INCOME TAXES - Summary of Income Tax Contingencies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$ 2,003	$ 1,905	$ 995
Gross additions to tax positions related to current year	66	76	170
Gross additions to tax positions related to prior years	75	325	19
Gross additions to tax positions assumed in acquisitions	0	51	852
Gross reductions to tax positions related to prior years	(22)	(352)	(35)
Settlements	(70)	(7)	(23)
Reductions to tax positions related to lapse of statute	(5)	(5)	(72)
Cumulative translation adjustment, increase		10
Cumulative translation adjustment, decrease	(5)		(1)
Balance at end of year	$ 2,042	$ 2,003	$ 1,905