SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Allowance for Credit Loss Roll-forward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit loss at beginning of year	$ 95	$ 88	$ 92
Accounts receivable, credit loss expense (reversal)	19	7	3
Accounts receivable, allowance for credit loss, write-offs, net of recoveries	(5)	0	(7)
Allowance for credit loss at end of year	$ 109	$ 95	$ 88