost		5	8	16
Plan participants' contributions		0	0
Actuarial (gain) loss		(8)	9
Benefits paid		(21)	(24)
Plan amendments	0		(156)
Transfer of liabilities		0	0
Other adjustments		0	0
Special termination benefit		0	0
Settlements / curtailment (gain)		0	0
Foreign currency exchange rates		(1)	(5)
Reclassification of obligation to held for sale		0	0
Benefit obligation, end of year		166	191	355
United States Pension Benefits | Pension Benefits
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation, beginning of year	3,237	3,237	3,141
Service cost		3	3	2
Interest cost		77	94	123
Plan participants' contributions		0	0
Actuarial (gain) loss		(99)	282
Benefits paid		(234)	(186)
Plan amendments		0	0
Transfer of liabilities		0	0
Other adjustments		0	0
Special termination benefit		0	0
Settlements / curtailment (gain)		(16)	(97)
Foreign currency exchange rates		0	0
Reclassification of obligation to held for sale		0	0
Benefit obligation, end of year		2,968	3,237	3,141
Accumulated benefit obligation, end of year		2,955	3,222
Foreign Pension Benefits | Pension Benefits
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation, beginning of year	$ 1,029	1,029	941
Service cost		5	6	6
Interest cost		14	17	23
Plan participants' contributions		1	1
Actuarial (gain) loss		(45)	96
Benefits paid		(29)	(33)
Plan amendments		0	0
Transfer of liabilities		(23)	0
Other adjustments		0	0
Special termination benefit		0	0
Settlements / curtailment (gain)		(18)	(37)
Foreign currency exchange rates		(10)	38
Reclassification of obligation to held for sale		0	0
Benefit obligation, end of year		924	1,029	$ 941
Accumulated benefit obligation, end of year		$ 891	$ 987